Merge branch 'release/debian/0.32.1-1'debian/0.32.1-1

158 files changed, 9519 insertions, 6154 deletions

diff --git a/src/AppDirs.vala b/src/AppDirs.vala
index 6c4541c..20df920 100644
--- a/src/AppDirs.vala
+++ b/src/AppDirs.vala
@@ -169,15 +169,14 @@ class AppDirs {
     }
     
     // Library folder + photo folder, based on user's preferred directory pattern.
-    public static File get_baked_import_dir(time_t tm) {
+    public static File get_baked_import_dir(DateTime tm) {
         string? pattern = Config.Facade.get_instance().get_directory_pattern();
         if (is_string_empty(pattern))
             pattern = Config.Facade.get_instance().get_directory_pattern_custom();
         if (is_string_empty(pattern))
             pattern = "%Y" + Path.DIR_SEPARATOR_S + "%m" + Path.DIR_SEPARATOR_S + "%d"; // default
             
-        DateTime date = new DateTime.from_unix_local(tm);
-        return File.new_for_path(get_import_dir().get_path() + Path.DIR_SEPARATOR_S + date.format(pattern));
+        return File.new_for_path(get_import_dir().get_path() + Path.DIR_SEPARATOR_S + tm.to_local().format(pattern));
     }
     
     // Returns true if the File is in or is equal to the library/import directory.
@@ -210,7 +209,7 @@ class AppDirs {
         
         return tmp_dir;
     }
-    
+
     public static File get_data_subdir(string name, string? subname = null) {
         File subdir = get_data_dir().get_child(name);
         if (subname != null)
@@ -262,7 +261,7 @@ class AppDirs {
         File? install_dir = get_install_dir();
         
         return (install_dir != null) ? install_dir.get_child("share").get_child("shotwell")
-            : get_exec_dir();
+            : get_lib_dir();
     }
     
     public static File get_lib_dir() {
@@ -317,32 +316,67 @@ class AppDirs {
         return f;
     }
 
+    public static File get_metadata_helper() {
+        const string filename = "shotwell-video-metadata-handler";
+        File f = AppDirs.get_libexec_dir().get_child("video-support").get_child (filename);
+        if (!f.query_exists()) {
+            // If we're running installed.
+            f = AppDirs.get_libexec_dir () .get_child ("shotwell").get_child (filename);
+        }
+        return f;
+    }
+
     public static File get_settings_migrator_bin() {
         const string filename = "shotwell-settings-migrator";
-        File f = AppDirs.get_libexec_dir().get_child ("settings-migrator").get_child (filename);
+        File f = AppDirs.get_libexec_dir().get_child("settings-migrator").get_child (filename);
         if (!f.query_exists()) {
             // If we're running installed.
             f = AppDirs.get_libexec_dir () .get_child ("shotwell").get_child (filename);
         }
+
+        if (!f.query_exists()) {
+            f = AppDirs.get_libexec_dir().get_parent().get_child("settings-migrator").get_child(filename);
+        }
+
         return f;
     }
 
+    public static File get_haarcascade_file() {
+        const string filename = "facedetect-haarcascade.xml";
+        var f = AppDirs.get_resources_dir().get_parent().get_child("subprojects").get_child("shotwell-facedetect").get_child (filename);
+        if (f.query_exists()) {//testing meson builddir
+            return f;
+        }
+        return get_resources_dir().get_child("facedetect-haarcascade.xml");
+    }
+
+
+#if ENABLE_FACE_DETECTION
     public static File get_facedetect_bin() {
         const string filename = "shotwell-facedetect";
-        File f = AppDirs.get_libexec_dir().get_parent().get_child("facedetect").get_child (filename);
+        File f = AppDirs.get_libexec_dir().get_parent().get_child("subprojects").get_child(filename).get_child (filename);
         if (!f.query_exists()) {
             f = AppDirs.get_libexec_dir().get_child("shotwell").get_child(filename);
         }
         return f;
     }
-    
-    public static File get_haarcascade_file() {
-        File f = File.new_for_path(AppDirs.get_exec_dir().get_parent().get_parent().get_child("facedetect").get_child("facedetect-haarcascade.xml").get_path());
+
+    public static File get_openface_dnn_dir() {
+        return File.new_for_path(Environment.get_user_data_dir()).get_child(DEFAULT_DATA_DIR).get_child("facedetect");
+    }
+
+    public static File get_openface_dnn_system_dir() {
+        var f = File.new_for_path("/app/extra");
+        if (f.query_exists())
+            return f;
+
+        f = AppDirs.get_resources_dir().get_parent().get_child("subprojects").get_child("shotwell-facedetect");
         if (f.query_exists()) {//testing meson builddir
             return f;
         }
-        return get_resources_dir().get_child("facedetect-haarcascade.xml");
+    
+        return AppDirs.get_resources_dir().get_child("facedetect");
     }
 
+#endif
 }
-
diff --git a/src/AppWindow.vala b/src/AppWindow.vala
index a5b27a4..438806c 100644
--- a/src/AppWindow.vala
+++ b/src/AppWindow.vala
@@ -6,7 +6,7 @@
 
 public class FullscreenWindow : PageWindow {
     public const int TOOLBAR_INVOCATION_MSEC = 250;
-    public const int TOOLBAR_DISMISSAL_SEC = 2;
+    public const int TOOLBAR_DISMISSAL_SEC = 2 * 1000000;
     public const int TOOLBAR_CHECK_DISMISSAL_MSEC = 500;
     
     private Gtk.Overlay overlay = new Gtk.Overlay();
@@ -15,7 +15,7 @@ public class FullscreenWindow : PageWindow {
     private Gtk.ToggleToolButton pin_button = new Gtk.ToggleToolButton();
     private bool is_toolbar_shown = false;
     private bool waiting_for_invoke = false;
-    private time_t left_toolbar_time = 0;
+    private int64 left_toolbar_time = 0;
     private bool switched_to = false;
     private bool is_toolbar_dismissal_enabled;
 
@@ -246,13 +246,13 @@ public class FullscreenWindow : PageWindow {
         
         // if this is the first time noticed, start the timer and keep checking
         if (left_toolbar_time == 0) {
-            left_toolbar_time = time_t();
+            left_toolbar_time = GLib.get_monotonic_time();
             
             return true;
         }
         
         // see if enough time has elapsed
-        time_t now = time_t();
+        int64 now = GLib.get_monotonic_time();
         assert(now >= left_toolbar_time);
 
         if (now - left_toolbar_time < TOOLBAR_DISMISSAL_SEC)
@@ -367,7 +367,6 @@ public abstract class PageWindow : Gtk.ApplicationWindow {
         var display = get_window ().get_display ();
         var cursor = new Gdk.Cursor.for_display (display, Gdk.CursorType.WATCH);
         get_window().set_cursor (cursor);
-        spin_event_loop();
     }
     
     public void set_normal_cursor() {
@@ -381,7 +380,6 @@ public abstract class PageWindow : Gtk.ApplicationWindow {
         var display = get_window ().get_display ();
         var cursor = new Gdk.Cursor.for_display (display, Gdk.CursorType.LEFT_PTR);
         get_window().set_cursor (cursor);
-        spin_event_loop();
     }
     
 }
@@ -415,7 +413,7 @@ public abstract class AppWindow : PageWindow {
         instance = this;
 
         title = Resources.APP_TITLE;
-        set_default_icon_name("shotwell");
+        set_default_icon_name("org.gnome.Shotwell");
 
         // restore previous size and maximization state
         if (this is LibraryWindow) {
@@ -441,10 +439,6 @@ public abstract class AppWindow : PageWindow {
         // with each ActionGroup while we're adding the groups to the UIManager.
 
         add_actions ();
-        
-        Gtk.CssProvider provider = new Gtk.CssProvider();
-        provider.load_from_resource("/org/gnome/Shotwell/misc/org.gnome.Shotwell.css");
-        Gtk.StyleContext.add_provider_for_screen(Gdk.Screen.get_default(), provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
     }
 
     private const GLib.ActionEntry[] common_actions = {
@@ -475,19 +469,6 @@ public abstract class AppWindow : PageWindow {
         return fullscreen_window;
     }
 
-    public static Gtk.Builder create_builder(string glade_filename = "shotwell.ui", void *user = null) {
-        Gtk.Builder builder = new Gtk.Builder();
-        try {
-            builder.add_from_resource(Resources.get_ui(glade_filename));
-        } catch(GLib.Error error) {
-            warning("Unable to create Gtk.Builder: %s\n", error.message);
-        }
-        
-        builder.connect_signals(user);
-        
-        return builder;
-    }
-    
     public static void error_message(string message, Gtk.Window? parent = null) {
         error_message_with_title(Resources.APP_TITLE, message, parent);
     }
@@ -560,27 +541,26 @@ public abstract class AppWindow : PageWindow {
         return (Gtk.ResponseType) response;
     }
     
-    public static Gtk.ResponseType negate_affirm_all_cancel_question(string message, 
-        string negative, string affirmative, string affirmative_all, string? title = null,
-        Gtk.Window? parent = null) {
+	public static int export_overwrite_or_replace_question(string message,
+		string alt1, string alt2, string alt3, string alt4, string alt5, string alt6,
+        string? title = null, Gtk.Window? parent = null) {
         Gtk.MessageDialog dialog = new Gtk.MessageDialog((parent != null) ? parent : get_instance(),
             Gtk.DialogFlags.MODAL, Gtk.MessageType.QUESTION, Gtk.ButtonsType.NONE, "%s", message);
         dialog.title = (title != null) ? title : Resources.APP_TITLE;
-        dialog.add_buttons(negative, Gtk.ResponseType.NO, affirmative, Gtk.ResponseType.YES,
-            affirmative_all, Gtk.ResponseType.APPLY,  _("_Cancel"), Gtk.ResponseType.CANCEL);
+        dialog.add_buttons(alt1, 1, alt2, 2, alt3, 3, alt4, 4, alt5, 5, alt6, 6);
         
         int response = dialog.run();
         
         dialog.destroy();
         
-        return (Gtk.ResponseType) response;
+        return response;
     }
-    
-    public static void database_error(DatabaseError err) {
+
+    public static void database_error(Error err) {
         panic(_("A fatal error occurred when accessing Shotwell’s library. Shotwell cannot continue.\n\n%s").printf(
             err.message));
     }
-    
+
     public static void panic(string msg) {
         critical(msg);
         error_message(msg);
@@ -591,9 +571,13 @@ public abstract class AppWindow : PageWindow {
     public abstract string get_app_role();
 
     protected void on_about() {
-        const string[] artists = { "Celler Schloss created by Hajotthu, CC BY-SA 3.0, https://commons.wikimedia.org/wiki/File:Celler_Schloss_April_2010.jpg#file", null };
+        var hash = "";
+        if (Resources.GIT_VERSION != null && Resources.GIT_VERSION != "" && Resources.GIT_VERSION != Resources.APP_VERSION) {
+            hash = " (%s)".printf(Resources.GIT_VERSION.substring(0,7));
+        }
+        string[] artists = {"Image of the Delmenhorst Town Hall by Charlie1965nrw, source: https://commons.wikimedia.org/wiki/File:Delmenhorst_Rathaus.jpg", null};
         Gtk.show_about_dialog(this,
-            "version", Resources.APP_VERSION + " \u2013 “Celle”",
+            "version", Resources.APP_VERSION + hash + " — Delmenhorst",
             "comments", get_app_role(),
             "copyright", Resources.COPYRIGHT,
             "website", Resources.HOME_URL,
@@ -601,8 +585,8 @@ public abstract class AppWindow : PageWindow {
             "website-label", _("Visit the Shotwell web site"),
             "authors", Resources.AUTHORS,
             "logo", Resources.get_icon(Resources.ICON_ABOUT_LOGO, -1),
-            "artists", artists,
             "translator-credits", _("translator-credits"),
+            "artists", artists,
             null
         );
     }
diff --git a/src/Application.vala b/src/Application.vala
index 36acc41..59bae36 100644
--- a/src/Application.vala
+++ b/src/Application.vala
@@ -69,6 +69,16 @@ public class Application {
         system_app.startup.connect(on_activated);
     }
 
+    public static double get_scale() {
+        var instance = get_instance().system_app;
+        unowned GLib.List<Gtk.Window> windows = instance.get_windows();
+
+        if (windows == null)
+            return 1.0;
+
+        return windows.data.get_scale_factor();
+    }
+
     /**
      * @brief This is a helper for library mode that should only be
      * called if we've gotten a camera mount and are _not_ the primary
@@ -104,7 +114,7 @@ public class Application {
     }
 
     /**
-     * @brief Signal handler for GApplication's 'command-line' signal.
+     * @brief Signal handler for GApplication's 'activate' signal.
      *
      * The most likely scenario for this to be fired is if the user
      * either tried to run us twice in library mode, or we've just gotten
diff --git a/src/BatchImport.vala b/src/BatchImport.vala
index 0e31441..90ccba8 100644
--- a/src/BatchImport.vala
+++ b/src/BatchImport.vala
@@ -201,10 +201,10 @@ public abstract class BatchImportJob {
         return false;
     }
     
-    // returns a non-zero time_t value if this has a valid exposure time override, returns zero
+    // returns a non-null DateTime value if this has a valid exposure time override, returns zero
     // otherwise
-    public virtual time_t get_exposure_time_override() {
-        return 0;
+    public virtual DateTime? get_exposure_time_override() {
+        return null;
     }
 
     public virtual bool recurse() {
@@ -1597,6 +1597,11 @@ private class WorkSniffer : BackgroundImportJob {
     }
     
     public void search_dir(BatchImportJob job, File dir, bool copy_to_library, bool recurse) throws Error {
+        if (dir.get_child(".nomedia").query_exists()) {
+            debug("Folder %s contains \".nomedia\" file, ignoring.", dir.get_path());
+            return;
+        }
+
         FileEnumerator enumerator = dir.enumerate_children("standard::*",
             FileQueryInfoFlags.NOFOLLOW_SYMLINKS, null);
         
diff --git a/src/CheckerboardItem.vala b/src/CheckerboardItem.vala
new file mode 100644
index 0000000..a8a5e63
--- /dev/null
+++ b/src/CheckerboardItem.vala
@@ -0,0 +1,734 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+public abstract class CheckerboardItem : ThumbnailView {
+    // Collection properties CheckerboardItem understands
+    // SHOW_TITLES (bool)
+    public const string PROP_SHOW_TITLES = "show-titles";
+    // SHOW_COMMENTS (bool)
+    public const string PROP_SHOW_COMMENTS = "show-comments";
+    // SHOW_SUBTITLES (bool)
+    public const string PROP_SHOW_SUBTITLES = "show-subtitles";
+    
+    public const int FRAME_WIDTH = 8;
+    public const int LABEL_PADDING = 4;
+    public const int BORDER_WIDTH = 1;
+
+    public const int SHADOW_RADIUS = 4;
+    public const float SHADOW_INITIAL_ALPHA = 0.5f;
+    
+    public const int TRINKET_SCALE = 12;
+    public const int TRINKET_PADDING = 1;
+    
+    public const int BRIGHTEN_SHIFT = 0x18;
+    
+    public Dimensions requisition = Dimensions();
+    public Gdk.Rectangle allocation = Gdk.Rectangle();
+    
+    private bool exposure = false;
+    private CheckerboardItemText? title = null;
+    private bool title_visible = true;
+    private CheckerboardItemText? comment = null;
+    private bool comment_visible = true;
+    private CheckerboardItemText? subtitle = null;
+    private bool subtitle_visible = false;
+    private bool is_cursor = false;
+    private Pango.Alignment tag_alignment = Pango.Alignment.LEFT;
+    private Gee.List<Tag>? user_visible_tag_list = null;
+    private Gee.Collection<Tag> tags;
+    private Gdk.Pixbuf pixbuf = null;
+    private Gdk.Pixbuf display_pixbuf = null;
+    private Gdk.Pixbuf brightened = null;
+    private Dimensions pixbuf_dim = Dimensions();
+    private int col = -1;
+    private int row = -1;
+    private int horizontal_trinket_offset = 0;
+    
+    protected CheckerboardItem(ThumbnailSource source, Dimensions initial_pixbuf_dim, string title, string? comment,
+        bool marked_up = false, Pango.Alignment alignment = Pango.Alignment.LEFT) {
+        base(source);
+        
+        pixbuf_dim = initial_pixbuf_dim;
+        this.title = new CheckerboardItemText(title, alignment, marked_up);
+        // on the checkboard page we display the comment in 
+        // one line, i.e., replacing all newlines with spaces.
+        // that means that the display will contain "..." if the comment
+        // is too long.
+        // warning: changes here have to be done in set_comment, too!
+        if (comment != null)
+            this.comment = new CheckerboardItemText(comment.replace("\n", " "), alignment,
+                marked_up);
+        
+        // Don't calculate size here, wait for the item to be assigned to a ViewCollection
+        // (notify_membership_changed) and calculate when the collection's property settings
+        // are known
+    }
+
+    public bool has_tags { get; private set; }
+
+    public override string get_name() {
+        return (title != null) ? title.get_text() : base.get_name();
+    }
+    
+    public string get_title() {
+        return (title != null) ? title.get_text() : "";
+    }
+    
+    public string get_comment() {
+        return (comment != null) ? comment.get_text() : "";
+    }
+    
+    public void set_title(string text, bool marked_up = false,
+        Pango.Alignment alignment = Pango.Alignment.LEFT) {
+        if (title != null && title.is_set_to(text, marked_up, alignment))
+            return;
+        
+        title = new CheckerboardItemText(text, alignment, marked_up);
+        
+        if (title_visible) {
+            recalc_size("set_title");
+            notify_view_altered();
+        }
+    }
+
+    public void translate_coordinates(ref int x, ref int y) {
+        x -= allocation.x + FRAME_WIDTH;
+        y -= allocation.y + FRAME_WIDTH;
+    }
+    
+    public void clear_title() {
+        if (title == null)
+            return;
+        
+        title = null;
+        
+        if (title_visible) {
+            recalc_size("clear_title");
+            notify_view_altered();
+        }
+    }
+    
+    private void set_title_visible(bool visible) {
+        if (title_visible == visible)
+            return;
+        
+        title_visible = visible;
+        
+        recalc_size("set_title_visible");
+        notify_view_altered();
+    }
+    
+    public void set_comment(string text, bool marked_up = false,
+        Pango.Alignment alignment = Pango.Alignment.LEFT) {
+        if (comment != null && comment.is_set_to(text, marked_up, alignment))
+            return;
+        
+        comment = new CheckerboardItemText(text.replace("\n", " "), alignment, marked_up);
+        
+        if (comment_visible) {
+            recalc_size("set_comment");
+            notify_view_altered();
+        }
+    }
+    
+    public void clear_comment() {
+        if (comment == null)
+            return;
+        
+        comment = null;
+        
+        if (comment_visible) {
+            recalc_size("clear_comment");
+            notify_view_altered();
+        }
+    }
+    
+    private void set_comment_visible(bool visible) {
+        if (comment_visible == visible)
+            return;
+        
+        comment_visible = visible;
+        
+        recalc_size("set_comment_visible");
+        notify_view_altered();
+    }
+
+    public void set_tags(Gee.Collection<Tag>? tags,
+            Pango.Alignment alignment = Pango.Alignment.LEFT) {
+        has_tags = (tags != null && tags.size > 0);
+        tag_alignment = alignment;
+        string text;
+        if (has_tags) {
+            this.tags = tags;
+            user_visible_tag_list = Tag.make_user_visible_tag_list(tags);
+            text = Tag.make_tag_markup_string(user_visible_tag_list);
+        } else {
+            text = "<small>.</small>";
+        }
+
+        if (subtitle != null && subtitle.is_set_to(text, true, alignment))
+            return;
+        subtitle = new CheckerboardItemText(text, alignment, true);
+
+        if (subtitle_visible) {
+            recalc_size("set_subtitle");
+            notify_view_altered();
+        }
+    }
+
+    public void clear_tags() {
+        clear_subtitle();
+        has_tags = false;
+        user_visible_tag_list = null;
+    }
+
+    public void highlight_user_visible_tag(int index)
+            requires (user_visible_tag_list != null) {
+        string text = Tag.make_tag_markup_string(user_visible_tag_list, index);
+        subtitle = new CheckerboardItemText(text, tag_alignment, true);
+
+        if (subtitle_visible)
+            notify_view_altered();
+    }
+
+    public Tag get_user_visible_tag(int index)
+            requires (index >= 0 && index < user_visible_tag_list.size) {
+        return user_visible_tag_list.get(index);
+    }
+
+    public Pango.Layout? get_tag_list_layout() {
+        return has_tags ? subtitle.get_pango_layout() : null;
+    }
+
+    public Gdk.Rectangle get_subtitle_allocation() {
+        return subtitle.allocation;
+    }
+
+    public string get_subtitle() {
+        return (subtitle != null) ? subtitle.get_text() : "";
+    }
+    
+    public void set_subtitle(string text, bool marked_up = false, 
+        Pango.Alignment alignment = Pango.Alignment.LEFT) {
+        if (subtitle != null && subtitle.is_set_to(text, marked_up, alignment))
+            return;
+        
+        subtitle = new CheckerboardItemText(text, alignment, marked_up);
+        
+        if (subtitle_visible) {
+            recalc_size("set_subtitle");
+            notify_view_altered();
+        }
+    }
+    
+    public void clear_subtitle() {
+        if (subtitle == null)
+            return;
+        
+        subtitle = null;
+        
+        if (subtitle_visible) {
+            recalc_size("clear_subtitle");
+            notify_view_altered();
+        }
+    }
+    
+    private void set_subtitle_visible(bool visible) {
+        if (subtitle_visible == visible)
+            return;
+        
+        subtitle_visible = visible;
+        
+        recalc_size("set_subtitle_visible");
+        notify_view_altered();
+    }
+
+    public void set_is_cursor(bool is_cursor) {
+        this.is_cursor = is_cursor;
+    }
+
+    public bool get_is_cursor() {
+        return is_cursor;
+    }
+    
+    public virtual void handle_mouse_motion(int x, int y, int height, int width) {
+
+    }
+
+    public virtual void handle_mouse_leave() {
+        unbrighten();
+    }
+
+    public virtual void handle_mouse_enter() {
+        brighten();
+    }
+
+    protected override void notify_membership_changed(DataCollection? collection) {
+        bool title_visible = (bool) get_collection_property(PROP_SHOW_TITLES, true);
+        bool comment_visible = (bool) get_collection_property(PROP_SHOW_COMMENTS, true);
+        bool subtitle_visible = (bool) get_collection_property(PROP_SHOW_SUBTITLES, false);
+        
+        bool altered = false;
+        if (this.title_visible != title_visible) {
+            this.title_visible = title_visible;
+            altered = true;
+        }
+        
+        if (this.comment_visible != comment_visible) {
+            this.comment_visible = comment_visible;
+            altered = true;
+        }
+        
+        if (this.subtitle_visible != subtitle_visible) {
+            this.subtitle_visible = subtitle_visible;
+            altered = true;
+        }
+        
+        if (altered || !requisition.has_area()) {
+            recalc_size("notify_membership_changed");
+            notify_view_altered();
+        }
+        
+        base.notify_membership_changed(collection);
+    }
+    
+    protected override void notify_collection_property_set(string name, Value? old, Value val) {
+        switch (name) {
+            case PROP_SHOW_TITLES:
+                set_title_visible((bool) val);
+            break;
+            
+            case PROP_SHOW_COMMENTS:
+                set_comment_visible((bool) val);
+            break;
+            
+            case PROP_SHOW_SUBTITLES:
+                set_subtitle_visible((bool) val);
+            break;
+        }
+        
+        base.notify_collection_property_set(name, old, val);
+    }
+    
+    // The alignment point is the coordinate on the y-axis (relative to the top of the
+    // CheckerboardItem) which this item should be aligned to.  This allows for
+    // bottom-alignment along the bottom edge of the thumbnail.
+    public int get_alignment_point() {
+        return FRAME_WIDTH + BORDER_WIDTH + pixbuf_dim.height;
+    }
+    
+    public virtual void exposed() {
+        exposure = true;
+    }
+    
+    public virtual void unexposed() {
+        exposure = false;
+        
+        if (title != null)
+            title.clear_pango_layout();
+        
+        if (comment != null)
+            comment.clear_pango_layout();
+        
+        if (subtitle != null)
+            subtitle.clear_pango_layout();
+    }
+    
+    public virtual bool is_exposed() {
+        return exposure;
+    }
+
+    public bool has_image() {
+        return pixbuf != null;
+    }
+    
+    public Gdk.Pixbuf? get_image() {
+        return pixbuf;
+    }
+    
+    public void set_image(Gdk.Pixbuf pixbuf) {
+        this.pixbuf = pixbuf;
+        display_pixbuf = pixbuf;
+        pixbuf_dim = Dimensions.for_pixbuf(pixbuf);
+        
+        recalc_size("set_image");
+        notify_view_altered();
+    }
+    
+    public void clear_image(Dimensions dim) {
+        bool had_image = pixbuf != null;
+        
+        pixbuf = null;
+        display_pixbuf = null;
+        pixbuf_dim = dim;
+        
+        recalc_size("clear_image");
+        
+        if (had_image)
+            notify_view_altered();
+    }
+    
+    public static int get_max_width(int scale) {
+        // width is frame width (two sides) + frame padding (two sides) + width of pixbuf (text
+        // never wider)
+        return (FRAME_WIDTH * 2) + scale;
+    }
+    
+    private void recalc_size(string reason) {
+        Dimensions old_requisition = requisition;
+        
+        // only add in the text heights if they're displayed
+        int title_height = (title != null && title_visible)
+            ? title.get_height() + LABEL_PADDING : 0;
+        int comment_height = (comment != null && comment_visible)
+            ? comment.get_height() + LABEL_PADDING : 0;
+        int subtitle_height = (subtitle != null && subtitle_visible)
+            ? subtitle.get_height() + LABEL_PADDING : 0;
+        
+        // width is frame width (two sides) + frame padding (two sides) + width of pixbuf
+        // (text never wider)
+        requisition.width = (FRAME_WIDTH * 2) + (BORDER_WIDTH * 2) + pixbuf_dim.width;
+        
+        // height is frame width (two sides) + frame padding (two sides) + height of pixbuf
+        // + height of text + label padding (between pixbuf and text)
+        requisition.height = (FRAME_WIDTH * 2) + (BORDER_WIDTH * 2)
+            + pixbuf_dim.height + title_height + comment_height + subtitle_height;
+        
+#if TRACE_REFLOW_ITEMS
+        debug("recalc_size %s: %s title_height=%d comment_height=%d subtitle_height=%d requisition=%s", 
+            get_source().get_name(), reason, title_height, comment_height, subtitle_height,
+            requisition.to_string());
+#endif
+        
+        if (!requisition.approx_equals(old_requisition)) {
+#if TRACE_REFLOW_ITEMS
+            debug("recalc_size %s: %s notifying geometry altered", get_source().get_name(), reason);
+#endif
+            notify_geometry_altered();
+        }
+    }
+    
+    protected static Dimensions get_border_dimensions(Dimensions object_dim, int border_width) {
+        Dimensions dimensions = Dimensions();
+        dimensions.width = object_dim.width + (border_width * 2);
+        dimensions.height = object_dim.height + (border_width * 2);
+        return dimensions;
+    }
+    
+    protected static Gdk.Point get_border_origin(Gdk.Point object_origin, int border_width) {
+        Gdk.Point origin = Gdk.Point();
+        origin.x = object_origin.x - border_width;
+        origin.y = object_origin.y - border_width;
+        return origin;
+    }
+
+    protected virtual void paint_shadow(Cairo.Context ctx, Dimensions dimensions, Gdk.Point origin, 
+        int radius, float initial_alpha) { 
+        double rgb_all = 0.0;
+        
+        // top right corner
+        paint_shadow_in_corner(ctx, origin.x + dimensions.width, origin.y + radius, rgb_all, radius, 
+            initial_alpha, -0.5 * Math.PI, 0);
+        // bottom right corner
+        paint_shadow_in_corner(ctx, origin.x + dimensions.width, origin.y + dimensions.height, rgb_all, 
+            radius, initial_alpha, 0, 0.5 * Math.PI);
+        // bottom left corner
+        paint_shadow_in_corner(ctx, origin.x + radius, origin.y + dimensions.height, rgb_all, radius, 
+            initial_alpha, 0.5 * Math.PI, Math.PI);
+
+        // left right 
+        Cairo.Pattern lr = new Cairo.Pattern.linear(0, origin.y + dimensions.height, 
+            0, origin.y + dimensions.height + radius);
+        lr.add_color_stop_rgba(0.0, rgb_all, rgb_all, rgb_all, initial_alpha);
+        lr.add_color_stop_rgba(1.0, rgb_all, rgb_all, rgb_all, 0.0);
+        ctx.set_source(lr);
+        ctx.rectangle(origin.x + radius, origin.y + dimensions.height, dimensions.width - radius, radius);
+        ctx.fill();
+
+        // top down
+        Cairo.Pattern td = new Cairo.Pattern.linear(origin.x + dimensions.width, 
+            0, origin.x + dimensions.width + radius, 0);
+        td.add_color_stop_rgba(0.0, rgb_all, rgb_all, rgb_all, initial_alpha);
+        td.add_color_stop_rgba(1.0, rgb_all, rgb_all, rgb_all, 0.0);
+        ctx.set_source(td);
+        ctx.rectangle(origin.x + dimensions.width, origin.y + radius, 
+            radius, dimensions.height - radius);
+        ctx.fill();
+    }
+
+    protected void paint_shadow_in_corner(Cairo.Context ctx, int x, int y, 
+	double rgb_all, float radius, float initial_alpha, double arc1, double arc2) {
+        Cairo.Pattern p = new Cairo.Pattern.radial(x, y, 0, x, y, radius);
+        p.add_color_stop_rgba(0.0, rgb_all, rgb_all, rgb_all, initial_alpha);
+        p.add_color_stop_rgba(1.0, rgb_all, rgb_all, rgb_all, 0);
+        ctx.set_source(p);
+        ctx.move_to(x, y);
+        ctx.arc(x, y, radius, arc1, arc2);
+        ctx.close_path();
+        ctx.fill(); 
+    }
+
+    protected virtual void paint_border(Cairo.Context ctx, Dimensions object_dimensions,
+        Gdk.Point object_origin, int border_width) {
+        if (border_width == 1) {
+            ctx.rectangle(object_origin.x - border_width, object_origin.y - border_width,
+                object_dimensions.width + (border_width * 2),
+                object_dimensions.height + (border_width * 2));
+            ctx.fill();
+        } else {
+            Dimensions dimensions = get_border_dimensions(object_dimensions, border_width);
+            Gdk.Point origin = get_border_origin(object_origin, border_width);
+            
+            // amount of rounding needed on corners varies by size of object
+            double scale = int.max(object_dimensions.width, object_dimensions.height);
+            draw_rounded_corners_filled(ctx, dimensions, origin, 0.25 * scale);
+        }
+    }
+
+    protected virtual void paint_image(Cairo.Context ctx, Gdk.Pixbuf pixbuf, Gdk.Point origin) {
+        paint_pixmap_with_background(ctx, pixbuf, origin.x, origin.y);
+    }
+
+    private int get_selection_border_width(int scale) {
+        return ((scale <= ((Thumbnail.MIN_SCALE + Thumbnail.MAX_SCALE) / 3)) ? 5 : 4)
+            + BORDER_WIDTH;
+    }
+    
+    protected virtual Gdk.Pixbuf? get_top_left_trinket(int scale) {
+        return null;
+    }
+    
+    protected virtual Gdk.Pixbuf? get_top_right_trinket(int scale) {
+        return null;
+    }
+    
+    protected virtual Gdk.Pixbuf? get_bottom_left_trinket(int scale) {
+        return null;
+    }
+    
+    protected virtual Gdk.Pixbuf? get_bottom_right_trinket(int scale) {
+        return null;
+    }
+    
+    public void paint(Gtk.StyleContext style_context, Cairo.Context ctx, Gdk.RGBA bg_color, Gdk.RGBA selected_color,
+        Gdk.RGBA? border_color, Gdk.RGBA? focus_color) {
+        ctx.save();
+        ctx.translate(allocation.x + FRAME_WIDTH,
+                      allocation.y + FRAME_WIDTH);
+        // calc the top-left point of the pixbuf
+        Gdk.Point pixbuf_origin = Gdk.Point();
+        pixbuf_origin.x = BORDER_WIDTH;
+        pixbuf_origin.y = BORDER_WIDTH;
+        
+        ctx.set_line_width(FRAME_WIDTH);
+        ctx.set_source_rgba(selected_color.red, selected_color.green, selected_color.blue,
+            selected_color.alpha);
+
+        // draw shadow
+        if (border_color != null) {
+            ctx.save();
+            Dimensions shadow_dim = Dimensions();
+            shadow_dim.width = pixbuf_dim.width + BORDER_WIDTH;
+            shadow_dim.height = pixbuf_dim.height + BORDER_WIDTH;
+            paint_shadow(ctx, shadow_dim, pixbuf_origin, SHADOW_RADIUS, SHADOW_INITIAL_ALPHA);
+            ctx.restore();
+        }
+        
+        // draw a border for the cursor with the selection width and normal border color
+        if (is_cursor) {
+            ctx.save();
+            ctx.set_source_rgba(focus_color.red, focus_color.green, focus_color.blue,
+                    focus_color.alpha);
+            paint_border(ctx, pixbuf_dim, pixbuf_origin,
+                get_selection_border_width(int.max(pixbuf_dim.width, pixbuf_dim.height)));
+            ctx.restore();
+        }
+        
+        // draw selection border
+        if (is_selected()) {
+            // border thickness depends on the size of the thumbnail
+            ctx.save();
+            paint_border(ctx, pixbuf_dim, pixbuf_origin,
+                get_selection_border_width(int.max(pixbuf_dim.width, pixbuf_dim.height)));
+            ctx.restore();
+        }
+        
+        if (display_pixbuf != null) {
+            ctx.save();
+            ctx.set_source_rgba(bg_color.red, bg_color.green, bg_color.blue, bg_color.alpha);
+            paint_image(ctx, display_pixbuf, pixbuf_origin);
+            ctx.restore();
+        }
+        
+        // title and subtitles are LABEL_PADDING below bottom of pixbuf
+        int text_y = pixbuf_dim.height + FRAME_WIDTH + LABEL_PADDING;
+        if (title != null && title_visible) {
+            // get the layout sized so its width is no more than the pixbuf's
+            // resize the text width to be no more than the pixbuf's
+            title.allocation.x = 0;
+            title.allocation.y = text_y;
+            title.allocation.width = pixbuf_dim.width;
+            title.allocation.height = title.get_height();
+            style_context.render_layout(ctx, title.allocation.x, title.allocation.y,
+                    title.get_pango_layout(pixbuf_dim.width));
+
+            text_y += title.get_height() + LABEL_PADDING;
+        }
+
+        if (comment != null && comment_visible) {
+            comment.allocation.x = 0;
+            comment.allocation.y = text_y;
+            comment.allocation.width = pixbuf_dim.width;
+            comment.allocation.height = comment.get_height();
+            style_context.render_layout(ctx, comment.allocation.x, comment.allocation.y,
+                    comment.get_pango_layout(pixbuf_dim.width));
+
+            text_y += comment.get_height() + LABEL_PADDING;
+        }
+
+        if (subtitle != null && subtitle_visible) {
+            subtitle.allocation.x = 0;
+            subtitle.allocation.y = text_y;
+            subtitle.allocation.width = pixbuf_dim.width;
+            subtitle.allocation.height = subtitle.get_height();
+
+            style_context.render_layout(ctx, subtitle.allocation.x, subtitle.allocation.y,
+                    subtitle.get_pango_layout(pixbuf_dim.width));
+
+            // increment text_y if more text lines follow
+        }
+        
+        ctx.set_source_rgba(selected_color.red, selected_color.green, selected_color.blue,
+            selected_color.alpha);
+        
+        // draw trinkets last
+        Gdk.Pixbuf? trinket = get_bottom_left_trinket(TRINKET_SCALE);
+        if (trinket != null) {
+            int x = pixbuf_origin.x + TRINKET_PADDING + get_horizontal_trinket_offset();
+            int y = pixbuf_origin.y + pixbuf_dim.height - trinket.get_height() -
+                TRINKET_PADDING;
+            Gdk.cairo_set_source_pixbuf(ctx, trinket, x, y);
+            ctx.rectangle(x, y, trinket.get_width(), trinket.get_height());
+            ctx.fill();
+        }
+        
+        trinket = get_top_left_trinket(TRINKET_SCALE);
+        if (trinket != null) {
+            int x = pixbuf_origin.x + TRINKET_PADDING + get_horizontal_trinket_offset();
+            int y = pixbuf_origin.y + TRINKET_PADDING;
+            Gdk.cairo_set_source_pixbuf(ctx, trinket, x, y);
+            ctx.rectangle(x, y, trinket.get_width(), trinket.get_height());
+            ctx.fill();
+        }
+        
+        trinket = get_top_right_trinket(TRINKET_SCALE);
+        if (trinket != null) {
+            int x = pixbuf_origin.x + pixbuf_dim.width - trinket.width - 
+                get_horizontal_trinket_offset() - TRINKET_PADDING;
+            int y = pixbuf_origin.y + TRINKET_PADDING;
+            Gdk.cairo_set_source_pixbuf(ctx, trinket, x, y);
+            ctx.rectangle(x, y, trinket.get_width(), trinket.get_height());
+            ctx.fill();
+        }
+        
+        trinket = get_bottom_right_trinket(TRINKET_SCALE);
+        if (trinket != null) {
+            int x = pixbuf_origin.x + pixbuf_dim.width - trinket.width - 
+                get_horizontal_trinket_offset() - TRINKET_PADDING;
+            int y = pixbuf_origin.y + pixbuf_dim.height - trinket.height - 
+                TRINKET_PADDING;
+            Gdk.cairo_set_source_pixbuf(ctx, trinket, x, y);
+            ctx.rectangle(x, y, trinket.get_width(), trinket.get_height());
+            ctx.fill();
+        }
+        ctx.restore();
+    }
+    
+    protected void set_horizontal_trinket_offset(int horizontal_trinket_offset) {
+        assert(horizontal_trinket_offset >= 0);
+        this.horizontal_trinket_offset = horizontal_trinket_offset;
+    }
+    
+    protected int get_horizontal_trinket_offset() {
+        return horizontal_trinket_offset;
+    }
+
+    public void set_grid_coordinates(int col, int row) {
+        this.col = col;
+        this.row = row;
+    }
+    
+    public int get_column() {
+        return col;
+    }
+    
+    public int get_row() {
+        return row;
+    }
+    
+    public void brighten() {
+        // "should" implies "can" and "didn't already"
+        if (brightened != null || pixbuf == null)
+            return;
+        
+        // create a new lightened pixbuf to display
+        brightened = pixbuf.copy();
+        shift_colors(brightened, BRIGHTEN_SHIFT, BRIGHTEN_SHIFT, BRIGHTEN_SHIFT, 0);
+        
+        display_pixbuf = brightened;
+        
+        notify_view_altered();
+    }
+    
+
+    public void unbrighten() {
+        // "should", "can", "didn't already"
+        if (brightened == null || pixbuf == null)
+            return;
+        
+        brightened = null;
+
+        // return to the normal image
+        display_pixbuf = pixbuf;
+        
+        notify_view_altered();
+    }
+    
+    public override void visibility_changed(bool visible) {
+        // if going from visible to hidden, unbrighten
+        if (!visible)
+            unbrighten();
+        
+        base.visibility_changed(visible);
+    }
+    
+    private bool query_tooltip_on_text(CheckerboardItemText text, Gtk.Tooltip tooltip) {
+        if (!text.get_pango_layout().is_ellipsized())
+            return false;
+        
+        if (text.is_marked_up())
+            tooltip.set_markup(text.get_text());
+        else
+            tooltip.set_text(text.get_text());
+        
+        return true;
+    }
+    
+    public bool query_tooltip(int x, int y, Gtk.Tooltip tooltip) {
+        if (title != null && title_visible && coord_in_rectangle(x, y, title.allocation))
+            return query_tooltip_on_text(title, tooltip);
+        
+        if (comment != null && comment_visible && coord_in_rectangle(x, y, comment.allocation))
+            return query_tooltip_on_text(comment, tooltip);
+        
+        if (subtitle != null && subtitle_visible && coord_in_rectangle(x, y, subtitle.allocation))
+            return query_tooltip_on_text(subtitle, tooltip);
+        
+        return false;
+    }
+}
+
+
diff --git a/src/CheckerboardItemText.vala b/src/CheckerboardItemText.vala
new file mode 100644
index 0000000..8924938
--- /dev/null
+++ b/src/CheckerboardItemText.vala
@@ -0,0 +1,98 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+private class CheckerboardItemText {
+    private static int one_line_height = 0;
+    
+    private string text;
+    private bool marked_up;
+    private Pango.Alignment alignment;
+    private Pango.Layout layout = null;
+    private bool single_line = true;
+    private int height = 0;
+    
+    public Gdk.Rectangle allocation = Gdk.Rectangle();
+    
+    public CheckerboardItemText(string text, Pango.Alignment alignment = Pango.Alignment.LEFT,
+        bool marked_up = false) {
+        this.text = text;
+        this.marked_up = marked_up;
+        this.alignment = alignment;
+        
+        single_line = is_single_line();
+    }
+    
+    private bool is_single_line() {
+        return !String.contains_char(text, '\n');
+    }
+    
+    public bool is_marked_up() {
+        return marked_up;
+    }
+    
+    public bool is_set_to(string text, bool marked_up, Pango.Alignment alignment) {
+        return (this.marked_up == marked_up && this.alignment == alignment && this.text == text);
+    }
+    
+    public string get_text() {
+        return text;
+    }
+    
+    public int get_height() {
+        if (height == 0)
+            update_height();
+        
+        return height;
+    }
+    
+    public Pango.Layout get_pango_layout(int max_width = 0) {
+        if (layout == null)
+            create_pango();
+        
+        if (max_width > 0)
+            layout.set_width(max_width * Pango.SCALE);
+        
+        return layout;
+    }
+    
+    public void clear_pango_layout() {
+        layout = null;
+    }
+    
+    private void update_height() {
+        if (one_line_height != 0 && single_line)
+            height = one_line_height;
+        else
+            create_pango();
+    }
+    
+    private void create_pango() {
+        // create layout for this string and ellipsize so it never extends past its laid-down width
+        layout = AppWindow.get_instance().create_pango_layout(null);
+        if (!marked_up)
+            layout.set_text(text, -1);
+        else
+            layout.set_markup(text, -1);
+        
+        layout.set_ellipsize(Pango.EllipsizeMode.END);
+        layout.set_alignment(alignment);
+        
+        // getting pixel size is expensive, and we only need the height, so use cached values
+        // whenever possible
+        if (one_line_height != 0 && single_line) {
+            height = one_line_height;
+        } else {
+            int width;
+            layout.get_pixel_size(out width, out height);
+            
+            // cache first one-line height discovered
+            if (one_line_height == 0 && single_line)
+                one_line_height = height;
+        }
+    }
+}
+
+
diff --git a/src/CheckerboardLayout.vala b/src/CheckerboardLayout.vala
index 70e3b5c..85232f3 100644
--- a/src/CheckerboardLayout.vala
+++ b/src/CheckerboardLayout.vala
@@ -4,824 +4,6 @@
  * See the COPYING file in this distribution.
  */
 
-private class CheckerboardItemText {
-    private static int one_line_height = 0;
-    
-    private string text;
-    private bool marked_up;
-    private Pango.Alignment alignment;
-    private Pango.Layout layout = null;
-    private bool single_line = true;
-    private int height = 0;
-    
-    public Gdk.Rectangle allocation = Gdk.Rectangle();
-    
-    public CheckerboardItemText(string text, Pango.Alignment alignment = Pango.Alignment.LEFT,
-        bool marked_up = false) {
-        this.text = text;
-        this.marked_up = marked_up;
-        this.alignment = alignment;
-        
-        single_line = is_single_line();
-    }
-    
-    private bool is_single_line() {
-        return !String.contains_char(text, '\n');
-    }
-    
-    public bool is_marked_up() {
-        return marked_up;
-    }
-    
-    public bool is_set_to(string text, bool marked_up, Pango.Alignment alignment) {
-        return (this.marked_up == marked_up && this.alignment == alignment && this.text == text);
-    }
-    
-    public string get_text() {
-        return text;
-    }
-    
-    public int get_height() {
-        if (height == 0)
-            update_height();
-        
-        return height;
-    }
-    
-    public Pango.Layout get_pango_layout(int max_width = 0) {
-        if (layout == null)
-            create_pango();
-        
-        if (max_width > 0)
-            layout.set_width(max_width * Pango.SCALE);
-        
-        return layout;
-    }
-    
-    public void clear_pango_layout() {
-        layout = null;
-    }
-    
-    private void update_height() {
-        if (one_line_height != 0 && single_line)
-            height = one_line_height;
-        else
-            create_pango();
-    }
-    
-    private void create_pango() {
-        // create layout for this string and ellipsize so it never extends past its laid-down width
-        layout = AppWindow.get_instance().create_pango_layout(null);
-        if (!marked_up)
-            layout.set_text(text, -1);
-        else
-            layout.set_markup(text, -1);
-        
-        layout.set_ellipsize(Pango.EllipsizeMode.END);
-        layout.set_alignment(alignment);
-        
-        // getting pixel size is expensive, and we only need the height, so use cached values
-        // whenever possible
-        if (one_line_height != 0 && single_line) {
-            height = one_line_height;
-        } else {
-            int width;
-            layout.get_pixel_size(out width, out height);
-            
-            // cache first one-line height discovered
-            if (one_line_height == 0 && single_line)
-                one_line_height = height;
-        }
-    }
-}
-
-public abstract class CheckerboardItem : ThumbnailView {
-    // Collection properties CheckerboardItem understands
-    // SHOW_TITLES (bool)
-    public const string PROP_SHOW_TITLES = "show-titles";
-    // SHOW_COMMENTS (bool)
-    public const string PROP_SHOW_COMMENTS = "show-comments";
-    // SHOW_SUBTITLES (bool)
-    public const string PROP_SHOW_SUBTITLES = "show-subtitles";
-    
-    public const int FRAME_WIDTH = 8;
-    public const int LABEL_PADDING = 4;
-    public const int BORDER_WIDTH = 1;
-
-    public const int SHADOW_RADIUS = 4;
-    public const float SHADOW_INITIAL_ALPHA = 0.5f;
-    
-    public const int TRINKET_SCALE = 12;
-    public const int TRINKET_PADDING = 1;
-    
-    public const int BRIGHTEN_SHIFT = 0x18;
-    
-    public Dimensions requisition = Dimensions();
-    public Gdk.Rectangle allocation = Gdk.Rectangle();
-    
-    private bool exposure = false;
-    private CheckerboardItemText? title = null;
-    private bool title_visible = true;
-    private CheckerboardItemText? comment = null;
-    private bool comment_visible = true;
-    private CheckerboardItemText? subtitle = null;
-    private bool subtitle_visible = false;
-    private bool is_cursor = false;
-    private Pango.Alignment tag_alignment = Pango.Alignment.LEFT;
-    private Gee.List<Tag>? user_visible_tag_list = null;
-    private Gee.Collection<Tag> tags;
-    private Gdk.Pixbuf pixbuf = null;
-    private Gdk.Pixbuf display_pixbuf = null;
-    private Gdk.Pixbuf brightened = null;
-    private Dimensions pixbuf_dim = Dimensions();
-    private int col = -1;
-    private int row = -1;
-    private int horizontal_trinket_offset = 0;
-    
-    protected CheckerboardItem(ThumbnailSource source, Dimensions initial_pixbuf_dim, string title, string? comment,
-        bool marked_up = false, Pango.Alignment alignment = Pango.Alignment.LEFT) {
-        base(source);
-        
-        pixbuf_dim = initial_pixbuf_dim;
-        this.title = new CheckerboardItemText(title, alignment, marked_up);
-        // on the checkboard page we display the comment in 
-        // one line, i.e., replacing all newlines with spaces.
-        // that means that the display will contain "..." if the comment
-        // is too long.
-        // warning: changes here have to be done in set_comment, too!
-        if (comment != null)
-            this.comment = new CheckerboardItemText(comment.replace("\n", " "), alignment,
-                marked_up);
-        
-        // Don't calculate size here, wait for the item to be assigned to a ViewCollection
-        // (notify_membership_changed) and calculate when the collection's property settings
-        // are known
-    }
-
-    public bool has_tags { get; private set; }
-
-    public override string get_name() {
-        return (title != null) ? title.get_text() : base.get_name();
-    }
-    
-    public string get_title() {
-        return (title != null) ? title.get_text() : "";
-    }
-    
-    public string get_comment() {
-        return (comment != null) ? comment.get_text() : "";
-    }
-    
-    public void set_title(string text, bool marked_up = false,
-        Pango.Alignment alignment = Pango.Alignment.LEFT) {
-        if (title != null && title.is_set_to(text, marked_up, alignment))
-            return;
-        
-        title = new CheckerboardItemText(text, alignment, marked_up);
-        
-        if (title_visible) {
-            recalc_size("set_title");
-            notify_view_altered();
-        }
-    }
-
-    public void translate_coordinates(ref int x, ref int y) {
-        x -= allocation.x + FRAME_WIDTH;
-        y -= allocation.y + FRAME_WIDTH;
-    }
-    
-    public void clear_title() {
-        if (title == null)
-            return;
-        
-        title = null;
-        
-        if (title_visible) {
-            recalc_size("clear_title");
-            notify_view_altered();
-        }
-    }
-    
-    private void set_title_visible(bool visible) {
-        if (title_visible == visible)
-            return;
-        
-        title_visible = visible;
-        
-        recalc_size("set_title_visible");
-        notify_view_altered();
-    }
-    
-    public void set_comment(string text, bool marked_up = false,
-        Pango.Alignment alignment = Pango.Alignment.LEFT) {
-        if (comment != null && comment.is_set_to(text, marked_up, alignment))
-            return;
-        
-        comment = new CheckerboardItemText(text.replace("\n", " "), alignment, marked_up);
-        
-        if (comment_visible) {
-            recalc_size("set_comment");
-            notify_view_altered();
-        }
-    }
-    
-    public void clear_comment() {
-        if (comment == null)
-            return;
-        
-        comment = null;
-        
-        if (comment_visible) {
-            recalc_size("clear_comment");
-            notify_view_altered();
-        }
-    }
-    
-    private void set_comment_visible(bool visible) {
-        if (comment_visible == visible)
-            return;
-        
-        comment_visible = visible;
-        
-        recalc_size("set_comment_visible");
-        notify_view_altered();
-    }
-
-    public void set_tags(Gee.Collection<Tag>? tags,
-            Pango.Alignment alignment = Pango.Alignment.LEFT) {
-        has_tags = (tags != null && tags.size > 0);
-        tag_alignment = alignment;
-        string text;
-        if (has_tags) {
-            this.tags = tags;
-            user_visible_tag_list = Tag.make_user_visible_tag_list(tags);
-            text = Tag.make_tag_markup_string(user_visible_tag_list);
-        } else {
-            text = "<small>.</small>";
-        }
-
-        if (subtitle != null && subtitle.is_set_to(text, true, alignment))
-            return;
-        subtitle = new CheckerboardItemText(text, alignment, true);
-
-        if (subtitle_visible) {
-            recalc_size("set_subtitle");
-            notify_view_altered();
-        }
-    }
-
-    public void clear_tags() {
-        clear_subtitle();
-        has_tags = false;
-        user_visible_tag_list = null;
-    }
-
-    public void highlight_user_visible_tag(int index)
-            requires (user_visible_tag_list != null) {
-        string text = Tag.make_tag_markup_string(user_visible_tag_list, index);
-        subtitle = new CheckerboardItemText(text, tag_alignment, true);
-
-        if (subtitle_visible)
-            notify_view_altered();
-    }
-
-    public Tag get_user_visible_tag(int index)
-            requires (index >= 0 && index < user_visible_tag_list.size) {
-        return user_visible_tag_list.get(index);
-    }
-
-    public Pango.Layout? get_tag_list_layout() {
-        return has_tags ? subtitle.get_pango_layout() : null;
-    }
-
-    public Gdk.Rectangle get_subtitle_allocation() {
-        return subtitle.allocation;
-    }
-
-    public string get_subtitle() {
-        return (subtitle != null) ? subtitle.get_text() : "";
-    }
-    
-    public void set_subtitle(string text, bool marked_up = false, 
-        Pango.Alignment alignment = Pango.Alignment.LEFT) {
-        if (subtitle != null && subtitle.is_set_to(text, marked_up, alignment))
-            return;
-        
-        subtitle = new CheckerboardItemText(text, alignment, marked_up);
-        
-        if (subtitle_visible) {
-            recalc_size("set_subtitle");
-            notify_view_altered();
-        }
-    }
-    
-    public void clear_subtitle() {
-        if (subtitle == null)
-            return;
-        
-        subtitle = null;
-        
-        if (subtitle_visible) {
-            recalc_size("clear_subtitle");
-            notify_view_altered();
-        }
-    }
-    
-    private void set_subtitle_visible(bool visible) {
-        if (subtitle_visible == visible)
-            return;
-        
-        subtitle_visible = visible;
-        
-        recalc_size("set_subtitle_visible");
-        notify_view_altered();
-    }
-
-    public void set_is_cursor(bool is_cursor) {
-        this.is_cursor = is_cursor;
-    }
-
-    public bool get_is_cursor() {
-        return is_cursor;
-    }
-    
-    public virtual void handle_mouse_motion(int x, int y, int height, int width) {
-
-    }
-
-    public virtual void handle_mouse_leave() {
-        unbrighten();
-    }
-
-    public virtual void handle_mouse_enter() {
-        brighten();
-    }
-
-    protected override void notify_membership_changed(DataCollection? collection) {
-        bool title_visible = (bool) get_collection_property(PROP_SHOW_TITLES, true);
-        bool comment_visible = (bool) get_collection_property(PROP_SHOW_COMMENTS, true);
-        bool subtitle_visible = (bool) get_collection_property(PROP_SHOW_SUBTITLES, false);
-        
-        bool altered = false;
-        if (this.title_visible != title_visible) {
-            this.title_visible = title_visible;
-            altered = true;
-        }
-        
-        if (this.comment_visible != comment_visible) {
-            this.comment_visible = comment_visible;
-            altered = true;
-        }
-        
-        if (this.subtitle_visible != subtitle_visible) {
-            this.subtitle_visible = subtitle_visible;
-            altered = true;
-        }
-        
-        if (altered || !requisition.has_area()) {
-            recalc_size("notify_membership_changed");
-            notify_view_altered();
-        }
-        
-        base.notify_membership_changed(collection);
-    }
-    
-    protected override void notify_collection_property_set(string name, Value? old, Value val) {
-        switch (name) {
-            case PROP_SHOW_TITLES:
-                set_title_visible((bool) val);
-            break;
-            
-            case PROP_SHOW_COMMENTS:
-                set_comment_visible((bool) val);
-            break;
-            
-            case PROP_SHOW_SUBTITLES:
-                set_subtitle_visible((bool) val);
-            break;
-        }
-        
-        base.notify_collection_property_set(name, old, val);
-    }
-    
-    // The alignment point is the coordinate on the y-axis (relative to the top of the
-    // CheckerboardItem) which this item should be aligned to.  This allows for
-    // bottom-alignment along the bottom edge of the thumbnail.
-    public int get_alignment_point() {
-        return FRAME_WIDTH + BORDER_WIDTH + pixbuf_dim.height;
-    }
-    
-    public virtual void exposed() {
-        exposure = true;
-    }
-    
-    public virtual void unexposed() {
-        exposure = false;
-        
-        if (title != null)
-            title.clear_pango_layout();
-        
-        if (comment != null)
-            comment.clear_pango_layout();
-        
-        if (subtitle != null)
-            subtitle.clear_pango_layout();
-    }
-    
-    public virtual bool is_exposed() {
-        return exposure;
-    }
-
-    public bool has_image() {
-        return pixbuf != null;
-    }
-    
-    public Gdk.Pixbuf? get_image() {
-        return pixbuf;
-    }
-    
-    public void set_image(Gdk.Pixbuf pixbuf) {
-        this.pixbuf = pixbuf;
-        display_pixbuf = pixbuf;
-        pixbuf_dim = Dimensions.for_pixbuf(pixbuf);
-        
-        recalc_size("set_image");
-        notify_view_altered();
-    }
-    
-    public void clear_image(Dimensions dim) {
-        bool had_image = pixbuf != null;
-        
-        pixbuf = null;
-        display_pixbuf = null;
-        pixbuf_dim = dim;
-        
-        recalc_size("clear_image");
-        
-        if (had_image)
-            notify_view_altered();
-    }
-    
-    public static int get_max_width(int scale) {
-        // width is frame width (two sides) + frame padding (two sides) + width of pixbuf (text
-        // never wider)
-        return (FRAME_WIDTH * 2) + scale;
-    }
-    
-    private void recalc_size(string reason) {
-        Dimensions old_requisition = requisition;
-        
-        // only add in the text heights if they're displayed
-        int title_height = (title != null && title_visible)
-            ? title.get_height() + LABEL_PADDING : 0;
-        int comment_height = (comment != null && comment_visible)
-            ? comment.get_height() + LABEL_PADDING : 0;
-        int subtitle_height = (subtitle != null && subtitle_visible)
-            ? subtitle.get_height() + LABEL_PADDING : 0;
-        
-        // width is frame width (two sides) + frame padding (two sides) + width of pixbuf
-        // (text never wider)
-        requisition.width = (FRAME_WIDTH * 2) + (BORDER_WIDTH * 2) + pixbuf_dim.width;
-        
-        // height is frame width (two sides) + frame padding (two sides) + height of pixbuf
-        // + height of text + label padding (between pixbuf and text)
-        requisition.height = (FRAME_WIDTH * 2) + (BORDER_WIDTH * 2)
-            + pixbuf_dim.height + title_height + comment_height + subtitle_height;
-        
-#if TRACE_REFLOW_ITEMS
-        debug("recalc_size %s: %s title_height=%d comment_height=%d subtitle_height=%d requisition=%s", 
-            get_source().get_name(), reason, title_height, comment_height, subtitle_height,
-            requisition.to_string());
-#endif
-        
-        if (!requisition.approx_equals(old_requisition)) {
-#if TRACE_REFLOW_ITEMS
-            debug("recalc_size %s: %s notifying geometry altered", get_source().get_name(), reason);
-#endif
-            notify_geometry_altered();
-        }
-    }
-    
-    protected static Dimensions get_border_dimensions(Dimensions object_dim, int border_width) {
-        Dimensions dimensions = Dimensions();
-        dimensions.width = object_dim.width + (border_width * 2);
-        dimensions.height = object_dim.height + (border_width * 2);
-        return dimensions;
-    }
-    
-    protected static Gdk.Point get_border_origin(Gdk.Point object_origin, int border_width) {
-        Gdk.Point origin = Gdk.Point();
-        origin.x = object_origin.x - border_width;
-        origin.y = object_origin.y - border_width;
-        return origin;
-    }
-
-    protected virtual void paint_shadow(Cairo.Context ctx, Dimensions dimensions, Gdk.Point origin, 
-        int radius, float initial_alpha) { 
-        double rgb_all = 0.0;
-        
-        // top right corner
-        paint_shadow_in_corner(ctx, origin.x + dimensions.width, origin.y + radius, rgb_all, radius, 
-            initial_alpha, -0.5 * Math.PI, 0);
-        // bottom right corner
-        paint_shadow_in_corner(ctx, origin.x + dimensions.width, origin.y + dimensions.height, rgb_all, 
-            radius, initial_alpha, 0, 0.5 * Math.PI);
-        // bottom left corner
-        paint_shadow_in_corner(ctx, origin.x + radius, origin.y + dimensions.height, rgb_all, radius, 
-            initial_alpha, 0.5 * Math.PI, Math.PI);
-
-        // left right 
-        Cairo.Pattern lr = new Cairo.Pattern.linear(0, origin.y + dimensions.height, 
-            0, origin.y + dimensions.height + radius);
-        lr.add_color_stop_rgba(0.0, rgb_all, rgb_all, rgb_all, initial_alpha);
-        lr.add_color_stop_rgba(1.0, rgb_all, rgb_all, rgb_all, 0.0);
-        ctx.set_source(lr);
-        ctx.rectangle(origin.x + radius, origin.y + dimensions.height, dimensions.width - radius, radius);
-        ctx.fill();
-
-        // top down
-        Cairo.Pattern td = new Cairo.Pattern.linear(origin.x + dimensions.width, 
-            0, origin.x + dimensions.width + radius, 0);
-        td.add_color_stop_rgba(0.0, rgb_all, rgb_all, rgb_all, initial_alpha);
-        td.add_color_stop_rgba(1.0, rgb_all, rgb_all, rgb_all, 0.0);
-        ctx.set_source(td);
-        ctx.rectangle(origin.x + dimensions.width, origin.y + radius, 
-            radius, dimensions.height - radius);
-        ctx.fill();
-    }
-
-    protected void paint_shadow_in_corner(Cairo.Context ctx, int x, int y, 
-	double rgb_all, float radius, float initial_alpha, double arc1, double arc2) {
-        Cairo.Pattern p = new Cairo.Pattern.radial(x, y, 0, x, y, radius);
-        p.add_color_stop_rgba(0.0, rgb_all, rgb_all, rgb_all, initial_alpha);
-        p.add_color_stop_rgba(1.0, rgb_all, rgb_all, rgb_all, 0);
-        ctx.set_source(p);
-        ctx.move_to(x, y);
-        ctx.arc(x, y, radius, arc1, arc2);
-        ctx.close_path();
-        ctx.fill(); 
-    }
-
-    protected virtual void paint_border(Cairo.Context ctx, Dimensions object_dimensions,
-        Gdk.Point object_origin, int border_width) {
-        if (border_width == 1) {
-            ctx.rectangle(object_origin.x - border_width, object_origin.y - border_width,
-                object_dimensions.width + (border_width * 2),
-                object_dimensions.height + (border_width * 2));
-            ctx.fill();
-        } else {
-            Dimensions dimensions = get_border_dimensions(object_dimensions, border_width);
-            Gdk.Point origin = get_border_origin(object_origin, border_width);
-            
-            // amount of rounding needed on corners varies by size of object
-            double scale = int.max(object_dimensions.width, object_dimensions.height);
-            draw_rounded_corners_filled(ctx, dimensions, origin, 0.25 * scale);
-        }
-    }
-
-    protected virtual void paint_image(Cairo.Context ctx, Gdk.Pixbuf pixbuf, Gdk.Point origin) {
-        paint_pixmap_with_background(ctx, pixbuf, origin.x, origin.y);
-    }
-
-    private int get_selection_border_width(int scale) {
-        return ((scale <= ((Thumbnail.MIN_SCALE + Thumbnail.MAX_SCALE) / 3)) ? 5 : 4)
-            + BORDER_WIDTH;
-    }
-    
-    protected virtual Gdk.Pixbuf? get_top_left_trinket(int scale) {
-        return null;
-    }
-    
-    protected virtual Gdk.Pixbuf? get_top_right_trinket(int scale) {
-        return null;
-    }
-    
-    protected virtual Gdk.Pixbuf? get_bottom_left_trinket(int scale) {
-        return null;
-    }
-    
-    protected virtual Gdk.Pixbuf? get_bottom_right_trinket(int scale) {
-        return null;
-    }
-    
-    public void paint(Gtk.StyleContext style_context, Cairo.Context ctx, Gdk.RGBA bg_color, Gdk.RGBA selected_color,
-        Gdk.RGBA? border_color, Gdk.RGBA? focus_color) {
-        ctx.save();
-        ctx.translate(allocation.x + FRAME_WIDTH,
-                      allocation.y + FRAME_WIDTH);
-        // calc the top-left point of the pixbuf
-        Gdk.Point pixbuf_origin = Gdk.Point();
-        pixbuf_origin.x = BORDER_WIDTH;
-        pixbuf_origin.y = BORDER_WIDTH;
-        
-        ctx.set_line_width(FRAME_WIDTH);
-        ctx.set_source_rgba(selected_color.red, selected_color.green, selected_color.blue,
-            selected_color.alpha);
-
-        // draw shadow
-        if (border_color != null) {
-            ctx.save();
-            Dimensions shadow_dim = Dimensions();
-            shadow_dim.width = pixbuf_dim.width + BORDER_WIDTH;
-            shadow_dim.height = pixbuf_dim.height + BORDER_WIDTH;
-            paint_shadow(ctx, shadow_dim, pixbuf_origin, SHADOW_RADIUS, SHADOW_INITIAL_ALPHA);
-            ctx.restore();
-        }
-        
-        // draw a border for the cursor with the selection width and normal border color
-        if (is_cursor) {
-            ctx.save();
-            ctx.set_source_rgba(focus_color.red, focus_color.green, focus_color.blue,
-                    focus_color.alpha);
-            paint_border(ctx, pixbuf_dim, pixbuf_origin,
-                get_selection_border_width(int.max(pixbuf_dim.width, pixbuf_dim.height)));
-            ctx.restore();
-        }
-        
-        // draw selection border
-        if (is_selected()) {
-            // border thickness depends on the size of the thumbnail
-            ctx.save();
-            paint_border(ctx, pixbuf_dim, pixbuf_origin,
-                get_selection_border_width(int.max(pixbuf_dim.width, pixbuf_dim.height)));
-            ctx.restore();
-        }
-        
-        if (display_pixbuf != null) {
-            ctx.save();
-            ctx.set_source_rgba(bg_color.red, bg_color.green, bg_color.blue, bg_color.alpha);
-            paint_image(ctx, display_pixbuf, pixbuf_origin);
-            ctx.restore();
-        }
-        
-        // title and subtitles are LABEL_PADDING below bottom of pixbuf
-        int text_y = pixbuf_dim.height + FRAME_WIDTH + LABEL_PADDING;
-        if (title != null && title_visible) {
-            // get the layout sized so its width is no more than the pixbuf's
-            // resize the text width to be no more than the pixbuf's
-            title.allocation.x = 0;
-            title.allocation.y = text_y;
-            title.allocation.width = pixbuf_dim.width;
-            title.allocation.height = title.get_height();
-            style_context.render_layout(ctx, title.allocation.x, title.allocation.y,
-                    title.get_pango_layout(pixbuf_dim.width));
-
-            text_y += title.get_height() + LABEL_PADDING;
-        }
-
-        if (comment != null && comment_visible) {
-            comment.allocation.x = 0;
-            comment.allocation.y = text_y;
-            comment.allocation.width = pixbuf_dim.width;
-            comment.allocation.height = comment.get_height();
-            style_context.render_layout(ctx, comment.allocation.x, comment.allocation.y,
-                    comment.get_pango_layout(pixbuf_dim.width));
-
-            text_y += comment.get_height() + LABEL_PADDING;
-        }
-
-        if (subtitle != null && subtitle_visible) {
-            subtitle.allocation.x = 0;
-            subtitle.allocation.y = text_y;
-            subtitle.allocation.width = pixbuf_dim.width;
-            subtitle.allocation.height = subtitle.get_height();
-
-            style_context.render_layout(ctx, subtitle.allocation.x, subtitle.allocation.y,
-                    subtitle.get_pango_layout(pixbuf_dim.width));
-
-            // increment text_y if more text lines follow
-        }
-        
-        ctx.set_source_rgba(selected_color.red, selected_color.green, selected_color.blue,
-            selected_color.alpha);
-        
-        // draw trinkets last
-        Gdk.Pixbuf? trinket = get_bottom_left_trinket(TRINKET_SCALE);
-        if (trinket != null) {
-            int x = pixbuf_origin.x + TRINKET_PADDING + get_horizontal_trinket_offset();
-            int y = pixbuf_origin.y + pixbuf_dim.height - trinket.get_height() -
-                TRINKET_PADDING;
-            Gdk.cairo_set_source_pixbuf(ctx, trinket, x, y);
-            ctx.rectangle(x, y, trinket.get_width(), trinket.get_height());
-            ctx.fill();
-        }
-        
-        trinket = get_top_left_trinket(TRINKET_SCALE);
-        if (trinket != null) {
-            int x = pixbuf_origin.x + TRINKET_PADDING + get_horizontal_trinket_offset();
-            int y = pixbuf_origin.y + TRINKET_PADDING;
-            Gdk.cairo_set_source_pixbuf(ctx, trinket, x, y);
-            ctx.rectangle(x, y, trinket.get_width(), trinket.get_height());
-            ctx.fill();
-        }
-        
-        trinket = get_top_right_trinket(TRINKET_SCALE);
-        if (trinket != null) {
-            int x = pixbuf_origin.x + pixbuf_dim.width - trinket.width - 
-                get_horizontal_trinket_offset() - TRINKET_PADDING;
-            int y = pixbuf_origin.y + TRINKET_PADDING;
-            Gdk.cairo_set_source_pixbuf(ctx, trinket, x, y);
-            ctx.rectangle(x, y, trinket.get_width(), trinket.get_height());
-            ctx.fill();
-        }
-        
-        trinket = get_bottom_right_trinket(TRINKET_SCALE);
-        if (trinket != null) {
-            int x = pixbuf_origin.x + pixbuf_dim.width - trinket.width - 
-                get_horizontal_trinket_offset() - TRINKET_PADDING;
-            int y = pixbuf_origin.y + pixbuf_dim.height - trinket.height - 
-                TRINKET_PADDING;
-            Gdk.cairo_set_source_pixbuf(ctx, trinket, x, y);
-            ctx.rectangle(x, y, trinket.get_width(), trinket.get_height());
-            ctx.fill();
-        }
-        ctx.restore();
-    }
-    
-    protected void set_horizontal_trinket_offset(int horizontal_trinket_offset) {
-        assert(horizontal_trinket_offset >= 0);
-        this.horizontal_trinket_offset = horizontal_trinket_offset;
-    }
-    
-    protected int get_horizontal_trinket_offset() {
-        return horizontal_trinket_offset;
-    }
-
-    public void set_grid_coordinates(int col, int row) {
-        this.col = col;
-        this.row = row;
-    }
-    
-    public int get_column() {
-        return col;
-    }
-    
-    public int get_row() {
-        return row;
-    }
-    
-    public void brighten() {
-        // "should" implies "can" and "didn't already"
-        if (brightened != null || pixbuf == null)
-            return;
-        
-        // create a new lightened pixbuf to display
-        brightened = pixbuf.copy();
-        shift_colors(brightened, BRIGHTEN_SHIFT, BRIGHTEN_SHIFT, BRIGHTEN_SHIFT, 0);
-        
-        display_pixbuf = brightened;
-        
-        notify_view_altered();
-    }
-    
-
-    public void unbrighten() {
-        // "should", "can", "didn't already"
-        if (brightened == null || pixbuf == null)
-            return;
-        
-        brightened = null;
-
-        // return to the normal image
-        display_pixbuf = pixbuf;
-        
-        notify_view_altered();
-    }
-    
-    public override void visibility_changed(bool visible) {
-        // if going from visible to hidden, unbrighten
-        if (!visible)
-            unbrighten();
-        
-        base.visibility_changed(visible);
-    }
-    
-    private bool query_tooltip_on_text(CheckerboardItemText text, Gtk.Tooltip tooltip) {
-        if (!text.get_pango_layout().is_ellipsized())
-            return false;
-        
-        if (text.is_marked_up())
-            tooltip.set_markup(text.get_text());
-        else
-            tooltip.set_text(text.get_text());
-        
-        return true;
-    }
-    
-    public bool query_tooltip(int x, int y, Gtk.Tooltip tooltip) {
-        if (title != null && title_visible && coord_in_rectangle(x, y, title.allocation))
-            return query_tooltip_on_text(title, tooltip);
-        
-        if (comment != null && comment_visible && coord_in_rectangle(x, y, comment.allocation))
-            return query_tooltip_on_text(comment, tooltip);
-        
-        if (subtitle != null && subtitle_visible && coord_in_rectangle(x, y, subtitle.allocation))
-            return query_tooltip_on_text(subtitle, tooltip);
-        
-        return false;
-    }
-}
-
 public class CheckerboardLayout : Gtk.DrawingArea {
     public const int TOP_PADDING = 16;
     public const int BOTTOM_PADDING = 16;
@@ -836,7 +18,7 @@ public class CheckerboardLayout : Gtk.DrawingArea {
     // The number of pixels that the scrollbars of Gtk.ScrolledWindows allocate for themselves
     // before their final size is computed. This must be taken into account when computing
     // the width of this widget. This value was 0 in Gtk+ 2.x but is 1 in Gtk+ 3.x. See
-    // ticket #3870 (http://redmine.yorba.org/issues/3870) for more information
+    // ticket #3870 (https://bugzilla.gnome.org/show_bug.cgi?id=717754) for more information
     private const int SCROLLBAR_PLACEHOLDER_WIDTH = 1;
     
     private class LayoutRow {
@@ -857,7 +39,6 @@ public class CheckerboardLayout : Gtk.DrawingArea {
     private Gee.HashSet<CheckerboardItem> exposed_items = new Gee.HashSet<CheckerboardItem>();
     private Gtk.Adjustment hadjustment = null;
     private Gtk.Adjustment vadjustment = null;
-    private string message = null;
     private Gdk.RGBA selected_color;
     private Gdk.RGBA unselected_color;
     private Gdk.RGBA focus_color;
@@ -963,23 +144,18 @@ public class CheckerboardLayout : Gtk.DrawingArea {
         Gtk.Allocation parent_allocation;
         parent.get_allocation(out parent_allocation);
         
-        if (message == null) {
-            // set the layout's new size to be the same as the parent's width but maintain 
-            // it's own height
+        // set the layout's new size to be the same as the parent's width but maintain
+        // it's own height
 #if TRACE_REFLOW
-            debug("on_viewport_resized: due_to_reflow=%s set_size_request %dx%d",
-                size_allocate_due_to_reflow.to_string(), parent_allocation.width, req.height);
+        debug("on_viewport_resized: due_to_reflow=%s set_size_request %dx%d",
+              size_allocate_due_to_reflow.to_string(), parent_allocation.width, req.height);
 #endif
-            // But if the current height is 0, don't request a size yet. Delay
-            // it to do_reflow (bgo#766864)
-            if (req.height != 0) {
-                set_size_request(parent_allocation.width - SCROLLBAR_PLACEHOLDER_WIDTH, req.height);
-            }
-        } else {
-            // set the layout's width and height to always match the parent's
-            set_size_request(parent_allocation.width, parent_allocation.height);
+        // But if the current height is 0, don't request a size yet. Delay
+        // it to do_reflow (bgo#766864)
+        if (req.height != 0) {
+            set_size_request(parent_allocation.width - SCROLLBAR_PLACEHOLDER_WIDTH, req.height);
         }
-        
+
         // possible for this widget's size_allocate not to be called, so need to update the page
         // rect here
         viewport_resized();
@@ -1070,8 +246,6 @@ public class CheckerboardLayout : Gtk.DrawingArea {
     
     private void on_contents_altered(Gee.Iterable<DataObject>? added, 
         Gee.Iterable<DataObject>? removed) {
-        if (added != null)
-            message = null;
         
         if (removed != null) {
             foreach (DataObject object in removed)
@@ -1142,31 +316,6 @@ public class CheckerboardLayout : Gtk.DrawingArea {
         queue_draw();
     }
     
-    public void set_message(string? text) {
-        if (text == message)
-            return;
-        
-        message = text;
-        
-        if (text != null) {
-            // message is being set, change size to match parent's; if no parent, then the size 
-            // will be set later when added to the parent
-            if (parent != null) {
-                Gtk.Allocation parent_allocation;
-                parent.get_allocation(out parent_allocation);
-                
-                set_size_request(parent_allocation.width, parent_allocation.height);
-            }
-        } else {
-            // message is being cleared, layout all the items again
-            need_reflow("set_message");
-        }
-    }
-    
-    public void unset_message() {
-        set_message(null);
-    }
-    
     private void update_visible_page() {
         if (hadjustment != null && vadjustment != null)
             visible_page = get_adjustment_page(hadjustment, vadjustment);
@@ -1185,7 +334,7 @@ public class CheckerboardLayout : Gtk.DrawingArea {
     }
     
     public CheckerboardItem? get_item_at_pixel(double xd, double yd) {
-        if (message != null || item_rows == null)
+        if (item_rows == null)
             return null;
             
         int x = (int) xd;
@@ -1560,10 +709,6 @@ public class CheckerboardLayout : Gtk.DrawingArea {
     private void reflow(string caller) {
         reflow_needed = false;
         
-        // if set in message mode, nothing to do here
-        if (message != null)
-            return;
-        
         Gtk.Allocation allocation;
         get_allocation(out allocation);
         
@@ -1957,35 +1102,17 @@ public class CheckerboardLayout : Gtk.DrawingArea {
         get_allocation(out allocation);
         get_style_context().render_background (ctx, 0, 0, allocation.width, allocation.height);
         
-        // watch for message mode
-        if (message == null) {
 #if TRACE_REFLOW
-            debug("draw %s: %s", page_name, rectangle_to_string(visible_page));
+        debug("draw %s: %s", page_name, rectangle_to_string(visible_page));
 #endif
-            
-            if (exposure_dirty)
-                expose_items("draw");
-            
-            // have all items in the exposed area paint themselves
-            foreach (CheckerboardItem item in intersection(visible_page)) {
-                item.paint(get_style_context(), ctx, bg_color, item.is_selected() ? selected_color : unselected_color,
-                    border_color, focus_color);
-            }
-        } else {
-            // draw the message in the center of the window
-            Pango.Layout pango_layout = create_pango_layout(message);
-            int text_width, text_height;
-            pango_layout.get_pixel_size(out text_width, out text_height);
-            
-            get_allocation(out allocation);
-            
-            int x = allocation.width - text_width;
-            x = (x > 0) ? x / 2 : 0;
-            
-            int y = allocation.height - text_height;
-            y = (y > 0) ? y / 2 : 0;
-            
-            get_style_context().render_layout(ctx, x, y, pango_layout);
+
+        if (exposure_dirty)
+            expose_items("draw");
+
+        // have all items in the exposed area paint themselves
+        foreach (CheckerboardItem item in intersection(visible_page)) {
+            item.paint(get_style_context(), ctx, bg_color, item.is_selected() ? selected_color : unselected_color,
+                border_color, focus_color);
         }
         
         bool result = (base.draw != null) ? base.draw(ctx) : true;
@@ -2025,7 +1152,14 @@ public class CheckerboardLayout : Gtk.DrawingArea {
     public override bool query_tooltip(int x, int y, bool keyboard_mode, Gtk.Tooltip tooltip) {
         CheckerboardItem? item = get_item_at_pixel(x, y);
         
-        return (item != null) ? item.query_tooltip(x, y, tooltip) : false;
+        // Note: X & Y allocations are relative to parents, so we need to query the item's tooltip
+        // relative to its INTERNAL coordinates, otherwise tooltips don't work
+        if (item != null) {
+            item.translate_coordinates(ref x, ref y);
+            return item.query_tooltip(x, y, tooltip);
+        } else {
+            return false;
+        }
     }
     
     private void on_colors_changed() {
diff --git a/src/CheckerboardPage.vala b/src/CheckerboardPage.vala
new file mode 100644
index 0000000..24a252a
--- /dev/null
+++ b/src/CheckerboardPage.vala
@@ -0,0 +1,758 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+public abstract class CheckerboardPage : Page {
+    private const int AUTOSCROLL_PIXELS = 50;
+    private const int AUTOSCROLL_TICKS_MSEC = 50;
+
+    private CheckerboardLayout layout;
+    private Gtk.Stack stack;
+    private PageMessagePane message_pane;
+    private string item_context_menu_path = null;
+    private string page_context_menu_path = null;
+    private Gtk.Viewport viewport = new Gtk.Viewport(null, null);
+    protected CheckerboardItem anchor = null;
+    protected CheckerboardItem cursor = null;
+    private CheckerboardItem current_hovered_item = null;
+    private bool autoscroll_scheduled = false;
+    private CheckerboardItem activated_item = null;
+    private Gee.ArrayList<CheckerboardItem> previously_selected = null;
+
+    public enum Activator {
+        KEYBOARD,
+        MOUSE
+    }
+
+    public struct KeyboardModifiers {
+        public KeyboardModifiers(Page page) {
+            ctrl_pressed = page.get_ctrl_pressed();
+            alt_pressed = page.get_alt_pressed();
+            shift_pressed = page.get_shift_pressed();
+            super_pressed = page.get_super_pressed();
+        }
+
+        public bool ctrl_pressed;
+        public bool alt_pressed;
+        public bool shift_pressed;
+        public bool super_pressed;
+    }
+
+    protected CheckerboardPage(string page_name) {
+        base (page_name);
+
+        stack = new Gtk.Stack();
+        message_pane = new PageMessagePane();
+
+        layout = new CheckerboardLayout(get_view());
+        layout.set_name(page_name);
+        stack.add_named (layout, "layout");
+        stack.add_named (message_pane, "message");
+        stack.set_visible_child(layout);
+
+        set_event_source(layout);
+
+        set_border_width(0);
+        set_shadow_type(Gtk.ShadowType.NONE);
+
+        viewport.set_border_width(0);
+        viewport.set_shadow_type(Gtk.ShadowType.NONE);
+
+        viewport.add(stack);
+
+        // want to set_adjustments before adding to ScrolledWindow to let our signal handlers
+        // run first ... otherwise, the thumbnails draw late
+        layout.set_adjustments(get_hadjustment(), get_vadjustment());
+
+        add(viewport);
+
+        // need to monitor items going hidden when dealing with anchor/cursor/highlighted items
+        get_view().items_hidden.connect(on_items_hidden);
+        get_view().contents_altered.connect(on_contents_altered);
+        get_view().items_state_changed.connect(on_items_state_changed);
+        get_view().items_visibility_changed.connect(on_items_visibility_changed);
+
+        // scrollbar policy
+        set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC);
+    }
+
+    public void init_item_context_menu(string path) {
+        item_context_menu_path = path;
+    }
+
+    public void init_page_context_menu(string path) {
+        page_context_menu_path = path;
+    }
+
+    public Gtk.Menu? get_context_menu() {
+        // show page context menu if nothing is selected
+        return (get_view().get_selected_count() != 0) ? get_item_context_menu() :
+            get_page_context_menu();
+    }
+
+    private Gtk.Menu item_context_menu;
+    public virtual Gtk.Menu? get_item_context_menu() {
+        if (item_context_menu == null) {
+            var model = this.builder.get_object (item_context_menu_path)
+                as GLib.MenuModel;
+            item_context_menu = new Gtk.Menu.from_model (model);
+            item_context_menu.attach_to_widget (this, null);
+        }
+
+        return item_context_menu;
+    }
+
+    private Gtk.Menu page_context_menu;
+    public override Gtk.Menu? get_page_context_menu() {
+        if (page_context_menu_path == null)
+            return null;
+
+        if (page_context_menu == null) {
+            var model = this.builder.get_object (page_context_menu_path)
+                as GLib.MenuModel;
+            page_context_menu = new Gtk.Menu.from_model (model);
+            page_context_menu.attach_to_widget (this, null);
+        }
+
+        return page_context_menu;
+    }
+
+    protected override bool on_context_keypress() {
+        return popup_context_menu(get_context_menu());
+    }
+
+    protected virtual string get_view_empty_icon() {
+        return "image-x-generic-symbolic";
+    }
+
+    protected virtual string get_view_empty_message() {
+        return _("No photos/videos");
+    }
+
+    protected virtual string get_filter_no_match_message() {
+        return _("No photos/videos found which match the current filter");
+    }
+
+    protected virtual void on_item_activated(CheckerboardItem item, Activator activator, 
+        KeyboardModifiers modifiers) {
+    }
+
+    public CheckerboardLayout get_checkerboard_layout() {
+        return layout;
+    }
+
+    // Gets the search view filter for this page.
+    public abstract SearchViewFilter get_search_view_filter();
+
+    public virtual Core.ViewTracker? get_view_tracker() {
+        return null;
+    }
+
+    public override void switching_from() {
+        layout.set_in_view(false);
+        get_search_view_filter().refresh.disconnect(on_view_filter_refresh);
+
+        // unselect everything so selection won't persist after page loses focus 
+        get_view().unselect_all();
+
+        base.switching_from();
+    }
+
+    public void scroll_to_item(CheckerboardItem item) {
+        Gtk.Adjustment vadj = get_vadjustment();
+        if (!(get_adjustment_relation(vadj, item.allocation.y) == AdjustmentRelation.IN_RANGE
+              && (get_adjustment_relation(vadj, item.allocation.y + item.allocation.height) == AdjustmentRelation.IN_RANGE))) {
+
+            // scroll to see the new item
+            int top = 0;
+            if (item.allocation.y < vadj.get_value()) {
+                top = item.allocation.y;
+                top -= CheckerboardLayout.ROW_GUTTER_PADDING / 2;
+            } else {
+                top = item.allocation.y + item.allocation.height - (int) vadj.get_page_size();
+                top += CheckerboardLayout.ROW_GUTTER_PADDING / 2;
+            }
+
+            vadj.set_value(top);
+
+        }
+    }
+
+    public override void switched_to() {
+        layout.set_in_view(true);
+        get_search_view_filter().refresh.connect(on_view_filter_refresh);
+        on_view_filter_refresh();
+
+        if (get_view().get_selected_count() > 0) {
+            CheckerboardItem? item = (CheckerboardItem?) get_view().get_selected_at(0);
+
+            // if item is in any way out of view, scroll to it
+            scroll_to_item(item);
+        }
+
+        base.switched_to();
+    }
+
+    private void on_view_filter_refresh() {
+        update_view_filter_message();
+    }
+
+    private void on_contents_altered(Gee.Iterable<DataObject>? added,
+        Gee.Iterable<DataObject>? removed) {
+        update_view_filter_message();
+    }
+
+    private void on_items_state_changed(Gee.Iterable<DataView> changed) {
+        update_view_filter_message();
+    }
+
+    private void on_items_visibility_changed(Gee.Collection<DataView> changed) {
+        update_view_filter_message();
+    }
+
+    private void update_view_filter_message() {
+        if (get_view().are_items_filtered_out() && get_view().get_count() == 0) {
+            set_page_message(get_filter_no_match_message());
+        } else if (get_view().get_count() == 0) {
+            set_page_message(get_view_empty_message());
+        } else {
+            unset_page_message();
+        }
+    }
+
+    public void set_page_message(string message) {
+        message_pane.label.label = message;
+        try {
+            message_pane.icon_image.icon_name = null;
+            message_pane.icon_image.gicon = Icon.new_for_string (get_view_empty_icon());
+        } catch (Error error) {
+            message_pane.icon_image.gicon = null;
+            message_pane.icon_image.icon_name = "image-x-generic-symbolic";
+        }
+        stack.set_visible_child_name ("message");
+    }
+
+    public void unset_page_message() {
+        stack.set_visible_child (layout);
+    }
+
+    public override void set_page_name(string name) {
+        base.set_page_name(name);
+
+        layout.set_name(name);
+    }
+
+    public CheckerboardItem? get_item_at_pixel(double x, double y) {
+        return layout.get_item_at_pixel(x, y);
+    }
+
+    private void on_items_hidden(Gee.Iterable<DataView> hidden) {
+        foreach (DataView view in hidden) {
+            CheckerboardItem item = (CheckerboardItem) view;
+
+            if (anchor == item)
+                anchor = null;
+
+            if (cursor == item)
+                cursor = null;
+
+            if (current_hovered_item == item)
+                current_hovered_item = null;
+        }
+    }
+
+    protected override bool key_press_event(Gdk.EventKey event) {
+        bool handled = true;
+
+        // mask out the modifiers we're interested in
+        uint state = event.state & Gdk.ModifierType.SHIFT_MASK;
+
+        switch (Gdk.keyval_name(event.keyval)) {
+            case "Up":
+            case "KP_Up":
+                move_cursor(CompassPoint.NORTH);
+                select_anchor_to_cursor(state);
+            break;
+
+            case "Down":
+            case "KP_Down":
+                move_cursor(CompassPoint.SOUTH);
+                select_anchor_to_cursor(state);
+            break;
+
+            case "Left":
+            case "KP_Left":
+                move_cursor(CompassPoint.WEST);
+                select_anchor_to_cursor(state);
+            break;
+
+            case "Right":
+            case "KP_Right":
+                move_cursor(CompassPoint.EAST);
+                select_anchor_to_cursor(state);
+            break;
+
+            case "Home":
+            case "KP_Home":
+                CheckerboardItem? first = (CheckerboardItem?) get_view().get_first();
+                if (first != null)
+                    cursor_to_item(first);
+                select_anchor_to_cursor(state);
+            break;
+
+            case "End":
+            case "KP_End":
+                CheckerboardItem? last = (CheckerboardItem?) get_view().get_last();
+                if (last != null)
+                    cursor_to_item(last);
+                select_anchor_to_cursor(state);
+            break;
+
+            case "Return":
+            case "KP_Enter":
+                if (get_view().get_selected_count() == 1)
+                    on_item_activated((CheckerboardItem) get_view().get_selected_at(0),
+                        Activator.KEYBOARD, KeyboardModifiers(this));
+                else
+                    handled = false;
+            break;
+
+            case "space":
+                Marker marker = get_view().mark(layout.get_cursor());
+                get_view().toggle_marked(marker);
+            break;
+
+            default:
+                handled = false;
+            break;
+        }
+
+        if (handled)
+            return true;
+
+        return (base.key_press_event != null) ? base.key_press_event(event) : true;
+    }
+
+    protected override bool on_left_click(Gdk.EventButton event) {
+        // only interested in single-click and double-clicks for now
+        if ((event.type != Gdk.EventType.BUTTON_PRESS) && (event.type != Gdk.EventType.2BUTTON_PRESS))
+            return false;
+
+        // mask out the modifiers we're interested in
+        uint state = event.state & (Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK);
+
+        // use clicks for multiple selection and activation only; single selects are handled by
+        // button release, to allow for multiple items to be selected then dragged ...
+        CheckerboardItem item = get_item_at_pixel(event.x, event.y);
+        if (item != null) {
+            // ... however, there is no dragging if the user clicks on an interactive part of the
+            // CheckerboardItem (e.g. a tag)
+            if (layout.handle_left_click(item, event.x, event.y, event.state))
+                return true;
+
+            switch (state) {
+                case Gdk.ModifierType.CONTROL_MASK:
+                    // with only Ctrl pressed, multiple selections are possible ... chosen item
+                    // is toggled
+                    Marker marker = get_view().mark(item);
+                    get_view().toggle_marked(marker);
+
+                    if (item.is_selected()) {
+                        anchor = item;
+                        cursor = item;
+                    }
+                break;
+
+                case Gdk.ModifierType.SHIFT_MASK:
+                    get_view().unselect_all();
+
+                    if (anchor == null)
+                        anchor = item;
+
+                    select_between_items(anchor, item);
+
+                    cursor = item;
+                break;
+
+                case Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK:
+                    // Ticket #853 - Make Ctrl + Shift + Mouse Button 1 able to start a new run
+                    // of contiguous selected items without unselecting previously-selected items
+                    // a la Nautilus.
+                    // Same as the case for SHIFT_MASK, but don't unselect anything first.
+                    if (anchor == null)
+                        anchor = item;
+
+                    select_between_items(anchor, item);
+
+                    cursor = item;
+                break;
+
+                default:
+                    if (event.type == Gdk.EventType.2BUTTON_PRESS) {
+                        activated_item = item;
+                    } else {
+                        // if the user has selected one or more items and is preparing for a drag,
+                        // don't want to blindly unselect: if they've clicked on an unselected item
+                        // unselect all and select that one; if they've clicked on a previously
+                        // selected item, do nothing
+                        if (!item.is_selected()) {
+                            Marker all = get_view().start_marking();
+                            all.mark_many(get_view().get_selected());
+
+                            get_view().unselect_and_select_marked(all, get_view().mark(item));
+                        }
+                    }
+
+                    anchor = item;
+                    cursor = item;
+                break;
+            }
+            layout.set_cursor(item);
+        } else {
+            // user clicked on "dead" area; only unselect if control is not pressed
+            // do we want similar behavior for shift as well?
+            if (state != Gdk.ModifierType.CONTROL_MASK)
+                get_view().unselect_all();
+
+            // grab previously marked items
+            previously_selected = new Gee.ArrayList<CheckerboardItem>();
+            foreach (DataView view in get_view().get_selected())
+                previously_selected.add((CheckerboardItem) view);
+
+            layout.set_drag_select_origin((int) event.x, (int) event.y);
+
+            return true;
+        }
+
+        // need to determine if the signal should be passed to the DnD handlers
+        // Return true to block the DnD handler, false otherwise
+
+        return get_view().get_selected_count() == 0;
+    }
+
+    protected override bool on_left_released(Gdk.EventButton event) {
+        previously_selected = null;
+
+        // if drag-selecting, stop here and do nothing else
+        if (layout.is_drag_select_active()) {
+            layout.clear_drag_select();
+            anchor = cursor;
+
+            return true;
+        }
+
+        // only interested in non-modified button releases
+        if ((event.state & (Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK)) != 0)
+            return false;
+
+        // if the item was activated in the double-click, report it now
+        if (activated_item != null) {
+            on_item_activated(activated_item, Activator.MOUSE, KeyboardModifiers(this));
+            activated_item = null;
+
+            return true;
+        }
+
+        CheckerboardItem item = get_item_at_pixel(event.x, event.y);
+        if (item == null) {
+            // released button on "dead" area
+            return true;
+        }
+
+        if (cursor != item) {
+            // user released mouse button after moving it off the initial item, or moved from dead
+            // space onto one.  either way, unselect everything
+            get_view().unselect_all();
+        } else {
+            // the idea is, if a user single-clicks on an item with no modifiers, then all other items
+            // should be deselected, however, if they single-click in order to drag one or more items,
+            // they should remain selected, hence performing this here rather than on_left_click
+            // (item may not be selected if an unimplemented modifier key was used)
+            if (item.is_selected())
+                get_view().unselect_all_but(item);
+        }
+
+        return true;
+    }
+
+    protected override bool on_right_click(Gdk.EventButton event) {
+        // only interested in single-clicks for now
+        if (event.type != Gdk.EventType.BUTTON_PRESS)
+            return false;
+
+        // get what's right-clicked upon
+        CheckerboardItem item = get_item_at_pixel(event.x, event.y);
+        if (item != null) {
+            // mask out the modifiers we're interested in
+            switch (event.state & (Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK)) {
+                case Gdk.ModifierType.CONTROL_MASK:
+                    // chosen item is toggled
+                    Marker marker = get_view().mark(item);
+                    get_view().toggle_marked(marker);
+                break;
+
+                case Gdk.ModifierType.SHIFT_MASK:
+                    // TODO
+                break;
+
+                case Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK:
+                    // TODO
+                break;
+
+                default:
+                    // if the item is already selected, proceed; if item is not selected, a bare right
+                    // click unselects everything else but it
+                    if (!item.is_selected()) {
+                        Marker all = get_view().start_marking();
+                        all.mark_many(get_view().get_selected());
+
+                        get_view().unselect_and_select_marked(all, get_view().mark(item));
+                    }
+                break;
+            }
+        } else {
+            // clicked in "dead" space, unselect everything
+            get_view().unselect_all();
+        }
+
+        Gtk.Menu context_menu = get_context_menu();
+        return popup_context_menu(context_menu, event);
+    }
+
+    protected virtual bool on_mouse_over(CheckerboardItem? item, int x, int y, Gdk.ModifierType mask) {
+        if (item != null)
+            layout.handle_mouse_motion(item, x, y, mask);
+
+        // if hovering over the last hovered item, or both are null (nothing highlighted and
+        // hovering over empty space), do nothing
+        if (item == current_hovered_item)
+            return true;
+
+        // either something new is highlighted or now hovering over empty space, so dim old item
+        if (current_hovered_item != null) {
+            current_hovered_item.handle_mouse_leave();
+            current_hovered_item = null;
+        }
+
+        // if over empty space, done
+        if (item == null)
+            return true;
+
+        // brighten the new item
+        current_hovered_item = item;
+        current_hovered_item.handle_mouse_enter();
+
+        return true;
+    }
+
+    protected override bool on_motion(Gdk.EventMotion event, int x, int y, Gdk.ModifierType mask) {
+        // report what item the mouse is hovering over
+        if (!on_mouse_over(get_item_at_pixel(x, y), x, y, mask))
+            return false;
+
+        // go no further if not drag-selecting
+        if (!layout.is_drag_select_active())
+            return false;
+
+        // set the new endpoint of the drag selection
+        layout.set_drag_select_endpoint(x, y);
+
+        updated_selection_band();
+
+        // if out of bounds, schedule a check to auto-scroll the viewport
+        if (!autoscroll_scheduled 
+            && get_adjustment_relation(get_vadjustment(), y) != AdjustmentRelation.IN_RANGE) {
+            Timeout.add(AUTOSCROLL_TICKS_MSEC, selection_autoscroll);
+            autoscroll_scheduled = true;
+        }
+
+        // return true to stop a potential drag-and-drop operation
+        return true;
+    }
+
+    private void updated_selection_band() {
+        assert(layout.is_drag_select_active());
+
+        // get all items inside the selection
+        Gee.List<CheckerboardItem>? intersection = layout.items_in_selection_band();
+        if (intersection == null)
+            return;
+
+        Marker to_unselect = get_view().start_marking();
+        Marker to_select = get_view().start_marking();
+
+        // mark all selected items to be unselected
+        to_unselect.mark_many(get_view().get_selected());
+
+        // except for the items that were selected before the drag began
+        assert(previously_selected != null);
+        to_unselect.unmark_many(previously_selected);        
+        to_select.mark_many(previously_selected);   
+
+        // toggle selection on everything in the intersection and update the cursor
+        cursor = null;
+
+        foreach (CheckerboardItem item in intersection) {
+            if (to_select.toggle(item))
+                to_unselect.unmark(item);
+            else
+                to_unselect.mark(item);
+
+            if (cursor == null)
+                cursor = item;
+        }
+
+        get_view().select_marked(to_select);
+        get_view().unselect_marked(to_unselect);
+    }
+
+    private bool selection_autoscroll() {
+        if (!layout.is_drag_select_active()) { 
+            autoscroll_scheduled = false;
+
+            return false;
+        }
+
+        // as the viewport never scrolls horizontally, only interested in vertical
+        Gtk.Adjustment vadj = get_vadjustment();
+
+        int x, y;
+        Gdk.ModifierType mask;
+        get_event_source_pointer(out x, out y, out mask);
+
+        int new_value = (int) vadj.get_value();
+        switch (get_adjustment_relation(vadj, y)) {
+            case AdjustmentRelation.BELOW:
+                // pointer above window, scroll up
+                new_value -= AUTOSCROLL_PIXELS;
+                layout.set_drag_select_endpoint(x, new_value);
+            break;
+
+            case AdjustmentRelation.ABOVE:
+                // pointer below window, scroll down, extend selection to bottom of page
+                new_value += AUTOSCROLL_PIXELS;
+                layout.set_drag_select_endpoint(x, new_value + (int) vadj.get_page_size());
+            break;
+
+            case AdjustmentRelation.IN_RANGE:
+                autoscroll_scheduled = false;
+
+                return false;
+
+            default:
+                warn_if_reached();
+            break;
+        }
+
+        // It appears that in GTK+ 2.18, the adjustment is not clamped the way it was in 2.16.
+        // This may have to do with how adjustments are different w/ scrollbars, that they're upper
+        // clamp is upper - page_size ... either way, enforce these limits here
+        vadj.set_value(new_value.clamp((int) vadj.get_lower(), 
+            (int) vadj.get_upper() - (int) vadj.get_page_size()));
+
+        updated_selection_band();
+
+        return true;
+    }
+
+    public void cursor_to_item(CheckerboardItem item) {
+        assert(get_view().contains(item));
+
+        cursor = item;
+
+        if (!get_ctrl_pressed()) {
+            get_view().unselect_all();
+            Marker marker = get_view().mark(item);
+            get_view().select_marked(marker);
+        }
+        layout.set_cursor(item);
+        scroll_to_item(item);
+    }
+
+    public void move_cursor(CompassPoint point) {
+        // if no items, nothing to do
+        if (get_view().get_count() == 0)
+            return;
+
+        // if there is no better starting point, simply select the first and exit
+        // The right half of the or is related to Bug #732334, the cursor might be non-null and still not contained in
+        // the view, if the user dragged a full screen Photo off screen
+        if (cursor == null && layout.get_cursor() == null || cursor != null && !get_view().contains(cursor)) {
+            CheckerboardItem item = layout.get_item_at_coordinate(0, 0);
+            cursor_to_item(item);
+            anchor = item;
+
+            return;
+        }
+
+        if (cursor == null) {
+            cursor = layout.get_cursor() as CheckerboardItem;
+        }
+
+        // move the cursor relative to the "first" item
+        CheckerboardItem? item = layout.get_item_relative_to(cursor, point);
+        if (item != null)
+            cursor_to_item(item);
+   }
+
+    public void set_cursor(CheckerboardItem item) {
+        Marker marker = get_view().mark(item);
+        get_view().select_marked(marker);
+
+        cursor = item;
+        anchor = item;
+   }
+
+    public void select_between_items(CheckerboardItem item_start, CheckerboardItem item_end) {
+        Marker marker = get_view().start_marking();
+
+        bool passed_start = false;
+        bool passed_end = false;
+
+        foreach (DataObject object in get_view().get_all()) {
+            CheckerboardItem item = (CheckerboardItem) object;
+
+            if (item_start == item)
+                passed_start = true;
+
+            if (item_end == item)
+                passed_end = true;
+
+            if (passed_start || passed_end)
+                marker.mark((DataView) object);
+
+            if (passed_start && passed_end)
+                break;
+        }
+
+        get_view().select_marked(marker);
+    }
+
+    public void select_anchor_to_cursor(uint state) {
+        if (cursor == null || anchor == null)
+            return;
+
+        if (state == Gdk.ModifierType.SHIFT_MASK) {
+            get_view().unselect_all();
+            select_between_items(anchor, cursor);
+        } else {
+            anchor = cursor;
+        }
+    }
+
+    protected virtual void set_display_titles(bool display) {
+        get_view().freeze_notifications();
+        get_view().set_property(CheckerboardItem.PROP_SHOW_TITLES, display);
+        get_view().thaw_notifications();
+    }
+
+    protected virtual void set_display_comments(bool display) {
+        get_view().freeze_notifications();
+        get_view().set_property(CheckerboardItem.PROP_SHOW_COMMENTS, display);
+        get_view().thaw_notifications();
+    }
+}
+
+
diff --git a/src/Commands.vala b/src/Commands.vala
index 589ae38..76aecb4 100644
--- a/src/Commands.vala
+++ b/src/Commands.vala
@@ -1316,8 +1316,17 @@ public class AdjustDateTimePhotoCommand : SingleDataSourceCommand {
         this.modify_original = modify_original;
     }
 
+    private DateTime get_base_time() {
+        var exposure_time = dateable.get_exposure_time();
+        if (exposure_time == null) {
+            exposure_time = new DateTime.from_unix_utc(0);
+        }
+
+        return exposure_time;
+    }
+
     public override void execute() {
-        set_time(dateable, dateable.get_exposure_time() + (time_t) time_shift);
+        set_time(dateable, get_base_time().add_seconds(time_shift));
 
         prev_event = dateable.get_event();
 
@@ -1333,12 +1342,12 @@ public class AdjustDateTimePhotoCommand : SingleDataSourceCommand {
     }
 
     public override void undo() {
-        set_time(dateable, dateable.get_exposure_time() - (time_t) time_shift);
+        set_time(dateable, get_base_time().add_seconds(-1 * time_shift));
 
         dateable.set_event(prev_event);
     }
 
-    private void set_time(Dateable dateable, time_t exposure_time) {
+    private void set_time(Dateable dateable, DateTime exposure_time) {
         if (modify_original && dateable is Photo) {
             try {
                 ((Photo)dateable).set_exposure_time_persistent(exposure_time);
@@ -1358,8 +1367,8 @@ public class AdjustDateTimePhotosCommand : MultipleDataSourceCommand {
     private Gee.Map<Dateable, Event?> prev_events;
 
     // used when photos are batch changed instead of shifted uniformly
-    private time_t? new_time = null;
-    private Gee.HashMap<Dateable, time_t?> old_times;
+    private DateTime? new_time = null;
+    private Gee.HashMap<Dateable, DateTime?> old_times;
     private Gee.ArrayList<Dateable> error_list;
 
     public AdjustDateTimePhotosCommand(Gee.Iterable<DataView> iter, int64 time_shift,
@@ -1377,16 +1386,24 @@ public class AdjustDateTimePhotosCommand : MultipleDataSourceCommand {
 
         // this should be replaced by a first function when we migrate to Gee's List
         foreach (DataView view in iter) {
-            prev_events.set(view.get_source() as Dateable, (view.get_source() as MediaSource).get_event());
+            prev_events.set(view.get_source() as Dateable, ((MediaSource) view.get_source()).get_event());
             
             if (new_time == null) {
-                new_time = ((Dateable) view.get_source()).get_exposure_time() +
-                    (time_t) time_shift;
+                new_time = get_base_time((Dateable)view.get_source()).add_seconds(time_shift);
                 break;
             }
         }
 
-        old_times = new Gee.HashMap<Dateable, time_t?>();
+        old_times = new Gee.HashMap<Dateable, DateTime?>();
+    }
+
+    private DateTime get_base_time(Dateable dateable) {
+        var exposure_time = dateable.get_exposure_time();
+        if (exposure_time == null) {
+            exposure_time = new DateTime.from_unix_utc(0);
+        }
+
+        return exposure_time;
     }
 
     public override void execute() {
@@ -1425,7 +1442,7 @@ public class AdjustDateTimePhotosCommand : MultipleDataSourceCommand {
         }
     }
 
-    private void set_time(Dateable dateable, time_t exposure_time) {
+    private void set_time(Dateable dateable, DateTime exposure_time) {
         // set_exposure_time_persistent wouldn't work on videos,
         // since we can't actually write them from inside shotwell,
         // so check whether we're working on a Photo or a Video
@@ -1445,8 +1462,8 @@ public class AdjustDateTimePhotosCommand : MultipleDataSourceCommand {
     public override void execute_on_source(DataSource source) {
         Dateable dateable = ((Dateable) source);
 
-        if (keep_relativity && dateable.get_exposure_time() != 0) {
-            set_time(dateable, dateable.get_exposure_time() + (time_t) time_shift);
+        if (keep_relativity && dateable.get_exposure_time() != null) {
+            set_time(dateable, dateable.get_exposure_time().add_seconds(time_shift));
         } else {
             old_times.set(dateable, dateable.get_exposure_time());
             set_time(dateable, new_time);
@@ -1470,10 +1487,10 @@ public class AdjustDateTimePhotosCommand : MultipleDataSourceCommand {
             set_time(photo, old_times.get(photo));
             old_times.unset(photo);
         } else {
-            set_time(photo, photo.get_exposure_time() - (time_t) time_shift);
+            set_time(photo, photo.get_exposure_time().add_seconds(-1 * time_shift));
         }
         
-        (source as MediaSource).set_event(prev_events.get(source as Dateable));
+        ((MediaSource) source).set_event(prev_events.get(source as Dateable));
     }
 }
 
@@ -2165,8 +2182,6 @@ public class ModifyTagsCommand : SingleDataSourceCommand {
         }
         
         foreach (string path in new_paths) {
-            assert(Tag.global.exists(path));
-
             SourceProxy proxy = Tag.for_path(path).get_proxy();
             to_add.add(proxy);
             proxy.broken.connect(on_proxy_broken);
@@ -2541,7 +2556,8 @@ public class RemoveFacesFromPhotosCommand : SimpleProxyableCommand {
         
         face.attach_many(map_source_geometry.keys);
         foreach (Gee.Map.Entry<MediaSource, string> entry in map_source_geometry.entries)
-            FaceLocation.create(face.get_face_id(), ((Photo) entry.key).get_photo_id(), entry.value);
+            FaceLocation.create(face.get_face_id(), ((Photo) entry.key).get_photo_id(),
+                                                    { entry.value, null });
     }
     
     private void on_source_destroyed(DataSource source) {
@@ -2572,6 +2588,26 @@ public class RenameFaceCommand : SimpleProxyableCommand {
     }
 }
 
+public class SetFaceRefCommand : SimpleProxyableCommand {
+    private FaceLocation face_loc;
+    
+    public SetFaceRefCommand(Face face, MediaSource source) {
+        base (face, Resources.set_face_from_photo_label(face.get_name()), face.get_name());
+        Gee.Map<FaceID?, FaceLocation>? face_loc_map = FaceLocation.get_locations_by_photo((Photo)source);
+        face_loc = face_loc_map.get(face.get_face_id());
+    }
+    
+    protected override void execute_on_source(DataSource source) {
+        if (!((Face) source).set_reference(face_loc))
+            AppWindow.error_message(Resources.set_face_from_photo_error());
+    }
+
+    protected override void undo_on_source(DataSource source) {
+        //if (!((Face) source).rename(old_name))
+        //    AppWindow.error_message(Resources.rename_face_exists_message(old_name));
+    }
+}
+
 public class DeleteFaceCommand : SimpleProxyableCommand {
     private Gee.Map<PhotoID?, string> photo_geometry_map = new Gee.HashMap<PhotoID?, string>
         ((Gee.HashDataFunc)FaceLocation.photo_id_hash, (Gee.EqualDataFunc)FaceLocation.photo_ids_equal);
@@ -2607,7 +2643,8 @@ public class DeleteFaceCommand : SimpleProxyableCommand {
                 Face face = (Face) source;
                 
                 face.attach(photo);
-                FaceLocation.create(face.get_face_id(), entry.key, entry.value);
+                FaceLocation.create(face.get_face_id(), entry.key,
+                                                        { entry.value, null });
             }
         }
     }
@@ -2617,10 +2654,10 @@ public class ModifyFacesCommand : SingleDataSourceCommand {
     private MediaSource media;
     private Gee.ArrayList<SourceProxy> to_add = new Gee.ArrayList<SourceProxy>();
     private Gee.ArrayList<SourceProxy> to_remove = new Gee.ArrayList<SourceProxy>();
-    private Gee.Map<SourceProxy, string> to_update = new Gee.HashMap<SourceProxy, string>();
-    private Gee.Map<SourceProxy, string> geometries = new Gee.HashMap<SourceProxy, string>();
+    private Gee.Map<SourceProxy, FaceLocationData?> to_update = new Gee.HashMap<SourceProxy, FaceLocationData?>();
+    private Gee.Map<SourceProxy, FaceLocationData?> geometries = new Gee.HashMap<SourceProxy, FaceLocationData?>();
     
-    public ModifyFacesCommand(MediaSource media, Gee.Map<Face, string> new_face_list) {
+    public ModifyFacesCommand(MediaSource media, Gee.Map<Face, FaceLocationData?> new_face_list) {
         base (media, Resources.MODIFY_FACES_LABEL, "");
         
         this.media = media;
@@ -2639,13 +2676,13 @@ public class ModifyFacesCommand : SingleDataSourceCommand {
                         FaceLocation.get_face_location(face.get_face_id(), ((Photo) media).get_photo_id());
                     assert(face_location != null);
                     
-                    geometries.set(proxy, face_location.get_serialized_geometry());
+                    geometries.set(proxy, face_location.get_face_data());
                 }
             }
         }
         
         // Add any face that's in the new list but not the original
-        foreach (Gee.Map.Entry<Face, string> entry in new_face_list.entries) {
+        foreach (Gee.Map.Entry<Face, FaceLocationData?> entry in new_face_list.entries) {
             if (original_faces == null || !original_faces.contains(entry.key)) {
                 SourceProxy proxy = entry.key.get_proxy();
                 
@@ -2661,13 +2698,13 @@ public class ModifyFacesCommand : SingleDataSourceCommand {
                 assert(face_location != null);
                 
                 string old_geometry = face_location.get_serialized_geometry();
-                if (old_geometry != entry.value) {
+                if (old_geometry != entry.value.geometry) {
                     SourceProxy proxy = entry.key.get_proxy();
                     
                     to_update.set(proxy, entry.value);
                     proxy.broken.connect(on_proxy_broken);
                     
-                    geometries.set(proxy, old_geometry);
+                    geometries.set(proxy, face_location.get_face_data());
                 }
             }
         }
@@ -2694,7 +2731,7 @@ public class ModifyFacesCommand : SingleDataSourceCommand {
         foreach (SourceProxy proxy in to_remove)
             ((Face) proxy.get_source()).detach(media);
         
-        foreach (Gee.Map.Entry<SourceProxy, string> entry in to_update.entries) {
+        foreach (Gee.Map.Entry<SourceProxy, FaceLocationData?> entry in to_update.entries) {
             Face face = (Face) entry.key.get_source();
             FaceLocation.create(face.get_face_id(), ((Photo) media).get_photo_id(), entry.value);
         }
diff --git a/src/Debug.vala b/src/Debug.vala
index f159b0d..799a94f 100644
--- a/src/Debug.vala
+++ b/src/Debug.vala
@@ -33,7 +33,7 @@ namespace Debug {
         
         string log_file_error_msg = null;
         
-        // logging to disk is currently off for viewer more; see http://trac.yorba.org/ticket/2078
+        // logging to disk is currently off for viewer more; see https://bugzilla.gnome.org/show_bug.cgi?id=716474
         File? log_file = (log_app_version_prefix == LIBRARY_PREFIX) ? AppDirs.get_log_file() : null;
         if(log_file != null) {
             File log_dir = log_file.get_parent();
@@ -104,11 +104,10 @@ namespace Debug {
     }
     
     private void log(FileStream stream, string prefix, string message) {
-        time_t now = time_t();
         stream.printf("%s %d %s [%s] %s\n",
             log_app_version_prefix,
             Posix.getpid(),
-            Time.local(now).to_string(),
+            new DateTime.now_local().format("%F %T"),
             prefix,
             message
         );
diff --git a/src/DesktopIntegration.vala b/src/DesktopIntegration.vala
index 024bc8b..754d9a1 100644
--- a/src/DesktopIntegration.vala
+++ b/src/DesktopIntegration.vala
@@ -9,7 +9,6 @@ namespace DesktopIntegration {
 private const string DESKTOP_SLIDESHOW_XML_FILENAME = "wallpaper.xml";
 
 private int init_count = 0;
-private bool send_to_installed = false;
 private ExporterUI send_to_exporter = null;
 private ExporterUI desktop_slideshow_exporter = null;
 private double desktop_slideshow_transition = 0.0;
@@ -21,12 +20,6 @@ private bool set_screensaver = false;
 public void init() {
     if (init_count++ != 0)
         return;
-    try{
-        Portal.get_instance();
-        send_to_installed =  true;
-    } catch (Error error) {
-        send_to_installed = false;
-    }
 }
 
 public void terminate() {
@@ -93,46 +86,33 @@ public string? get_app_open_command(AppInfo app_info) {
 }
 
 public bool is_send_to_installed() {
-    // FIXME: Check if portal is available
-    return send_to_installed;
+    return true;
 }
 
 public async void files_send_to(File[] files) {
     if (files.length == 0)
         return;
-    
+    var parent = Xdp.parent_new_gtk(AppWindow.get_instance());
+
     var file_names = new StringBuilder();
-    var files_builder = new VariantBuilder (new VariantType ("ah"));
-    var file_descriptors = new UnixFDList ();
+    var file_paths = new string[files.length];
     for (int i=0; i<files.length; i++){
-        var fd = Posix.open (files[i].get_path (), Posix.O_RDONLY | Posix.O_CLOEXEC);
-        if (fd == -1) {
-            warning ("Send to: cannot open file: '%s'", files[i].get_path ());
-            continue;
-        }
-        try {
-            files_builder.add ("h", file_descriptors.append (fd));
-        } catch (Error e) {
-            warning ("Send to: cannot append file %s to file descriptor list: %s",
-            files[i].get_path(), e.message);
-        }
         file_names.append(files[i].get_basename());
         if(i<files.length-1){
             file_names.append(", ");
         }
+        file_paths[i] = files[i].get_path();
     }
 
-    var options = new HashTable<string, Variant> (str_hash, str_equal);
-    options.insert ("subject", _("Send files per Mail: ") + file_names.str);
-    options.insert ("attachment_fds", files_builder.end());
-    options.insert ("addresses", new Variant ("as", null));
     AppWindow.get_instance().set_busy_cursor();
     try{
-        var response = yield Portal.get_instance().compose_email (options, file_descriptors);
-        if (response == null){
-            throw new DBusError.FAILED("Did not get response");
-        }
+        var portal = new Xdp.Portal();
+
+        // Use empty list for addresses instead of null to word around bug in xdg-desktop-portal-gtk
+        yield portal.compose_email(parent, {null}, null, null,
+            _("Send files per Mail: ")  + file_names.str, null, file_paths, Xdp.EmailFlags.NONE, null);
     } catch (Error e){
+        // Translators: The first %s is the name of the file, the second %s is the reason why it could not be sent
         AppWindow.error_message(_("Unable to send file %s, %s").printf(
         file_names.str, e.message));
     }
@@ -193,14 +173,15 @@ public void set_background(Photo photo, bool desktop, bool screensaver) {
         
         return;
     }
-    
-    if (desktop) {
-        Config.Facade.get_instance().set_desktop_background(save_as.get_path());
-    }
-    if (screensaver) {
-        Config.Facade.get_instance().set_screensaver(save_as.get_path());
-    }
-    
+
+    var parent = Xdp.parent_new_gtk(AppWindow.get_instance());
+    var portal = new Xdp.Portal();
+    Xdp.WallpaperFlags flags = Xdp.WallpaperFlags.PREVIEW;
+    if (desktop) flags |= Xdp.WallpaperFlags.BACKGROUND;
+    if (screensaver) flags |= Xdp.WallpaperFlags.LOCKSCREEN;
+
+    portal.set_wallpaper.begin(parent, save_as.get_uri(), flags, null);
+
     GLib.FileUtils.chmod(save_as.get_parse_name(), 0644);
 }
 
@@ -226,7 +207,7 @@ private class BackgroundSlideshowXMLBuilder {
     
     public void open() throws Error {
         outs = new DataOutputStream(tmp_file.replace(null, false, FileCreateFlags.NONE, null));
-        outs.put_string("<background>\n");
+        outs.put_string("<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n<background>\n");
     }
     
     private void write_transition(File from, File to) throws Error {
@@ -331,12 +312,13 @@ private void on_desktop_slideshow_exported(Exporter exporter, bool is_cancelled)
         return;
     }
     
-    if (set_desktop_background) {
-        Config.Facade.get_instance().set_desktop_background(xml_file.get_path());
-    }
-    if (set_screensaver) {
-        Config.Facade.get_instance().set_screensaver(xml_file.get_path());
-    }
+    var parent = Xdp.parent_new_gtk(AppWindow.get_instance());
+    var portal = new Xdp.Portal();
+    Xdp.WallpaperFlags flags = Xdp.WallpaperFlags.PREVIEW;
+    if (set_desktop_background) flags |= Xdp.WallpaperFlags.BACKGROUND;
+    if (set_screensaver) flags |= Xdp.WallpaperFlags.LOCKSCREEN;
+
+    portal.set_wallpaper.begin(parent, xml_file.get_uri(), flags, null);
 }
 
 }
diff --git a/src/Dialogs.vala b/src/Dialogs.vala
index b1f6e08..70dc76d 100644
--- a/src/Dialogs.vala
+++ b/src/Dialogs.vala
@@ -5,7 +5,7 @@
  */
 
 // namespace for future migration of AppWindow alert and other question dialogs into single
-// place: http://trac.yorba.org/ticket/3452
+// place: https://bugzilla.gnome.org/show_bug.cgi?id=717659
 namespace Dialogs {
 
 public bool confirm_delete_tag(Tag tag) {
@@ -67,7 +67,7 @@ public File? choose_file(string current_file_basename) {
         current_export_dir = File.new_for_path(Environment.get_home_dir());
 
     string file_chooser_title = VideoReader.is_supported_video_filename(current_file_basename) ?
-        _("Export Video") : _("Export Photo");
+        _("Export Video") : GLib.dpgettext2 (null, "Dialog Title", "Export Photo");
         
     var chooser = new Gtk.FileChooserNative(file_chooser_title,
         AppWindow.get_instance(), Gtk.FileChooserAction.SAVE, Resources.SAVE_LABEL, Resources.CANCEL_LABEL);
@@ -214,7 +214,7 @@ public string create_result_report_from_manifest(ImportManifest manifest) {
     StringBuilder builder = new StringBuilder();
     
     string header = _("Import Results Report") + " (Shotwell " + Resources.APP_VERSION + " @ " +
-        TimeVal().to_iso8601() + ")\n\n";
+        new DateTime.now_utc().format_iso8601() + ")\n\n";
     builder.append(header);
     
     string subhead = (ngettext("Attempted to import %d file.", "Attempted to import %d files.",
@@ -817,8 +817,14 @@ public void multiple_object_error_dialog(Gee.ArrayList<DataObject> objects, stri
 
 public abstract class TagsDialog : TextEntryDialogMediator {
     protected TagsDialog(string title, string label, string? initial_text = null) {
-        base (title, label, initial_text, HierarchicalTagIndex.get_global_index().get_all_tags(),
-            ",");
+        var all = new Gee.ArrayList<string>();
+        all.add_all(HierarchicalTagIndex.get_global_index().get_all_tags());
+        var paths = HierarchicalTagIndex.get_global_index().get_all_paths();
+        foreach (var p in paths) {
+            if (p.has_prefix("/")) all.add(p);
+        }
+        
+        base (title, label, initial_text, all, ",");
     }
 }
 
@@ -840,14 +846,24 @@ public class AddTagsDialog : TagsDialog {
     }
 
     protected override bool on_modify_validate(string text) {
-        if (text.contains(Tag.PATH_SEPARATOR_STRING))
-            return false;
-            
-        // Can't simply call Tag.prep_tag_names().length because of this bug:
-        // https://bugzilla.gnome.org/show_bug.cgi?id=602208
         string[] names = Tag.prep_tag_names(text.split(","));
-        
-        return names.length > 0;
+        if (names.length == 0)
+            return false;
+
+        // If allowing hierarchies, they have to start with a "/"
+        for (int i = 0; i < names.length; i++) {
+            if (names[i].contains(Tag.PATH_SEPARATOR_STRING) && !names[i].strip().has_prefix(Tag.PATH_SEPARATOR_STRING))
+                return false;
+
+            if (names[i].strip().has_prefix(Tag.PATH_SEPARATOR_STRING) && names[i].strip().length == 1)
+                return false;
+
+            if (names[i].strip().contains(Tag.PATH_SEPARATOR_STRING + Tag.PATH_SEPARATOR_STRING)) {
+                return false;
+            }
+        }
+
+        return true;
     }
 }
 
@@ -904,7 +920,26 @@ public class ModifyTagsDialog : TagsDialog {
     }
     
     protected override bool on_modify_validate(string text) {
-        return (!text.contains(Tag.PATH_SEPARATOR_STRING));
+        string[] names = Tag.prep_tag_names(text.split(","));
+        if (names.length == 0)
+            return false;
+
+        // If allowing hierarchies, they have to start with a "/"
+        for (int i = 0; i < names.length; i++) {
+            if (names[i].contains(Tag.PATH_SEPARATOR_STRING) && !names[i].strip().has_prefix(Tag.PATH_SEPARATOR_STRING)) {
+                return false;
+            }
+
+            if (names[i].strip().has_prefix(Tag.PATH_SEPARATOR_STRING) && names[i].strip().length == 1)
+                return false;
+
+            if (names[i].strip().contains(Tag.PATH_SEPARATOR_STRING + Tag.PATH_SEPARATOR_STRING)) {
+                return false;
+            }
+        }
+
+        return true;
+
     }
     
 }
@@ -930,7 +965,7 @@ public Gtk.ResponseType copy_files_dialog() {
 
 public void remove_photos_from_library(Gee.Collection<LibraryPhoto> photos) {
     remove_from_app(photos, _("Remove From Library"),
-        (photos.size == 1) ? _("Removing Photo From Library") : _("Removing Photos From Library"));
+        ngettext("Removing Photo From Library", "Removing Photos From Library", photos.size));
 }
 
 public void remove_from_app(Gee.Collection<MediaSource> sources, string dialog_title, 
diff --git a/src/Dimensions.vala b/src/Dimensions.vala
index 3b4163c..32bf32c 100644
--- a/src/Dimensions.vala
+++ b/src/Dimensions.vala
@@ -59,8 +59,9 @@ public struct Dimensions {
     public static Dimensions for_widget_allocation(Gtk.Widget widget) {
         Gtk.Allocation allocation;
         widget.get_allocation(out allocation);
+        var scale = widget.get_scale_factor();
         
-        return Dimensions(allocation.width, allocation.height);
+        return Dimensions(allocation.width * scale, allocation.height * scale);
     }
     
     public static Dimensions for_rectangle(Gdk.Rectangle rect) {
diff --git a/src/DirectoryMonitor.vala b/src/DirectoryMonitor.vala
index a37b124..19992dd 100644
--- a/src/DirectoryMonitor.vala
+++ b/src/DirectoryMonitor.vala
@@ -60,7 +60,7 @@
 public class DirectoryMonitor : Object {
     public const int DEFAULT_PRIORITY = Priority.LOW;
     public const FileQueryInfoFlags DIR_INFO_FLAGS = FileQueryInfoFlags.NONE;
-    public const FileQueryInfoFlags FILE_INFO_FLAGS = FileQueryInfoFlags.NOFOLLOW_SYMLINKS;
+    public const FileQueryInfoFlags FILE_INFO_FLAGS = FileQueryInfoFlags.NONE;
     
     // when using UNKNOWN_FILE_FLAGS, check if the resulting FileInfo's symlink status matches
     // symlink support for files and directories by calling is_file_symlink_supported().
@@ -290,7 +290,7 @@ public class DirectoryMonitor : Object {
             
             // get all the interesting matchable items from the supplied FileInfo
             int64 match_size = match.get_size();
-            TimeVal match_time = match.get_modification_time();
+            var match_time = match.get_modification_date_time();
             
             foreach (File file in map.keys) {
                 FileInfo info = map.get(file);
@@ -303,9 +303,9 @@ public class DirectoryMonitor : Object {
                 if (match_size != info.get_size())
                     continue;
                 
-                TimeVal time = info.get_modification_time();
+                var time = info.get_modification_date_time();
                 
-                if (time.tv_sec != match_time.tv_sec)
+                if (!time.equal(match_time))
                     continue;
                 
                 return file;
diff --git a/src/DragAndDropHandler.vala b/src/DragAndDropHandler.vala
new file mode 100644
index 0000000..ece6d9d
--- /dev/null
+++ b/src/DragAndDropHandler.vala
@@ -0,0 +1,182 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+//
+// DragAndDropHandler attaches signals to a Page to properly handle drag-and-drop requests for the
+// Page as a DnD Source.  (DnD Destination handling is handled by the appropriate AppWindow, i.e.
+// LibraryWindow and DirectWindow). Assumes the Page's ViewCollection holds MediaSources.
+//
+public class DragAndDropHandler {
+    private enum TargetType {
+        XDS,
+        MEDIA_LIST
+    }
+
+    private const Gtk.TargetEntry[] SOURCE_TARGET_ENTRIES = {
+        { "XdndDirectSave0", Gtk.TargetFlags.OTHER_APP, TargetType.XDS },
+        { "shotwell/media-id-atom", Gtk.TargetFlags.SAME_APP, TargetType.MEDIA_LIST }
+    };
+
+    private static Gdk.Atom? XDS_ATOM = null;
+    private static Gdk.Atom? TEXT_ATOM = null;
+    private static uint8[]? XDS_FAKE_TARGET = null;
+
+    private weak Page page;
+    private Gtk.Widget event_source;
+    private File? drag_destination = null;
+    private ExporterUI exporter = null;
+
+    public DragAndDropHandler(Page page) {
+        this.page = page;
+        this.event_source = page.get_event_source();
+        assert(event_source != null);
+        assert(event_source.get_has_window());
+
+        // Need to do this because static member variables are not properly handled
+        if (XDS_ATOM == null)
+            XDS_ATOM = Gdk.Atom.intern_static_string("XdndDirectSave0");
+
+        if (TEXT_ATOM == null)
+            TEXT_ATOM = Gdk.Atom.intern_static_string("text/plain");
+
+        if (XDS_FAKE_TARGET == null)
+            XDS_FAKE_TARGET = string_to_uchar_array("shotwell.txt");
+
+        // register what's available on this DnD Source
+        Gtk.drag_source_set(event_source, Gdk.ModifierType.BUTTON1_MASK, SOURCE_TARGET_ENTRIES,
+            Gdk.DragAction.COPY);
+
+        // attach to the event source's DnD signals, not the Page's, which is a NO_WINDOW widget
+        // and does not emit them
+        event_source.drag_begin.connect(on_drag_begin);
+        event_source.drag_data_get.connect(on_drag_data_get);
+        event_source.drag_end.connect(on_drag_end);
+        event_source.drag_failed.connect(on_drag_failed);
+    }
+
+    ~DragAndDropHandler() {
+        if (event_source != null) {
+            event_source.drag_begin.disconnect(on_drag_begin);
+            event_source.drag_data_get.disconnect(on_drag_data_get);
+            event_source.drag_end.disconnect(on_drag_end);
+            event_source.drag_failed.disconnect(on_drag_failed);
+        }
+
+        page = null;
+        event_source = null;
+    }
+
+    private void on_drag_begin(Gdk.DragContext context) {
+        debug("on_drag_begin (%s)", page.get_page_name());
+
+        if (page == null || page.get_view().get_selected_count() == 0 || exporter != null)
+            return;
+
+        drag_destination = null;
+
+        // use the first media item as the icon
+        ThumbnailSource thumb = (ThumbnailSource) page.get_view().get_selected_at(0).get_source();
+
+        try {
+            Gdk.Pixbuf icon = thumb.get_thumbnail(AppWindow.DND_ICON_SCALE);
+            Gtk.drag_source_set_icon_pixbuf(event_source, icon);
+        } catch (Error err) {
+            warning("Unable to fetch icon for drag-and-drop from %s: %s", thumb.to_string(),
+                err.message);
+        }
+
+        // set the XDS property to indicate an XDS save is available
+        Gdk.property_change(context.get_source_window(), XDS_ATOM, TEXT_ATOM, 8, Gdk.PropMode.REPLACE,
+            XDS_FAKE_TARGET, 1);
+    }
+
+    private void on_drag_data_get(Gdk.DragContext context, Gtk.SelectionData selection_data,
+        uint target_type, uint time) {
+        debug("on_drag_data_get (%s)", page.get_page_name());
+
+        if (page == null || page.get_view().get_selected_count() == 0)
+            return;
+
+        switch (target_type) {
+            case TargetType.XDS:
+                // Fetch the XDS property that has been set with the destination path
+                uchar[] data = new uchar[4096];
+                Gdk.Atom actual_type;
+                int actual_format = 0;
+                bool fetched = Gdk.property_get(context.get_source_window(), XDS_ATOM, TEXT_ATOM,
+                    0, data.length, 0, out actual_type, out actual_format, out data);
+
+                // the destination path is actually for our XDS_FAKE_TARGET, use its parent
+                // to determine where the file(s) should go
+                if (fetched && data != null && data.length > 0)
+                    drag_destination = File.new_for_uri(uchar_array_to_string(data)).get_parent();
+
+                debug("on_drag_data_get (%s): %s", page.get_page_name(),
+                    (drag_destination != null) ? drag_destination.get_path() : "(no path)");
+
+                // Set the property to "S" for Success or "E" for Error
+                selection_data.set(XDS_ATOM, 8,
+                    string_to_uchar_array((drag_destination != null) ? "S" : "E"));
+            break;
+
+            case TargetType.MEDIA_LIST:
+                Gee.Collection<MediaSource> sources =
+                    (Gee.Collection<MediaSource>) page.get_view().get_selected_sources();
+
+                // convert the selected media sources to Gdk.Atom-encoded sourceID strings for
+                // internal drag-and-drop
+                selection_data.set(Gdk.Atom.intern_static_string("SourceIDAtom"), (int) sizeof(Gdk.Atom),
+                    serialize_media_sources(sources));
+            break;
+
+            default:
+                warning("on_drag_data_get (%s): unknown target type %u", page.get_page_name(),
+                    target_type);
+            break;
+        }
+    }
+
+    private void on_drag_end() {
+        debug("on_drag_end (%s)", page.get_page_name());
+
+        if (page == null || page.get_view().get_selected_count() == 0 || drag_destination == null
+            || exporter != null) {
+            return;
+        }
+
+        debug("Exporting to %s", drag_destination.get_path());
+
+        // drag-and-drop export doesn't pop up an export dialog, so use what are likely the
+        // most common export settings (the current -- or "working" -- file format, with
+        // all transformations applied, at the image's original size).
+        if (drag_destination.get_path() != null) {
+            exporter = new ExporterUI(new Exporter(
+                (Gee.Collection<Photo>) page.get_view().get_selected_sources(),
+                drag_destination, Scaling.for_original(), ExportFormatParameters.current()));
+            exporter.export(on_export_completed);
+        } else {
+            AppWindow.error_message(_("Photos cannot be exported to this directory."));
+        }
+
+        drag_destination = null;
+    }
+
+    private bool on_drag_failed(Gdk.DragContext context, Gtk.DragResult drag_result) {
+        debug("on_drag_failed (%s): %d", page.get_page_name(), (int) drag_result);
+
+        if (page == null)
+            return false;
+
+        drag_destination = null;
+
+        return false;
+    }
+
+    private void on_export_completed() {
+        exporter = null;
+    }
+
+}
diff --git a/src/Event.vala b/src/Event.vala
index 084df97..69d27d0 100644
--- a/src/Event.vala
+++ b/src/Event.vala
@@ -100,8 +100,6 @@ public class Event : EventSource, ContainerSource, Proxyable, Indexable {
     // In 24-hour time.
     public const int EVENT_BOUNDARY_HOUR = 4;
     
-    private const time_t TIME_T_DAY = 24 * 60 * 60;
-    
     private class EventSnapshot : SourceSnapshot {
         private EventRow row;
         private MediaSource primary_source;
@@ -303,8 +301,10 @@ public class Event : EventSource, ContainerSource, Proxyable, Indexable {
     }
 
     private static int64 view_comparator(void *a, void *b) {
-        return ((MediaSource) ((ThumbnailView *) a)->get_source()).get_exposure_time()
-            - ((MediaSource) ((ThumbnailView *) b)->get_source()).get_exposure_time() ;
+        var time_a = ((MediaSource) ((ThumbnailView *) a)->get_source()).get_exposure_time();
+        var time_b = ((MediaSource) ((ThumbnailView *) b)->get_source()).get_exposure_time();
+
+        return nullsafe_date_time_comperator(time_a, time_b);
     }
     
     private static bool view_comparator_predicate(DataObject object, Alteration alteration) {
@@ -591,7 +591,7 @@ public class Event : EventSource, ContainerSource, Proxyable, Indexable {
         return indexable_keywords;
     }
     
-    public bool is_in_starting_day(time_t time) {
+    public bool is_in_starting_day(DateTime time) {
         // it's possible the Event ref is held although it's been emptied
         // (such as the user removing items during an import, when events
         // are being generate on-the-fly) ... return false here and let
@@ -601,30 +601,25 @@ public class Event : EventSource, ContainerSource, Proxyable, Indexable {
         
         // media sources are stored in ViewCollection from earliest to latest
         MediaSource earliest_media = (MediaSource) ((DataView) view.get_at(0)).get_source();
-        Time earliest_tm = Time.local(earliest_media.get_exposure_time());
+        var earliest_tm = earliest_media.get_exposure_time().to_local();
         
         // use earliest to generate the boundary hour for that day
-        Time start_boundary_tm = Time();
-        start_boundary_tm.second = 0;
-        start_boundary_tm.minute = 0;
-        start_boundary_tm.hour = EVENT_BOUNDARY_HOUR;
-        start_boundary_tm.day = earliest_tm.day;
-        start_boundary_tm.month = earliest_tm.month;
-        start_boundary_tm.year = earliest_tm.year;
-        start_boundary_tm.isdst = -1;
-        
-        time_t start_boundary = start_boundary_tm.mktime();
-        
+        var start_boundary = new DateTime.local(earliest_tm.get_year(),
+                                            earliest_tm.get_month(),
+                                            earliest_tm.get_day_of_month(),
+                                            EVENT_BOUNDARY_HOUR,
+                                            0,
+                                            0);        
         // if the earliest's exposure time was on the day but *before* the boundary hour,
         // step it back a day to the prior day's boundary
-        if (earliest_tm.hour < EVENT_BOUNDARY_HOUR) {
+        if (earliest_tm.get_hour() < EVENT_BOUNDARY_HOUR) {
             debug("Hour before boundary, shifting back one day");
-            start_boundary -= TIME_T_DAY;
+            start_boundary = start_boundary.add_days(-1);
         }
         
-        time_t end_boundary = (start_boundary + TIME_T_DAY - 1);
-        
-        return time >= start_boundary && time <= end_boundary;
+        var end_boundary = start_boundary.add_days(1).add_seconds(-1);
+
+        return time.compare(start_boundary) >= 0 && time.compare(end_boundary) <= 0;
     }
     
     // This method attempts to add a media source to an event in the supplied list that it would
@@ -632,9 +627,9 @@ public class Event : EventSource, ContainerSource, Proxyable, Indexable {
     // photo).  Otherwise, a new Event is generated and the source is added to it and the list.
     private static Event? generate_event(MediaSource media, ViewCollection events_so_far,
         string? event_name, out bool new_event) {
-        time_t exposure_time = media.get_exposure_time();
+        DateTime? exposure_time = media.get_exposure_time();
         
-        if (exposure_time == 0 && event_name == null) {
+        if (exposure_time == null && event_name == null) {
             debug("Skipping event assignment to %s: no exposure time and no event name", media.to_string());
             new_event = false;
 
@@ -754,22 +749,20 @@ public class Event : EventSource, ContainerSource, Proxyable, Indexable {
     }
     
     public string? get_formatted_daterange() {
-        time_t start_time = get_start_time();
-        time_t end_time = get_end_time();
+        DateTime? start_time = get_start_time();
+        DateTime? end_time = get_end_time();
         
-        if (end_time == 0 && start_time == 0)
+        if (end_time == null && start_time == null)
             return null;
         
-        if (end_time == 0 && start_time != 0)
-            return format_local_date(Time.local(start_time));
-        
-        Time start = Time.local(start_time);
-        Time end = Time.local(end_time);
+        if (end_time == null && start_time != null)
+            return format_local_date(start_time.to_local());
         
-        if (start.day == end.day && start.month == end.month && start.day == end.day)
-            return format_local_date(Time.local(start_time));
+        if (start_time.get_year() == end_time.get_year() &&
+            start_time.get_day_of_year() == end_time.get_day_of_year())
+            return format_local_date(start_time.to_local());
         
-        return format_local_datespan(start, end);
+        return format_local_datespan(start_time.to_local(), end_time.to_local());
     }
     
     public string? get_raw_name() {
@@ -811,30 +804,30 @@ public class Event : EventSource, ContainerSource, Proxyable, Indexable {
         return committed;
     }
     
-    public time_t get_creation_time() {
+    public DateTime? get_creation_time() {
         return event_table.get_time_created(event_id);
     }
     
-    public override time_t get_start_time() {
+    public override DateTime? get_start_time() {
         // Because the ViewCollection is sorted by a DateComparator, the start time is the
         // first item.  However, we keep looking if it has no start time.
         int count = view.get_count();
         for (int i = 0; i < count; i++) {
-            time_t time = ((MediaSource) (((DataView) view.get_at(i)).get_source())).get_exposure_time();
-            if (time != 0)
+            var time = ((MediaSource) (((DataView) view.get_at(i)).get_source())).get_exposure_time();
+            if (time != null)
                 return time;
         }
 
-        return 0;
+        return null;
     }
     
-    public override time_t get_end_time() {
+    public override DateTime? get_end_time() {
         int count = view.get_count();
         
         // Because the ViewCollection is sorted by a DateComparator, the end time is the
         // last item--no matter what.
         if (count == 0)
-            return 0;
+            return null;
        
         return  ((MediaSource) (((DataView) view.get_at(count - 1)).get_source())).get_exposure_time();
     }
diff --git a/src/Exporter.vala b/src/Exporter.vala
index b9596f5..a7f7b6b 100644
--- a/src/Exporter.vala
+++ b/src/Exporter.vala
@@ -55,7 +55,9 @@ public class Exporter : Object {
         YES,
         NO,
         CANCEL,
-        REPLACE_ALL
+        REPLACE_ALL,
+        RENAME,
+        RENAME_ALL,
     }
     
     public delegate void CompletionCallback(Exporter exporter, bool is_cancelled);
@@ -116,8 +118,10 @@ public class Exporter : Object {
     private unowned ProgressMonitor? monitor = null;
     private Cancellable cancellable;
     private bool replace_all = false;
+    private bool rename_all = false;
     private bool aborted = false;
     private ExportFormatParameters export_params;
+    private static File? USE_TEMPORARY_EXPORT_FOLDER = null; 
 
     public Exporter(Gee.Collection<MediaSource> to_export, File? dir, Scaling scaling,
         ExportFormatParameters export_params, bool auto_replace_all = false) {
@@ -131,7 +135,7 @@ public class Exporter : Object {
     public Exporter.for_temp_file(Gee.Collection<MediaSource> to_export, Scaling scaling,
         ExportFormatParameters export_params) {
         this.to_export.add_all(to_export);
-        this.dir = null;
+        this.dir = USE_TEMPORARY_EXPORT_FOLDER;
         this.scaling = scaling;
         this.export_params = export_params;
     }
@@ -193,6 +197,7 @@ public class Exporter : Object {
     
     private bool process_queue() {
         int submitted = 0;
+        Gee.HashSet<string> used = new Gee.HashSet<string>();
         foreach (MediaSource source in to_export) {
             File? use_source_file = null;
             PhotoFileFormat real_export_format = PhotoFileFormat.get_system_default_format();
@@ -227,7 +232,7 @@ public class Exporter : Object {
             if (export_dir == null) {
                 try {
                     bool collision;
-                    dest = generate_unique_file(AppDirs.get_temp_dir(), basename, out collision);
+                    dest = generate_unique_file(AppDirs.get_temp_dir(), basename, out collision, used);
                 } catch (Error err) {
                     AppWindow.error_message(_("Unable to generate a temporary file for %s: %s").printf(
                         source.get_file().get_basename(), err.message));
@@ -236,17 +241,30 @@ public class Exporter : Object {
                 }
             } else {
                 dest = dir.get_child(basename);
+				bool rename = false;
                 
-                if (!replace_all && dest.query_exists(null)) {
-                    switch (overwrite_callback(this, dest)) {
+                if (!replace_all && (dest.query_exists(null) || used.contains(basename))) {
+                    if (rename_all) {
+                        rename = true;
+                    } else {
+                        switch (overwrite_callback(this, dest)) {
                         case Overwrite.YES:
                             // continue
-                        break;
+                            break;
                         
                         case Overwrite.REPLACE_ALL:
                             replace_all = true;
-                        break;
-                        
+                            break;
+
+                        case Overwrite.RENAME:
+                            rename = true;
+                            break;
+
+                        case Overwrite.RENAME_ALL:
+                            rename = true;
+                            rename_all = true;
+                            break;
+
                         case Overwrite.CANCEL:
                             cancellable.cancel();
                             
@@ -264,10 +282,22 @@ public class Exporter : Object {
                             }
                             
                             continue;
+                        }
+                    }
+                    if (rename) {
+                        try {
+                            bool collision;
+                            dest = generate_unique_file(dir, basename, out collision, used);
+                        } catch (Error err) {
+                            AppWindow.error_message(_("Unable to generate a temporary file for %s: %s").printf(
+                                                        source.get_file().get_basename(), err.message));
+                            break;
+                        }
                     }
                 }
             }
 
+            used.add(dest.get_basename());
             workers.enqueue(new ExportJob(this, source, dest, scaling, export_params.quality,
                 real_export_format, cancellable, export_params.mode == ExportFormatMode.UNMODIFIED, export_params.export_metadata));
             submitted++;
@@ -315,24 +345,30 @@ public class ExporterUI {
     private Exporter.Overwrite on_export_overwrite(Exporter exporter, File file) {
         progress_dialog.set_modal(false);
         string question = _("File %s already exists. Replace?").printf(file.get_basename());
-        Gtk.ResponseType response = AppWindow.negate_affirm_all_cancel_question(question, 
-            _("_Skip"), _("_Replace"), _("Replace _All"), _("Export"));
+        int response = AppWindow.export_overwrite_or_replace_question(question, 
+            _("_Skip"), _("Rename"), _("Rename All"),_("_Replace"), _("Replace _All"), _("_Cancel"), _("Export"));
         
         progress_dialog.set_modal(true);
 
         switch (response) {
-            case Gtk.ResponseType.APPLY:
-                return Exporter.Overwrite.REPLACE_ALL;
+        case 2:
+            return Exporter.Overwrite.RENAME;
+            
+        case 3:
+            return Exporter.Overwrite.RENAME_ALL;
             
-            case Gtk.ResponseType.YES:
-                return Exporter.Overwrite.YES;
+        case 4:
+            return Exporter.Overwrite.YES;
             
-            case Gtk.ResponseType.CANCEL:
-                return Exporter.Overwrite.CANCEL;
+        case 5:
+            return Exporter.Overwrite.REPLACE_ALL;
             
-            case Gtk.ResponseType.NO:
-            default:
-                return Exporter.Overwrite.NO;
+        case 6:
+            return Exporter.Overwrite.CANCEL;
+            
+        case 1:
+        default:
+            return Exporter.Overwrite.NO;
         }
     }
     
@@ -340,4 +376,3 @@ public class ExporterUI {
         return export_error_dialog(file, remaining > 0) != Gtk.ResponseType.CANCEL;
     }
 }
-
diff --git a/src/LibraryFiles.vala b/src/LibraryFiles.vala
index bbacb6c..4941742 100644
--- a/src/LibraryFiles.vala
+++ b/src/LibraryFiles.vala
@@ -26,18 +26,18 @@ public void select_copy_function() {
 // Thus, when the method returns success a file may exist already, and should be overwritten.
 //
 // This function is thread safe.
-public File? generate_unique_file(string basename, MediaMetadata? metadata, time_t ts, out bool collision)
+public File? generate_unique_file(string basename, MediaMetadata? metadata, DateTime ts, out bool collision)
     throws Error {
     // use exposure timestamp over the supplied one (which probably comes from the file's
     // modified time, or is simply time()), unless it's zero, in which case use current time
     
-    time_t timestamp = ts;
+    DateTime timestamp = ts;
     if (metadata != null) {
         MetadataDateTime? date_time = metadata.get_creation_date_time();
         if (date_time != null)
             timestamp = date_time.get_timestamp();
-        else if (timestamp == 0)
-            timestamp = time_t();
+        else if (timestamp == null)
+            timestamp = new DateTime.now_utc();
     }
     
     // build a directory tree inside the library
@@ -71,7 +71,7 @@ public string convert_basename(string basename) {
 
 // This function is thread-safe.
 private File duplicate(File src, FileProgressCallback? progress_callback, bool blacklist) throws Error {
-    time_t timestamp = 0;
+    DateTime? timestamp = null;
     try {
         timestamp = query_file_modified(src);
     } catch (Error err) {
diff --git a/src/LibraryMonitor.vala b/src/LibraryMonitor.vala
index f9291d7..a291f15 100644
--- a/src/LibraryMonitor.vala
+++ b/src/LibraryMonitor.vala
@@ -96,7 +96,7 @@ public class LibraryMonitorPool {
 
 public class LibraryMonitor : DirectoryMonitor {
     private const int FLUSH_IMPORT_QUEUE_SEC = 3;
-    private const int IMPORT_ROLL_QUIET_SEC = 5 * 60;
+    private const int IMPORT_ROLL_QUIET_SEC = 5 * 60 * 1000 * 1000;
     private const int MIN_BLACKLIST_DURATION_MSEC = 5 * 1000;
     private const int MAX_VERIFY_EXISTING_MEDIA_JOBS = 5;
     
@@ -217,7 +217,7 @@ public class LibraryMonitor : DirectoryMonitor {
     private Gee.HashSet<File> pending_imports = new Gee.HashSet<File>(file_hash, file_equal);
     private Gee.ArrayList<BatchImport> batch_import_queue = new Gee.ArrayList<BatchImport>();
     private BatchImportRoll current_import_roll = null;
-    private time_t last_import_roll_use = 0;
+    private int64 last_import_roll_use = 0;
     private BatchImport current_batch_import = null;
     private int checksums_completed = 0;
     private int checksums_total = 0;
@@ -583,7 +583,7 @@ public class LibraryMonitor : DirectoryMonitor {
         // If no import roll, or it's been over IMPORT_ROLL_QUIET_SEC since using the last one,
         // create a new one.  This allows for multiple files to come in back-to-back and be
         // imported on the same roll.
-        time_t now = (time_t) now_sec();
+        var now = GLib.get_monotonic_time();
         if (current_import_roll == null || (now - last_import_roll_use) >= IMPORT_ROLL_QUIET_SEC)
             current_import_roll = new BatchImportRoll();
         last_import_roll_use = now;
@@ -996,7 +996,7 @@ public class LibraryMonitor : DirectoryMonitor {
         }
         
         if (!known) {
-            // ressurrect tombstone if deleted
+            // resurrect tombstone if deleted
             Tombstone? tombstone = Tombstone.global.locate(file);
             if (tombstone != null) {
                 debug("Resurrecting tombstoned file %s", file.get_path());
diff --git a/src/MapWidget.vala b/src/MapWidget.vala
new file mode 100644
index 0000000..ddfae38
--- /dev/null
+++ b/src/MapWidget.vala
@@ -0,0 +1,788 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+private class MarkerImageSet {
+    public float marker_image_width;
+    public float marker_image_height;
+    public Clutter.Image? marker_image;
+    public Clutter.Image? marker_selected_image;
+    public Clutter.Image? marker_highlighted_image;
+}
+
+private enum SelectionAction {
+    SET,
+    ADD,
+    REMOVE
+}
+
+private abstract class PositionMarker : Object {
+    protected bool _highlighted = false;
+    protected bool _selected = false;
+    protected MarkerImageSet image_set;
+
+    protected PositionMarker(Champlain.Marker champlain_marker, MarkerImageSet image_set) {
+        this.champlain_marker = champlain_marker;
+        this.image_set = image_set;
+        champlain_marker.selectable = true;
+        champlain_marker.set_content(image_set.marker_image);
+        float w = image_set.marker_image_width;
+        float h = image_set.marker_image_height;
+        champlain_marker.set_size(w, h);
+        champlain_marker.set_translation(-w * MapWidget.MARKER_IMAGE_HORIZONTAL_PIN_RATIO,
+                                         -h * MapWidget.MARKER_IMAGE_VERTICAL_PIN_RATIO, 0);
+    }
+
+    public Champlain.Marker champlain_marker { get; protected set; }
+
+    public bool highlighted {
+        get {
+            return _highlighted;
+        }
+        set {
+            if (_highlighted == value)
+                return;
+            _highlighted = value;
+            var base_image = _selected ? image_set.marker_selected_image : image_set.marker_image;
+            champlain_marker.set_content(value ? image_set.marker_highlighted_image : base_image);
+        }
+    }
+    public bool selected {
+        get {
+            return _selected;
+        }
+        set {
+            if (_selected == value)
+                return;
+            _selected = value;
+            if (!_highlighted) {
+                var base_image = value ?  image_set.marker_selected_image : image_set.marker_image;
+                champlain_marker.set_content(base_image);
+            }
+            champlain_marker.set_selected(value);
+        }
+    }
+}
+
+private class DataViewPositionMarker : PositionMarker {
+    private Gee.LinkedList<weak DataViewPositionMarker> _data_view_position_markers =
+            new Gee.LinkedList<weak DataViewPositionMarker>();
+
+    public weak DataView view { get; protected set; }
+
+    public DataViewPositionMarker(DataView view, Champlain.Marker champlain_marker,
+            MarkerImageSet image_set) {
+        base(champlain_marker, image_set);
+        this.view = view;
+
+        this._data_view_position_markers.add(this);
+    }
+
+    public void bind_mouse_events(MapWidget map_widget) {
+        champlain_marker.button_release_event.connect ((event) => {
+            if (event.button > 1)
+                return true;
+            bool mod = (bool)(event.modifier_state &
+                    (Clutter.ModifierType.CONTROL_MASK | Clutter.ModifierType.SHIFT_MASK));
+            SelectionAction action = SelectionAction.SET;
+            if (mod)
+                action = _selected ? SelectionAction.REMOVE : SelectionAction.ADD;
+            selected = (action != SelectionAction.REMOVE);
+            map_widget.select_data_views(_data_view_position_markers, action);
+            return true;
+        });
+        champlain_marker.enter_event.connect ((event) => {
+            highlighted = true;
+            map_widget.highlight_data_views(_data_view_position_markers);
+            return true;
+        });
+        champlain_marker.leave_event.connect ((event) => {
+            highlighted = false;
+            map_widget.unhighlight_data_views(_data_view_position_markers);
+            return true;
+        });
+    }
+}
+
+private class MarkerGroup : PositionMarker {
+    private Gee.Collection<weak DataViewPositionMarker> _data_view_position_markers =
+        new Gee.LinkedList<weak DataViewPositionMarker>();
+    private Gee.Collection<PositionMarker> _position_markers = new Gee.LinkedList<PositionMarker>();
+    private Champlain.BoundingBox bbox = new Champlain.BoundingBox();
+
+    public void bind_mouse_events(MapWidget map_widget) {
+        champlain_marker.button_release_event.connect ((event) => {
+            if (event.button > 1)
+                return true;
+            bool mod = (bool)(event.modifier_state &
+                    (Clutter.ModifierType.CONTROL_MASK | Clutter.ModifierType.SHIFT_MASK));
+            SelectionAction action = SelectionAction.SET;
+            if (mod)
+                action = _selected ? SelectionAction.REMOVE : SelectionAction.ADD;
+            selected = (action != SelectionAction.REMOVE);
+            foreach (var m in _data_view_position_markers) {
+                m.selected = _selected;
+            }
+            map_widget.select_data_views(_data_view_position_markers.read_only_view, action);
+            return true;
+        });
+        champlain_marker.enter_event.connect ((event) => {
+            highlighted = true;
+            map_widget.highlight_data_views(_data_view_position_markers.read_only_view);
+            return true;
+        });
+        champlain_marker.leave_event.connect ((event) => {
+            highlighted = false;
+            map_widget.unhighlight_data_views(_data_view_position_markers.read_only_view);
+            return true;
+        });
+    }
+
+    public Gee.Collection<PositionMarker> position_markers {
+        owned get { return _position_markers.read_only_view; }
+    }
+
+    public MarkerGroup(Champlain.Marker champlain_marker, MarkerImageSet image_set) {
+        base(champlain_marker, image_set);
+    }
+
+    public void add_position_marker(PositionMarker marker) {
+        var data_view_position_marker = marker as DataViewPositionMarker;
+        if (data_view_position_marker != null)
+            _data_view_position_markers.add(data_view_position_marker);
+        var new_champlain_marker = marker.champlain_marker;
+        bbox.extend(new_champlain_marker.latitude, new_champlain_marker.longitude);
+        double lat, lon;
+        bbox.get_center(out lat, out lon);
+        champlain_marker.set_location(lat, lon);
+        _position_markers.add(marker);
+    }
+}
+
+private class MarkerGroupRaster : Object {
+    private const long MARKER_GROUP_RASTER_WIDTH_PX = 30l;
+    private const long MARKER_GROUP_RASTER_HEIGHT_PX = 30l;
+
+    private weak MapWidget map_widget;
+    private weak Champlain.View map_view;
+    private weak Champlain.MarkerLayer marker_layer;
+
+    public bool is_empty {
+        get {
+            return position_markers.is_empty;
+        }
+    }
+
+    // position_markers_tree is a two-dimensional tree for grouping position
+    // markers indexed by x (outer tree) and y (inner tree) raster coordinates.
+    // It maps coordinates to the PositionMarker (DataViewMarker or MarkerGroup)
+    // corresponding to them.
+    // If either raster index keys are empty, there is no marker within the
+    // raster cell. If both exist there are two possibilities:
+    // (1) the value is a MarkerGroup which means that multiple markers are
+    // grouped together, or (2) the value is a PositionMarker (but not a
+    // MarkerGroup) which means that there is exactly one marker in the raster
+    // cell. The tree is recreated every time the zoom level changes.
+    private Gee.TreeMap<long, Gee.TreeMap<long, unowned PositionMarker?>?> position_markers_tree =
+        new Gee.TreeMap<long, Gee.TreeMap<long, unowned PositionMarker?>?>();
+    // The marker group's collection keeps track of and owns all PositionMarkers including the marker groups
+    private Gee.Map<DataView, unowned PositionMarker> data_view_map = new Gee.HashMap<DataView, unowned PositionMarker>();
+    private Gee.Set<PositionMarker> position_markers = new Gee.HashSet<PositionMarker>();
+
+    public MarkerGroupRaster(MapWidget map_widget, Champlain.View map_view, Champlain.MarkerLayer marker_layer) {
+        this.map_widget = map_widget;
+        this.map_view = map_view;
+        this.marker_layer = marker_layer;
+        map_widget.zoom_changed.connect(regroup);
+    }
+
+    public void clear() {
+        lock (position_markers) {
+            data_view_map.clear();
+            position_markers_tree.clear();
+            position_markers.clear();
+        }
+    }
+
+    public void clear_selection() {
+        lock (position_markers) {
+            foreach (PositionMarker m in position_markers) {
+                m.selected = false;
+            }
+        }
+    }
+
+    public unowned PositionMarker? find_position_marker(DataView data_view) {
+        if (!data_view_map.has_key(data_view))
+            return null;
+        unowned PositionMarker? m;
+        lock (position_markers) {
+            m = data_view_map.get(data_view);
+        }
+        return m;
+    }
+
+    public void rasterize_marker(PositionMarker position_marker, bool already_on_map=false) {
+        var data_view_position_marker = position_marker as DataViewPositionMarker;
+        var champlain_marker = position_marker.champlain_marker;
+        long x, y;
+
+        lock (position_markers) {
+            rasterize_coords(champlain_marker.longitude, champlain_marker.latitude, out x, out y);
+            var yg = position_markers_tree.get(x);
+            if (yg == null) {
+                yg = new Gee.TreeMap<long, unowned PositionMarker?>();
+                position_markers_tree.set(x, yg);
+            }
+            var cell = yg.get(y);
+            if (cell == null) {
+                // first marker in this raster cell
+                yg.set(y, position_marker);
+                position_markers.add(position_marker);
+                if (!already_on_map)
+                    marker_layer.add_marker(position_marker.champlain_marker);
+                if (data_view_position_marker != null)
+                    data_view_map.set(data_view_position_marker.view, position_marker);
+
+            } else {
+                var marker_group = cell as MarkerGroup;
+                if (marker_group == null) {
+                    // single marker already occupies raster cell: create new group
+                    GpsCoords rasterized_gps_coords = GpsCoords() {
+                        has_gps = 1,
+                        longitude = map_view.x_to_longitude(x),
+                        latitude = map_view.y_to_latitude(y)
+                    };
+                    marker_group = map_widget.create_marker_group(rasterized_gps_coords);
+                    marker_group.add_position_marker(cell);
+                    if (cell.selected) // group becomes selected if any contained marker is
+                        marker_group.selected = true;
+                    if (cell is DataViewPositionMarker)
+                        data_view_map.set(((DataViewPositionMarker) cell).view, marker_group);
+                    yg.set(y, marker_group);
+                    position_markers.add(marker_group);
+                    position_markers.remove(cell);
+                    marker_layer.add_marker(marker_group.champlain_marker);
+                    marker_layer.remove_marker(cell.champlain_marker);
+                }
+                // group already exists, add new marker to it
+                marker_group.add_position_marker(position_marker);
+                if (already_on_map)
+                    marker_layer.remove_marker(position_marker.champlain_marker);
+                if (data_view_position_marker != null)
+                    data_view_map.set(data_view_position_marker.view, marker_group);
+            }
+        }
+    }
+
+    private void rasterize_coords(double longitude, double latitude, out long x, out long y) {
+        x = (Math.lround(map_view.longitude_to_x(longitude) / MARKER_GROUP_RASTER_WIDTH_PX)) *
+            MARKER_GROUP_RASTER_WIDTH_PX + (MARKER_GROUP_RASTER_WIDTH_PX / 2);
+        y = (Math.lround(map_view.latitude_to_y(latitude) / MARKER_GROUP_RASTER_HEIGHT_PX)) *
+            MARKER_GROUP_RASTER_HEIGHT_PX + (MARKER_GROUP_RASTER_HEIGHT_PX / 2);
+    }
+
+    internal void regroup() {
+        lock (position_markers) {
+            var position_markers_current = (owned) position_markers;
+            position_markers = new Gee.HashSet<PositionMarker>();
+            position_markers_tree.clear();
+
+            foreach (var pm in position_markers_current) {
+                var marker_group = pm as MarkerGroup;
+                if (marker_group != null) {
+                    marker_layer.remove_marker(marker_group.champlain_marker);
+                    foreach (var position_marker in marker_group.position_markers) {
+                        rasterize_marker(position_marker, false);
+                    }
+                } else {
+                    rasterize_marker(pm, true);
+                }
+            }
+            position_markers_current = null;
+        }
+    }
+}
+
+private class MapWidget : Gtk.Bin {
+    private const string MAPBOX_API_TOKEN = "pk.eyJ1IjoiamVuc2dlb3JnIiwiYSI6ImNqZ3FtYmhrMTBkOW8yeHBlNG8xN3hlNTAifQ.ek7i8UHeNIlkKi10fhgFgg";
+    private const uint DEFAULT_ZOOM_LEVEL = 8;
+
+    private static MapWidget instance = null;
+    private bool hide_map = false;
+
+    private GtkChamplain.Embed gtk_champlain_widget = new GtkChamplain.Embed();
+    private Champlain.View map_view = null;
+    private Champlain.Scale map_scale = new Champlain.Scale();
+    private Champlain.MarkerLayer marker_layer = new Champlain.MarkerLayer();
+    public bool map_edit_lock { get; set; }
+    private MarkerGroupRaster marker_group_raster = null;
+    private Gee.Map<DataView, unowned DataViewPositionMarker> data_view_marker_cache =
+        new Gee.HashMap<DataView, unowned DataViewPositionMarker>();
+    private weak Page? page = null;
+    private Clutter.Image? map_edit_locked_image;
+    private Clutter.Image? map_edit_unlocked_image;
+    private Clutter.Actor map_edit_lock_button = new Clutter.Actor();
+    private uint position_markers_timeout = 0;
+
+    public const float MARKER_IMAGE_HORIZONTAL_PIN_RATIO = 0.5f;
+    public const float MARKER_IMAGE_VERTICAL_PIN_RATIO = 0.825f;
+    public float map_edit_lock_image_width { get; private set; }
+    public float map_edit_lock_image_height { get; private set; }
+    public MarkerImageSet marker_image_set { get; private set; }
+    public MarkerImageSet marker_group_image_set { get; private set; }
+    public const Clutter.Color marker_point_color = { 10, 10, 255, 192 };
+
+    public signal void zoom_changed();
+
+    private MapWidget() {
+        setup_map();
+        add(gtk_champlain_widget);
+    }
+
+    public static MapWidget get_instance() {
+        if (instance == null)
+            instance = new MapWidget();
+        return instance;
+    }
+
+    public override bool drag_motion(Gdk.DragContext context, int x, int y, uint time) {
+        if (!map_edit_lock)
+            map_view.stop_go_to();
+        else
+            Gdk.drag_status(context, 0, time);
+        return true;
+    }
+
+    public override void drag_data_received(Gdk.DragContext context, int x, int y,
+            Gtk.SelectionData selection_data, uint info, uint time) {
+        bool success = false;
+        Gee.List<MediaSource>? media = unserialize_media_sources(selection_data.get_data(),
+            selection_data.get_length());
+        if (media != null && media.size > 0) {
+            double lat = map_view.y_to_latitude(y);
+            double lon = map_view.x_to_longitude(x);
+            success = internal_drop_received(media, lat, lon);
+        }
+
+        Gtk.drag_finish(context, success, false, time);
+    }
+
+    public new void set_visible(bool visible) {
+        /* hides Gtk.Widget.set_visible */
+        hide_map = !visible;
+        base.set_visible(visible);
+    }
+
+    public override void show_all() {
+        if (!hide_map)
+            base.show_all();
+    }
+
+    public void set_page(Page page) {
+        bool page_changed = false;
+        if (this.page != page) {
+            this.page = page;
+            page_changed = true;
+            clear();
+        }
+        ViewCollection view_collection = page.get_view();
+        if (view_collection == null)
+            return;
+
+        if (page_changed) {
+            data_view_marker_cache.clear();
+            foreach (DataObject view in view_collection.get_all()) {
+                if (view is DataView)
+                    add_data_view((DataView) view);
+            }
+            show_position_markers();
+        }
+        // In any case, the selection did change..
+        var selected = view_collection.get_selected();
+        if (selected != null) {
+            marker_group_raster.clear_selection();
+            foreach (DataView v in view_collection.get_selected()) {
+
+                var position_marker = marker_group_raster.find_position_marker(v);
+                if (position_marker != null)
+                    position_marker.selected = true;
+                if (position_marker is MarkerGroup) {
+                    DataViewPositionMarker? m = data_view_marker_cache.get(v);
+                    if (m != null)
+                        m.selected = true;
+                }
+            }
+        }
+    }
+
+    public void clear() {
+        data_view_marker_cache.clear();
+        marker_layer.remove_all();
+        marker_group_raster.clear();
+    }
+
+    public void add_data_view(DataView view) {
+        DataSource view_source = view.get_source();
+        if (!(view_source is Positionable))
+            return;
+        Positionable p = (Positionable) view_source;
+        GpsCoords gps_coords = p.get_gps_coords();
+        if (gps_coords.has_gps <= 0)
+            return;
+        PositionMarker position_marker = create_position_marker(view);
+        marker_group_raster.rasterize_marker(position_marker);
+    }
+
+    public void show_position_markers() {
+        if (marker_group_raster.is_empty)
+            return;
+
+        map_view.stop_go_to();
+        double lat, lon;
+        var bbox = marker_layer.get_bounding_box();
+        var zoom_level = map_view.get_zoom_level();
+        var zoom_level_test = zoom_level < 2 ? 0 : zoom_level - 2;
+        bbox.get_center(out lat, out lon);
+
+        if (map_view.get_bounding_box_for_zoom_level(zoom_level_test).covers(lat, lon)) {
+            // Don't zoom in/out if target is in proximity
+            map_view.ensure_visible(bbox, true);
+        } else if (zoom_level >= DEFAULT_ZOOM_LEVEL) {
+            // zoom out to DEFAULT_ZOOM_LEVEL first, then move
+            map_view.set_zoom_level(DEFAULT_ZOOM_LEVEL);
+            map_view.ensure_visible(bbox, true);
+        } else {
+            // move first, then zoom in to DEFAULT_ZOOM_LEVEL
+            map_view.go_to(lat, lon);
+            // There seems to be a runtime issue with the animation_completed signal
+            // sig = map_view.animation_completed["go-to"].connect((v) => { ... }
+            // so we're using a timeout-based approach instead. It should be kept in sync with
+            // the animation time (500ms by default.)
+            if (position_markers_timeout > 0)
+                Source.remove(position_markers_timeout);
+            position_markers_timeout = Timeout.add(500, () => {
+                map_view.center_on(lat, lon); // ensure the timeout wasn't too fast
+                if (map_view.get_zoom_level() < DEFAULT_ZOOM_LEVEL)
+                    map_view.set_zoom_level(DEFAULT_ZOOM_LEVEL);
+                map_view.ensure_visible(bbox, true);
+                position_markers_timeout = 0;
+                return Source.REMOVE;
+            });
+        }
+    }
+
+    public void select_data_views(Gee.Collection<unowned DataViewPositionMarker> ms,
+            SelectionAction action = SelectionAction.SET) {
+        if (page == null)
+            return;
+
+        ViewCollection page_view = page.get_view();
+        if (page_view != null) {
+            Marker marked = page_view.start_marking();
+            foreach (var m in ms) {
+                if (m.view is CheckerboardItem) {
+                    marked.mark(m.view);
+                }
+            }
+            if (action == SelectionAction.REMOVE) {
+                page_view.unselect_marked(marked);
+            } else {
+                if (action == SelectionAction.SET)
+                    page_view.unselect_all();
+                page_view.select_marked(marked);
+            }
+        }
+    }
+
+    public void highlight_data_views(Gee.Collection<unowned DataViewPositionMarker> ms) {
+        if (page == null)
+            return;
+
+        bool did_adjust_view = false;
+        foreach (var m in ms) {
+            if (!(m.view is CheckerboardItem)) {
+                continue;
+            }
+
+            CheckerboardItem item = m.view as CheckerboardItem;
+
+            if (!did_adjust_view && page is CheckerboardPage) {
+                ((CheckerboardPage) page).scroll_to_item(item);
+                did_adjust_view = true;
+            }
+            item.brighten();
+        }
+    }
+
+    public void unhighlight_data_views(Gee.Collection<unowned DataViewPositionMarker> ms) {
+        if (page == null)
+            return;
+
+        foreach (var m in ms) {
+            if (m.view is CheckerboardItem) {
+                CheckerboardItem item = (CheckerboardItem) m.view;
+                item.unbrighten();
+            }
+        }
+    }
+
+    public void highlight_position_marker(DataView v) {
+        var position_marker = marker_group_raster.find_position_marker(v);
+        if (position_marker != null) {
+            position_marker.highlighted = true;
+        }
+    }
+
+    public void unhighlight_position_marker(DataView v) {
+        var position_marker = marker_group_raster.find_position_marker(v);
+        if (position_marker != null) {
+            position_marker.highlighted = false;
+        }
+    }
+
+    public void media_source_position_changed(Gee.List<MediaSource> media, GpsCoords gps_coords) {
+        if (page == null)
+            return;
+        var view_collection = page.get_view();
+        foreach (var source in media) {
+            var view = view_collection.get_view_for_source(source);
+            if (view == null)
+                continue;
+            var marker = data_view_marker_cache.get(view);
+            if (marker != null) {
+                if (gps_coords.has_gps > 0) {
+                    // update individual marker cache
+                    marker.champlain_marker.set_location(gps_coords.latitude, gps_coords.longitude);
+                } else {
+                    // TODO: position removal not supported by GUI
+                    // remove marker from cache, map_layer
+                    // remove from marker_group_raster (needs a removal method which also removes the
+                    // item from the group if (marker_group_raster.find_position_marker(view) is MarkerGroup)
+                }
+            }
+        }
+        marker_group_raster.regroup();
+    }
+
+    private Champlain.MapSource create_map_source() {
+        var map_source = new Champlain.MapSourceChain();
+        var file_cache = new Champlain.FileCache.full(10 * 1024 * 1024,
+            AppDirs.get_cache_dir().get_child("tiles").get_child("mapbox-outdoors").get_path(),
+            new Champlain.ImageRenderer());
+        var memory_cache = new Champlain.MemoryCache.full(10 * 1024 * 1024, new Champlain.ImageRenderer());
+        var error_source = new Champlain.NullTileSource.full(new Champlain.ImageRenderer());
+
+        var tile_source = new Champlain.NetworkTileSource.full("mapbox-outdoors",
+                                                               "Mapbox outdoors tiles",
+                                                               "",
+                                                               "",
+                                                               0,
+                                                               19,
+                                                               512,
+                                                               Champlain.MapProjection.MERCATOR,
+                                                               "https://api.mapbox.com/styles/v1/mapbox/outdoors-v11/tiles/#Z#/#X#/#Y#?access_token=" +
+                                                               MAPBOX_API_TOKEN,
+                                                               new Champlain.ImageRenderer());
+
+        var user_agent = "Shotwell/%s libchamplain/%s".printf(_VERSION, Champlain.VERSION_S);
+        tile_source.set_user_agent(user_agent);
+        tile_source.max_conns = 2;
+
+        map_source.push(error_source);
+        map_source.push(tile_source);
+        map_source.push(file_cache);
+        map_source.push(memory_cache);
+
+        return map_source;
+    }
+
+    private Clutter.Actor create_attribution_actor() {
+        const string IMPROVE_TEXT = N_("Improve this map");
+        var label = new Gtk.Label(null);
+        label.set_markup("<a href=\"https://www.mapbox.com/about/maps/\">© Mapbox</a> <a href=\"https://openstreetmap.org/about/\">© OpenStreetMap</a> <a href=\"https://www.mapbox.com/map-feedback/\">%s</a>".printf(IMPROVE_TEXT));
+        label.get_style_context().add_class("map-attribution");
+
+        return new GtkClutter.Actor.with_contents(label);
+    }
+
+    private void setup_map() {
+        map_view = gtk_champlain_widget.get_view();
+        map_view.add_layer(marker_layer);
+        map_view.set_map_source(create_map_source());
+
+        var map_attribution_text = create_attribution_actor();
+        map_attribution_text.content_gravity = Clutter.ContentGravity.BOTTOM_RIGHT;
+        map_attribution_text.set_x_align(Clutter.ActorAlign.END);
+        map_attribution_text.set_x_expand(true);
+        map_attribution_text.set_y_align(Clutter.ActorAlign.END);
+        map_attribution_text.set_y_expand(true);
+
+        // add lock/unlock button to top left corner of map
+        map_edit_lock_button.content_gravity = Clutter.ContentGravity.TOP_RIGHT;
+        map_edit_lock_button.reactive = true;
+        map_edit_lock_button.set_x_align(Clutter.ActorAlign.END);
+        map_edit_lock_button.set_x_expand(true);
+        map_edit_lock_button.set_y_align(Clutter.ActorAlign.START);
+        map_edit_lock_button.set_y_expand(true);
+
+        map_edit_lock_button.button_release_event.connect((a, e) => {
+            if (e.button != 1 /* CLUTTER_BUTTON_PRIMARY */)
+                return false;
+            map_edit_lock = !map_edit_lock;
+            map_edit_lock_button.set_content(map_edit_lock ?
+                map_edit_locked_image : map_edit_unlocked_image);
+            return true;
+        });
+        map_view.add_child(map_edit_lock_button);
+        map_view.add_child(map_attribution_text);
+
+        gtk_champlain_widget.has_tooltip = true;
+        gtk_champlain_widget.query_tooltip.connect((x, y, keyboard_tooltip, tooltip) => {
+            Gdk.Rectangle lock_rect = {
+                (int) map_edit_lock_button.x,
+                (int) map_edit_lock_button.y,
+                (int) map_edit_lock_button.width,
+                (int) map_edit_lock_button.height,
+            };
+            Gdk.Rectangle mouse_pos = { x, y, 1, 1 };
+            if (!lock_rect.intersect(mouse_pos, null))
+                return false;
+            tooltip.set_text(_("Lock or unlock map for geotagging by dragging pictures onto the map"));
+            return true;
+        });
+
+        // add scale to bottom left corner of the map
+        map_scale.content_gravity = Clutter.ContentGravity.BOTTOM_LEFT;
+        map_scale.connect_view(map_view);
+        map_scale.set_x_align(Clutter.ActorAlign.START);
+        map_scale.set_x_expand(true);
+        map_scale.set_y_align(Clutter.ActorAlign.END);
+        map_scale.set_y_expand(true);
+        map_view.add_child(map_scale);
+
+        map_view.set_zoom_on_double_click(false);
+        map_view.notify.connect((o, p) => {
+            if (p.name == "zoom-level")
+                zoom_changed();
+        });
+
+        Gtk.TargetEntry[] dnd_targets = {
+            LibraryWindow.DND_TARGET_ENTRIES[LibraryWindow.TargetType.URI_LIST],
+            LibraryWindow.DND_TARGET_ENTRIES[LibraryWindow.TargetType.MEDIA_LIST]
+        };
+        Gtk.drag_dest_set(this, Gtk.DestDefaults.ALL, dnd_targets,
+            Gdk.DragAction.COPY | Gdk.DragAction.LINK | Gdk.DragAction.ASK);
+        button_press_event.connect(map_zoom_handler);
+        set_size_request(200, 200);
+
+        marker_group_raster = new MarkerGroupRaster(this, map_view, marker_layer);
+
+        // Load icons
+        float w, h;
+        marker_image_set = new MarkerImageSet();
+        marker_group_image_set = new MarkerImageSet();
+        marker_image_set.marker_image = Resources.get_icon_as_clutter_image(
+                Resources.ICON_GPS_MARKER, out w, out h);
+        marker_image_set.marker_image_width = w;
+        marker_image_set.marker_image_height = h;
+        marker_image_set.marker_selected_image = Resources.get_icon_as_clutter_image(
+                Resources.ICON_GPS_MARKER_SELECTED, out w, out h);
+        marker_image_set.marker_highlighted_image = Resources.get_icon_as_clutter_image(
+                Resources.ICON_GPS_MARKER_HIGHLIGHTED, out w, out h);
+
+        marker_group_image_set.marker_image = Resources.get_icon_as_clutter_image(
+                Resources.ICON_GPS_GROUP_MARKER, out w, out h);
+        marker_group_image_set.marker_image_width = w;
+        marker_group_image_set.marker_image_height = h;
+        marker_group_image_set.marker_selected_image = Resources.get_icon_as_clutter_image(
+                Resources.ICON_GPS_GROUP_MARKER_SELECTED, out w, out h);
+        marker_group_image_set.marker_highlighted_image = Resources.get_icon_as_clutter_image(
+                Resources.ICON_GPS_GROUP_MARKER_HIGHLIGHTED, out w, out h);
+
+        map_edit_locked_image = Resources.get_icon_as_clutter_image(
+                Resources.ICON_MAP_EDIT_LOCKED, out w, out h);
+        map_edit_unlocked_image = Resources.get_icon_as_clutter_image(
+                Resources.ICON_MAP_EDIT_UNLOCKED, out w, out h);
+        map_edit_lock_image_width = w;
+        map_edit_lock_image_height = h;
+        if (map_edit_locked_image == null) {
+            warning("Couldn't load map edit lock image");
+        } else {
+            map_edit_lock_button.set_content(map_edit_locked_image);
+            map_edit_lock_button.set_size(map_edit_lock_image_width, map_edit_lock_image_height);
+            map_edit_lock = true;
+        }
+    }
+
+    private Champlain.Marker create_champlain_marker(GpsCoords gps_coords) {
+        assert(gps_coords.has_gps > 0);
+
+        Champlain.Marker champlain_marker;
+        champlain_marker = new Champlain.Marker();
+        champlain_marker.set_pivot_point(0.5f, 0.5f); // set center of marker
+        champlain_marker.set_location(gps_coords.latitude, gps_coords.longitude);
+        return champlain_marker;
+    }
+
+    private DataViewPositionMarker create_position_marker(DataView view) {
+        var position_marker = data_view_marker_cache.get(view);
+        if (position_marker != null)
+            return position_marker;
+        DataSource data_source = view.get_source();
+        Positionable p = (Positionable) data_source;
+        GpsCoords gps_coords = p.get_gps_coords();
+        Champlain.Marker champlain_marker = create_champlain_marker(gps_coords);
+        position_marker = new DataViewPositionMarker(view, champlain_marker, marker_image_set);
+        position_marker.bind_mouse_events(this);
+        data_view_marker_cache.set(view, position_marker);
+        return (owned) position_marker;
+    }
+
+    internal MarkerGroup create_marker_group(GpsCoords gps_coords) {
+        Champlain.Marker champlain_marker = create_champlain_marker(gps_coords);
+        var g = new MarkerGroup(champlain_marker, marker_group_image_set);
+        g.bind_mouse_events(this);
+        return (owned) g;
+    }
+
+    private bool map_zoom_handler(Gdk.EventButton event) {
+        if (event.type == Gdk.EventType.2BUTTON_PRESS) {
+            if (event.button == 1 || event.button == 3) {
+                double lat = map_view.y_to_latitude(event.y);
+                double lon = map_view.x_to_longitude(event.x);
+                if (event.button == 1) {
+                    map_view.zoom_in();
+                } else {
+                    map_view.zoom_out();
+                }
+                map_view.center_on(lat, lon);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private bool internal_drop_received(Gee.List<MediaSource> media, double lat, double lon) {
+        if (map_edit_lock)
+            return false;
+
+        bool success = false;
+        GpsCoords gps_coords = GpsCoords() {
+            has_gps = 1,
+            latitude = lat,
+            longitude = lon
+        };
+        foreach (var m in media) {
+            Positionable p = m as Positionable;
+            if (p != null) {
+                p.set_gps_coords(gps_coords);
+                success = true;
+            }
+        }
+        media_source_position_changed(media, gps_coords);
+        return success;
+    }
+}
diff --git a/src/MediaDataRepresentation.vala b/src/MediaDataRepresentation.vala
index 6e6af00..3400577 100644
--- a/src/MediaDataRepresentation.vala
+++ b/src/MediaDataRepresentation.vala
@@ -7,10 +7,10 @@
 public class BackingFileState {
     public string filepath;
     public int64 filesize;
-    public time_t modification_time;
+    public DateTime modification_time;
     public string? md5;
     
-    public BackingFileState(string filepath, int64 filesize, time_t modification_time, string? md5) {
+    public BackingFileState(string filepath, int64 filesize, DateTime modification_time, string? md5) {
         this.filepath = filepath;
         this.filesize = filesize;
         this.modification_time = modification_time;
@@ -154,7 +154,7 @@ public abstract class MediaSource : ThumbnailSource, Indexable {
     public abstract File get_master_file();
     public abstract uint64 get_master_filesize();
     public abstract uint64 get_filesize();
-    public abstract time_t get_timestamp();
+    public abstract DateTime? get_timestamp();
     
     // Must return at least one, for the master file.
     public abstract BackingFileState[] get_backing_files_state();
@@ -262,7 +262,7 @@ public abstract class MediaSource : ThumbnailSource, Indexable {
         controller.commit();
     }
     
-    public abstract time_t get_exposure_time();
+    public abstract DateTime? get_exposure_time();
 
     public abstract ImportID get_import_id();
 }
diff --git a/src/MediaInterfaces.vala b/src/MediaInterfaces.vala
index 1a352a2..f2f570c 100644
--- a/src/MediaInterfaces.vala
+++ b/src/MediaInterfaces.vala
@@ -206,7 +206,7 @@ public interface Monitorable : MediaSource {
 // from Photo to here in order to add this capability to videos. It should 
 // fire a "metadata:exposure-time" alteration when called.
 public interface Dateable : MediaSource {
-    public abstract void set_exposure_time(time_t target_time);    
+    public abstract void set_exposure_time(DateTime target_time);    
     
-    public abstract time_t get_exposure_time();
+    public abstract DateTime? get_exposure_time();
 }
diff --git a/src/MediaMetadata.vala b/src/MediaMetadata.vala
deleted file mode 100644
index b2ba1b7..0000000
--- a/src/MediaMetadata.vala
+++ /dev/null
@@ -1,125 +0,0 @@
-/* Copyright 2016 Software Freedom Conservancy Inc.
- *
- * This software is licensed under the GNU Lesser General Public License
- * (version 2.1 or later).  See the COPYING file in this distribution.
- */
-
-public abstract class MediaMetadata {
-    public abstract void read_from_file(File file) throws Error;
-    
-    public abstract MetadataDateTime? get_creation_date_time();
-    
-    public abstract string? get_title();
-
-    public abstract string? get_comment();
-}
-
-public struct MetadataRational {
-    public int numerator;
-    public int denominator;
-    
-    public MetadataRational(int numerator, int denominator) {
-        this.numerator = numerator;
-        this.denominator = denominator;
-    }
-    
-    private bool is_component_valid(int component) {
-        return (component >= 0) && (component <= 1000000);
-    }
-    
-    public bool is_valid() {
-        return (is_component_valid(numerator) && is_component_valid(denominator));
-    }
-    
-    public string to_string() {
-        return (is_valid()) ? ("%d/%d".printf(numerator, denominator)) : "";
-    }
-}
-
-public errordomain MetadataDateTimeError {
-    INVALID_FORMAT,
-    UNSUPPORTED_FORMAT
-}
-
-public class MetadataDateTime {
-    
-    private time_t timestamp;
-    
-    public MetadataDateTime(time_t timestamp) {
-        this.timestamp = timestamp;
-    }
-    
-    public MetadataDateTime.from_exif(string label) throws MetadataDateTimeError {
-        if (!from_exif_date_time(label, out timestamp))
-            throw new MetadataDateTimeError.INVALID_FORMAT("%s is not EXIF format date/time", label);
-    }
-    
-    public MetadataDateTime.from_iptc(string date, string time) throws MetadataDateTimeError {
-        // TODO: Support IPTC date/time format
-        throw new MetadataDateTimeError.UNSUPPORTED_FORMAT("IPTC date/time format not currently supported");
-    }
-    
-    public MetadataDateTime.from_xmp(string label) throws MetadataDateTimeError {
-        TimeVal time_val = TimeVal();
-        if (!time_val.from_iso8601(label))
-            throw new MetadataDateTimeError.INVALID_FORMAT("%s is not XMP format date/time", label);
-        
-        timestamp = time_val.tv_sec;
-    }
-    
-    public time_t get_timestamp() {
-        return timestamp;
-    }
-    
-    public string get_exif_label() {
-        return to_exif_date_time(timestamp);
-    }
-    
-    // TODO: get_iptc_date() and get_iptc_time()
-    
-    public string get_xmp_label() {
-        TimeVal time_val = TimeVal();
-        time_val.tv_sec = timestamp;
-        time_val.tv_usec = 0;
-        
-        return time_val.to_iso8601();
-    }
-    
-    public static bool from_exif_date_time(string date_time, out time_t timestamp) {
-        timestamp = 0;
-        
-        Time tm = Time();
-        
-        // Check standard EXIF format 
-        if (date_time.scanf("%d:%d:%d %d:%d:%d", 
-                            &tm.year, &tm.month, &tm.day, &tm.hour, &tm.minute, &tm.second) != 6) {
-            // Fallback in a more generic format
-            string tmp = date_time.dup();
-            tmp.canon("0123456789", ' ');
-            if (tmp.scanf("%4d%2d%2d%2d%2d%2d", 
-                          &tm.year, &tm.month, &tm.day, &tm.hour, &tm.minute,&tm.second) != 6)
-                return false;
-        }
-        
-        // watch for bogosity
-        if (tm.year <= 1900 || tm.month <= 0 || tm.day < 0 || tm.hour < 0 || tm.minute < 0 || tm.second < 0)
-            return false;
-        
-        tm.year -= 1900;
-        tm.month--;
-        tm.isdst = -1;
-        
-        timestamp = tm.mktime();
-        
-        return true;
-    }
-    
-    public static string to_exif_date_time(time_t timestamp) {
-        return Time.local(timestamp).format("%Y:%m:%d %H:%M:%S");
-    }
-    
-    public string to_string() {
-        return to_exif_date_time(timestamp);
-    }
-}
-
diff --git a/src/MediaPage.vala b/src/MediaPage.vala
index f849ac3..5fa3fca 100644
--- a/src/MediaPage.vala
+++ b/src/MediaPage.vala
@@ -90,10 +90,7 @@ public abstract class MediaPage : CheckerboardPage {
         }
         
         public static double scale_to_slider(int value) {
-            assert(value >= Thumbnail.MIN_SCALE);
-            assert(value <= Thumbnail.MAX_SCALE);
-            
-            return (double) ((value - Thumbnail.MIN_SCALE) / SLIDER_STEPPING);
+            return (double) ((value.clamp(Thumbnail.MIN_SCALE, Thumbnail.MAX_SCALE) - Thumbnail.MIN_SCALE) / SLIDER_STEPPING);
         }
 
         public static int slider_to_scale(double value) {
@@ -887,7 +884,7 @@ public abstract class MediaPage : CheckerboardPage {
             case SortBy.EXPOSURE_DATE:
                 if (ascending)
                     comparator = Thumbnail.exposure_time_ascending_comparator;
-                else comparator = Thumbnail.exposure_time_desending_comparator;
+                else comparator = Thumbnail.exposure_time_descending_comparator;
                 predicate = Thumbnail.exposure_time_comparator_predicate;
                 break;
             
diff --git a/src/MetadataWriter.vala b/src/MetadataWriter.vala
index 0c23260..5fc26d1 100644
--- a/src/MetadataWriter.vala
+++ b/src/MetadataWriter.vala
@@ -15,7 +15,7 @@ public class MetadataWriter : Object {
     public const uint COMMIT_DELAY_MSEC = 3000;
     public const uint COMMIT_SPACING_MSEC = 50;
     
-    private const string[] INTERESTED_PHOTO_METADATA_DETAILS = { "name", "comment", "rating", "exposure-time" };
+    private const string[] INTERESTED_PHOTO_METADATA_DETAILS = { "name", "comment", "rating", "exposure-time", "gps" };
     
     private class CommitJob : BackgroundJob {
         public LibraryPhoto photo;
@@ -108,18 +108,26 @@ public class MetadataWriter : Object {
             }
             
             // exposure date/time
-            time_t current_exposure_time = photo.get_exposure_time();
-            time_t metadata_exposure_time = 0;
+            DateTime? current_exposure_time = photo.get_exposure_time();
+            DateTime? metadata_exposure_time = null;
             MetadataDateTime? metadata_exposure_date_time = metadata.get_exposure_date_time();
             if (metadata_exposure_date_time != null)
                 metadata_exposure_time = metadata_exposure_date_time.get_timestamp();
             if (current_exposure_time != metadata_exposure_time) {
-                metadata.set_exposure_date_time(current_exposure_time != 0
+                metadata.set_exposure_date_time(current_exposure_time != null
                     ? new MetadataDateTime(current_exposure_time)
                     : null);
                 changed = true;
             }
 
+            // gps location
+            GpsCoords current_gps_coords = photo.get_gps_coords();
+            GpsCoords metadata_gps_coords = metadata.get_gps_coords();
+            if (!current_gps_coords.equals(ref metadata_gps_coords)) {
+                metadata.set_gps_coords(current_gps_coords);
+                changed = true;
+            }
+
             // tags (keywords) ... replace (or clear) entirely rather than union or intersection
             Gee.Set<string> safe_keywords = new Gee.HashSet<string>();
 
@@ -681,7 +689,7 @@ public class MetadataWriter : Object {
         
         try {
             job.photo.set_master_metadata_dirty(false);
-        } catch (DatabaseError err) {
+        } catch (Error err) {
             AppWindow.database_error(err);
         }
         
diff --git a/src/Page.vala b/src/Page.vala
index 65b263b..6b07568 100644
--- a/src/Page.vala
+++ b/src/Page.vala
@@ -13,13 +13,13 @@ public class InjectionGroup {
         }
         public string name;
         public string action;
-        public string? accellerator;
+        public string? accelerator;
         public ItemType kind;
 
-        public Element(string name, string? action, string? accellerator, ItemType kind) {
+        public Element(string name, string? action, string? accelerator, ItemType kind) {
             this.name = name;
             this.action = action != null ? action : name;
-            this.accellerator = accellerator;
+            this.accelerator = accelerator;
             this.kind = kind;
         }
     }
@@ -40,8 +40,8 @@ public class InjectionGroup {
         return elements;
     }
 
-    public void add_menu_item(string name, string? action = null, string? accellerator = null) {
-        elements.add(new Element(name, action, accellerator, Element.ItemType.MENUITEM));
+    public void add_menu_item(string name, string? action = null, string? accelerator = null) {
+        elements.add(new Element(name, action, accelerator, Element.ItemType.MENUITEM));
     }
 
     public void add_menu(string name, string? action = null) {
@@ -68,7 +68,6 @@ public abstract class Page : Gtk.ScrolledWindow {
     private string toolbar_path;
     private Gdk.Rectangle last_position = Gdk.Rectangle();
     private Gtk.Widget event_source = null;
-    private bool dnd_enabled = false;
     private ulong last_configure_ms = 0;
     private bool report_move_finished = false;
     private bool report_resize_finished = false;
@@ -85,6 +84,9 @@ public abstract class Page : Gtk.ScrolledWindow {
     private int cursor_hide_time_cached = 0;
     private bool are_actions_attached = false;
     private OneShotScheduler? update_actions_scheduler = null;
+
+    protected double wheel_factor = 0.0;
+    protected double modified_wheel_factor = 1.0;
     
     protected Page(string page_name) {
         this.page_name = page_name;
@@ -193,8 +195,6 @@ public abstract class Page : Gtk.ScrolledWindow {
         event_source.leave_notify_event.disconnect(on_leave_notify_event);
         event_source.scroll_event.disconnect(on_mousewheel_internal);
         
-        disable_drag_source();
-        
         event_source = null;
     }
     
@@ -230,10 +230,10 @@ public abstract class Page : Gtk.ScrolledWindow {
                             case InjectionGroup.Element.ItemType.MENUITEM:
                                 var item = new GLib.MenuItem (element.name,
                                                               "win." + element.action);
-                                if (element.accellerator != null) {
+                                if (element.accelerator != null) {
                                     item.set_attribute ("accel",
                                                         "s",
-                                                        element.accellerator);
+                                                        element.accelerator);
                                 }
 
                                 menu.append_item (item);
@@ -592,76 +592,6 @@ public abstract class Page : Gtk.ScrolledWindow {
     protected virtual void update_actions(int selected_count, int count) {
     }
     
-    // This method enables drag-and-drop on the event source and routes its events through this
-    // object
-    public void enable_drag_source(Gdk.DragAction actions, Gtk.TargetEntry[] source_target_entries) {
-        if (dnd_enabled)
-            return;
-            
-        assert(event_source != null);
-        
-        Gtk.drag_source_set(event_source, Gdk.ModifierType.BUTTON1_MASK, source_target_entries, actions);
-        
-        // hook up handlers which route the event_source's DnD signals to the Page's (necessary
-        // because Page is a NO_WINDOW widget and cannot support DnD on its own).
-        event_source.drag_begin.connect(on_drag_begin);
-        event_source.drag_data_get.connect(on_drag_data_get);
-        event_source.drag_data_delete.connect(on_drag_data_delete);
-        event_source.drag_end.connect(on_drag_end);
-        event_source.drag_failed.connect(on_drag_failed);
-        
-        dnd_enabled = true;
-    }
-    
-    public void disable_drag_source() {
-        if (!dnd_enabled)
-            return;
-
-        assert(event_source != null);
-        
-        event_source.drag_begin.disconnect(on_drag_begin);
-        event_source.drag_data_get.disconnect(on_drag_data_get);
-        event_source.drag_data_delete.disconnect(on_drag_data_delete);
-        event_source.drag_end.disconnect(on_drag_end);
-        event_source.drag_failed.disconnect(on_drag_failed);
-        Gtk.drag_source_unset(event_source);
-        
-        dnd_enabled = false;
-    }
-    
-    public bool is_dnd_enabled() {
-        return dnd_enabled;
-    }
-    
-    private void on_drag_begin(Gdk.DragContext context) {
-        drag_begin(context);
-    }
-    
-    private void on_drag_data_get(Gdk.DragContext context, Gtk.SelectionData selection_data,
-        uint info, uint time) {
-        drag_data_get(context, selection_data, info, time);
-    }
-    
-    private void on_drag_data_delete(Gdk.DragContext context) {
-        drag_data_delete(context);
-    }
-    
-    private void on_drag_end(Gdk.DragContext context) {
-        drag_end(context);
-    }
-    
-    // wierdly, Gtk 2.16.1 doesn't supply a drag_failed virtual method in the GtkWidget impl ...
-    // Vala binds to it, but it's not available in gtkwidget.h, and so gcc complains.  Have to
-    // makeshift one for now.
-    // https://bugzilla.gnome.org/show_bug.cgi?id=584247
-    public virtual bool source_drag_failed(Gdk.DragContext context, Gtk.DragResult drag_result) {
-        return false;
-    }
-    
-    private bool on_drag_failed(Gdk.DragContext context, Gtk.DragResult drag_result) {
-        return source_drag_failed(context, drag_result);
-    }
-    
     // Use this function rather than GDK or GTK's get_pointer, especially if called during a 
     // button-down mouse drag (i.e. a window grab).
     //
@@ -1032,13 +962,13 @@ public abstract class Page : Gtk.ScrolledWindow {
                     double dx, dy;
                     event.get_scroll_deltas(out dx, out dy);
 
-                    if (dy < 0)
+                    if (dy < -1.0 * this.wheel_factor)
                         return on_mousewheel_up(event);
-                    else if (dy > 0)
+                    else if (dy > this.wheel_factor)
                         return on_mousewheel_down(event);
-                    else if (dx < 0)
+                    else if (dx < -1.0 * this.wheel_factor)
                         return on_mousewheel_left(event);
-                    else if (dx > 0)
+                    else if (dx > this.wheel_factor)
                         return on_mousewheel_right(event);
                     else
                         return false;
@@ -1115,15 +1045,19 @@ public abstract class Page : Gtk.ScrolledWindow {
     }
 
     public void stop_cursor_hiding() {
-        if (last_timeout_id != 0)
+        if (last_timeout_id != 0) {
             Source.remove(last_timeout_id);
+            last_timeout_id = 0;
+        }
     }
 
     public void suspend_cursor_hiding() {
         cursor_hide_time_cached = cursor_hide_msec;
 
-        if (last_timeout_id != 0)
+        if (last_timeout_id != 0) {
             Source.remove(last_timeout_id);
+            last_timeout_id = 0;
+        }
 
         cursor_hide_msec = 0;
     }
@@ -1209,1454 +1143,3 @@ public abstract class Page : Gtk.ScrolledWindow {
 
 }
 
-public abstract class CheckerboardPage : Page {
-    private const int AUTOSCROLL_PIXELS = 50;
-    private const int AUTOSCROLL_TICKS_MSEC = 50;
-    
-    private CheckerboardLayout layout;
-    private string item_context_menu_path = null;
-    private string page_context_menu_path = null;
-    private Gtk.Viewport viewport = new Gtk.Viewport(null, null);
-    protected CheckerboardItem anchor = null;
-    protected CheckerboardItem cursor = null;
-    private CheckerboardItem current_hovered_item = null;
-    private bool autoscroll_scheduled = false;
-    private CheckerboardItem activated_item = null;
-    private Gee.ArrayList<CheckerboardItem> previously_selected = null;
-
-    public enum Activator {
-        KEYBOARD,
-        MOUSE
-    }
-
-    public struct KeyboardModifiers {
-        public KeyboardModifiers(Page page) {
-            ctrl_pressed = page.get_ctrl_pressed();
-            alt_pressed = page.get_alt_pressed();
-            shift_pressed = page.get_shift_pressed();
-            super_pressed = page.get_super_pressed();
-        }
-
-        public bool ctrl_pressed;
-        public bool alt_pressed;
-        public bool shift_pressed;
-        public bool super_pressed;
-    }
-
-    protected CheckerboardPage(string page_name) {
-        base (page_name);
-        
-        layout = new CheckerboardLayout(get_view());
-        layout.set_name(page_name);
-        
-        set_event_source(layout);
-
-        set_border_width(0);
-        set_shadow_type(Gtk.ShadowType.NONE);
-        
-        viewport.set_border_width(0);
-        viewport.set_shadow_type(Gtk.ShadowType.NONE);
-        
-        viewport.add(layout);
-        
-        // want to set_adjustments before adding to ScrolledWindow to let our signal handlers
-        // run first ... otherwise, the thumbnails draw late
-        layout.set_adjustments(get_hadjustment(), get_vadjustment());
-        
-        add(viewport);
-        
-        // need to monitor items going hidden when dealing with anchor/cursor/highlighted items
-        get_view().items_hidden.connect(on_items_hidden);
-        get_view().contents_altered.connect(on_contents_altered);
-        get_view().items_state_changed.connect(on_items_state_changed);
-        get_view().items_visibility_changed.connect(on_items_visibility_changed);
-        
-        // scrollbar policy
-        set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC);
-    }
-    
-    public void init_item_context_menu(string path) {
-        item_context_menu_path = path;
-    }
-
-    public void init_page_context_menu(string path) {
-        page_context_menu_path = path;
-    }
-    
-    public Gtk.Menu? get_context_menu() {
-        // show page context menu if nothing is selected
-        return (get_view().get_selected_count() != 0) ? get_item_context_menu() :
-            get_page_context_menu();
-    }
-    
-    private Gtk.Menu item_context_menu;
-    public virtual Gtk.Menu? get_item_context_menu() {
-        if (item_context_menu == null) {
-            var model = this.builder.get_object (item_context_menu_path)
-                as GLib.MenuModel;
-            item_context_menu = new Gtk.Menu.from_model (model);
-            item_context_menu.attach_to_widget (this, null);
-        }
-
-        return item_context_menu;
-    }
-    
-    private Gtk.Menu page_context_menu;
-    public override Gtk.Menu? get_page_context_menu() {
-        if (page_context_menu_path == null)
-            return null;
-
-        if (page_context_menu == null) {
-            var model = this.builder.get_object (page_context_menu_path)
-                as GLib.MenuModel;
-            page_context_menu = new Gtk.Menu.from_model (model);
-            page_context_menu.attach_to_widget (this, null);
-        }
-
-        return page_context_menu;
-    }
-    
-    protected override bool on_context_keypress() {
-        return popup_context_menu(get_context_menu());
-    }
-    
-    protected virtual string get_view_empty_message() {
-        return _("No photos/videos");
-    }
-
-    protected virtual string get_filter_no_match_message() {
-        return _("No photos/videos found which match the current filter");
-    }
-
-    protected virtual void on_item_activated(CheckerboardItem item, Activator activator, 
-        KeyboardModifiers modifiers) {
-    }
-    
-    public CheckerboardLayout get_checkerboard_layout() {
-        return layout;
-    }
-    
-    // Gets the search view filter for this page.
-    public abstract SearchViewFilter get_search_view_filter();
-    
-    public virtual Core.ViewTracker? get_view_tracker() {
-        return null;
-    }
-    
-    public override void switching_from() {
-        layout.set_in_view(false);
-        get_search_view_filter().refresh.disconnect(on_view_filter_refresh);
-
-        // unselect everything so selection won't persist after page loses focus 
-        get_view().unselect_all();
-        
-        base.switching_from();
-    }
-    
-    public override void switched_to() {
-        layout.set_in_view(true);
-        get_search_view_filter().refresh.connect(on_view_filter_refresh);
-        on_view_filter_refresh();
-
-        if (get_view().get_selected_count() > 0) {
-            CheckerboardItem? item = (CheckerboardItem?) get_view().get_selected_at(0);
-
-            // if item is in any way out of view, scroll to it
-            Gtk.Adjustment vadj = get_vadjustment();
-            if (!(get_adjustment_relation(vadj, item.allocation.y) == AdjustmentRelation.IN_RANGE
-                && (get_adjustment_relation(vadj, item.allocation.y + item.allocation.height) == AdjustmentRelation.IN_RANGE))) {
-
-                    // scroll to see the new item
-                    int top = 0;
-                    if (item.allocation.y < vadj.get_value()) {
-                        top = item.allocation.y;
-                        top -= CheckerboardLayout.ROW_GUTTER_PADDING / 2;
-                    } else {
-                        top = item.allocation.y + item.allocation.height - (int) vadj.get_page_size();
-                        top += CheckerboardLayout.ROW_GUTTER_PADDING / 2;
-                    }
-
-                    vadj.set_value(top);
-
-                }
-        }
-
-        base.switched_to();
-    }
-    
-    private void on_view_filter_refresh() {
-        update_view_filter_message();
-    }
-    
-    private void on_contents_altered(Gee.Iterable<DataObject>? added,
-        Gee.Iterable<DataObject>? removed) {
-        update_view_filter_message();
-    }
-    
-    private void on_items_state_changed(Gee.Iterable<DataView> changed) {
-        update_view_filter_message();
-    }
-    
-    private void on_items_visibility_changed(Gee.Collection<DataView> changed) {
-        update_view_filter_message();
-    }
-    
-    private void update_view_filter_message() {
-        if (get_view().are_items_filtered_out() && get_view().get_count() == 0) {
-            set_page_message(get_filter_no_match_message());
-        } else if (get_view().get_count() == 0) {
-            set_page_message(get_view_empty_message());
-        } else {
-            unset_page_message();
-        }
-    }
-    
-    public void set_page_message(string message) {
-        layout.set_message(message);
-        if (is_in_view())
-            layout.queue_draw();
-    }
-    
-    public void unset_page_message() {
-        layout.unset_message();
-        if (is_in_view())
-            layout.queue_draw();
-    }
-    
-    public override void set_page_name(string name) {
-        base.set_page_name(name);
-        
-        layout.set_name(name);
-    }
-    
-    public CheckerboardItem? get_item_at_pixel(double x, double y) {
-        return layout.get_item_at_pixel(x, y);
-    }
-    
-    private void on_items_hidden(Gee.Iterable<DataView> hidden) {
-        foreach (DataView view in hidden) {
-            CheckerboardItem item = (CheckerboardItem) view;
-            
-            if (anchor == item)
-                anchor = null;
-            
-            if (cursor == item)
-                cursor = null;
-            
-            if (current_hovered_item == item)
-                current_hovered_item = null;
-        }
-    }
-
-    protected override bool key_press_event(Gdk.EventKey event) {
-        bool handled = true;
-
-        // mask out the modifiers we're interested in
-        uint state = event.state & Gdk.ModifierType.SHIFT_MASK;
-        
-        switch (Gdk.keyval_name(event.keyval)) {
-            case "Up":
-            case "KP_Up":
-                move_cursor(CompassPoint.NORTH);
-                select_anchor_to_cursor(state);
-            break;
-            
-            case "Down":
-            case "KP_Down":
-                move_cursor(CompassPoint.SOUTH);
-                select_anchor_to_cursor(state);
-            break;
-            
-            case "Left":
-            case "KP_Left":
-                move_cursor(CompassPoint.WEST);
-                select_anchor_to_cursor(state);
-            break;
-            
-            case "Right":
-            case "KP_Right":
-                move_cursor(CompassPoint.EAST);
-                select_anchor_to_cursor(state);
-            break;
-            
-            case "Home":
-            case "KP_Home":
-                CheckerboardItem? first = (CheckerboardItem?) get_view().get_first();
-                if (first != null)
-                    cursor_to_item(first);
-                select_anchor_to_cursor(state);
-            break;
-            
-            case "End":
-            case "KP_End":
-                CheckerboardItem? last = (CheckerboardItem?) get_view().get_last();
-                if (last != null)
-                    cursor_to_item(last);
-                select_anchor_to_cursor(state);
-            break;
-            
-            case "Return":
-            case "KP_Enter":
-                if (get_view().get_selected_count() == 1)
-                    on_item_activated((CheckerboardItem) get_view().get_selected_at(0),
-                        Activator.KEYBOARD, KeyboardModifiers(this));
-                else
-                    handled = false;
-            break;
-            
-            case "space":
-                Marker marker = get_view().mark(layout.get_cursor());
-                get_view().toggle_marked(marker);
-            break;
-            
-            default:
-                handled = false;
-            break;
-        }
-        
-        if (handled)
-            return true;
-        
-        return (base.key_press_event != null) ? base.key_press_event(event) : true;
-    }
-    
-    protected override bool on_left_click(Gdk.EventButton event) {
-        // only interested in single-click and double-clicks for now
-        if ((event.type != Gdk.EventType.BUTTON_PRESS) && (event.type != Gdk.EventType.2BUTTON_PRESS))
-            return false;
-        
-        // mask out the modifiers we're interested in
-        uint state = event.state & (Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK);
-        
-        // use clicks for multiple selection and activation only; single selects are handled by
-        // button release, to allow for multiple items to be selected then dragged ...
-        CheckerboardItem item = get_item_at_pixel(event.x, event.y);
-        if (item != null) {
-            // ... however, there is no dragging if the user clicks on an interactive part of the
-            // CheckerboardItem (e.g. a tag)
-            if (layout.handle_left_click(item, event.x, event.y, event.state))
-                return true;
-
-            switch (state) {
-                case Gdk.ModifierType.CONTROL_MASK:
-                    // with only Ctrl pressed, multiple selections are possible ... chosen item
-                    // is toggled
-                    Marker marker = get_view().mark(item);
-                    get_view().toggle_marked(marker);
-
-                    if (item.is_selected()) {
-                        anchor = item;
-                        cursor = item;
-                    }
-                break;
-                
-                case Gdk.ModifierType.SHIFT_MASK:
-                    get_view().unselect_all();
-                    
-                    if (anchor == null)
-                        anchor = item;
-                    
-                    select_between_items(anchor, item);
-                    
-                    cursor = item;
-                break;
-                
-                case Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK:
-                    // Ticket #853 - Make Ctrl + Shift + Mouse Button 1 able to start a new run
-                    // of contiguous selected items without unselecting previously-selected items
-                    // a la Nautilus.
-                    // Same as the case for SHIFT_MASK, but don't unselect anything first.
-                    if (anchor == null)
-                        anchor = item;
-                    
-                    select_between_items(anchor, item);
-                    
-                    cursor = item;
-                break;
-                
-                default:
-                    if (event.type == Gdk.EventType.2BUTTON_PRESS) {
-                        activated_item = item;
-                    } else {
-                        // if the user has selected one or more items and is preparing for a drag,
-                        // don't want to blindly unselect: if they've clicked on an unselected item
-                        // unselect all and select that one; if they've clicked on a previously
-                        // selected item, do nothing
-                        if (!item.is_selected()) {
-                            Marker all = get_view().start_marking();
-                            all.mark_many(get_view().get_selected());
-                            
-                            get_view().unselect_and_select_marked(all, get_view().mark(item));
-                        }
-                    }
-
-                    anchor = item;
-                    cursor = item;
-                break;
-            }
-            layout.set_cursor(item);
-        } else {
-            // user clicked on "dead" area; only unselect if control is not pressed
-            // do we want similar behavior for shift as well?
-            if (state != Gdk.ModifierType.CONTROL_MASK)
-                get_view().unselect_all();
-
-            // grab previously marked items
-            previously_selected = new Gee.ArrayList<CheckerboardItem>();
-            foreach (DataView view in get_view().get_selected())
-                previously_selected.add((CheckerboardItem) view);
-
-            layout.set_drag_select_origin((int) event.x, (int) event.y);
-
-            return true;
-        }
-
-        // need to determine if the signal should be passed to the DnD handlers
-        // Return true to block the DnD handler, false otherwise
-
-        return get_view().get_selected_count() == 0;
-    }
-    
-    protected override bool on_left_released(Gdk.EventButton event) {
-        previously_selected = null;
-
-        // if drag-selecting, stop here and do nothing else
-        if (layout.is_drag_select_active()) {
-            layout.clear_drag_select();
-            anchor = cursor;
-
-            return true;
-        }
-        
-        // only interested in non-modified button releases
-        if ((event.state & (Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK)) != 0)
-            return false;
-        
-        // if the item was activated in the double-click, report it now
-        if (activated_item != null) {
-            on_item_activated(activated_item, Activator.MOUSE, KeyboardModifiers(this));
-            activated_item = null;
-            
-            return true;
-        }
-        
-        CheckerboardItem item = get_item_at_pixel(event.x, event.y);
-        if (item == null) {
-            // released button on "dead" area
-            return true;
-        }
-
-        if (cursor != item) {
-            // user released mouse button after moving it off the initial item, or moved from dead
-            // space onto one.  either way, unselect everything
-            get_view().unselect_all();
-        } else {
-            // the idea is, if a user single-clicks on an item with no modifiers, then all other items
-            // should be deselected, however, if they single-click in order to drag one or more items,
-            // they should remain selected, hence performing this here rather than on_left_click
-            // (item may not be selected if an unimplemented modifier key was used)
-            if (item.is_selected())
-                get_view().unselect_all_but(item);
-        }
-
-        return true;
-    }
-    
-    protected override bool on_right_click(Gdk.EventButton event) {
-        // only interested in single-clicks for now
-        if (event.type != Gdk.EventType.BUTTON_PRESS)
-            return false;
-        
-        // get what's right-clicked upon
-        CheckerboardItem item = get_item_at_pixel(event.x, event.y);
-        if (item != null) {
-            // mask out the modifiers we're interested in
-            switch (event.state & (Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK)) {
-                case Gdk.ModifierType.CONTROL_MASK:
-                    // chosen item is toggled
-                    Marker marker = get_view().mark(item);
-                    get_view().toggle_marked(marker);
-                break;
-                
-                case Gdk.ModifierType.SHIFT_MASK:
-                    // TODO
-                break;
-                
-                case Gdk.ModifierType.CONTROL_MASK | Gdk.ModifierType.SHIFT_MASK:
-                    // TODO
-                break;
-                
-                default:
-                    // if the item is already selected, proceed; if item is not selected, a bare right
-                    // click unselects everything else but it
-                    if (!item.is_selected()) {
-                        Marker all = get_view().start_marking();
-                        all.mark_many(get_view().get_selected());
-                        
-                        get_view().unselect_and_select_marked(all, get_view().mark(item));
-                    }
-                break;
-            }
-        } else {
-            // clicked in "dead" space, unselect everything
-            get_view().unselect_all();
-        }
-       
-        Gtk.Menu context_menu = get_context_menu();
-        return popup_context_menu(context_menu, event);
-    }
-    
-    protected virtual bool on_mouse_over(CheckerboardItem? item, int x, int y, Gdk.ModifierType mask) {
-        if (item != null)
-            layout.handle_mouse_motion(item, x, y, mask);
-
-        // if hovering over the last hovered item, or both are null (nothing highlighted and
-        // hovering over empty space), do nothing
-        if (item == current_hovered_item)
-            return true;
-        
-        // either something new is highlighted or now hovering over empty space, so dim old item
-        if (current_hovered_item != null) {
-            current_hovered_item.handle_mouse_leave();
-            current_hovered_item = null;
-        }
-        
-        // if over empty space, done
-        if (item == null)
-            return true;
-        
-        // brighten the new item
-        current_hovered_item = item;
-        current_hovered_item.handle_mouse_enter();
-        
-        return true;
-    }
-    
-    protected override bool on_motion(Gdk.EventMotion event, int x, int y, Gdk.ModifierType mask) {
-        // report what item the mouse is hovering over
-        if (!on_mouse_over(get_item_at_pixel(x, y), x, y, mask))
-            return false;
-        
-        // go no further if not drag-selecting
-        if (!layout.is_drag_select_active())
-            return false;
-        
-        // set the new endpoint of the drag selection
-        layout.set_drag_select_endpoint(x, y);
-        
-        updated_selection_band();
-
-        // if out of bounds, schedule a check to auto-scroll the viewport
-        if (!autoscroll_scheduled 
-            && get_adjustment_relation(get_vadjustment(), y) != AdjustmentRelation.IN_RANGE) {
-            Timeout.add(AUTOSCROLL_TICKS_MSEC, selection_autoscroll);
-            autoscroll_scheduled = true;
-        }
-
-        // return true to stop a potential drag-and-drop operation
-        return true;
-    }
-    
-    private void updated_selection_band() {
-        assert(layout.is_drag_select_active());
-        
-        // get all items inside the selection
-        Gee.List<CheckerboardItem>? intersection = layout.items_in_selection_band();
-        if (intersection == null)
-            return;
-        
-        Marker to_unselect = get_view().start_marking();
-        Marker to_select = get_view().start_marking();
-
-        // mark all selected items to be unselected
-        to_unselect.mark_many(get_view().get_selected());
-
-        // except for the items that were selected before the drag began
-        assert(previously_selected != null);
-        to_unselect.unmark_many(previously_selected);        
-        to_select.mark_many(previously_selected);   
-        
-        // toggle selection on everything in the intersection and update the cursor
-        cursor = null;
-        
-        foreach (CheckerboardItem item in intersection) {
-            if (to_select.toggle(item))
-                to_unselect.unmark(item);
-            else
-                to_unselect.mark(item);
-
-            if (cursor == null)
-                cursor = item;
-        }
-        
-        get_view().select_marked(to_select);
-        get_view().unselect_marked(to_unselect);
-    }
-    
-    private bool selection_autoscroll() {
-        if (!layout.is_drag_select_active()) { 
-            autoscroll_scheduled = false;
-            
-            return false;
-        }
-        
-        // as the viewport never scrolls horizontally, only interested in vertical
-        Gtk.Adjustment vadj = get_vadjustment();
-        
-        int x, y;
-        Gdk.ModifierType mask;
-        get_event_source_pointer(out x, out y, out mask);
-        
-        int new_value = (int) vadj.get_value();
-        switch (get_adjustment_relation(vadj, y)) {
-            case AdjustmentRelation.BELOW:
-                // pointer above window, scroll up
-                new_value -= AUTOSCROLL_PIXELS;
-                layout.set_drag_select_endpoint(x, new_value);
-            break;
-            
-            case AdjustmentRelation.ABOVE:
-                // pointer below window, scroll down, extend selection to bottom of page
-                new_value += AUTOSCROLL_PIXELS;
-                layout.set_drag_select_endpoint(x, new_value + (int) vadj.get_page_size());
-            break;
-            
-            case AdjustmentRelation.IN_RANGE:
-                autoscroll_scheduled = false;
-                
-                return false;
-            
-            default:
-                warn_if_reached();
-            break;
-        }
-        
-        // It appears that in GTK+ 2.18, the adjustment is not clamped the way it was in 2.16.
-        // This may have to do with how adjustments are different w/ scrollbars, that they're upper
-        // clamp is upper - page_size ... either way, enforce these limits here
-        vadj.set_value(new_value.clamp((int) vadj.get_lower(), 
-            (int) vadj.get_upper() - (int) vadj.get_page_size()));
-        
-        updated_selection_band();
-        
-        return true;
-    }
-    
-    public void cursor_to_item(CheckerboardItem item) {
-        assert(get_view().contains(item));
-
-        cursor = item;
-        
-        if (!get_ctrl_pressed()) {
-            get_view().unselect_all();
-            Marker marker = get_view().mark(item);
-            get_view().select_marked(marker);
-        }
-        layout.set_cursor(item);
-        
-        // if item is in any way out of view, scroll to it
-        Gtk.Adjustment vadj = get_vadjustment();
-        if (get_adjustment_relation(vadj, item.allocation.y) == AdjustmentRelation.IN_RANGE
-            && (get_adjustment_relation(vadj, item.allocation.y + item.allocation.height) == AdjustmentRelation.IN_RANGE))
-            return;
-
-        // scroll to see the new item
-        int top = 0;
-        if (item.allocation.y < vadj.get_value()) {
-            top = item.allocation.y;
-            top -= CheckerboardLayout.ROW_GUTTER_PADDING / 2;
-        } else {
-            top = item.allocation.y + item.allocation.height - (int) vadj.get_page_size();
-            top += CheckerboardLayout.ROW_GUTTER_PADDING / 2;
-        }
-        
-        vadj.set_value(top);
-    }
-    
-    public void move_cursor(CompassPoint point) {
-        // if no items, nothing to do
-        if (get_view().get_count() == 0)
-            return;
-            
-        // if there is no better starting point, simply select the first and exit
-        // The right half of the or is related to Bug #732334, the cursor might be non-null and still not contained in
-        // the view, if the user dragged a full screen Photo off screen
-        if (cursor == null && layout.get_cursor() == null || cursor != null && !get_view().contains(cursor)) {
-            CheckerboardItem item = layout.get_item_at_coordinate(0, 0);
-            cursor_to_item(item);
-            anchor = item;
-
-            return;
-        }
-
-        if (cursor == null) {
-            cursor = layout.get_cursor() as CheckerboardItem;
-        }
-               
-        // move the cursor relative to the "first" item
-        CheckerboardItem? item = layout.get_item_relative_to(cursor, point);
-        if (item != null)
-            cursor_to_item(item);
-   }
-
-    public void set_cursor(CheckerboardItem item) {
-        Marker marker = get_view().mark(item);
-        get_view().select_marked(marker);
-            
-        cursor = item;
-        anchor = item;
-   }
-
-    public void select_between_items(CheckerboardItem item_start, CheckerboardItem item_end) {
-        Marker marker = get_view().start_marking();
-
-        bool passed_start = false;
-        bool passed_end = false;
-
-        foreach (DataObject object in get_view().get_all()) {
-            CheckerboardItem item = (CheckerboardItem) object;
-            
-            if (item_start == item)
-                passed_start = true;
-
-            if (item_end == item)
-                passed_end = true;
-
-            if (passed_start || passed_end)
-                marker.mark((DataView) object);
-
-            if (passed_start && passed_end)
-                break;
-        }
-        
-        get_view().select_marked(marker);
-    }
-
-    public void select_anchor_to_cursor(uint state) {
-        if (cursor == null || anchor == null)
-            return;
-
-        if (state == Gdk.ModifierType.SHIFT_MASK) {
-            get_view().unselect_all();
-            select_between_items(anchor, cursor);
-        } else {
-            anchor = cursor;
-        }
-    }
-
-    protected virtual void set_display_titles(bool display) {
-        get_view().freeze_notifications();
-        get_view().set_property(CheckerboardItem.PROP_SHOW_TITLES, display);
-        get_view().thaw_notifications();
-    }
-
-    protected virtual void set_display_comments(bool display) {
-        get_view().freeze_notifications();
-        get_view().set_property(CheckerboardItem.PROP_SHOW_COMMENTS, display);
-        get_view().thaw_notifications();
-    }
-}
-
-public abstract class SinglePhotoPage : Page {
-    public const Gdk.InterpType FAST_INTERP = Gdk.InterpType.NEAREST;
-    public const Gdk.InterpType QUALITY_INTERP = Gdk.InterpType.BILINEAR;
-    public const int KEY_REPEAT_INTERVAL_MSEC = 200;
-    
-    public enum UpdateReason {
-        NEW_PIXBUF,
-        QUALITY_IMPROVEMENT,
-        RESIZED_CANVAS
-    }
-    
-    protected Gtk.DrawingArea canvas = new Gtk.DrawingArea();
-    protected Gtk.Viewport viewport = new Gtk.Viewport(null, null);
-    
-    private bool scale_up_to_viewport;
-    private TransitionClock transition_clock;
-    private int transition_duration_msec = 0;
-    private Cairo.Surface pixmap = null;
-    private Cairo.Context pixmap_ctx = null;
-    private Cairo.Context text_ctx = null;
-    private Dimensions pixmap_dim = Dimensions();
-    private Gdk.Pixbuf unscaled = null;
-    private Dimensions max_dim = Dimensions();
-    private Gdk.Pixbuf scaled = null;
-    private Gdk.Pixbuf old_scaled = null; // previous scaled image
-    private Gdk.Rectangle scaled_pos = Gdk.Rectangle();
-    private ZoomState static_zoom_state;
-    private bool zoom_high_quality = true;
-    private ZoomState saved_zoom_state;
-    private bool has_saved_zoom_state = false;
-    private uint32 last_nav_key = 0;
-    
-    protected SinglePhotoPage(string page_name, bool scale_up_to_viewport) {
-        base(page_name);
-        
-        this.scale_up_to_viewport = scale_up_to_viewport;
-        
-        transition_clock = TransitionEffectsManager.get_instance().create_null_transition_clock();
-        
-        // With the current code automatically resizing the image to the viewport, scrollbars
-        // should never be shown, but this may change if/when zooming is supported
-        set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC);
-
-        set_border_width(0);
-        set_shadow_type(Gtk.ShadowType.NONE);
-        
-        viewport.set_shadow_type(Gtk.ShadowType.NONE);
-        viewport.set_border_width(0);
-        viewport.add(canvas);
-        
-        add(viewport);
-
-        canvas.add_events(Gdk.EventMask.EXPOSURE_MASK | Gdk.EventMask.STRUCTURE_MASK 
-            | Gdk.EventMask.SUBSTRUCTURE_MASK);
-        
-        viewport.size_allocate.connect(on_viewport_resize);
-        canvas.draw.connect(on_canvas_exposed);
-        
-        set_event_source(canvas);
-        Config.Facade.get_instance().colors_changed.connect(on_colors_changed);
-    }
-
-    ~SinglePhotoPage() {
-        Config.Facade.get_instance().colors_changed.disconnect(on_colors_changed);
-    }
-    
-    public bool is_transition_in_progress() {
-        return transition_clock.is_in_progress();
-    }
-    
-    public void cancel_transition() {
-        if (transition_clock.is_in_progress())
-            transition_clock.cancel();
-    }
-    
-    public void set_transition(string effect_id, int duration_msec) {
-        cancel_transition();
-        
-        transition_clock = TransitionEffectsManager.get_instance().create_transition_clock(effect_id);
-        if (transition_clock == null)
-            transition_clock = TransitionEffectsManager.get_instance().create_null_transition_clock();
-        
-        transition_duration_msec = duration_msec;
-    }
-    
-    // This method includes a call to pixmap_ctx.paint().
-    private void render_zoomed_to_pixmap(ZoomState zoom_state) {
-        assert(is_zoom_supported());
-        
-        Gdk.Rectangle view_rect = zoom_state.get_viewing_rectangle_wrt_content();
-        
-        Gdk.Pixbuf zoomed;
-        if (get_zoom_buffer() != null) {
-            zoomed = (zoom_high_quality) ? get_zoom_buffer().get_zoomed_image(zoom_state) :
-                get_zoom_buffer().get_zoom_preview_image(zoom_state);
-        } else {
-            Gdk.Rectangle view_rect_proj = zoom_state.get_viewing_rectangle_projection(unscaled);
-            
-            Gdk.Pixbuf proj_subpixbuf = new Gdk.Pixbuf.subpixbuf(unscaled, view_rect_proj.x,
-                view_rect_proj.y, view_rect_proj.width, view_rect_proj.height);
-            
-            zoomed = proj_subpixbuf.scale_simple(view_rect.width, view_rect.height,
-                Gdk.InterpType.BILINEAR);
-        }
-
-        if (zoomed == null) {
-            return;
-        }
-        
-        int draw_x = (pixmap_dim.width - view_rect.width) / 2;
-        draw_x = draw_x.clamp(0, int.MAX);
-
-        int draw_y = (pixmap_dim.height - view_rect.height) / 2;
-        draw_y = draw_y.clamp(0, int.MAX);
-        paint_pixmap_with_background(pixmap_ctx, zoomed, draw_x, draw_y);
-    }
-
-    protected void on_interactive_zoom(ZoomState interactive_zoom_state) {
-        assert(is_zoom_supported());
-        
-        set_source_color_from_string(pixmap_ctx, "#000");
-        pixmap_ctx.paint();
-        
-        bool old_quality_setting = zoom_high_quality;
-        zoom_high_quality = false;
-        render_zoomed_to_pixmap(interactive_zoom_state);
-        zoom_high_quality = old_quality_setting;
-        
-        canvas.queue_draw();
-    }
-
-    protected void on_interactive_pan(ZoomState interactive_zoom_state) {
-        assert(is_zoom_supported());
-        
-        set_source_color_from_string(pixmap_ctx, "#000");
-        pixmap_ctx.paint();
-        
-        bool old_quality_setting = zoom_high_quality;
-        zoom_high_quality = true;
-        render_zoomed_to_pixmap(interactive_zoom_state);
-        zoom_high_quality = old_quality_setting;
-        
-        canvas.queue_draw();
-    }
-
-    protected virtual bool is_zoom_supported() {
-        return false;
-    }
-
-    protected virtual void cancel_zoom() {
-        if (pixmap != null) {
-            set_source_color_from_string(pixmap_ctx, "#000");
-            pixmap_ctx.paint();
-        }
-    }
-
-    protected virtual void save_zoom_state() {
-        saved_zoom_state = static_zoom_state;
-        has_saved_zoom_state = true;
-    }
-    
-    protected virtual void restore_zoom_state() {
-        if (!has_saved_zoom_state)
-            return;
-
-        static_zoom_state = saved_zoom_state;
-        repaint();
-        has_saved_zoom_state = false;
-    }
-    
-    protected virtual ZoomBuffer? get_zoom_buffer() {
-        return null;
-    }
-    
-    protected ZoomState get_saved_zoom_state() {
-        return saved_zoom_state;
-    }
-
-    protected void set_zoom_state(ZoomState zoom_state) {
-        assert(is_zoom_supported());
-
-        static_zoom_state = zoom_state;
-    }
-
-    protected ZoomState get_zoom_state() {
-        assert(is_zoom_supported());
-
-        return static_zoom_state;
-    }
-
-    public override void switched_to() {
-        base.switched_to();
-        
-        if (unscaled != null)
-            repaint();
-    }
-    
-    public override void set_container(Gtk.Window container) {
-        base.set_container(container);
-        
-        // scrollbar policy in fullscreen mode needs to be auto/auto, else the pixbuf will shift
-        // off the screen
-        if (container is FullscreenWindow)
-            set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC);
-    }
-    
-    // max_dim represents the maximum size of the original pixbuf (i.e. pixbuf may be scaled and
-    // the caller capable of producing larger ones depending on the viewport size).  max_dim
-    // is used when scale_up_to_viewport is set to true.  Pass a Dimensions with no area if
-    // max_dim should be ignored (i.e. scale_up_to_viewport is false).
-    public void set_pixbuf(Gdk.Pixbuf unscaled, Dimensions max_dim, Direction? direction = null) {
-        static_zoom_state = ZoomState(max_dim, pixmap_dim,
-            static_zoom_state.get_interpolation_factor(),
-            static_zoom_state.get_viewport_center());
-
-        cancel_transition();
-        
-        this.unscaled = unscaled;
-        this.max_dim = max_dim;
-        this.old_scaled = scaled;
-        scaled = null;
-        
-        // need to make sure this has happened
-        canvas.realize();
-        
-        repaint(direction);
-    }
-    
-    public void blank_display() {
-        unscaled = null;
-        max_dim = Dimensions();
-        scaled = null;
-        pixmap = null;
-        
-        // this has to have happened
-        canvas.realize();
-        
-        // force a redraw
-        invalidate_all();
-    }
-    
-    public Cairo.Surface? get_surface() {
-        return pixmap;
-    }
-    
-    public Dimensions get_surface_dim() {
-        return pixmap_dim;
-    }
-    
-    public Cairo.Context get_cairo_context() {
-        return pixmap_ctx;
-    }
-    
-    public void paint_text(Pango.Layout pango_layout, int x, int y) {
-        text_ctx.move_to(x, y);
-        Pango.cairo_show_layout(text_ctx, pango_layout);
-    }
-    
-    public Scaling get_canvas_scaling() {
-        return (get_container() is FullscreenWindow) ? Scaling.for_screen(AppWindow.get_instance(), scale_up_to_viewport)
-            : Scaling.for_widget(viewport, scale_up_to_viewport);
-    }
-
-    public Gdk.Pixbuf? get_unscaled_pixbuf() {
-        return unscaled;
-    }
-    
-    public Gdk.Pixbuf? get_scaled_pixbuf() {
-        return scaled;
-    }
-    
-    // Returns a rectangle describing the pixbuf in relation to the canvas
-    public Gdk.Rectangle get_scaled_pixbuf_position() {
-        return scaled_pos;
-    }
-    
-    public bool is_inside_pixbuf(int x, int y) {
-        return coord_in_rectangle(x, y, scaled_pos);
-    }
-    
-    public void invalidate(Gdk.Rectangle rect) {
-        if (canvas.get_window() != null)
-            canvas.get_window().invalidate_rect(rect, false);
-    }
-    
-    public void invalidate_all() {
-        if (canvas.get_window() != null)
-            canvas.get_window().invalidate_rect(null, false);
-    }
-    
-    private void on_viewport_resize() {
-        // do fast repaints while resizing
-        internal_repaint(true, null);
-    }
-    
-    protected override void on_resize_finished(Gdk.Rectangle rect) {
-        base.on_resize_finished(rect);
-       
-        // when the resize is completed, do a high-quality repaint
-        repaint();
-    }
-
-    private bool on_canvas_exposed(Cairo.Context exposed_ctx) {
-        // draw pixmap onto canvas unless it's not been instantiated, in which case draw black
-        // (so either old image or contents of another page is not left on screen)
-        if (pixmap != null)
-            exposed_ctx.set_source_surface(pixmap, 0, 0);
-        else
-            set_source_color_from_string(exposed_ctx, "#000");
-        
-        exposed_ctx.rectangle(0, 0, get_allocated_width(), get_allocated_height());
-        exposed_ctx.paint();
-        
-        return true;
-    }
-    
-    protected virtual void new_surface(Cairo.Context ctx, Dimensions ctx_dim) {
-    }
-    
-    protected virtual void updated_pixbuf(Gdk.Pixbuf pixbuf, UpdateReason reason, Dimensions old_dim) {
-    }
-
-    protected virtual void paint(Cairo.Context ctx, Dimensions ctx_dim) {
-        if (is_zoom_supported() && (!static_zoom_state.is_default())) {
-            set_source_color_from_string(ctx, "#000");
-            ctx.rectangle(0, 0, pixmap_dim.width, pixmap_dim.height);
-            ctx.fill();
-            
-            render_zoomed_to_pixmap(static_zoom_state);
-        } else if (!transition_clock.paint(ctx, ctx_dim.width, ctx_dim.height)) {
-            // transition is not running, so paint the full image on a black background
-            set_source_color_from_string(ctx, "#000");
-
-            ctx.rectangle(0, 0, pixmap_dim.width, pixmap_dim.height);
-            ctx.fill();
-
-            paint_pixmap_with_background(ctx, scaled, scaled_pos.x, scaled_pos.y);
-        }
-    }
-    
-    private void repaint_pixmap() {
-        if (pixmap_ctx == null)
-            return;
-        
-        paint(pixmap_ctx, pixmap_dim);
-        invalidate_all();
-    }
-    
-    public void repaint(Direction? direction = null) {
-        internal_repaint(false, direction);
-    }
-    
-    private void internal_repaint(bool fast, Direction? direction) {
-        // if not in view, assume a full repaint needed in future but do nothing more
-        if (!is_in_view()) {
-            pixmap = null;
-            scaled = null;
-            
-            return;
-        }
-        
-        // no image or window, no painting
-        if (unscaled == null || canvas.get_window() == null)
-            return;
-        
-        Gtk.Allocation allocation;
-        viewport.get_allocation(out allocation);
-        
-        int width = allocation.width;
-        int height = allocation.height;
-        
-        if (width <= 0 || height <= 0)
-            return;
-            
-        bool new_pixbuf = (scaled == null);
-        
-        // save if reporting an image being rescaled
-        Dimensions old_scaled_dim = Dimensions.for_rectangle(scaled_pos);
-        Gdk.Rectangle old_scaled_pos = scaled_pos;
-
-        // attempt to reuse pixmap
-        if (pixmap_dim.width != width || pixmap_dim.height != height)
-            pixmap = null;
-        
-        // if necessary, create a pixmap as large as the entire viewport
-        bool new_pixmap = false;
-        if (pixmap == null) {
-            init_pixmap(width, height);
-            new_pixmap = true;
-        }
-        
-        if (new_pixbuf || new_pixmap) {
-            Dimensions unscaled_dim = Dimensions.for_pixbuf(unscaled);
-            
-            // determine scaled size of pixbuf ... if a max dimensions is set and not scaling up,
-            // respect it
-            Dimensions scaled_dim = Dimensions();
-            if (!scale_up_to_viewport && max_dim.has_area() && max_dim.width < width && max_dim.height < height)
-                scaled_dim = max_dim;
-            else
-                scaled_dim = unscaled_dim.get_scaled_proportional(pixmap_dim);
-            
-            assert(width >= scaled_dim.width);
-            assert(height >= scaled_dim.height);
-
-            // center pixbuf on the canvas
-            scaled_pos.x = (width - scaled_dim.width) / 2;
-            scaled_pos.y = (height - scaled_dim.height) / 2;
-            scaled_pos.width = scaled_dim.width;
-            scaled_pos.height = scaled_dim.height;
-        }
-        
-        Gdk.InterpType interp = (fast) ? FAST_INTERP : QUALITY_INTERP;
-        
-        // rescale if canvas rescaled or better quality is requested
-        if (scaled == null) {
-            scaled = resize_pixbuf(unscaled, Dimensions.for_rectangle(scaled_pos), interp);
-            
-            UpdateReason reason = UpdateReason.RESIZED_CANVAS;
-            if (new_pixbuf)
-                reason = UpdateReason.NEW_PIXBUF;
-            else if (!new_pixmap && interp == QUALITY_INTERP)
-                reason = UpdateReason.QUALITY_IMPROVEMENT;
-
-            static_zoom_state = ZoomState(max_dim, pixmap_dim,
-                static_zoom_state.get_interpolation_factor(),
-                static_zoom_state.get_viewport_center());
-
-            updated_pixbuf(scaled, reason, old_scaled_dim);
-        }
-
-        zoom_high_quality = !fast;
-        
-        if (direction != null && !transition_clock.is_in_progress()) {
-            Spit.Transitions.Visuals visuals = new Spit.Transitions.Visuals(old_scaled,
-                old_scaled_pos, scaled, scaled_pos, parse_color("#000"));
-            
-            transition_clock.start(visuals, direction.to_transition_direction(), transition_duration_msec,
-                repaint_pixmap);
-        }
-        
-        if (!transition_clock.is_in_progress())
-            repaint_pixmap();
-    }
-    
-    private void init_pixmap(int width, int height) {
-        assert(unscaled != null);
-        assert(canvas.get_window() != null);
-        
-        // Cairo backing surface (manual double-buffering)
-        pixmap = new Cairo.ImageSurface(Cairo.Format.ARGB32, width, height);
-        pixmap_dim = Dimensions(width, height);
-        
-        // Cairo context for drawing on the pixmap
-        pixmap_ctx = new Cairo.Context(pixmap);
-        
-        // need a new pixbuf to fit this scale
-        scaled = null;
-        
-        // Cairo context for drawing text on the pixmap
-        text_ctx = new Cairo.Context(pixmap);
-        set_source_color_from_string(text_ctx, "#fff");
-        
-        
-        // no need to resize canvas, viewport does that automatically
-        
-        new_surface(pixmap_ctx, pixmap_dim);
-    }
-
-    protected override bool on_context_keypress() {
-        return popup_context_menu(get_page_context_menu());
-    }
-    
-    protected virtual void on_previous_photo() {
-    }
-    
-    protected virtual void on_next_photo() {
-    }
-    
-    public override bool key_press_event(Gdk.EventKey event) {
-        // if the user holds the arrow keys down, we will receive a steady stream of key press
-        // events for an operation that isn't designed for a rapid succession of output ... 
-        // we staunch the supply of new photos to under a quarter second (#533)
-        bool nav_ok = (event.time - last_nav_key) > KEY_REPEAT_INTERVAL_MSEC;
-        
-        bool handled = true;
-        switch (Gdk.keyval_name(event.keyval)) {
-            case "Left":
-            case "KP_Left":
-            case "BackSpace":
-                if (nav_ok) {
-                    on_previous_photo();
-                    last_nav_key = event.time;
-                }
-            break;
-            
-            case "Right":
-            case "KP_Right":
-            case "space":
-                if (nav_ok) {
-                    on_next_photo();
-                    last_nav_key = event.time;
-                }
-            break;
-            
-            default:
-                handled = false;
-            break;
-        }
-        
-        if (handled)
-            return true;
-        
-        return (base.key_press_event != null) ? base.key_press_event(event) : true;
-    }
-
-    private void on_colors_changed() {
-        invalidate_transparent_background();
-        repaint();
-    }
-}
-
-//
-// DragAndDropHandler attaches signals to a Page to properly handle drag-and-drop requests for the
-// Page as a DnD Source.  (DnD Destination handling is handled by the appropriate AppWindow, i.e.
-// LibraryWindow and DirectWindow). Assumes the Page's ViewCollection holds MediaSources.
-//
-public class DragAndDropHandler {
-    private enum TargetType {
-        XDS,
-        MEDIA_LIST
-    }
-    
-    private const Gtk.TargetEntry[] SOURCE_TARGET_ENTRIES = {
-        { "XdndDirectSave0", Gtk.TargetFlags.OTHER_APP, TargetType.XDS },
-        { "shotwell/media-id-atom", Gtk.TargetFlags.SAME_APP, TargetType.MEDIA_LIST }
-    };
-    
-    private static Gdk.Atom? XDS_ATOM = null;
-    private static Gdk.Atom? TEXT_ATOM = null;
-    private static uint8[]? XDS_FAKE_TARGET = null;
-    
-    private weak Page page;
-    private Gtk.Widget event_source;
-    private File? drag_destination = null;
-    private ExporterUI exporter = null;
-    
-    public DragAndDropHandler(Page page) {
-        this.page = page;
-        this.event_source = page.get_event_source();
-        assert(event_source != null);
-        assert(event_source.get_has_window());
-        
-        // Need to do this because static member variables are not properly handled
-        if (XDS_ATOM == null)
-            XDS_ATOM = Gdk.Atom.intern_static_string("XdndDirectSave0");
-        
-        if (TEXT_ATOM == null)
-            TEXT_ATOM = Gdk.Atom.intern_static_string("text/plain");
-        
-        if (XDS_FAKE_TARGET == null)
-            XDS_FAKE_TARGET = string_to_uchar_array("shotwell.txt");
-        
-        // register what's available on this DnD Source
-        Gtk.drag_source_set(event_source, Gdk.ModifierType.BUTTON1_MASK, SOURCE_TARGET_ENTRIES,
-            Gdk.DragAction.COPY);
-        
-        // attach to the event source's DnD signals, not the Page's, which is a NO_WINDOW widget
-        // and does not emit them
-        event_source.drag_begin.connect(on_drag_begin);
-        event_source.drag_data_get.connect(on_drag_data_get);
-        event_source.drag_end.connect(on_drag_end);
-        event_source.drag_failed.connect(on_drag_failed);
-    }
-    
-    ~DragAndDropHandler() {
-        if (event_source != null) {
-            event_source.drag_begin.disconnect(on_drag_begin);
-            event_source.drag_data_get.disconnect(on_drag_data_get);
-            event_source.drag_end.disconnect(on_drag_end);
-            event_source.drag_failed.disconnect(on_drag_failed);
-        }
-        
-        page = null;
-        event_source = null;
-    }
-    
-    private void on_drag_begin(Gdk.DragContext context) {
-        debug("on_drag_begin (%s)", page.get_page_name());
-        
-        if (page == null || page.get_view().get_selected_count() == 0 || exporter != null)
-            return;
-        
-        drag_destination = null;
-        
-        // use the first media item as the icon
-        ThumbnailSource thumb = (ThumbnailSource) page.get_view().get_selected_at(0).get_source();
-        
-        try {
-            Gdk.Pixbuf icon = thumb.get_thumbnail(AppWindow.DND_ICON_SCALE);
-            Gtk.drag_source_set_icon_pixbuf(event_source, icon);
-        } catch (Error err) {
-            warning("Unable to fetch icon for drag-and-drop from %s: %s", thumb.to_string(),
-                err.message);
-        }
-        
-        // set the XDS property to indicate an XDS save is available
-#if VALA_0_20
-        Gdk.property_change(context.get_source_window(), XDS_ATOM, TEXT_ATOM, 8, Gdk.PropMode.REPLACE,
-            XDS_FAKE_TARGET, 1);
-#else
-        Gdk.property_change(context.get_source_window(), XDS_ATOM, TEXT_ATOM, 8, Gdk.PropMode.REPLACE,
-            XDS_FAKE_TARGET);
-#endif
-    }
-    
-    private void on_drag_data_get(Gdk.DragContext context, Gtk.SelectionData selection_data,
-        uint target_type, uint time) {
-        debug("on_drag_data_get (%s)", page.get_page_name());
-        
-        if (page == null || page.get_view().get_selected_count() == 0)
-            return;
-        
-        switch (target_type) {
-            case TargetType.XDS:
-                // Fetch the XDS property that has been set with the destination path
-                uchar[] data = new uchar[4096];
-                Gdk.Atom actual_type;
-                int actual_format = 0;
-                bool fetched = Gdk.property_get(context.get_source_window(), XDS_ATOM, TEXT_ATOM,
-                    0, data.length, 0, out actual_type, out actual_format, out data);
-                
-                // the destination path is actually for our XDS_FAKE_TARGET, use its parent
-                // to determine where the file(s) should go
-                if (fetched && data != null && data.length > 0)
-                    drag_destination = File.new_for_uri(uchar_array_to_string(data)).get_parent();
-                
-                debug("on_drag_data_get (%s): %s", page.get_page_name(),
-                    (drag_destination != null) ? drag_destination.get_path() : "(no path)");
-                
-                // Set the property to "S" for Success or "E" for Error
-                selection_data.set(XDS_ATOM, 8,
-                    string_to_uchar_array((drag_destination != null) ? "S" : "E"));
-            break;
-            
-            case TargetType.MEDIA_LIST:
-                Gee.Collection<MediaSource> sources =
-                    (Gee.Collection<MediaSource>) page.get_view().get_selected_sources();
-                
-                // convert the selected media sources to Gdk.Atom-encoded sourceID strings for
-                // internal drag-and-drop
-                selection_data.set(Gdk.Atom.intern_static_string("SourceIDAtom"), (int) sizeof(Gdk.Atom),
-                    serialize_media_sources(sources));
-            break;
-            
-            default:
-                warning("on_drag_data_get (%s): unknown target type %u", page.get_page_name(),
-                    target_type);
-            break;
-        }
-    }
-    
-    private void on_drag_end() {
-        debug("on_drag_end (%s)", page.get_page_name());
-
-        if (page == null || page.get_view().get_selected_count() == 0 || drag_destination == null
-            || exporter != null) {
-            return;
-        }
-
-        debug("Exporting to %s", drag_destination.get_path());
-        
-        // drag-and-drop export doesn't pop up an export dialog, so use what are likely the
-        // most common export settings (the current -- or "working" -- file format, with
-        // all transformations applied, at the image's original size).
-        if (drag_destination.get_path() != null) {
-            exporter = new ExporterUI(new Exporter(
-                (Gee.Collection<Photo>) page.get_view().get_selected_sources(),
-                drag_destination, Scaling.for_original(), ExportFormatParameters.current()));
-            exporter.export(on_export_completed);
-        } else {
-            AppWindow.error_message(_("Photos cannot be exported to this directory."));
-        }
-        
-        drag_destination = null;
-    }
-    
-    private bool on_drag_failed(Gdk.DragContext context, Gtk.DragResult drag_result) {
-        debug("on_drag_failed (%s): %d", page.get_page_name(), (int) drag_result);
-        
-        if (page == null)
-            return false;
-        
-        drag_destination = null;
-        
-        return false;
-    }
-    
-    private void on_export_completed() {
-        exporter = null;
-    }
-
-}
diff --git a/src/PageMessagePane.vala b/src/PageMessagePane.vala
new file mode 100644
index 0000000..e773dad
--- /dev/null
+++ b/src/PageMessagePane.vala
@@ -0,0 +1,19 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+[GtkTemplate (ui = "/org/gnome/Shotwell/ui/message_pane.ui")]
+private class PageMessagePane : Gtk.Box {
+    [GtkChild]
+    public unowned Gtk.Label label;
+
+    [GtkChild]
+    public unowned Gtk.Image icon_image;
+
+    public PageMessagePane() {
+        Object();
+    }
+}
+
diff --git a/src/Photo.vala b/src/Photo.vala
index b67457e..f31a17d 100644
--- a/src/Photo.vala
+++ b/src/Photo.vala
@@ -155,7 +155,7 @@ public enum Rating {
 // particular photo without modifying the backing image file.  The interface allows for
 // transformations to be stored persistently elsewhere or in memory until they're committed en
 // masse to an image file.
-public abstract class Photo : PhotoSource, Dateable {
+public abstract class Photo : PhotoSource, Dateable, Positionable {
     // Need to use "thumb" rather than "photo" for historical reasons -- this name is used
     // directly to load thumbnails from disk by already-existing filenames
     public const string TYPENAME = "thumb";
@@ -183,7 +183,7 @@ public abstract class Photo : PhotoSource, Dateable {
         "pns", "jps", "mpo",
         
         // RAW extensions
-        "3fr", "arw", "srf", "sr2", "bay", "crw", "cr2", "cap", "iiq", "eip", "dcs", "dcr", "drf",
+        "3fr", "arw", "srf", "sr2", "bay", "crw", "cr2", "cr3", "cap", "iiq", "eip", "dcs", "dcr", "drf",
         "k25", "kdc", "dng", "erf", "fff", "mef", "mos", "mrw", "nef", "nrw", "orf", "ptx", "pef",
         "pxn", "r3d", "raf", "raw", "rw2", "rwl", "rwz", "x3f", "srw"
     };
@@ -210,7 +210,7 @@ public abstract class Photo : PhotoSource, Dateable {
     // Here, we cache the exposure time to avoid paying to access the row every time we
     // need to know it. This is initially set in the constructor, and updated whenever
     // the exposure time is set (please see set_exposure_time() for details).
-    private time_t cached_exposure_time;
+    private DateTime? cached_exposure_time;
     
     public enum Exception {
         NONE            = 0,
@@ -640,7 +640,7 @@ public abstract class Photo : PhotoSource, Dateable {
         File file = File.new_for_path(bpr.filepath);
         FileInfo info = file.query_info(DirectoryMonitor.SUPPLIED_ATTRIBUTES,
             FileQueryInfoFlags.NOFOLLOW_SYMLINKS, null);
-        TimeVal timestamp = info.get_modification_time();
+        var timestamp = info.get_modification_date_time();
         
         PhotoFileInterrogator interrogator = new PhotoFileInterrogator(
             file, PhotoFileSniffer.Options.GET_ALL);
@@ -655,7 +655,7 @@ public abstract class Photo : PhotoSource, Dateable {
         
         bpr.dim = detected.image_dim;
         bpr.filesize = info.get_size();
-        bpr.timestamp = timestamp.tv_sec;
+        bpr.timestamp = timestamp;
         bpr.original_orientation = detected.metadata != null ? detected.metadata.get_orientation() : 
             Orientation.TOP_LEFT;
         
@@ -832,7 +832,7 @@ public abstract class Photo : PhotoSource, Dateable {
             if (!developments.has_key(d))
                 return; // we tried!
             
-            // Disgard changes.
+            // Discard changes.
             revert_to_master(false);
             
             // Switch master to the new photo.
@@ -1185,7 +1185,7 @@ public abstract class Photo : PhotoSource, Dateable {
             return ImportResult.UNSUPPORTED_FORMAT;
         }
         
-        TimeVal timestamp = info.get_modification_time();
+        var timestamp = info.get_modification_date_time();
         
         // if all MD5s supplied, don't sniff for them
         if (params.exif_md5 != null && params.thumbnail_md5 != null && params.full_md5 != null)
@@ -1217,8 +1217,9 @@ public abstract class Photo : PhotoSource, Dateable {
         }
         
         Orientation orientation = Orientation.TOP_LEFT;
-        time_t exposure_time = 0;
+        DateTime? exposure_time = null;
         string title = "";
+        GpsCoords gps_coords = GpsCoords();
         string comment = "";
         Rating rating = Rating.UNRATED;
         
@@ -1234,6 +1235,7 @@ public abstract class Photo : PhotoSource, Dateable {
             
             orientation = detected.metadata.get_orientation();
             title = detected.metadata.get_title();
+            gps_coords = detected.metadata.get_gps_coords();
             comment = detected.metadata.get_comment();
             params.keywords = detected.metadata.get_keywords();
             rating = detected.metadata.get_rating();
@@ -1255,7 +1257,7 @@ public abstract class Photo : PhotoSource, Dateable {
         params.row.master.filepath = file.get_path();
         params.row.master.dim = detected.image_dim;
         params.row.master.filesize = info.get_size();
-        params.row.master.timestamp = timestamp.tv_sec;
+        params.row.master.timestamp = timestamp;
         params.row.exposure_time = exposure_time;
         params.row.orientation = orientation;
         params.row.master.original_orientation = orientation;
@@ -1269,6 +1271,7 @@ public abstract class Photo : PhotoSource, Dateable {
         params.row.flags = 0;
         params.row.master.file_format = detected.file_format;
         params.row.title = title;
+        params.row.gps_coords = gps_coords;
         params.row.comment = comment;
         params.row.rating = rating;
         
@@ -1296,8 +1299,8 @@ public abstract class Photo : PhotoSource, Dateable {
         params.row.master.filepath = file.get_path();
         params.row.master.dim = Dimensions(0,0);
         params.row.master.filesize = 0;
-        params.row.master.timestamp = 0;
-        params.row.exposure_time = 0;
+        params.row.master.timestamp = null;
+        params.row.exposure_time = null;
         params.row.orientation = Orientation.TOP_LEFT;
         params.row.master.original_orientation = Orientation.TOP_LEFT;
         params.row.import_id = params.import_id;
@@ -1310,6 +1313,7 @@ public abstract class Photo : PhotoSource, Dateable {
         params.row.flags = 0;
         params.row.master.file_format = PhotoFileFormat.JFIF;
         params.row.title = null;
+        params.row.gps_coords = GpsCoords();
         params.row.comment = null;
         params.row.rating = Rating.UNRATED;
         
@@ -1350,10 +1354,10 @@ public abstract class Photo : PhotoSource, Dateable {
             return null;
         }
         
-        TimeVal modification_time = info.get_modification_time();
+        var modification_time = info.get_modification_date_time();
         
         backing.filepath = file.get_path();
-        backing.timestamp = modification_time.tv_sec;
+        backing.timestamp = modification_time;
         backing.filesize = info.get_size();
         backing.file_format = detected.file_format;
         backing.dim = detected.image_dim;
@@ -1462,14 +1466,22 @@ public abstract class Photo : PhotoSource, Dateable {
             list += "image:orientation";
             updated_row.master.original_orientation = backing.original_orientation;
         }
-        
+
+        GpsCoords gps_coords = GpsCoords();
+
         if (detected.metadata != null) {
             MetadataDateTime? date_time = detected.metadata.get_exposure_date_time();
-            if (date_time != null && updated_row.exposure_time != date_time.get_timestamp())
+            if (date_time != null && updated_row.exposure_time != null &&
+                !updated_row.exposure_time.equal(date_time.get_timestamp()))
                 list += "metadata:exposure-time";
             
             if (updated_row.title != detected.metadata.get_title())
                 list += "metadata:name";
+
+            gps_coords = detected.metadata.get_gps_coords();
+            if (updated_row.gps_coords != gps_coords)
+                list += "metadata:gps";
+
             
             if (updated_row.comment != detected.metadata.get_comment())
                 list += "metadata:comment";
@@ -1490,7 +1502,8 @@ public abstract class Photo : PhotoSource, Dateable {
             MetadataDateTime? date_time = detected.metadata.get_exposure_date_time();
             if (date_time != null)
                 updated_row.exposure_time = date_time.get_timestamp();
-            
+
+            updated_row.gps_coords = gps_coords;
             updated_row.title = detected.metadata.get_title();
             updated_row.comment = detected.metadata.get_comment();
             updated_row.rating = detected.metadata.get_rating();
@@ -1601,6 +1614,7 @@ public abstract class Photo : PhotoSource, Dateable {
         
         if (reimport_state.metadata != null) {
             set_title(reimport_state.metadata.get_title());
+            set_gps_coords(reimport_state.metadata.get_gps_coords());
             set_comment(reimport_state.metadata.get_comment());
             set_rating(reimport_state.metadata.get_rating());
             apply_user_metadata_for_reimport(reimport_state.metadata);
@@ -1695,17 +1709,17 @@ public abstract class Photo : PhotoSource, Dateable {
     
     // Use this only if the master file's modification time has been changed (i.e. touched)
     public void set_master_timestamp(FileInfo info) {
-        TimeVal modification = info.get_modification_time();
+        var modification = info.get_modification_date_time();
         
         try {
             lock (row) {
-                if (row.master.timestamp == modification.tv_sec)
+                if (row.master.timestamp.equal(modification))
                     return;
 
-                PhotoTable.get_instance().update_timestamp(row.photo_id, modification.tv_sec);
-                row.master.timestamp = modification.tv_sec;
+                PhotoTable.get_instance().update_timestamp(row.photo_id, modification);
+                row.master.timestamp = modification;
             }
-        } catch (DatabaseError err) {
+        } catch (Error err) {
             AppWindow.database_error(err);
             
             return;
@@ -1718,15 +1732,15 @@ public abstract class Photo : PhotoSource, Dateable {
     }
     
     // Use this only if the editable file's modification time has been changed (i.e. touched)
-    public void update_editable_modification_time(FileInfo info) throws DatabaseError {
-        TimeVal modification = info.get_modification_time();
+    public void update_editable_modification_time(FileInfo info) throws Error {
+        var modification = info.get_modification_date_time();
         
         bool altered = false;
         lock (row) {
-            if (row.editable_id.is_valid() && editable.timestamp != modification.tv_sec) {
+            if (row.editable_id.is_valid() && !editable.timestamp.equal(modification)) {
                 BackingPhotoTable.get_instance().update_timestamp(row.editable_id,
-                    modification.tv_sec);
-                editable.timestamp = modification.tv_sec;
+                    modification);
+                editable.timestamp = modification;
                 altered = true;
             }
         }
@@ -1739,8 +1753,13 @@ public abstract class Photo : PhotoSource, Dateable {
     public static void update_many_editable_timestamps(Gee.Map<Photo, FileInfo> map)
         throws DatabaseError {
         DatabaseTable.begin_transaction();
-        foreach (Photo photo in map.keys)
-            photo.update_editable_modification_time(map.get(photo));
+        foreach (Photo photo in map.keys) {
+            try {
+                photo.update_editable_modification_time(map.get(photo));
+            } catch (Error err) {
+                debug("Failed to update modification time: %s", err.message);
+            }
+        }
         DatabaseTable.commit_transaction();
     }
     
@@ -1853,7 +1872,7 @@ public abstract class Photo : PhotoSource, Dateable {
                     }
                 }
             }
-        } catch (DatabaseError err) {
+        } catch (Error err) {
             AppWindow.database_error(err);
         }
         
@@ -1906,7 +1925,7 @@ public abstract class Photo : PhotoSource, Dateable {
                     }
                 }
             }
-        } catch (DatabaseError err) {
+        } catch (Error err) {
             AppWindow.database_error(err);
         }
         
@@ -1993,7 +2012,7 @@ public abstract class Photo : PhotoSource, Dateable {
         }
     }
     
-    public override time_t get_timestamp() {
+    public override DateTime? get_timestamp() {
         lock (row) {
             return backing_photo_row.timestamp;
         }
@@ -2169,7 +2188,7 @@ public abstract class Photo : PhotoSource, Dateable {
         }
     }
     
-    public void set_master_metadata_dirty(bool dirty) throws DatabaseError {
+    public void set_master_metadata_dirty(bool dirty) throws Error {
         bool committed = false;
         lock (row) {
             if (row.metadata_dirty != dirty) {
@@ -2277,7 +2296,7 @@ public abstract class Photo : PhotoSource, Dateable {
             error("Unable to read file information for %s: %s", to_string(), err.message);
         }
         
-        TimeVal timestamp = info.get_modification_time();
+        var timestamp = info.get_modification_date_time();
         
         // interrogate file for photo information
         PhotoFileInterrogator interrogator = new PhotoFileInterrogator(file);
@@ -2297,7 +2316,7 @@ public abstract class Photo : PhotoSource, Dateable {
         bool success;
         lock (row) {
             success = PhotoTable.get_instance().master_exif_updated(get_photo_id(), info.get_size(),
-                timestamp.tv_sec, detected.md5, detected.exif_md5, detected.thumbnail_md5, row);
+                timestamp, detected.md5, detected.exif_md5, detected.thumbnail_md5, row);
         }
         
         if (success)
@@ -2324,7 +2343,7 @@ public abstract class Photo : PhotoSource, Dateable {
         }
     }
     
-    public override time_t get_exposure_time() {
+    public override DateTime? get_exposure_time() {
         return cached_exposure_time;
     }
    
@@ -2362,6 +2381,29 @@ public abstract class Photo : PhotoSource, Dateable {
         if (committed)
             notify_altered(new Alteration("metadata", "name"));
     }
+
+    public GpsCoords get_gps_coords() {
+        lock (row) {
+            return row.gps_coords;
+        }
+    }
+
+    public void set_gps_coords(GpsCoords gps_coords) {
+        DatabaseError dberr = null;
+        lock (row) {
+            try {
+                PhotoTable.get_instance().set_gps_coords(row.photo_id, gps_coords);
+                row.gps_coords = gps_coords;
+            } catch (DatabaseError err) {
+                dberr = err;
+            }
+        }
+        if (dberr == null)
+            notify_altered(new Alteration("metadata", "gps"));
+        else
+            warning("Unable to write gps coordinates for %s: %s", to_string(), dberr.message);
+    }
+
     
     public override bool set_comment(string? comment) {
         string? new_comment = prep_comment(comment);
@@ -2455,7 +2497,7 @@ public abstract class Photo : PhotoSource, Dateable {
         file_exif_updated();
     }
 
-    public void set_exposure_time(time_t time) {
+    public void set_exposure_time(DateTime time) {
         bool committed;
         lock (row) {
             committed = PhotoTable.get_instance().set_exposure_time(row.photo_id, time);
@@ -2469,7 +2511,7 @@ public abstract class Photo : PhotoSource, Dateable {
             notify_altered(new Alteration("metadata", "exposure-time"));
     }
     
-    public void set_exposure_time_persistent(time_t time) throws Error {
+    public void set_exposure_time_persistent(DateTime time) throws Error {
         PhotoFileReader source = get_source_reader();
         
         // Try to write to backing file
@@ -2742,7 +2784,8 @@ public abstract class Photo : PhotoSource, Dateable {
         lock (row) {
             return row.transformations == null 
                 && (row.orientation != backing_photo_row.original_orientation 
-                || (date_time != null && row.exposure_time != date_time.get_timestamp()));
+                || (date_time != null && row.exposure_time != null &&
+                     !row.exposure_time.equal(date_time.get_timestamp())));
         }
     }
     
@@ -2763,7 +2806,7 @@ public abstract class Photo : PhotoSource, Dateable {
             // No, use file timestamp as date/time.
             lock (row) {
                 // Did we manually set an exposure date?
-                if(backing_photo_row.timestamp != row.exposure_time) {
+                if(nullsafe_date_time_comperator(backing_photo_row.timestamp, row.exposure_time) != 0) {
                     // Yes, we need to save this.
                     return true;            
                 }
@@ -2773,7 +2816,7 @@ public abstract class Photo : PhotoSource, Dateable {
         lock (row) {
             return row.transformations != null 
                 || row.orientation != backing_photo_row.original_orientation
-                || (date_time != null && row.exposure_time != date_time.get_timestamp())
+                || (date_time != null && !row.exposure_time.equal(date_time.get_timestamp()))
                 || (get_comment() != comment)
                 || (get_title() != title);
         }
@@ -3212,6 +3255,7 @@ public abstract class Photo : PhotoSource, Dateable {
         double orientation_time = 0.0;
         
         total_timer.start();
+
 #endif
         
         // get required fields all at once, to avoid holding the row lock
@@ -3618,7 +3662,7 @@ public abstract class Photo : PhotoSource, Dateable {
         
         debug("Updating metadata of %s", writer.get_filepath());
         
-        if (get_exposure_time() != 0)
+        if (get_exposure_time() != null)
             metadata.set_exposure_date_time(new MetadataDateTime(get_exposure_time()));
         else
             metadata.set_exposure_date_time(null);
@@ -3714,7 +3758,7 @@ public abstract class Photo : PhotoSource, Dateable {
             metadata.set_comment(get_comment());
             metadata.set_software(Resources.APP_TITLE, Resources.APP_VERSION);
             
-            if (get_exposure_time() != 0)
+            if (get_exposure_time() != null)
                 metadata.set_exposure_date_time(new MetadataDateTime(get_exposure_time()));
             else
                 metadata.set_exposure_date_time(null);
@@ -3970,15 +4014,15 @@ public abstract class Photo : PhotoSource, Dateable {
                 return;
             }
             
-            TimeVal timestamp = info.get_modification_time();
+            var timestamp = info.get_modification_date_time();
         
-            BackingPhotoTable.get_instance().update_attributes(editable_id, timestamp.tv_sec,
+            BackingPhotoTable.get_instance().update_attributes(editable_id, timestamp,
                 info.get_size());
             lock (row) {
-                timestamp_changed = editable.timestamp != timestamp.tv_sec;
+                timestamp_changed = !editable.timestamp.equal(timestamp);
                 filesize_changed = editable.filesize != info.get_size();
                 
-                editable.timestamp = timestamp.tv_sec;
+                editable.timestamp = timestamp;
                 editable.filesize = info.get_size();
             }
         } else {
@@ -4057,7 +4101,7 @@ public abstract class Photo : PhotoSource, Dateable {
                         PhotoTable.get_instance().detach_editable(row);
                     backing_photo_row = row.master;
                 }
-            } catch (DatabaseError err) {
+            } catch (Error err) {
                 warning("Unable to remove editable from PhotoTable: %s", err.message);
             }
             
@@ -4976,7 +5020,12 @@ public class LibraryPhoto : Photo, Flaggable, Monitorable {
         this.import_keywords = null;
         
         thumbnail_scheduler = new OneShotScheduler("LibraryPhoto", generate_thumbnails);
-        
+        // import gps coords of photos imported with prior versions of shotwell
+        if (row.gps_coords.has_gps == -1) {
+            var gps_import_scheduler = new OneShotScheduler("LibraryPhoto", import_gps_metadata);
+            gps_import_scheduler.at_priority_idle(Priority.LOW);
+        }
+
         // if marked in a state where they're held in an orphanage, rehydrate their backlinks
         if ((row.flags & (FLAG_TRASH | FLAG_OFFLINE)) != 0)
             rehydrate_backlinks(global, row.backlinks);
@@ -5097,7 +5146,12 @@ public class LibraryPhoto : Photo, Flaggable, Monitorable {
         // fire signal that thumbnails have changed
         notify_thumbnail_altered();
     }
-    
+
+    private void import_gps_metadata() {
+        GpsCoords gps_coords = get_metadata().get_gps_coords();
+        set_gps_coords(gps_coords);
+    }
+
     // These keywords are only used during import and should not be relied upon elsewhere.
     public Gee.Collection<string>? get_import_keywords() {
         return import_keywords;
@@ -5218,7 +5272,7 @@ public class LibraryPhoto : Photo, Flaggable, Monitorable {
                 if (location != null) {
                     face.attach(dupe);
                     FaceLocation.create(face.get_face_id(), dupe.get_photo_id(), 
-                        location.get_serialized_geometry());
+                        location.get_face_data());
                 }
              }
         }
@@ -5332,10 +5386,14 @@ public class LibraryPhoto : Photo, Flaggable, Monitorable {
         
         PhotoMetadata? metadata = get_metadata();
         if (metadata == null)
-            return tags != null || tags.size > 0 || get_rating() != Rating.UNRATED;
+            return tags != null || tags.size > 0 || get_rating() != Rating.UNRATED || get_gps_coords().has_gps != 0;
         
         if (get_rating() != metadata.get_rating())
             return true;
+
+        var old_coords = metadata.get_gps_coords();
+        if (!get_gps_coords().equals(ref old_coords))
+            return true;
         
         Gee.Set<string>? keywords = metadata.get_keywords();
         int tags_count = (tags != null) ? tags.size : 0;
@@ -5366,6 +5424,7 @@ public class LibraryPhoto : Photo, Flaggable, Monitorable {
             metadata.set_keywords(null);
         
         metadata.set_rating(get_rating());
+        metadata.set_gps_coords(get_gps_coords());
     }
     
     protected override void apply_user_metadata_for_reimport(PhotoMetadata metadata) {
diff --git a/src/PhotoPage.vala b/src/PhotoPage.vala
index fd513b2..10ebb10 100644
--- a/src/PhotoPage.vala
+++ b/src/PhotoPage.vala
@@ -759,7 +759,7 @@ public abstract class EditingHostPage : SinglePhotoPage {
             return false;
 
         zoom_about_event_cursor_point(event, ZOOM_INCREMENT_SIZE);
-        return false;
+        return true;
     }
     
     protected override bool on_mousewheel_down(Gdk.EventScroll event) {
@@ -767,7 +767,7 @@ public abstract class EditingHostPage : SinglePhotoPage {
             return false;
         
         zoom_about_event_cursor_point(event, -ZOOM_INCREMENT_SIZE);
-        return false;
+        return true;
     }
 
     protected override void restore_zoom_state() {
@@ -1466,8 +1466,9 @@ public abstract class EditingHostPage : SinglePhotoPage {
             return;
         }
 
-        if (unscaled != null)
+        if (unscaled != null) {
             set_pixbuf(unscaled, max_dim);
+        }
         
         // create the PhotoCanvas object for a two-way interface to the tool
         EditingTools.PhotoCanvas photo_canvas = new EditingHostCanvas(this);
@@ -1528,8 +1529,9 @@ public abstract class EditingHostPage : SinglePhotoPage {
             needs_improvement = true;
         }
         
-        if (replacement != null)
+        if (replacement != null) {
             set_pixbuf(replacement, new_max_dim);
+        }
         cancel_editing_pixbuf = null;
         
         // if this is a rough pixbuf, schedule an improvement
@@ -2458,7 +2460,7 @@ public class LibraryPhotoPage : EditingHostPage {
         base.add_actions (map);
 
         map.add_action_entries (entries, this);
-        (get_action ("ViewRatings") as GLib.SimpleAction).change_state (Config.Facade.get_instance ().get_display_photo_ratings ());
+        ((GLib.SimpleAction) get_action ("ViewRatings")).change_state (Config.Facade.get_instance ().get_display_photo_ratings ());
         var d = Config.Facade.get_instance().get_default_raw_developer();
         var action = new GLib.SimpleAction.stateful("RawDeveloper",
                 GLib.VariantType.STRING, d == RawDeveloper.SHOTWELL ? "Shotwell" : "Camera");
@@ -2888,7 +2890,8 @@ public class LibraryPhotoPage : EditingHostPage {
         Gee.Collection<LibraryPhoto> photos = new Gee.ArrayList<LibraryPhoto>();
         photos.add(photo);
         
-        remove_from_app(photos, _("Remove From Library"), _("Removing Photo From Library"));
+        remove_from_app(photos, GLib.dpgettext2(null, "Dialog Title", "Remove From Library"),
+            GLib.dpgettext2(null, "Dialog Title", "Removing Photo From Library"));
     }
     
     private void on_move_to_trash() {        
@@ -3012,7 +3015,7 @@ public class LibraryPhotoPage : EditingHostPage {
         if (!has_photo())
             return;
         
-        ExportDialog export_dialog = new ExportDialog(_("Export Photo"));
+        ExportDialog export_dialog = new ExportDialog(GLib.dpgettext2(null, "Dialog Title", "Export Photo"));
         
         int scale;
         ScaleConstraint constraint;
@@ -3171,7 +3174,7 @@ public class LibraryPhotoPage : EditingHostPage {
     }
     
     protected override void insert_faces_button(Gtk.Toolbar toolbar) {
-        faces_button = new Gtk.ToggleToolButton.from_stock(Resources.FACES_TOOL);
+        faces_button = new Gtk.ToggleToolButton();
         faces_button.set_icon_name(Resources.ICON_FACES);
         faces_button.set_label(Resources.FACES_LABEL);
         faces_button.set_tooltip_text(Resources.FACES_TOOLTIP);
diff --git a/src/Portal.vala b/src/Portal.vala
deleted file mode 100644
index c2e8e1e..0000000
--- a/src/Portal.vala
+++ /dev/null
@@ -1,71 +0,0 @@
-[DBus (name="org.freedesktop.portal.Email")]
-private interface PortalEmail : DBusProxy {
-    [DBus (name = "version")]
-    public abstract uint version { get; }
-}
-
-public class Portal : GLib.Object {
-    private static Portal portal;
-    public static Portal get_instance () {
-        if (portal == null){
-            portal = new Portal ();
-        }
-        return portal;
-    }
-
-    private const string BUS_NAME = "org.freedesktop.portal.Desktop";
-    private const string OBJECT_PATH = "/org/freedesktop/portal/desktop";
-
-    private GLib.DBusConnection bus;
-
-    public async Variant compose_email (HashTable<string, Variant> options,
-      UnixFDList attachments) throws Error{
-        if (bus == null){
-            bus = yield Bus.get(BusType.SESSION);
-        }
-
-        options.insert ("handle_token", Portal.generate_handle());
-
-        var options_builder = new VariantBuilder (VariantType.VARDICT);
-        options.foreach ((key, val) => {
-            options_builder.add ("{sv}", key, val);
-        });
-
-        PortalEmail? email = yield bus.get_proxy(BUS_NAME, OBJECT_PATH);
-
-        var response = email.call_with_unix_fd_list_sync (
-            "ComposeEmail",
-            new Variant ("(sa{sv})", yield Portal.get_parent_window(), options_builder),
-            DBusCallFlags.NONE,
-            -1,
-            attachments
-        );
-        return response;
-    }
-
-    private static string generate_handle () {
-        return "%s_%i".printf (
-            GLib.Application.get_default ().application_id.replace (".", "_").replace("-", "_"),
-            Random.int_range (0, int32.MAX)
-        );
-    }
-
-    private static async string get_parent_window () {
-        var window = AppWindow.get_instance().get_window ();
-
-        if (window is Gdk.Wayland.Window) {
-            var handle = "wayland:";
-            ((Gdk.Wayland.Window) window).export_handle ((w, h) => {
-                handle += h;
-                get_parent_window.callback ();
-            });
-            yield;
-            return handle;
-        } else if (window is Gdk.X11.Window) {
-            return "x11:%x".printf ((uint) ((Gdk.X11.Window) window).get_xid ());
-        } else {
-            warning ("Could not get parent window");
-            return "";
-        }
-    }
-}
diff --git a/src/Printing.vala b/src/Printing.vala
index 988a456..bef3476 100644
--- a/src/Printing.vala
+++ b/src/Printing.vala
@@ -271,29 +271,29 @@ public class CustomPrintTab : Gtk.Box {
     private const int CENTIMETERS_COMBO_CHOICE = 1;
 
     [GtkChild]
-    private Gtk.RadioButton standard_size_radio;
+    private unowned Gtk.RadioButton standard_size_radio;
     [GtkChild]
-    private Gtk.RadioButton custom_size_radio;
+    private unowned Gtk.RadioButton custom_size_radio;
     [GtkChild]
-    private Gtk.RadioButton image_per_page_radio;
+    private unowned Gtk.RadioButton image_per_page_radio;
     [GtkChild]
-    private Gtk.ComboBoxText image_per_page_combo;
+    private unowned Gtk.ComboBoxText image_per_page_combo;
     [GtkChild]
-    private Gtk.ComboBoxText standard_sizes_combo;
+    private unowned Gtk.ComboBoxText standard_sizes_combo;
     [GtkChild]
-    private Gtk.ComboBoxText units_combo;
+    private unowned Gtk.ComboBoxText units_combo;
     [GtkChild]
-    private Gtk.Entry custom_width_entry;
+    private unowned Gtk.Entry custom_width_entry;
     [GtkChild]
-    private Gtk.Entry custom_height_entry;
+    private unowned Gtk.Entry custom_height_entry;
     [GtkChild]
-    private Gtk.Entry ppi_entry;
+    private unowned Gtk.Entry ppi_entry;
     [GtkChild]
-    private Gtk.CheckButton aspect_ratio_check;
+    private unowned Gtk.CheckButton aspect_ratio_check;
     [GtkChild]
-    private Gtk.CheckButton title_print_check;
+    private unowned Gtk.CheckButton title_print_check;
     [GtkChild]
-    private Gtk.FontButton title_print_font;
+    private unowned Gtk.FontButton title_print_font;
 
     private Measurement local_content_width = Measurement(5.0, MeasurementUnit.INCHES);
     private Measurement local_content_height = Measurement(5.0, MeasurementUnit.INCHES);
@@ -683,7 +683,7 @@ public class CustomPrintTab : Gtk.Box {
     }
 
     private void set_print_titles_font(string fontname) {
-        title_print_font.set_font_name(fontname);
+        ((Gtk.FontChooser) title_print_font).set_font(fontname);
     }
 
 
@@ -696,7 +696,7 @@ public class CustomPrintTab : Gtk.Box {
     }
 
     private string get_print_titles_font() {
-        return title_print_font.get_font_name();
+        return ((Gtk.FontChooser) title_print_font).get_font();
     }
 
     public PrintJob get_source_job() {
diff --git a/src/ProfileBrowser.vala b/src/ProfileBrowser.vala
new file mode 100644
index 0000000..4532a20
--- /dev/null
+++ b/src/ProfileBrowser.vala
@@ -0,0 +1,294 @@
+// SPDX-FileCopyrightText: Jens Georg <mail@jensge.org>
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+namespace Shotwell {
+    class ProfileEditor : Gtk.Dialog {
+        public string profile_name {get; set;}
+        public string id{get; default = Uuid.string_random();}
+        public string library_folder{get; set;}
+        public string data_folder{get; set;}
+
+        public ProfileEditor() {
+            Object(use_header_bar : Resources.use_header_bar());
+        }
+
+        public override void constructed() {
+            base.constructed();
+
+            set_size_request(640, -1);
+
+            add_buttons(_("Create"), Gtk.ResponseType.OK, _("Cancel"), Gtk.ResponseType.CANCEL, null);
+            var create_button = get_widget_for_response(Gtk.ResponseType.OK);
+            create_button.get_style_context().add_class("suggested-action");
+            create_button.sensitive = false;
+            set_title(_("Create new Profile"));
+
+            data_folder = Path.build_filename(Environment.get_user_data_dir(), "shotwell", "profiles", id);
+            library_folder = Environment.get_user_special_dir(UserDirectory.PICTURES);
+
+            var grid = new Gtk.Grid();
+            grid.hexpand = true;
+            grid.vexpand = true;
+            grid.margin = 6;
+            grid.set_row_spacing(12);
+            grid.set_column_spacing(12);
+            var label = new Gtk.Label(_("Name"));
+            label.get_style_context().add_class("dim-label");
+            label.halign = Gtk.Align.END;
+            grid.attach(label, 0, 0, 1, 1);
+
+            var entry = new Gtk.Entry();
+            entry.hexpand = true;
+            entry.bind_property("text", this, "profile-name", GLib.BindingFlags.DEFAULT);
+            entry.bind_property("text", create_button, "sensitive", GLib.BindingFlags.DEFAULT, (binding, from, ref to) => {
+                to = from.get_string() != "";
+                return true;
+            });
+            grid.attach(entry, 1, 0, 2, 1);
+
+            label = new Gtk.Label(_("Library Folder"));
+            label.get_style_context().add_class("dim-label");
+            label.halign = Gtk.Align.END;
+            grid.attach(label, 0, 1, 1, 1);
+
+            entry = new Gtk.Entry();
+            entry.hexpand = true;
+            grid.attach(entry, 1, 1, 1, 1);
+            bind_property("library-folder", entry, "text", GLib.BindingFlags.SYNC_CREATE | GLib.BindingFlags.BIDIRECTIONAL);
+            entry.bind_property("text", create_button, "sensitive", GLib.BindingFlags.DEFAULT, (binding, from, ref to) => {
+                to = from.get_string() != "";
+                return true;
+            });
+
+            var button = new Gtk.Button.from_icon_name("folder-symbolic", Gtk.IconSize.BUTTON);
+            button.hexpand = false;
+            button.vexpand = false;
+            button.halign = Gtk.Align.FILL;
+            button.clicked.connect(() => {
+                var dialog = new Gtk.FileChooserNative(_("Choose Library Folder"), this, Gtk.FileChooserAction.SELECT_FOLDER, _("_OK"), _("_Cancel"));
+                dialog.set_current_folder(library_folder);
+                var result = dialog.run();
+                dialog.hide();
+                if (result == Gtk.ResponseType.ACCEPT) {
+                    library_folder = dialog.get_current_folder_file().get_path();
+                }
+                dialog.destroy();
+            });
+            grid.attach(button, 2, 1, 1, 1);
+
+
+            label = new Gtk.Label(_("Data Folder"));
+            label.get_style_context().add_class("dim-label");
+            label.halign = Gtk.Align.END;
+            grid.attach(label, 0, 2, 1, 1);
+
+            entry = new Gtk.Entry();
+            entry.set_text(Environment.get_user_special_dir(UserDirectory.PICTURES));
+            entry.hexpand = true;
+            bind_property("data-folder", entry, "text", GLib.BindingFlags.SYNC_CREATE | GLib.BindingFlags.BIDIRECTIONAL);
+            entry.bind_property("text", create_button, "sensitive", GLib.BindingFlags.DEFAULT, (binding, from, ref to) => {
+                to = from.get_string() != "";
+                return true;
+            });
+            grid.attach(entry, 1, 2, 1, 1);
+
+            button = new Gtk.Button.from_icon_name("folder-symbolic", Gtk.IconSize.BUTTON);
+            button.hexpand = false;
+            button.vexpand = false;
+            button.halign = Gtk.Align.FILL;
+            button.clicked.connect(() => {
+                var dialog = new Gtk.FileChooserNative(_("Choose Data Folder"), this, Gtk.FileChooserAction.SELECT_FOLDER, _("_OK"), _("_Cancel"));
+                dialog.set_current_folder(data_folder);
+                var result = dialog.run();
+                dialog.hide();
+                if (result == Gtk.ResponseType.ACCEPT) {
+                    data_folder = dialog.get_current_folder_file().get_path();
+                }
+                dialog.destroy();
+            });
+
+            grid.attach(button, 2, 2, 1, 1);
+
+            get_content_area().add(grid);
+
+            show_all();
+        }
+    }
+
+    private class ProfileRow : Gtk.Box {
+        public Profile profile{get; construct; }
+
+        public ProfileRow(Profile profile) {
+            Object(orientation: Gtk.Orientation.VERTICAL,
+                profile: profile, margin_top: 6, margin_bottom:6, margin_start:6, margin_end:6);
+        }
+    
+        public override void constructed() {
+            base.constructed();
+            var content = new Gtk.Box(Gtk.Orientation.HORIZONTAL, 6);
+            pack_start(content, true);
+    
+            var revealer = new Gtk.Revealer();
+            revealer.margin_top = 6;
+            pack_end(revealer, true);
+                
+            var label = new Gtk.Label(null);
+            label.set_markup("<span weight=\"bold\">%s</span>".printf(profile.name));
+            label.halign = Gtk.Align.START;
+            content.pack_start(label, true, true, 6);
+
+            Gtk.Image image;
+            if (profile.active) {
+                image = new Gtk.Image.from_icon_name ("emblem-default-symbolic", Gtk.IconSize.SMALL_TOOLBAR);
+                image.set_tooltip_text(_("This is the currently active profile"));
+
+            } else {
+                image = new Gtk.Image();
+            }
+            content.pack_start(image, false, false, 6);
+
+            var button = new Gtk.ToggleButton();
+            button.get_style_context().add_class("flat");
+            content.pack_start(button, false, false, 6);
+            button.bind_property("active", revealer, "reveal-child", BindingFlags.DEFAULT);
+            image = new Gtk.Image.from_icon_name("go-down-symbolic", Gtk.IconSize.SMALL_TOOLBAR);
+            button.add(image);
+
+            // FIXME: Would love to use the facade here, but this is currently hardwired to use a fixed profile
+            // and that even is not yet initialized
+            string settings_path;
+            if (profile.id == Profile.SYSTEM) {
+                settings_path = "/org/gnome/shotwell/preferences/files/";
+            } else {
+                settings_path = "/org/gnome/shotwell/profiles/" + profile.id + "/preferences/files/";
+            }
+
+            var settings = new Settings.with_path("org.gnome.shotwell.preferences.files", settings_path);
+            var import_dir = settings.get_string("import-dir");
+            if (import_dir == "") {
+                import_dir = Environment.get_user_special_dir(UserDirectory.PICTURES);
+            }
+
+            var grid = new Gtk.Grid();
+            grid.get_style_context().add_class("content");
+            grid.set_row_spacing(12);
+            grid.set_column_spacing(6);
+            revealer.add(grid);
+            label = new Gtk.Label(_("Library Folder"));
+            label.get_style_context().add_class("dim-label");
+            label.halign = Gtk.Align.END;
+            label.margin_start = 12;
+            grid.attach(label, 0, 0, 1, 1);
+            label = new Gtk.Label(import_dir);
+            label.halign = Gtk.Align.START;
+            label.set_ellipsize(Pango.EllipsizeMode.END);
+            grid.attach(label, 1, 0, 1, 1);
+    
+            label = new Gtk.Label(_("Data Folder"));
+            label.get_style_context().add_class("dim-label");
+            label.halign = Gtk.Align.END;
+            label.margin_start = 12;
+            grid.attach(label, 0, 1, 1, 1);
+            label = new Gtk.Label(profile.data_dir);
+            label.halign = Gtk.Align.START;
+            label.hexpand = true;
+            label.set_ellipsize(Pango.EllipsizeMode.END);
+            grid.attach(label, 1, 1, 1, 1);
+            
+            if (profile.id != Profile.SYSTEM && !profile.active) {
+                var remove_button = new Gtk.Button.with_label(_("Remove Profile"));
+                remove_button.get_style_context().add_class("destructive-action");
+                remove_button.set_tooltip_text(_("Remove this profile"));
+                remove_button.hexpand = false;
+                remove_button.halign = Gtk.Align.END;
+                grid.attach(remove_button, 1, 2, 1, 1);
+
+                remove_button.clicked.connect(() => {
+                    var flags = Gtk.DialogFlags.DESTROY_WITH_PARENT | Gtk.DialogFlags.MODAL;
+                    if (Resources.use_header_bar() == 1) {
+                        flags |= Gtk.DialogFlags.USE_HEADER_BAR;
+                    }
+
+                    var d = new Gtk.MessageDialog((Gtk.Window) this.get_toplevel(), flags, Gtk.MessageType.QUESTION, Gtk.ButtonsType.NONE, null);
+                    var title = _("Remove profile “%s”").printf(profile.name);
+                    var subtitle = _("None of the options will remove any of the images associated with this profile");
+                    d.set_markup(_("<b><span size=\"larger\">%s</span></b>\n<span weight=\"light\">%s</span>").printf(title, subtitle));
+
+                    d.add_buttons(_("Remove profile and files"), Gtk.ResponseType.OK, _("Remove profile only"), Gtk.ResponseType.ACCEPT, _("Cancel"), Gtk.ResponseType.CANCEL);
+                    d.get_widget_for_response(Gtk.ResponseType.OK).get_style_context().add_class("destructive-action");
+                    var response = d.run();
+                    d.destroy();
+                    if (response == Gtk.ResponseType.OK || response == Gtk.ResponseType.ACCEPT) {
+                        ProfileManager.get_instance().remove(profile.id, response == Gtk.ResponseType.OK);
+                    }
+                });
+            }
+        }
+    }
+
+    class ProfileBrowser : Gtk.Box {
+        public ProfileBrowser() {
+            Object(orientation: Gtk.Orientation.VERTICAL, vexpand: true, hexpand: true);
+        }
+
+        public signal void profile_activated(string? profile);
+
+        public override void constructed() {
+            var scrollable = new Gtk.ScrolledWindow(null, null);
+            scrollable.hexpand = true;
+            scrollable.vexpand = true;
+
+            var list_box = new Gtk.ListBox();
+            list_box.activate_on_single_click = false;
+            list_box.row_activated.connect((list_box, row) => {
+                var index = row.get_index();
+                var profile = (Profile) ProfileManager.get_instance().get_item(index);
+                if (profile.id == Profile.SYSTEM) {
+                    profile_activated(null);
+                } else {
+                    profile_activated(profile.name);
+                }
+            });
+            list_box.get_style_context().add_class("rich-list");
+            list_box.hexpand = true;
+            list_box.vexpand = true;
+            scrollable.add (list_box);
+            list_box.bind_model(ProfileManager.get_instance(), on_widget_create);
+            list_box.set_header_func(on_header);
+
+            var button = new Gtk.Button.with_label(_("Create new Profile"));
+            pack_start(button, false, false, 6);
+            button.clicked.connect(() => {
+                var editor = new ProfileEditor();
+                editor.set_transient_for((Gtk.Window)get_ancestor(typeof(Gtk.Window)));
+                var result = editor.run();
+                editor.hide();
+                if (result == Gtk.ResponseType.OK) {
+                    debug("Request to add new profile: %s %s %s %s", editor.id, editor.profile_name, editor.library_folder, editor.data_folder);
+                    ProfileManager.get_instance().add_profile(editor.id, editor.profile_name, editor.library_folder, editor.data_folder);
+                }
+                editor.destroy();
+            });
+            add(scrollable);
+            show_all();
+        }
+
+        private Gtk.Widget on_widget_create(Object item) {
+            var row = new Gtk.ListBoxRow();
+            row.add(new ProfileRow((Profile) item));
+            row.show_all();
+
+            return row;
+        }
+
+        private void on_header(Gtk.ListBoxRow row, Gtk.ListBoxRow? before) {
+            if (before == null || row.get_header() != null) {
+                return;
+            }
+
+            var separator = new Gtk.Separator(Gtk.Orientation.HORIZONTAL);
+            separator.show();
+            row.set_header(separator);
+        }
+    }
+}
diff --git a/src/Profiles.vala b/src/Profiles.vala
new file mode 100644
index 0000000..ec52800
--- /dev/null
+++ b/src/Profiles.vala
@@ -0,0 +1,303 @@
+/* Copyright 2019 Jens Georg.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+namespace Shotwell {
+    class Profile : Object {
+        public const string SYSTEM = "__shotwell_default_system";
+        public Profile(string name, string id, string data_dir, bool active) {
+            Object(name: name, id: id, data_dir: data_dir, active: active);
+        }
+        public string name {get; construct;}
+        public string id {get; construct;}
+        public string data_dir {get; construct;}
+        public bool active {get; construct;}
+    }
+
+    class ProfileManager : Object, GLib.ListModel {
+        // ListModel implementations
+        Type get_item_type() {
+            return typeof(Profile);
+        }
+
+        uint get_n_items() {
+            // All that is in the ini file plus one for the default profile
+            return profiles.get_groups().length + 1;
+        }
+
+        GLib.Object? get_item (uint position) {
+            if (position == 0) {
+                return new Profile(_("System Profile"), Profile.SYSTEM,
+                            Path.build_path(Path.DIR_SEPARATOR_S, Environment.get_user_data_dir(), "shotwell"),
+                            this.profile == null);
+            }
+
+            try {
+                var group = profiles.get_groups()[position - 1];
+                var id = profiles.get_value(group, "Id");
+                var name = profiles.get_value(group, "Name");
+                var active = this.profile == name;
+                return new Profile(profiles.get_value(group, "Name"),
+                                id,
+                                get_data_dir_for_profile(id, group),
+                                active);
+            } catch (KeyFileError err) {
+                if (err is KeyFileError.GROUP_NOT_FOUND) {
+                    assert_not_reached();
+                }
+
+                warning("Profile configuration file corrupt: %s", err.message);
+            }
+
+            return null;
+        }
+
+        private static ProfileManager instance;
+        public static ProfileManager get_instance() {
+            if (instance == null)
+                instance = new ProfileManager();
+
+            return instance;
+        }
+
+        private ProfileManager() {
+            Object();
+        }
+
+        private void write() {
+            try {
+                profiles.save_to_file(path);
+            } catch (Error error) {
+                critical("Failed to write profiles: %s", error.message);
+            }
+        }
+
+        private KeyFile profiles;
+        private string profile = null;
+        private string path;
+        private string group_name;
+
+        public override void constructed() {
+            base.constructed();
+
+            profiles = new KeyFile();
+            path = Path.build_filename(Environment.get_user_config_dir(), "shotwell");
+            DirUtils.create_with_parents(path, 0700);
+            path = Path.build_filename(path, "profiles.ini");
+
+            try {
+                profiles.load_from_file(path, KeyFileFlags.KEEP_COMMENTS);
+            } catch (Error error) {
+                debug("Could not read profiles: %s", error.message);
+            }
+        }
+
+        public bool has_profile (string profile, out string group_name = null) {
+            group_name = Base64.encode (profile.data);
+            return profiles.has_group(group_name);
+        }
+
+        public void set_profile(string profile) {
+            message("Using profile %s for this session", profile);
+            assert(this.profile == null);
+
+            this.profile = profile;
+
+            add_profile(Uuid.string_random(), profile, null, null);
+        }
+
+        public void add_profile(string id, string name, string? library_folder, string? data_folder) {
+            if (has_profile(name, out this.group_name)) {
+                return;
+            }
+
+            try {
+                profiles.set_string(group_name, "Name", name);
+                profiles.set_string(group_name, "Id", id);
+                if (data_folder != null) {
+                    profiles.set_string(group_name, "DataDir", data_folder);
+                }
+
+                // Need to set comment after setting keys since it does not create the group
+                profiles.set_comment(group_name, null, "Profile settings for \"%s\"".printf(name));
+
+                write();
+            } catch (Error err) {
+                error("Failed to create profile: %s", err.message);                
+            }
+
+            if (library_folder != null) {
+                errno = 0;
+                var f = File.new_for_commandline_arg(library_folder);
+                try {
+                    f.make_directory_with_parents();
+                } catch (Error err) {
+                    warning ("Failed to create library folder: %s", err.message);
+                }
+                var settings_path = "/org/gnome/shotwell/profiles/" + id + "/preferences/files/";
+
+    
+                var settings = new Settings.with_path("org.gnome.shotwell.preferences.files", settings_path);
+                settings.set_string("import-dir", library_folder);
+            }
+            
+            items_changed(profiles.get_groups().length, 0, 1);
+        }
+
+        public string derive_data_dir(string? data_dir) {
+            if (data_dir != null) {
+                debug ("Using user-provided data dir %s", data_dir);
+
+                try {
+                    profiles.get_string(group_name, "DataDir");
+                } catch (Error error) {
+                    if (profile != null && profile != "") {
+                        profiles.set_string(group_name ,"DataDir", data_dir);
+                        debug("Using %s as data dir for profile %s", data_dir, profile);
+                        write();
+                    }
+                }
+
+                return data_dir;
+            }
+
+            return Path.build_filename(Environment.get_user_data_dir(), "shotwell", "profiles", id());
+        }
+
+        public string id() {
+            // We are not running on any profile
+            if (profile == null || profile == "")
+                return "";
+
+            try {
+                return profiles.get_string(group_name, "Id");
+            } catch (Error error) {
+                assert_not_reached();
+            }
+        }
+
+        private string get_data_dir_for_profile(string id, string group) throws KeyFileError {
+            if ("DataDir" in profiles.get_keys(group)) {
+                return profiles.get_value(group, "DataDir");
+            } else {
+                return Path.build_filename(Environment.get_user_data_dir(), "shotwell", "profiles", id);
+            }
+        }
+
+        public void print_profiles() {
+            print("Available profiles:\n");
+            print("-------------------\n");
+            try {
+                foreach (var group in profiles.get_groups()) {
+                    print("Profile name: %s\n", profiles.get_value(group, "Name"));
+                    var id = profiles.get_value(group, "Id");
+                    print("Profile Id: %s\n", id);
+                    print("Data dir: %s\n", get_data_dir_for_profile(id, group));
+                    print("\n");
+                }
+            } catch (Error error) {
+                print("Failed to print profiles: %s", error.message);
+            }
+        }
+
+        const string SCHEMAS[] = {
+            "sharing",
+            "printing",
+            "plugins.enable-state",
+            "preferences.ui",
+            "preferences.slideshow",
+            "preferences.window",
+            "preferences.files",
+            "preferences.editing",
+            "preferences.export",        
+        };
+
+        void reset_all_keys(Settings settings) {
+            SettingsSchema schema;
+            ((Object)settings).get("settings-schema", out schema, null);
+        
+            foreach (var key in schema.list_keys()) {
+                debug("Resetting key %s", key);
+                settings.reset(key);
+            }
+        
+            foreach (var c in settings.list_children()) {
+                debug("Checking children %s", c);
+                var child = settings.get_child (c);
+                reset_all_keys (child);
+            }
+        }
+        
+        private void remove_settings_recursively(string id) {
+            var source = SettingsSchemaSource.get_default();
+            foreach (var schema in SCHEMAS) {
+                var path = "/org/gnome/shotwell/profiles/%s/%s/".printf(id, schema.replace(".", "/"));
+                var schema_name = "org.gnome.shotwell.%s".printf(schema);
+                debug("%s @ %s", schema_name, path);
+                var schema_definition = source.lookup(schema_name, false);
+                var settings = new Settings.full (schema_definition, null, path);
+                settings.delay();
+                reset_all_keys (settings);
+                foreach (var key in schema_definition.list_keys()) {
+                    debug("Resetting key %s", key);
+                    settings.reset(key);
+                }
+                settings.apply();
+                Settings.sync();
+            }        
+        }
+
+        public void remove(string id, bool remove_all) {
+            debug("Request to remove profile %s, with files? %s", id, remove_all.to_string());
+            int index = 1;
+            string group = null;
+
+            foreach (var g in profiles.get_groups()) {
+                try {
+                    if (profiles.get_value(g, "Id") == id) {
+                        group = g;
+                        break;
+                    }
+                    index++;
+                } catch (KeyFileError error) {
+                    assert_not_reached();
+                }
+            }
+
+            if (group != null) {
+                string? data_dir = null;
+
+                try {
+                    data_dir = get_data_dir_for_profile(id, group);
+                    // Remove profile
+                    string? key = null;
+                    profiles.remove_comment(group, key);
+                    profiles.remove_group(group);
+                } catch (KeyFileError err) {
+                    // We checked the existence of the group above.
+                    assert_not_reached();
+                }
+
+                remove_settings_recursively(id);
+
+                if (remove_all) {
+                    try {
+                        var file = File.new_for_commandline_arg(data_dir);
+                        file.trash();
+                    } catch (Error error) {
+                        warning("Failed to remove data folder: %s", error.message);
+                    }
+                }
+
+                Idle.add(() => {
+                    items_changed(index, 1, 0);
+
+                    return false;
+                });
+                write();
+            }
+        }
+    }
+}
diff --git a/src/Properties.vala b/src/Properties.vala
index ad0a041..c0cf2fd 100644
--- a/src/Properties.vala
+++ b/src/Properties.vala
@@ -4,12 +4,16 @@
  * See the COPYING file in this distribution.
  */
 
-private abstract class Properties : Gtk.Grid {
-    uint line_count = 0;
+private abstract class Properties : Gtk.Box {
+    protected Gtk.Grid grid = new Gtk.Grid();
+    protected uint line_count = 0;
 
     protected Properties() {
-        row_spacing = 6;
-        column_spacing = 12;
+        Object(orientation: Gtk.Orientation.VERTICAL, homogeneous : false);
+
+        grid.row_spacing = 6;
+        grid.column_spacing = 12;
+        pack_start(grid, false, false, 0);
     }
 
     protected void add_line(string label_text, string info_text, bool multi_line = false, string? href = null) {
@@ -62,18 +66,18 @@ private abstract class Properties : Gtk.Grid {
             info = (Gtk.Widget) info_label;
         }
 
-        attach(label, 0, (int) line_count, 1, 1);
+        grid.attach(label, 0, (int) line_count, 1, 1);
 
         if (multi_line) {
-            attach(info, 1, (int) line_count, 1, 3);
+            grid.attach(info, 1, (int) line_count, 1, 3);
         } else {
-            attach(info, 1, (int) line_count, 1, 1);
+            grid.attach(info, 1, (int) line_count, 1, 1);
         }
 
         line_count++;
     }
     
-    protected string get_prettyprint_time(Time time) {
+    protected string get_prettyprint_time(DateTime time) {
         string timestring = time.format(Resources.get_hh_mm_format_string());
         
         if (timestring[0] == '0')
@@ -82,7 +86,7 @@ private abstract class Properties : Gtk.Grid {
         return timestring;
     }
     
-    protected string get_prettyprint_time_with_seconds(Time time) {
+    protected string get_prettyprint_time_with_seconds(DateTime time) {
         string timestring = time.format(Resources.get_hh_mm_ss_format_string());
         
         if (timestring[0] == '0')
@@ -91,12 +95,12 @@ private abstract class Properties : Gtk.Grid {
         return timestring;
     }
     
-    protected string get_prettyprint_date(Time date) {
+    protected string get_prettyprint_date(DateTime date) {
         string date_string = null;
-        Time today = Time.local(time_t());
-        if (date.day_of_year == today.day_of_year && date.year == today.year) {
+        var today = new DateTime.now_local();
+        if (date.get_day_of_year() == today.get_day_of_year() && date.get_year() == today.get_year()) {
             date_string = _("Today");
-        } else if (date.day_of_year == (today.day_of_year - 1) && date.year == today.year) {
+        } else if (date.get_day_of_year() == (today.get_day_of_year() - 1) && date.get_year() == today.get_year()) {
             date_string = _("Yesterday");
         } else {
             date_string = format_local_date(date);
@@ -140,9 +144,9 @@ private abstract class Properties : Gtk.Grid {
     }
 
     protected virtual void clear_properties() {
-        foreach (Gtk.Widget child in get_children())
-            remove(child);
-        
+        foreach (Gtk.Widget child in grid.get_children())
+            grid.remove(child);
+
         line_count = 0;
     }
 
@@ -159,8 +163,8 @@ private abstract class Properties : Gtk.Grid {
 
 private class BasicProperties : Properties {
     private string title;
-    private time_t start_time = time_t();
-    private time_t end_time = time_t();
+    private DateTime? start_time = new DateTime.now_utc();
+    private DateTime? end_time = new DateTime.now_utc();
     private Dimensions dimensions;
     private int photo_count;
     private int event_count;
@@ -173,13 +177,14 @@ private class BasicProperties : Properties {
     private string raw_assoc;
 
     public BasicProperties() {
+        base();
     }
 
     protected override void clear_properties() {
         base.clear_properties();
         title = "";
-        start_time = 0;
-        end_time = 0;
+        start_time = null;
+        end_time = null;
         dimensions = Dimensions(0,0);
         photo_count = -1;
         event_count = -1;
@@ -269,20 +274,20 @@ private class BasicProperties : Properties {
         video_count = 0;
         foreach (DataView view in iter) {
             DataSource source = view.get_source();
-            
-            if (source is PhotoSource || source is PhotoImportSource) {                  
-                time_t exposure_time = (source is PhotoSource) ?
+
+            if (source is PhotoSource || source is PhotoImportSource) {
+                var exposure_time = (source is PhotoSource) ?
                     ((PhotoSource) source).get_exposure_time() :
                     ((PhotoImportSource) source).get_exposure_time();
 
-                if (exposure_time != 0) {
-                    if (start_time == 0 || exposure_time < start_time)
+                if (exposure_time != null) {
+                    if (start_time == null || exposure_time.compare(start_time) < 0)
                         start_time = exposure_time;
 
-                    if (end_time == 0 || exposure_time > end_time)
+                    if (end_time == null || exposure_time.compare(end_time) > 0)
                         end_time = exposure_time;
                 }
-                
+
                 photo_count++;
             } else if (source is EventSource) {
                 EventSource event_source = (EventSource) source;
@@ -290,14 +295,14 @@ private class BasicProperties : Properties {
                 if (event_count == -1)
                     event_count = 0;
 
-                if ((start_time == 0 || event_source.get_start_time() < start_time) &&
-                    event_source.get_start_time() != 0 ) {
+                if ((start_time == null || event_source.get_start_time().compare(start_time) < 0) &&
+                    event_source.get_start_time() != null ) {
                     start_time = event_source.get_start_time();
                 }
-                if ((end_time == 0 || event_source.get_end_time() > end_time) &&
-                    event_source.get_end_time() != 0 ) {
+                if ((end_time == null || event_source.get_end_time().compare(end_time) > 0) &&
+                    event_source.get_end_time() != null ) {
                     end_time = event_source.get_end_time();
-                } else if (end_time == 0 || event_source.get_start_time() > end_time) {
+                } else if (end_time == null || event_source.get_start_time().compare(end_time) > 0) {
                     end_time = event_source.get_start_time();
                 }
 
@@ -310,15 +315,15 @@ private class BasicProperties : Properties {
                 video_count += event_video_count;
                 event_count++;
             } else if (source is VideoSource || source is VideoImportSource) {
-                time_t exposure_time = (source is VideoSource) ?
+                var exposure_time = (source is VideoSource) ?
                     ((VideoSource) source).get_exposure_time() :
                     ((VideoImportSource) source).get_exposure_time();
 
-                if (exposure_time != 0) {
-                    if (start_time == 0 || exposure_time < start_time)
+                if (exposure_time != null) {
+                    if (start_time == null || exposure_time.compare(start_time) < 0)
                         start_time = exposure_time;
 
-                    if (end_time == 0 || exposure_time > end_time)
+                    if (end_time == null || exposure_time.compare(end_time) > 0)
                         end_time = exposure_time;
                 }
 
@@ -330,9 +335,9 @@ private class BasicProperties : Properties {
     protected override void get_properties(Page current_page) {
         base.get_properties(current_page);
 
-        if (end_time == 0)
+        if (end_time == null)
             end_time = start_time;
-        if (start_time == 0)
+        if (start_time == null)
             start_time = end_time;
     }
 
@@ -373,11 +378,11 @@ private class BasicProperties : Properties {
                 add_line("", video_num_string);
         }
 
-        if (start_time != 0) {
-            string start_date = get_prettyprint_date(Time.local(start_time));
-            string start_time = get_prettyprint_time(Time.local(start_time));
-            string end_date = get_prettyprint_date(Time.local(end_time));
-            string end_time = get_prettyprint_time(Time.local(end_time));
+        if (start_time != null) {
+            string start_date = get_prettyprint_date(start_time.to_local());
+            string start_time = get_prettyprint_time(start_time.to_local());
+            string end_date = get_prettyprint_date(end_time.to_local());
+            string end_time = get_prettyprint_time(end_time.to_local());
 
             if (start_date == end_date) {
                 // display only one date if start and end are the same
@@ -485,7 +490,7 @@ private class ExtendedProperties : Properties {
 
     public ExtendedProperties() {
         base();
-        row_spacing = 6;
+        grid.row_spacing = 6;
     }
 
     // Event stuff
@@ -574,9 +579,9 @@ private class ExtendedProperties : Properties {
             copyright = metadata.get_copyright();
             software = metadata.get_software();
             exposure_bias = metadata.get_exposure_bias();
-            time_t exposure_time_obj = metadata.get_exposure_date_time().get_timestamp();
-            exposure_date = get_prettyprint_date(Time.local(exposure_time_obj));
-            exposure_time = get_prettyprint_time_with_seconds(Time.local(exposure_time_obj));
+            DateTime exposure_time_obj = metadata.get_exposure_date_time().get_timestamp();
+            exposure_date = get_prettyprint_date(exposure_time_obj.to_local());
+            exposure_time = get_prettyprint_time_with_seconds(exposure_time_obj.to_local());
             comment = media.get_comment();
         } else if (source is EventSource) {
             Event event = (Event) source;
@@ -634,7 +639,7 @@ private class ExtendedProperties : Properties {
             add_line(_("GPS longitude:"), (gps_long != -1 && gps_long_ref != "" &&
                 gps_long_ref != null) ? "%f °%s".printf(gps_long, gps_long_ref) : NO_VALUE, false, osm_link);
 
-            add_line(_("Artist:"), (artist != "" && artist != null) ? artist : NO_VALUE);
+            add_line(_("Artist:"), (artist != "" && artist != null) ? Markup.escape_text(artist) : NO_VALUE);
 
             add_line(_("Copyright:"), (copyright != "" && copyright != null) ? copyright : NO_VALUE);
 
diff --git a/src/Resources.vala b/src/Resources.vala
index b65ec52..d03a214 100644
--- a/src/Resources.vala
+++ b/src/Resources.vala
@@ -24,6 +24,7 @@ namespace Resources {
     private const string LIBEXECDIR = _LIBEXECDIR;
 
     public const string PREFIX = _PREFIX;
+    public const string PIXBUF_LOADER_PATH = _PIXBUF_LOADER_PATH;
 
     public const double TRANSIENT_WINDOW_OPACITY = 0.90;
     
@@ -69,12 +70,20 @@ along with Shotwell; if not, write to the Free Software Foundation, Inc.,
     public const string GO_NEXT = "go-next-symbolic";
     public const string GO_PREVIOUS = "go-previous-symbolic";
 
-    public const string ICON_ABOUT_LOGO = "about-celle.jpg";
+    public const string ICON_ABOUT_LOGO = "Delmenhorst_Rathaus.jpg";
     public const string ICON_GENERIC_PLUGIN = "application-x-addon-symbolic";
     public const string ICON_SLIDESHOW_EXTENSION_POINT = "slideshow-extension-point";
     public const int ICON_FILTER_REJECTED_OR_BETTER_FIXED_SIZE = 32;
     public const int ICON_FILTER_UNRATED_OR_BETTER_FIXED_SIZE = 16;
     public const int ICON_ZOOM_SCALE = 16;
+    public const string ICON_GPS_MARKER = "gps-marker";
+    public const string ICON_GPS_MARKER_HIGHLIGHTED = "gps-marker-highlighted";
+    public const string ICON_GPS_MARKER_SELECTED = "gps-marker-selected";
+    public const string ICON_GPS_GROUP_MARKER = "gps-markers-many";
+    public const string ICON_GPS_GROUP_MARKER_HIGHLIGHTED = "gps-markers-many-highlighted";
+    public const string ICON_GPS_GROUP_MARKER_SELECTED = "gps-markers-many-selected";
+    public const string ICON_MAP_EDIT_LOCKED = "map-edit-locked";
+    public const string ICON_MAP_EDIT_UNLOCKED = "map-edit-unlocked";
 
     public const string ICON_CAMERAS = "camera-photo-symbolic";
     public const string ICON_EVENTS = "multiple-events-symbolic";
@@ -403,6 +412,20 @@ along with Shotwell; if not, write to the Free Software Foundation, Inc.,
         return ngettext ("Remove Face “%s” From Photo",
                          "Remove Face “%s” From Photos", count).printf(name);
     }
+
+    public string set_face_from_photo_menu(string name) {
+        /* Translators: This means to teach the face to the face recognition system */
+        return _("_Train Face “%s” From Photo").printf(name);
+    }
+    
+    public string set_face_from_photo_label(string name) {
+        /* Translators: This means to teach the face to the face recognition system */
+        return _("_Train Face “%s” From Photo").printf(name);
+    }
+
+    public static string set_face_from_photo_error() {
+        return "Unable to set face as reference";
+    }
     
     public string rename_face_menu(string name) {
         return _("Re_name Face “%s”…").printf(name);
@@ -777,7 +800,8 @@ along with Shotwell; if not, write to the Free Software Foundation, Inc.,
     private string END_MULTIMONTH_DATE_FORMAT_STRING = null;
 
     public void init () {
-        get_icon_theme_engine();
+        init_icon_theme_engine();
+        init_css_provider();
         // load application-wide stock icons as IconSets
         generate_rating_strings();
     }
@@ -969,12 +993,21 @@ along with Shotwell; if not, write to the Free Software Foundation, Inc.,
         
         return noninterpretable_badge_pixbuf;
     }
+
+    private void init_css_provider() {
+        Gtk.CssProvider provider = new Gtk.CssProvider();
+        provider.load_from_resource("/org/gnome/Shotwell/themes/org.gnome.Shotwell.css");
+        Gtk.StyleContext.add_provider_for_screen(Gdk.Screen.get_default(), provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
+    }
     
-    public Gtk.IconTheme get_icon_theme_engine() {
+    private void init_icon_theme_engine() {
         Gtk.IconTheme icon_theme = Gtk.IconTheme.get_default();
         icon_theme.add_resource_path("/org/gnome/Shotwell/icons");
-        
-        return icon_theme;
+        icon_theme.add_resource_path("/org/gnome/Shotwell/icons/hicolor");
+        icon_theme.add_resource_path("/org/gnome/Shotwell/Publishing/icons");
+        icon_theme.add_resource_path("/org/gnome/Shotwell/Publishing/icons/hicolor");
+        icon_theme.add_resource_path("/org/gnome/Shotwell/Transitions/icons");
+        icon_theme.add_resource_path("/org/gnome/Shotwell/Transitions/icons/hicolor");
     }
     
     // This method returns a reference to a cached pixbuf that may be shared throughout the system.
@@ -1038,7 +1071,7 @@ along with Shotwell; if not, write to the Free Software Foundation, Inc.,
 
         return (scale > 0) ? scale_pixbuf(pixbuf, scale, Gdk.InterpType.BILINEAR, false) : pixbuf;
     }
-    
+
     // Get the directory where our help files live.  Returns a string
     // describing the help path we want, or, if we're installed system
     // -wide already, returns null.
diff --git a/src/SearchFilter.vala b/src/SearchFilter.vala
index ad8b7ec..969591f 100644
--- a/src/SearchFilter.vala
+++ b/src/SearchFilter.vala
@@ -148,7 +148,7 @@ public abstract class SearchViewFilter : ViewFilter {
     }
     
     public void set_search_filter(string? text) {
-        search_filter = !is_string_empty(text) ? text.down() : null;
+        search_filter = !is_string_empty(text) ? String.remove_diacritics(text.down()) : null;
         search_filter_words = search_filter != null ? search_filter.split(" ") : null;
     }
     
@@ -775,12 +775,13 @@ public class SearchFilterToolbar : Gtk.Revealer {
 
             switch (filter) {
                 case RatingFilter.REJECTED_OR_HIGHER:
-                    icon = new Gtk.Box(Gtk.Orientation.HORIZONTAL, 0);
+                    var box = new Gtk.Box(Gtk.Orientation.HORIZONTAL, 0);
                     var image = new Gtk.Image.from_icon_name ("emblem-photos-symbolic", Gtk.IconSize.SMALL_TOOLBAR);
                     image.margin_end = 2;
-                    (icon as Gtk.Box).pack_start(image);
+                    box.pack_start(image);
                     image = new Gtk.Image.from_icon_name ("window-close-symbolic", Gtk.IconSize.SMALL_TOOLBAR);
-                    (icon as Gtk.Box).pack_start(image);
+                    box.pack_start(image);
+                    icon = box;
                     icon.show_all();
                 break;
                 
@@ -1015,7 +1016,8 @@ public class SearchFilterToolbar : Gtk.Revealer {
         }
 
         private SavedSearch get_search(Gtk.ListBoxRow row) {
-            DataButton button = (row.get_children().first().data as Gtk.Box).get_children().last().data as DataButton;
+            var box = (Gtk.Box) row.get_children().first().data;
+            DataButton button = box.get_children().last().data as DataButton;
             return button.search;
         }
 
@@ -1191,7 +1193,7 @@ public class SearchFilterToolbar : Gtk.Revealer {
         bool has_flagged) {
         if (has_photos || has_raw)
             // As a user, I would expect, that a raw photo is still a photo.
-            // Let's enable the photo button even if there ar only raw photos.
+            // Let's enable the photo button even if there are only raw photos.
             toolbtn_photos.set_icon_name("filter-photos-symbolic");
         else
             toolbtn_photos.set_icon_name("filter-photos-disabled-symbolic");
diff --git a/src/SinglePhotoPage.vala b/src/SinglePhotoPage.vala
new file mode 100644
index 0000000..754a649
--- /dev/null
+++ b/src/SinglePhotoPage.vala
@@ -0,0 +1,537 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+public abstract class SinglePhotoPage : Page {
+    public const Gdk.InterpType FAST_INTERP = Gdk.InterpType.NEAREST;
+    public const Gdk.InterpType QUALITY_INTERP = Gdk.InterpType.BILINEAR;
+    public const int KEY_REPEAT_INTERVAL_MSEC = 200;
+
+    public enum UpdateReason {
+        NEW_PIXBUF,
+        QUALITY_IMPROVEMENT,
+        RESIZED_CANVAS
+    }
+
+    protected Gtk.DrawingArea canvas = new Gtk.DrawingArea();
+    protected Gtk.Viewport viewport = new Gtk.Viewport(null, null);
+
+    private bool scale_up_to_viewport;
+    private TransitionClock transition_clock;
+    private int transition_duration_msec = 0;
+    private Cairo.Surface pixmap = null;
+    private Cairo.Context pixmap_ctx = null;
+    private Cairo.Context text_ctx = null;
+    private Dimensions pixmap_dim = Dimensions();
+    private Gdk.Pixbuf unscaled = null;
+    private Dimensions max_dim = Dimensions();
+    private Gdk.Pixbuf scaled = null;
+    private Gdk.Pixbuf old_scaled = null; // previous scaled image
+    private Gdk.Rectangle scaled_pos = Gdk.Rectangle();
+    private ZoomState static_zoom_state;
+    private bool zoom_high_quality = true;
+    private ZoomState saved_zoom_state;
+    private bool has_saved_zoom_state = false;
+    private uint32 last_nav_key = 0;
+
+    protected SinglePhotoPage(string page_name, bool scale_up_to_viewport) {
+        base(page_name);
+        this.wheel_factor = 0.9999;
+
+        this.scale_up_to_viewport = scale_up_to_viewport;
+
+        transition_clock = TransitionEffectsManager.get_instance().create_null_transition_clock();
+
+        // With the current code automatically resizing the image to the viewport, scrollbars
+        // should never be shown, but this may change if/when zooming is supported
+        set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC);
+
+        set_border_width(0);
+        set_shadow_type(Gtk.ShadowType.NONE);
+
+        viewport.set_shadow_type(Gtk.ShadowType.NONE);
+        viewport.set_border_width(0);
+        viewport.add(canvas);
+
+        add(viewport);
+
+        canvas.add_events(Gdk.EventMask.EXPOSURE_MASK | Gdk.EventMask.STRUCTURE_MASK 
+            | Gdk.EventMask.SUBSTRUCTURE_MASK);
+
+        viewport.size_allocate.connect(on_viewport_resize);
+        canvas.draw.connect(on_canvas_exposed);
+
+        set_event_source(canvas);
+        Config.Facade.get_instance().colors_changed.connect(on_colors_changed);
+    }
+
+    ~SinglePhotoPage() {
+        Config.Facade.get_instance().colors_changed.disconnect(on_colors_changed);
+    }
+
+    public bool is_transition_in_progress() {
+        return transition_clock.is_in_progress();
+    }
+
+    public void cancel_transition() {
+        if (transition_clock.is_in_progress())
+            transition_clock.cancel();
+    }
+
+    public void set_transition(string effect_id, int duration_msec) {
+        cancel_transition();
+
+        transition_clock = TransitionEffectsManager.get_instance().create_transition_clock(effect_id);
+        if (transition_clock == null)
+            transition_clock = TransitionEffectsManager.get_instance().create_null_transition_clock();
+
+        transition_duration_msec = duration_msec;
+    }
+
+    // This method includes a call to pixmap_ctx.paint().
+    private void render_zoomed_to_pixmap(ZoomState zoom_state) {
+        assert(is_zoom_supported());
+
+        Gdk.Rectangle view_rect = zoom_state.get_viewing_rectangle_wrt_content();
+
+        Gdk.Pixbuf zoomed;
+        if (get_zoom_buffer() != null) {
+            zoomed = (zoom_high_quality) ? get_zoom_buffer().get_zoomed_image(zoom_state) :
+                get_zoom_buffer().get_zoom_preview_image(zoom_state);
+        } else {
+            Gdk.Rectangle view_rect_proj = zoom_state.get_viewing_rectangle_projection(unscaled);
+
+            Gdk.Pixbuf proj_subpixbuf = new Gdk.Pixbuf.subpixbuf(unscaled, view_rect_proj.x,
+                view_rect_proj.y, view_rect_proj.width, view_rect_proj.height);
+
+            zoomed = proj_subpixbuf.scale_simple(view_rect.width, view_rect.height,
+                Gdk.InterpType.BILINEAR);
+        }
+
+        if (zoomed == null) {
+            return;
+        }
+
+        int draw_x = (pixmap_dim.width - view_rect.width) / 2;
+        draw_x = draw_x.clamp(0, int.MAX);
+
+        int draw_y = (pixmap_dim.height - view_rect.height) / 2;
+        draw_y = draw_y.clamp(0, int.MAX);
+        paint_pixmap_with_background(pixmap_ctx, zoomed, draw_x, draw_y);
+    }
+
+    protected void on_interactive_zoom(ZoomState interactive_zoom_state) {
+        assert(is_zoom_supported());
+
+        set_source_color_from_string(pixmap_ctx, "#000");
+        pixmap_ctx.paint();
+
+        bool old_quality_setting = zoom_high_quality;
+        zoom_high_quality = false;
+        render_zoomed_to_pixmap(interactive_zoom_state);
+        zoom_high_quality = old_quality_setting;
+
+        canvas.queue_draw();
+    }
+
+    protected void on_interactive_pan(ZoomState interactive_zoom_state) {
+        assert(is_zoom_supported());
+
+        set_source_color_from_string(pixmap_ctx, "#000");
+        pixmap_ctx.paint();
+
+        bool old_quality_setting = zoom_high_quality;
+        zoom_high_quality = true;
+        render_zoomed_to_pixmap(interactive_zoom_state);
+        zoom_high_quality = old_quality_setting;
+
+        canvas.queue_draw();
+    }
+
+    protected virtual bool is_zoom_supported() {
+        return false;
+    }
+
+    protected virtual void cancel_zoom() {
+        if (pixmap != null) {
+            set_source_color_from_string(pixmap_ctx, "#000");
+            pixmap_ctx.paint();
+        }
+    }
+
+    protected virtual void save_zoom_state() {
+        saved_zoom_state = static_zoom_state;
+        has_saved_zoom_state = true;
+    }
+
+    protected virtual void restore_zoom_state() {
+        if (!has_saved_zoom_state)
+            return;
+
+        static_zoom_state = saved_zoom_state;
+        repaint();
+        has_saved_zoom_state = false;
+    }
+
+    protected virtual ZoomBuffer? get_zoom_buffer() {
+        return null;
+    }
+
+    protected ZoomState get_saved_zoom_state() {
+        return saved_zoom_state;
+    }
+
+    protected void set_zoom_state(ZoomState zoom_state) {
+        assert(is_zoom_supported());
+
+        static_zoom_state = zoom_state;
+    }
+
+    protected ZoomState get_zoom_state() {
+        assert(is_zoom_supported());
+
+        return static_zoom_state;
+    }
+
+    public override void switched_to() {
+        base.switched_to();
+
+        if (unscaled != null)
+            repaint();
+    }
+
+    public override void set_container(Gtk.Window container) {
+        base.set_container(container);
+
+        // scrollbar policy in fullscreen mode needs to be auto/auto, else the pixbuf will shift
+        // off the screen
+        if (container is FullscreenWindow)
+            set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC);
+    }
+
+    // max_dim represents the maximum size of the original pixbuf (i.e. pixbuf may be scaled and
+    // the caller capable of producing larger ones depending on the viewport size).  max_dim
+    // is used when scale_up_to_viewport is set to true.  Pass a Dimensions with no area if
+    // max_dim should be ignored (i.e. scale_up_to_viewport is false).
+    public void set_pixbuf(Gdk.Pixbuf unscaled, Dimensions max_dim, Direction? direction = null) {
+        static_zoom_state = ZoomState(max_dim, pixmap_dim,
+            static_zoom_state.get_interpolation_factor(),
+            static_zoom_state.get_viewport_center());
+
+        cancel_transition();
+
+        this.unscaled = unscaled;
+        this.max_dim = max_dim;
+        this.old_scaled = scaled;
+        scaled = null;
+
+        // need to make sure this has happened
+        canvas.realize();
+
+        repaint(direction);
+    }
+
+    public void blank_display() {
+        unscaled = null;
+        max_dim = Dimensions();
+        scaled = null;
+        pixmap = null;
+
+        // this has to have happened
+        canvas.realize();
+
+        // force a redraw
+        invalidate_all();
+    }
+
+    public Cairo.Surface? get_surface() {
+        return pixmap;
+    }
+
+    public Dimensions get_surface_dim() {
+        return pixmap_dim;
+    }
+
+    public Cairo.Context get_cairo_context() {
+        return pixmap_ctx;
+    }
+
+    public void paint_text(Pango.Layout pango_layout, int x, int y) {
+        text_ctx.move_to(x, y);
+        Pango.cairo_show_layout(text_ctx, pango_layout);
+    }
+
+    public Scaling get_canvas_scaling() {
+        return (get_container() is FullscreenWindow) ? Scaling.for_screen(AppWindow.get_instance(), scale_up_to_viewport)
+            : Scaling.for_widget(viewport, scale_up_to_viewport);
+    }
+
+    public Gdk.Pixbuf? get_unscaled_pixbuf() {
+        return unscaled;
+    }
+
+    public Gdk.Pixbuf? get_scaled_pixbuf() {
+        return scaled;
+    }
+
+    // Returns a rectangle describing the pixbuf in relation to the canvas
+    public Gdk.Rectangle get_scaled_pixbuf_position() {
+        return scaled_pos;
+    }
+
+    public bool is_inside_pixbuf(int x, int y) {
+        return coord_in_rectangle((int)Math.lround(x * Application.get_scale()),
+        (int)Math.lround(y * Application.get_scale()), scaled_pos);
+    }
+
+    public void invalidate(Gdk.Rectangle rect) {
+        if (canvas.get_window() != null)
+            canvas.get_window().invalidate_rect(rect, false);
+    }
+
+    public void invalidate_all() {
+        if (canvas.get_window() != null)
+            canvas.get_window().invalidate_rect(null, false);
+    }
+
+    private void on_viewport_resize() {
+        // do fast repaints while resizing
+        internal_repaint(true, null);
+    }
+
+    protected override void on_resize_finished(Gdk.Rectangle rect) {
+        base.on_resize_finished(rect);
+
+        // when the resize is completed, do a high-quality repaint
+        repaint();
+    }
+
+    private bool on_canvas_exposed(Cairo.Context exposed_ctx) {
+        // draw pixmap onto canvas unless it's not been instantiated, in which case draw black
+        // (so either old image or contents of another page is not left on screen)
+        if (pixmap != null) {
+            pixmap.set_device_scale(Application.get_scale(), Application.get_scale());
+            exposed_ctx.set_source_surface(pixmap, 0, 0);
+        }
+        else
+            set_source_color_from_string(exposed_ctx, "#000");
+
+        exposed_ctx.rectangle(0, 0, get_allocated_width(), get_allocated_height());
+        exposed_ctx.paint();
+
+        if (pixmap != null) {
+            pixmap.set_device_scale(1.0, 1.0);
+        }
+
+        return true;
+    }
+
+    protected virtual void new_surface(Cairo.Context ctx, Dimensions ctx_dim) {
+    }
+
+    protected virtual void updated_pixbuf(Gdk.Pixbuf pixbuf, UpdateReason reason, Dimensions old_dim) {
+    }
+
+    protected virtual void paint(Cairo.Context ctx, Dimensions ctx_dim) {
+        if (is_zoom_supported() && (!static_zoom_state.is_default())) {
+            set_source_color_from_string(ctx, "#000");
+            ctx.rectangle(0, 0, pixmap_dim.width, pixmap_dim.height);
+            ctx.fill();
+
+            render_zoomed_to_pixmap(static_zoom_state);
+        } else if (!transition_clock.paint(ctx, ctx_dim.width, ctx_dim.height)) {
+            // transition is not running, so paint the full image on a black background
+            set_source_color_from_string(ctx, "#000");
+
+            ctx.rectangle(0, 0, pixmap_dim.width, pixmap_dim.height);
+            ctx.fill();
+
+            //scaled.save("src%010d.png".printf(buffer_counter), "png");
+            paint_pixmap_with_background(ctx, scaled, scaled_pos.x, scaled_pos.y);
+            //pixmap.write_to_png("%010d.png".printf(buffer_counter++));
+        }
+    }
+
+    private void repaint_pixmap() {
+        if (pixmap_ctx == null)
+            return;
+
+        paint(pixmap_ctx, pixmap_dim);
+        invalidate_all();
+    }
+
+    public void repaint(Direction? direction = null) {
+        internal_repaint(false, direction);
+    }
+
+    private void internal_repaint(bool fast, Direction? direction) {
+        // if not in view, assume a full repaint needed in future but do nothing more
+        if (!is_in_view()) {
+            pixmap = null;
+            scaled = null;
+
+            return;
+        }
+
+        // no image or window, no painting
+        if (unscaled == null || canvas.get_window() == null)
+            return;
+
+        Gtk.Allocation allocation;
+        viewport.get_allocation(out allocation);
+
+        int width = allocation.width;
+        int height = allocation.height;
+
+        if (width <= 0 || height <= 0)
+            return;
+
+        bool new_pixbuf = (scaled == null);
+
+        // save if reporting an image being rescaled
+        Dimensions old_scaled_dim = Dimensions.for_rectangle(scaled_pos);
+
+        Gdk.Rectangle old_scaled_pos = scaled_pos;
+
+        // attempt to reuse pixmap
+        if (pixmap_dim.width != width || pixmap_dim.height != height)
+            pixmap = null;
+
+        // if necessary, create a pixmap as large as the entire viewport
+        bool new_pixmap = false;
+        if (pixmap == null) {
+            init_pixmap((int)Math.lround(width * Application.get_scale()), (int)Math.lround(height * Application.get_scale()));
+            new_pixmap = true;
+        }
+
+        if (new_pixbuf || new_pixmap) {
+            Dimensions unscaled_dim = Dimensions.for_pixbuf(unscaled);
+
+            // determine scaled size of pixbuf ... if a max dimensions is set and not scaling up,
+            // respect it
+            Dimensions scaled_dim = Dimensions();
+            if (!scale_up_to_viewport && max_dim.has_area() && max_dim.width < width && max_dim.height < height)
+                scaled_dim = max_dim;
+            else
+                scaled_dim = unscaled_dim.get_scaled_proportional(pixmap_dim);
+
+            // center pixbuf on the canvas
+            scaled_pos.x = (int)Math.lround(((width * Application.get_scale()) - scaled_dim.width) / 2.0);
+            scaled_pos.y = (int)Math.lround(((height * Application.get_scale()) - scaled_dim.height) / 2.0);
+            scaled_pos.width = scaled_dim.width;
+            scaled_pos.height = scaled_dim.height;
+        }
+
+        Gdk.InterpType interp = (fast) ? FAST_INTERP : QUALITY_INTERP;
+
+        // rescale if canvas rescaled or better quality is requested
+        if (scaled == null) {
+            scaled = resize_pixbuf(unscaled, Dimensions.for_rectangle(scaled_pos), interp);
+
+            UpdateReason reason = UpdateReason.RESIZED_CANVAS;
+            if (new_pixbuf)
+                reason = UpdateReason.NEW_PIXBUF;
+            else if (!new_pixmap && interp == QUALITY_INTERP)
+                reason = UpdateReason.QUALITY_IMPROVEMENT;
+
+            static_zoom_state = ZoomState(max_dim, pixmap_dim,
+                static_zoom_state.get_interpolation_factor(),
+                static_zoom_state.get_viewport_center());
+
+            updated_pixbuf(scaled, reason, old_scaled_dim);
+        }
+
+        zoom_high_quality = !fast;
+
+        if (direction != null && !transition_clock.is_in_progress()) {
+            Spit.Transitions.Visuals visuals = new Spit.Transitions.Visuals(old_scaled,
+                old_scaled_pos, scaled, scaled_pos, parse_color("#000"));
+
+            transition_clock.start(visuals, direction.to_transition_direction(), transition_duration_msec,
+                repaint_pixmap);
+        }
+
+        if (!transition_clock.is_in_progress())
+            repaint_pixmap();
+    }
+
+    private void init_pixmap(int width, int height) {
+        assert(unscaled != null);
+        assert(canvas.get_window() != null);
+
+        // Cairo backing surface (manual double-buffering)
+        pixmap = new Cairo.ImageSurface(Cairo.Format.ARGB32, width, height);
+        pixmap_dim = Dimensions(width, height);
+
+        // Cairo context for drawing on the pixmap
+        pixmap_ctx = new Cairo.Context(pixmap);
+
+        // need a new pixbuf to fit this scale
+        scaled = null;
+
+        // Cairo context for drawing text on the pixmap
+        text_ctx = new Cairo.Context(pixmap);
+        set_source_color_from_string(text_ctx, "#fff");
+
+
+        // no need to resize canvas, viewport does that automatically
+
+        new_surface(pixmap_ctx, pixmap_dim);
+    }
+
+    protected override bool on_context_keypress() {
+        return popup_context_menu(get_page_context_menu());
+    }
+
+    protected virtual void on_previous_photo() {
+    }
+
+    protected virtual void on_next_photo() {
+    }
+
+    public override bool key_press_event(Gdk.EventKey event) {
+        // if the user holds the arrow keys down, we will receive a steady stream of key press
+        // events for an operation that isn't designed for a rapid succession of output ... 
+        // we staunch the supply of new photos to under a quarter second (#533)
+        bool nav_ok = (event.time - last_nav_key) > KEY_REPEAT_INTERVAL_MSEC;
+
+        bool handled = true;
+        switch (Gdk.keyval_name(event.keyval)) {
+            case "Left":
+            case "KP_Left":
+            case "BackSpace":
+                if (nav_ok) {
+                    on_previous_photo();
+                    last_nav_key = event.time;
+                }
+            break;
+
+            case "Right":
+            case "KP_Right":
+            case "space":
+                if (nav_ok) {
+                    on_next_photo();
+                    last_nav_key = event.time;
+                }
+            break;
+
+            default:
+                handled = false;
+            break;
+        }
+
+        if (handled)
+            return true;
+
+        return (base.key_press_event != null) ? base.key_press_event(event) : true;
+    }
+
+    private void on_colors_changed() {
+        invalidate_transparent_background();
+        repaint();
+    }
+}
+
+
diff --git a/src/SlideshowPage.vala b/src/SlideshowPage.vala
index 9810236..adfec7f 100644
--- a/src/SlideshowPage.vala
+++ b/src/SlideshowPage.vala
@@ -26,19 +26,19 @@ class SlideshowPage : SinglePhotoPage {
     [GtkTemplate (ui = "/org/gnome/Shotwell/ui/slideshow_settings.ui")]
     private class SettingsDialog : Gtk.Dialog {
         [GtkChild]
-        Gtk.Adjustment delay_adjustment;
+        unowned Gtk.Adjustment delay_adjustment;
         [GtkChild]
-        Gtk.SpinButton delay_entry;
+        unowned Gtk.SpinButton delay_entry;
         [GtkChild]
-        Gtk.ComboBoxText transition_effect_selector;
+        unowned Gtk.ComboBoxText transition_effect_selector;
         [GtkChild]
-        Gtk.Scale transition_effect_hscale;
+        unowned Gtk.Scale transition_effect_hscale;
         [GtkChild]
-        Gtk.SpinButton transition_effect_entry;
+        unowned Gtk.SpinButton transition_effect_entry;
         [GtkChild]
-        Gtk.Adjustment transition_effect_adjustment;
+        unowned Gtk.Adjustment transition_effect_adjustment;
         [GtkChild]
-        Gtk.CheckButton show_title_button;
+        unowned Gtk.CheckButton show_title_button;
         
         public SettingsDialog() {
             Object (use_header_bar: Resources.use_header_bar());
diff --git a/src/SortedList.vala b/src/SortedList.vala
index 20e6771..420190d 100644
--- a/src/SortedList.vala
+++ b/src/SortedList.vala
@@ -142,7 +142,7 @@ public class SortedList<G> : Object, Gee.Traversable<G>, Gee.Iterable<G>, Gee.Co
         return list.get(index);
     }
     
-    private int binary_search(G search, EqualFunc? equal_func) {
+    private int binary_search(G search, EqualFunc<G>? equal_func) {
         assert(cmp != null);
         
         int min = 0;
@@ -181,7 +181,7 @@ public class SortedList<G> : Object, Gee.Traversable<G>, Gee.Iterable<G>, Gee.Co
     }
     
     // See notes at index_of for the difference between this method and it.
-    public int locate(G search, bool altered, EqualFunc equal_func = direct_equal) {
+    public int locate(G search, bool altered, EqualFunc<G> equal_func = direct_equal) {
         if (cmp == null || altered) {
             int count = list.size;
             for (int ctr = 0; ctr < count; ctr++) {
diff --git a/src/Tag.vala b/src/Tag.vala
index 46cbfaa..baf5694 100644
--- a/src/Tag.vala
+++ b/src/Tag.vala
@@ -552,11 +552,13 @@ public class Tag : DataSource, ContainerSource, Proxyable, Indexable {
     // path should have already been prepared by prep_tag_name.
     public static Tag for_path(string name) {
         Tag? tag = global.fetch_by_name(name, true);
-        if (tag == null)
+        if (tag == null) {
             tag = global.restore_tag_from_holding_tank(name);
+        }
         
-        if (tag != null)
+        if (tag != null) {
             return tag;
+        }
         
         // create a new Tag for this name
         try {
diff --git a/src/Thumbnail.vala b/src/Thumbnail.vala
index f47fc69..51d2612 100644
--- a/src/Thumbnail.vala
+++ b/src/Thumbnail.vala
@@ -169,14 +169,15 @@ public class Thumbnail : MediaSourceItem {
     }
     
     public static int64 exposure_time_ascending_comparator(void *a, void *b) {
-        int64 time_a = (int64) (((Thumbnail *) a)->media.get_exposure_time());
-        int64 time_b = (int64) (((Thumbnail *) b)->media.get_exposure_time());
-        int64 result = (time_a - time_b);
+        var time_a = (((Thumbnail *) a)->media.get_exposure_time());
+        var time_b = (((Thumbnail *) b)->media.get_exposure_time());
+
+        var result = nullsafe_date_time_comperator(time_a, time_b);
         
         return (result != 0) ? result : filename_ascending_comparator(a, b);
     }
     
-    public static int64 exposure_time_desending_comparator(void *a, void *b) {
+    public static int64 exposure_time_descending_comparator(void *a, void *b) {
         int64 result = exposure_time_ascending_comparator(b, a);
         
         return (result != 0) ? result : filename_descending_comparator(a, b);
diff --git a/src/ThumbnailCache.vala b/src/ThumbnailCache.vala
index a0b27fd..5585708 100644
--- a/src/ThumbnailCache.vala
+++ b/src/ThumbnailCache.vala
@@ -33,7 +33,8 @@ public class ThumbnailCache : Object {
     // so be careful before changing any of these values (and especially careful before arbitrarily
     // manipulating a Size enum)
     public enum Size {
-        LARGEST = 360,
+        LARGEST = 512,
+        LARGE = 512,
         BIG = 360,
         MEDIUM = 128,
         SMALLEST = 128;
@@ -47,11 +48,18 @@ public class ThumbnailCache : Object {
         }
         
         public static Size get_best_size(int scale) {
-            return scale <= MEDIUM.get_scale() ? MEDIUM : BIG;
+            var real_scale = Application.get_scale() * scale;
+
+            if (real_scale <= MEDIUM.get_scale())
+                return MEDIUM;
+            if (real_scale <= BIG.get_scale())
+                return BIG;
+
+            return LARGE;
         }
     }
     
-    private static Size[] ALL_SIZES = { Size.BIG, Size.MEDIUM };
+    private static Size[] ALL_SIZES = { Size.LARGE, Size.BIG, Size.MEDIUM };
     
     public delegate void AsyncFetchCallback(Gdk.Pixbuf? pixbuf, Gdk.Pixbuf? unscaled, Dimensions dim,
         Gdk.InterpType interp, Error? err);
@@ -167,9 +175,11 @@ public class ThumbnailCache : Object {
     
     public const ulong MAX_BIG_CACHED_BYTES = 40 * 1024 * 1024;
     public const ulong MAX_MEDIUM_CACHED_BYTES = 30 * 1024 * 1024;
+    public const ulong MAX_LARGE_CACHED_BYTES = 15 * 1024 * 1024;
 
     private static ThumbnailCache big = null;
     private static ThumbnailCache medium = null;
+    private static ThumbnailCache large = null;
     
     private static OneShotScheduler debug_scheduler = null;
     private static int cycle_fetched_thumbnails = 0;
@@ -203,6 +213,7 @@ public class ThumbnailCache : Object {
         
         big = new ThumbnailCache(Size.BIG, MAX_BIG_CACHED_BYTES);
         medium = new ThumbnailCache(Size.MEDIUM, MAX_MEDIUM_CACHED_BYTES);
+        large = new ThumbnailCache(Size.LARGE, MAX_LARGE_CACHED_BYTES);
     }
     
     public static void terminate() {
@@ -213,27 +224,33 @@ public class ThumbnailCache : Object {
         debug("import from source: %s", source.to_string());
         big._import_from_source(source, force);
         medium._import_from_source(source, force);
+        large._import_from_source(source, force);
     }
     
     public static void import_thumbnails(ThumbnailSource source, Thumbnails thumbnails,
         bool force = false) throws Error {
         big._import_thumbnail(source, thumbnails.get(Size.BIG), force);
         medium._import_thumbnail(source, thumbnails.get(Size.MEDIUM), force);
+        large._import_thumbnail(source, thumbnails.get(Size.LARGE), force);
     }
     
     public static void duplicate(ThumbnailSource src_source, ThumbnailSource dest_source) {
         big._duplicate(src_source, dest_source);
         medium._duplicate(src_source, dest_source);
+        large._duplicate(src_source, dest_source);
     }
     
     public static void remove(ThumbnailSource source) {
         big._remove(source);
         medium._remove(source);
+        large._remove(source);
     }
     
     private static ThumbnailCache get_best_cache(int scale) {
         Size size = Size.get_best_size(scale);
-        if (size == Size.BIG) {
+        if (size == Size.LARGE) {
+            return large;
+        } else if (size == Size.BIG) {
             return big;
         } else {
             assert(size == Size.MEDIUM);
@@ -244,6 +261,9 @@ public class ThumbnailCache : Object {
     
     private static ThumbnailCache get_cache_for(Size size) {
         switch (size) {
+            case Size.LARGE:
+                return large;
+
             case Size.BIG:
                 return big;
             
diff --git a/src/TimedQueue.vala b/src/TimedQueue.vala
index 47faf3c..4ea6a23 100644
--- a/src/TimedQueue.vala
+++ b/src/TimedQueue.vala
@@ -50,7 +50,7 @@ public class TimedQueue<G> {
     // finding a workaround, namely using a delegate:
     // https://bugzilla.gnome.org/show_bug.cgi?id=628639
     public TimedQueue(uint hold_msec, DequeuedCallback<G> callback,
-        owned Gee.EqualDataFunc? equal_func = null, int priority = Priority.DEFAULT) {
+        owned Gee.EqualDataFunc<G>? equal_func = null, int priority = Priority.DEFAULT) {
         this.hold_msec = hold_msec;
         this.callback = callback;
         
diff --git a/src/Upgrades.vala b/src/Upgrades.vala
index 85349ae..b06ccad 100644
--- a/src/Upgrades.vala
+++ b/src/Upgrades.vala
@@ -62,7 +62,7 @@ private interface UpgradeTask : Object{
 
 // Deletes the mimics folder, if it still exists.
 // Note: for the step count to be consistent, files cannot be written
-// to the mimcs folder for the duration of this task.
+// to the mimics folder for the duration of this task.
 private class MimicsRemovalTask : Object, UpgradeTask {
     // Mimics folder (to be deleted, if present)
     private File mimic_dir = AppDirs.get_data_dir().get_child("mimics");
diff --git a/src/VideoMetadata.vala b/src/VideoMetadata.vala
deleted file mode 100644
index 49ba8ef..0000000
--- a/src/VideoMetadata.vala
+++ /dev/null
@@ -1,655 +0,0 @@
-/* Copyright 2016 Software Freedom Conservancy Inc.
- *
- * This software is licensed under the GNU Lesser General Public License
- * (version 2.1 or later).  See the COPYING file in this distribution.
- */
-
-public class VideoMetadata : MediaMetadata {
-    
-    private MetadataDateTime timestamp = null;
-    private string title = null;
-    private string comment = null;
-   
-    public VideoMetadata() {
-    }
-    
-    ~VideoMetadata() {
-    }
-    
-    public override void read_from_file(File file) throws Error {
-        QuickTimeMetadataLoader quicktime = new QuickTimeMetadataLoader(file);
-        if (quicktime.is_supported()) {
-            timestamp = quicktime.get_creation_date_time();
-            title = quicktime.get_title();
-	        // TODO: is there an quicktime.get_comment ??
-            comment = null;
-            return;
-        }    
-        AVIMetadataLoader avi = new AVIMetadataLoader(file);
-        if (avi.is_supported()) {
-            timestamp = avi.get_creation_date_time();
-            title = avi.get_title();
-            comment = null;
-            return;
-        }
-        
-        throw new IOError.NOT_SUPPORTED("File %s is not a supported video format", file.get_path());
-    }
-    
-    public override MetadataDateTime? get_creation_date_time() {
-        return timestamp;
-    }
-    
-    public override string? get_title() {
-        return title;
-    }
-    
-    public override string? get_comment() {
-        return comment;
-    }
-    
-}
-
-private class QuickTimeMetadataLoader {
-
-    // Quicktime calendar date/time format is number of seconds since January 1, 1904.
-    // This converts to UNIX time (66 years + 17 leap days).
-    public const time_t QUICKTIME_EPOCH_ADJUSTMENT = 2082844800;
-
-    private File file = null;
-
-    public QuickTimeMetadataLoader(File file) {
-        this.file = file;
-    }
-    
-    public MetadataDateTime? get_creation_date_time() {
-        return new MetadataDateTime((time_t) get_creation_date_time_for_quicktime());
-    }
-    
-    public string? get_title() {
-        // Not supported.
-        return null;
-    }
-
-    // Checks if the given file is a QuickTime file.
-    public bool is_supported() {
-        QuickTimeAtom test = new QuickTimeAtom(file);
-        
-        bool ret = false;
-        try {
-            test.open_file();
-            test.read_atom();
-            
-            // Look for the header.
-            if ("ftyp" == test.get_current_atom_name()) {
-                ret = true;
-            } else {
-                // Some versions of QuickTime don't have
-                // an ftyp section, so we'll just look
-                // for the mandatory moov section.
-                while(true) {
-                    if ("moov" == test.get_current_atom_name()) {
-                        ret = true;
-                        break;
-                    }
-                    test.next_atom();
-                    test.read_atom();
-                    if (test.is_last_atom()) {
-                        break;
-                    }
-                }
-            }
-        } catch (GLib.Error e) {
-            debug("Error while testing for QuickTime file for %s: %s", file.get_path(), e.message);
-        }
-        
-        try {
-            test.close_file();
-        } catch (GLib.Error e) {
-            debug("Error while closing Quicktime file: %s", e.message);
-        }
-        return ret;
-    }
-
-    private ulong get_creation_date_time_for_quicktime() {
-        QuickTimeAtom test = new QuickTimeAtom(file);
-        time_t timestamp = 0;
-        
-        try {
-            test.open_file();
-            bool done = false;
-            while(!done) {
-                // Look for "moov" section.
-                test.read_atom();
-                if (test.is_last_atom()) break;
-                if ("moov" == test.get_current_atom_name()) {
-                    QuickTimeAtom child = test.get_first_child_atom();
-                    while (!done) {
-                        // Look for "mvhd" section, or break if none is found.
-                        child.read_atom();
-                        if (child.is_last_atom() || 0 == child.section_size_remaining()) {
-                            done = true;
-                            break;
-                        }
-                        
-                        if ("mvhd" == child.get_current_atom_name()) {
-                            // Skip 4 bytes (version + flags)
-                            child.read_uint32();
-                            // Grab the timestamp.
-                            timestamp = child.read_uint32() - QUICKTIME_EPOCH_ADJUSTMENT;
-                            done = true;
-                            break;
-                        }
-                        child.next_atom();
-                    }
-                }
-                test.next_atom();
-            }
-        } catch (GLib.Error e) {
-            debug("Error while testing for QuickTime file: %s", e.message);
-        }
-        
-        try {
-            test.close_file();
-        } catch (GLib.Error e) {
-            debug("Error while closing Quicktime file: %s", e.message);
-        }
-        
-        // Some Android phones package videos recorded with their internal cameras in a 3GP
-        // container that looks suspiciously like a QuickTime container but really isn't -- for
-        // the timestamps of these Android 3GP videos are relative to the UNIX epoch
-        // (January 1, 1970) instead of the QuickTime epoch (January 1, 1904). So, if we detect a
-        // QuickTime movie with a negative timestamp, we can be pretty sure it isn't a valid
-        // QuickTime movie that was shot before 1904 but is instead a non-compliant 3GP video
-        // file. If we detect such a video, we correct its time. See this Redmine ticket
-        // (http://redmine.yorba.org/issues/3314) for more information.
-        if (timestamp < 0)
-            timestamp += QUICKTIME_EPOCH_ADJUSTMENT;
-        
-        return (ulong) timestamp;
-    }
-}
-
-private class QuickTimeAtom {
-    private GLib.File file = null;
-    private string section_name = "";
-    private uint64 section_size = 0;
-    private uint64 section_offset = 0;
-    private GLib.DataInputStream input = null;
-    private QuickTimeAtom? parent = null;
-    
-    public QuickTimeAtom(GLib.File file) {
-        this.file = file;
-    }
-    
-    private QuickTimeAtom.with_input_stream(GLib.DataInputStream input, QuickTimeAtom parent) {
-        this.input = input;
-        this.parent = parent;
-    }
-    
-    public void open_file() throws GLib.Error {
-        close_file();
-        input = new GLib.DataInputStream(file.read());
-        input.set_byte_order(DataStreamByteOrder.BIG_ENDIAN);
-        section_size = 0;
-        section_offset = 0;
-        section_name = "";
-    }
-    
-    public void close_file() throws GLib.Error {
-        if (null != input) {
-            input.close();
-            input = null;
-        }
-    }
-    
-    private void advance_section_offset(uint64 amount) {
-        section_offset += amount;
-        if (null != parent) {
-            parent.advance_section_offset(amount);
-        }
-    }
-    
-    public QuickTimeAtom get_first_child_atom() {
-        // Child will simply have the input stream
-        // but not the size/offset.  This works because
-        // child atoms follow immediately after a header,
-        // so no skipping is required to access the child
-        // from the current position.
-        return new QuickTimeAtom.with_input_stream(input, this);
-    }
-    
-    public uchar read_byte() throws GLib.Error {
-        advance_section_offset(1);
-        return input.read_byte();
-    }
-    
-    public uint32 read_uint32() throws GLib.Error {
-        advance_section_offset(4);
-        return input.read_uint32();
-    }
-    
-    public uint64 read_uint64() throws GLib.Error {
-        advance_section_offset(8);
-        return input.read_uint64();
-    }
-
-    public void read_atom() throws GLib.Error {
-        // Read atom size.
-        section_size = read_uint32();
-        
-        // Read atom name.
-        GLib.StringBuilder sb = new GLib.StringBuilder();
-        sb.append_c((char) read_byte());
-        sb.append_c((char) read_byte());
-        sb.append_c((char) read_byte());
-        sb.append_c((char) read_byte());
-        section_name = sb.str;
-        
-        // Check string.
-        if (section_name.length != 4) {
-            throw new IOError.NOT_SUPPORTED("QuickTime atom name length is invalid for %s", 
-                file.get_path());
-        }
-        for (int i = 0; i < section_name.length; i++) {
-            if (!section_name[i].isprint()) {
-                throw new IOError.NOT_SUPPORTED("Bad QuickTime atom in file %s", file.get_path());
-            }
-        }
-        
-        if (1 == section_size) {
-            // This indicates the section size is a 64-bit
-            // value, specified below the atom name.
-            section_size = read_uint64();
-        }
-    }
-    
-    private void skip(uint64 skip_amount) throws GLib.Error {
-        skip_uint64(input, skip_amount);
-    }
-    
-    public uint64 section_size_remaining() {
-        assert(section_size >= section_offset);
-        return section_size - section_offset;
-    }
-    
-    public void next_atom() throws GLib.Error {
-        skip(section_size_remaining());
-        section_size = 0;
-        section_offset = 0;
-    }
-    
-    public string get_current_atom_name() {
-        return section_name;
-    }
-   
-    public bool is_last_atom() {
-        return 0 == section_size;
-    }
-    
-}
-
-private class AVIMetadataLoader {
-
-    private File file = null;
-    
-    // A numerical date string, i.e 2010:01:28 14:54:25
-    private const int NUMERICAL_DATE_LENGTH = 19;
-    
-    // Marker for timestamp section in a Nikon nctg blob.
-    private const uint16 NIKON_NCTG_TIMESTAMP_MARKER = 0x13;
-    
-    // Size limit to ensure we don't parse forever on a bad file.
-    private const int MAX_STRD_LENGTH = 100;
-
-    public AVIMetadataLoader(File file) {
-        this.file = file;
-    }
-    
-    public MetadataDateTime? get_creation_date_time() {
-        return new MetadataDateTime((time_t) get_creation_date_time_for_avi());
-    }
-    
-    public string? get_title() {
-        // Not supported.
-        return null;
-    }
-
-    // Checks if the given file is an AVI file.
-    public bool is_supported() {
-        AVIChunk chunk = new AVIChunk(file);
-        bool ret = false;
-        try {
-            chunk.open_file();
-            chunk.read_chunk();
-            // Look for the header and identifier.
-            if ("RIFF" == chunk.get_current_chunk_name() &&
-                "AVI " == chunk.read_name()) {
-                ret = true;
-            }
-        } catch (GLib.Error e) {
-            debug("Error while testing for AVI file: %s", e.message);
-        }
-        
-        try {
-            chunk.close_file();
-        } catch (GLib.Error e) {
-            debug("Error while closing AVI file: %s", e.message);
-        } 
-        return ret;
-    }
-    
-    // Parses a Nikon nctg tag.  Based losely on avi_read_nikon() in FFmpeg.
-    private string read_nikon_nctg_tag(AVIChunk chunk) throws GLib.Error {
-        bool found_date = false;
-        while (chunk.section_size_remaining() > sizeof(uint16)*2) {
-            uint16 tag = chunk.read_uint16();
-            uint16 size = chunk.read_uint16();
-            if (NIKON_NCTG_TIMESTAMP_MARKER == tag) {
-                found_date = true;
-                break;
-            }
-            chunk.skip(size);
-        }
-        
-        if (found_date) {
-            // Read numerical date string, example: 2010:01:28 14:54:25
-            GLib.StringBuilder sb = new GLib.StringBuilder();
-            for (int i = 0; i < NUMERICAL_DATE_LENGTH; i++) {
-                sb.append_c((char) chunk.read_byte());
-            }
-            return sb.str;
-        }
-        return "";
-    }
-    
-    // Parses a Fujifilm strd tag. Based on information from:
-    // http://www.eden-foundation.org/products/code/film_date_stamp/index.html
-    private string read_fuji_strd_tag(AVIChunk chunk) throws GLib.Error {
-        chunk.skip(98); // Ignore 98-byte binary blob.
-        chunk.skip(8); // Ignore the string "FUJIFILM"
-        // Read until we find four colons, then two more chars.
-        int colons = 0;
-        int post_colons = 0;
-        GLib.StringBuilder sb = new GLib.StringBuilder();
-        // End of date is two chars past the fourth colon.
-        while (colons <= 4 && post_colons < 2) {
-            char c = (char) chunk.read_byte();
-            if (4 == colons) {
-                post_colons++;
-            }
-            if (':' == c) {
-                colons++;
-            }
-            if (c.isprint()) {
-                sb.append_c(c);
-            }
-            if (sb.len > MAX_STRD_LENGTH) {
-                return ""; // Give up searching.
-            }
-        }
-        
-        if (sb.str.length < NUMERICAL_DATE_LENGTH) {
-            return ""; 
-        }
-        // Date is now at the end of the string.
-        return sb.str.substring(sb.str.length - NUMERICAL_DATE_LENGTH);
-    }
-    
-    // Recursively read file until the section is found.
-    private string? read_section(AVIChunk chunk) throws GLib.Error {
-        while (true) {
-            chunk.read_chunk();
-            string name = chunk.get_current_chunk_name();
-            if ("IDIT" == name) {
-                return chunk.section_to_string();
-            } else if ("nctg" == name) {
-                return read_nikon_nctg_tag(chunk);
-            } else if ("strd" == name) {
-                return read_fuji_strd_tag(chunk);
-            }
-            
-            if ("LIST" == name) {
-                chunk.read_name(); // Read past list name.
-                string result = read_section(chunk.get_first_child_chunk());
-                if (null != result) {
-                    return result;
-                }
-            }
-            
-            if (chunk.is_last_chunk()) {
-                break;
-            }
-            chunk.next_chunk();
-        }
-        return null;
-    }
-    
-    // Parses a date from a string.
-    // Largely based on GStreamer's avi/gstavidemux.c 
-    // and the information here: 
-    // http://www.eden-foundation.org/products/code/film_date_stamp/index.html
-    private ulong parse_date(string sdate) {
-        if (sdate.length == 0) {
-            return 0;
-        }
-        
-        Date date = Date();
-        uint seconds = 0;
-        int year, month, day, hour, min, sec;
-        char weekday[4];
-        char monthstr[4];
-        
-        if (sdate[0].isdigit()) {
-            // Format is: 2005:08:17 11:42:43
-            // Format is: 2010/11/30/ 19:42
-            // Format is: 2010/11/30 19:42
-            string tmp = sdate.dup();
-            tmp.canon("0123456789 ", ' '); // strip everything but numbers and spaces
-            sec = 0;
-            int result = tmp.scanf("%d %d %d %d %d %d", out year, out month, out day, out hour, out min, out sec);
-            if(result < 5) {
-                return 0;
-            }
-            date.set_dmy((DateDay) day, (DateMonth) month, (DateYear) year);
-            seconds = sec + min * 60 + hour * 3600;
-        } else {
-            // Format is: Mon Mar  3 09:44:56 2008
-            if(7 != sdate.scanf("%3s %3s %d %d:%d:%d %d", weekday, monthstr, out day, out hour,
-                  out min, out sec, out year)) {
-                return 0; // Error
-            }
-            date.set_dmy((DateDay) day, month_from_string((string) monthstr), (DateYear) year);
-            seconds = sec + min * 60 + hour * 3600;
-        }
-        
-        Time time = Time();
-        date.to_time(out time);
-        
-        // watch for overflow (happens on quasi-bogus dates, like Year 200)
-        time_t tm = time.mktime();
-        ulong result = tm + seconds;
-        if (result < tm) {
-            debug("Overflow for timestamp in video file %s", file.get_path());
-            
-            return 0;
-        }
-        
-        return result;
-    }
-    
-    private DateMonth month_from_string(string s) {
-        switch (s.down()) {
-        case "jan":
-            return DateMonth.JANUARY;
-        case "feb":
-            return DateMonth.FEBRUARY;
-        case "mar":
-            return DateMonth.MARCH;
-        case "apr":
-            return DateMonth.APRIL;
-        case "may":
-            return DateMonth.MAY;
-        case "jun":
-            return DateMonth.JUNE;
-        case "jul":
-            return DateMonth.JULY;
-        case "aug":
-            return DateMonth.AUGUST;
-        case "sep":
-            return DateMonth.SEPTEMBER;
-        case "oct":
-            return DateMonth.OCTOBER;
-        case "nov":
-            return DateMonth.NOVEMBER;
-        case "dec":
-            return DateMonth.DECEMBER;
-        }
-        return DateMonth.BAD_MONTH;
-    }
-
-    private ulong get_creation_date_time_for_avi() {
-        AVIChunk chunk = new AVIChunk(file);
-        ulong timestamp = 0;
-        try {
-            chunk.open_file();
-            chunk.nonsection_skip(12); // Advance past 12 byte header.
-            string sdate = read_section(chunk);
-            if (null != sdate) {
-                timestamp = parse_date(sdate.strip());
-            }
-        } catch (GLib.Error e) {
-            debug("Error while reading AVI file: %s", e.message);
-        }
-        
-        try {
-            chunk.close_file();
-        } catch (GLib.Error e) {
-            debug("Error while closing AVI file: %s", e.message);
-        } 
-        return timestamp;
-    }
-}
-
-private class AVIChunk {
-    private GLib.File file = null;
-    private string section_name = "";
-    private uint64 section_size = 0;
-    private uint64 section_offset = 0;
-    private GLib.DataInputStream input = null;
-    private AVIChunk? parent = null;
-    private const int MAX_STRING_TO_SECTION_LENGTH = 1024;
-    
-    public AVIChunk(GLib.File file) {
-        this.file = file;
-    }
-    
-    private AVIChunk.with_input_stream(GLib.DataInputStream input, AVIChunk parent) {
-        this.input = input;
-        this.parent = parent;
-    }   
-    
-    public void open_file() throws GLib.Error {
-        close_file();
-        input = new GLib.DataInputStream(file.read());
-        input.set_byte_order(DataStreamByteOrder.LITTLE_ENDIAN);
-        section_size = 0;
-        section_offset = 0;
-        section_name = "";
-    }
-    
-    public void close_file() throws GLib.Error {
-        if (null != input) {
-            input.close();
-            input = null;
-        }
-    }
-    
-    public void nonsection_skip(uint64 skip_amount) throws GLib.Error {
-        skip_uint64(input, skip_amount);
-    }
-    
-    public void skip(uint64 skip_amount) throws GLib.Error {
-        advance_section_offset(skip_amount);
-        skip_uint64(input, skip_amount);
-    }
-    
-    public AVIChunk get_first_child_chunk() {
-        return new AVIChunk.with_input_stream(input, this);
-    }
-    
-    private void advance_section_offset(uint64 amount) {
-        if ((section_offset + amount) > section_size)
-            amount = section_size - section_offset;
-        
-        section_offset += amount;
-        if (null != parent) {
-            parent.advance_section_offset(amount);
-        }
-    }
-    
-    public uchar read_byte() throws GLib.Error {
-        advance_section_offset(1);
-        return input.read_byte();
-    }
-    
-    public uint16 read_uint16() throws GLib.Error {
-       advance_section_offset(2);
-       return input.read_uint16();
-    }
-    
-    public void read_chunk() throws GLib.Error {
-        // don't use checked reads here because they advance the section offset, which we're trying
-        // to determine here
-        GLib.StringBuilder sb = new GLib.StringBuilder();
-        sb.append_c((char) input.read_byte());
-        sb.append_c((char) input.read_byte());
-        sb.append_c((char) input.read_byte());
-        sb.append_c((char) input.read_byte());
-        section_name = sb.str;
-        section_size = input.read_uint32();
-        section_offset = 0;
-    }
-    
-    public string read_name() throws GLib.Error {
-        GLib.StringBuilder sb = new GLib.StringBuilder();
-        sb.append_c((char) read_byte());
-        sb.append_c((char) read_byte());
-        sb.append_c((char) read_byte());
-        sb.append_c((char) read_byte());
-        return sb.str;
-    }
-    
-    public void next_chunk() throws GLib.Error {
-        skip(section_size_remaining());
-        section_size = 0;
-        section_offset = 0;
-    }
-    
-    public string get_current_chunk_name() {
-        return section_name;
-    }
-   
-    public bool is_last_chunk() {
-        return section_size == 0;
-    }
-    
-    public uint64 section_size_remaining() {
-        assert(section_size >= section_offset);
-        return section_size - section_offset;
-    }
-    
-    // Reads section contents into a string.
-    public string section_to_string() throws GLib.Error {
-        GLib.StringBuilder sb = new GLib.StringBuilder();
-        while (section_offset < section_size) {
-            sb.append_c((char) read_byte());
-            if (sb.len > MAX_STRING_TO_SECTION_LENGTH) {
-                return sb.str;
-            }
-        }
-        return sb.str;
-    }
-    
-}
-
diff --git a/src/camera/CameraBranch.vala b/src/camera/CameraBranch.vala
index 052f093..83e6a66 100644
--- a/src/camera/CameraBranch.vala
+++ b/src/camera/CameraBranch.vala
@@ -104,7 +104,7 @@ public class Camera.SidebarEntry : Sidebar.SimplePageEntry {
     }
     
     protected override Page create_page() {
-        return new ImportPage(camera.gcamera, uri, get_sidebar_name(), get_sidebar_icon());
+        return new ImportPage(camera);
     }
     
     public string get_uri() {
diff --git a/src/camera/CameraTable.vala b/src/camera/CameraTable.vala
index 5f888ac..172c00a 100644
--- a/src/camera/CameraTable.vala
+++ b/src/camera/CameraTable.vala
@@ -4,20 +4,6 @@
  * (version 2.1 or later).  See the COPYING file in this distribution.
  */
 
-public class DiscoveredCamera {
-    public GPhoto.Camera gcamera;
-    public string uri;
-    public string display_name;
-    public string? icon;
-    
-    public DiscoveredCamera(GPhoto.Camera gcamera, string uri, string display_name, string? icon) {
-        this.gcamera = gcamera;
-        this.uri = uri;
-        this.display_name = display_name;
-        this.icon = icon;
-    }
-}
-
 public class CameraTable {
     private const int UPDATE_DELAY_MSEC = 1000;
     
@@ -119,32 +105,6 @@ public class CameraTable {
         return "gphoto2://[%s]/".printf(port);
     }
     
-    public static string? get_port_path(string port) {
-        // Accepted format is usb:001,005
-        return port.has_prefix("usb:") ? 
-            "/dev/bus/usb/%s".printf(port.substring(4).replace(",", "/")) : null;
-    }
-    
-#if HAVE_UDEV
-    private string? get_name_for_uuid(string uuid) {
-        foreach (Volume volume in volume_monitor.get_volumes()) {
-            if (volume.get_identifier(VolumeIdentifier.UUID) == uuid) {
-                return volume.get_name();
-            }
-        }
-        return null;
-    }
-    
-    private string? get_icon_for_uuid(string uuid) {
-        foreach (Volume volume in volume_monitor.get_volumes()) {
-            if (volume.get_identifier(VolumeIdentifier.UUID) == uuid) {
-                return volume.get_symbolic_icon().to_string();
-            }
-        }
-        return null;
-    }
-#endif
-
     private void update_camera_table() throws GPhotoError {
         // need to do this because virtual ports come and go in the USB world (and probably others)
         GPhoto.PortInfoList port_info_list;
@@ -217,8 +177,6 @@ public class CameraTable {
         // add cameras which were not present before
         foreach (string port in detected_map.keys) {
             string name = detected_map.get(port);
-            string display_name = null;
-            string? icon = null;
             string uri = get_port_uri(port);
 
             if (camera_map.has_key(uri)) {
@@ -227,41 +185,7 @@ public class CameraTable {
                 
                 continue;
             }
-            
-#if HAVE_UDEV
-            // Get display name for camera.
-            string path = get_port_path(port);
-            if (null != path) {
-                GUdev.Device device = client.query_by_device_file(path);
-                string serial = device.get_property("ID_SERIAL_SHORT");
-                if (null != serial) {
-                    // Try to get the name and icon.
-                    display_name = get_name_for_uuid(serial);
-                    icon = get_icon_for_uuid(serial);
-                }
-                if (null == display_name) {
-                    display_name = device.get_sysfs_attr("product");
-                } 
-                if (null == display_name) {
-                    display_name = device.get_property("ID_MODEL");
-                }
-            }
-#endif
-
-            if (port.has_prefix("disk:")) {
-                try {
-                    var mount = File.new_for_path (port.substring(5)).find_enclosing_mount();
-                    var volume = mount.get_volume();
-                    // Translators: First %s is the name of camera as gotten from GPhoto, second is the GVolume name, e.g. Mass storage camera (510MB volume)
-                    display_name = _("%s (%s)").printf (name, volume.get_name ());
-                    icon = volume.get_symbolic_icon().to_string();
 
-                } catch (Error e) { }
-            }
-            if (null == display_name) {
-                // Default to GPhoto detected name.
-                display_name = name;
-            }
             int index = port_info_list.lookup_path(port);
             if (index < 0)
                 do_op((GPhoto.Result) index, "lookup port %s".printf(port));
@@ -283,14 +207,9 @@ public class CameraTable {
             do_op(abilities_list.get_abilities(index, out camera_abilities), 
                 "lookup camera abilities for %s".printf(name));
                 
-            GPhoto.Camera gcamera;
-            do_op(GPhoto.Camera.create(out gcamera), "create camera object for %s".printf(name));
-            do_op(gcamera.set_abilities(camera_abilities), "set camera abilities for %s".printf(name));
-            do_op(gcamera.set_port_info(port_info), "set port info for %s on %s".printf(name, port));
-            
             debug("Adding to camera table: %s @ %s", name, port);
             
-            DiscoveredCamera camera = new DiscoveredCamera(gcamera, uri, display_name, icon);
+            var camera = new DiscoveredCamera(name, port, port_info, camera_abilities);
             camera_map.set(uri, camera);
             
             camera_added(camera);
diff --git a/src/camera/DiscoveredCamera.vala b/src/camera/DiscoveredCamera.vala
new file mode 100644
index 0000000..700af8b
--- /dev/null
+++ b/src/camera/DiscoveredCamera.vala
@@ -0,0 +1,119 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later).  See the COPYING file in this distribution.
+ */
+
+public class DiscoveredCamera {
+    public GPhoto.Camera gcamera;
+    public string uri;
+    public string display_name;
+    public string? icon;
+
+    private string port;
+    private string camera_name;
+    private string[] mount_uris;
+
+    public DiscoveredCamera(string name, string port, GPhoto.PortInfo port_info, GPhoto.CameraAbilities camera_abilities) throws GPhotoError {
+        this.port = port;
+        this.camera_name = name;
+        this.uri = "gphoto2://[%s]".printf(port);
+
+        this.mount_uris = new string[0];
+        this.mount_uris += this.uri;
+        this.mount_uris += "mtp://[%s]".printf(port);
+
+        var res = GPhoto.Camera.create(out this.gcamera);
+
+        if (res != GPhoto.Result.OK) {
+            throw new GPhotoError.LIBRARY("[%d] Unable to create camera object for %s: %s",
+                (int) res, name, res.as_string());
+        }
+
+        res = gcamera.set_abilities(camera_abilities);
+        if (res != GPhoto.Result.OK) {
+            throw new GPhotoError.LIBRARY("[%d] Unable to set camera abilities for %s: %s",
+                (int) res, name, res.as_string());
+        }
+
+        res = gcamera.set_port_info(port_info);
+        if (res != GPhoto.Result.OK) {
+            throw new GPhotoError.LIBRARY("[%d] Unable to set port infor for %s: %s",
+                (int) res, name, res.as_string());
+        }
+
+        var path = get_port_path(port);
+        if (path != null) {
+            var monitor = VolumeMonitor.get();
+            foreach (var volume in monitor.get_volumes()) {
+                if (volume.get_identifier(VolumeIdentifier.UNIX_DEVICE) == path) {
+                    this.display_name = volume.get_name();
+                    this.icon = volume.get_symbolic_icon().to_string();
+                }
+            }
+
+#if HAVE_UDEV
+            var client = new GUdev.Client(null);
+            var device = client.query_by_device_file(path);
+
+
+            // Create alternative uris (used for unmount)
+            var serial = device.get_property("ID_SERIAL");
+            this.mount_uris += "gphoto2://%s".printf(serial);
+            this.mount_uris += "mtp://%s".printf(serial);
+
+            // Look-up alternative display names
+            if (display_name == null) {
+                display_name = device.get_sysfs_attr("product");
+            }
+
+            if (display_name == null) {
+                display_name = device.get_property("ID_MODEL");
+            }
+#endif
+        }
+
+        if (port.has_prefix("disk:")) {
+            try {
+                var mount = File.new_for_path (port.substring(5)).find_enclosing_mount();
+                var volume = mount.get_volume();
+                if (volume != null) {
+                    // Translators: First %s is the name of camera as gotten from GPhoto, second is the GVolume name, e.g. Mass storage camera (510MB volume)
+                    display_name = _("%s (%s)").printf (name, volume.get_name ());
+                    icon = volume.get_symbolic_icon().to_string();
+                } else {
+                    // Translators: First %s is the name of camera as gotten from GPhoto, second is the GMount name, e.g. Mass storage camera (510MB volume)
+                    display_name = _("%s (%s)").printf (name, mount.get_name ());
+                    icon = mount.get_symbolic_icon().to_string();
+                }
+
+            } catch (Error e) { }
+        }
+
+        if (display_name == null) {
+            this.display_name = camera_name;
+        }
+    }
+
+    public Mount? get_mount() {
+        foreach (var uri in this.mount_uris) {
+            var f = File.new_for_uri(uri);
+            try {
+                var mount = f.find_enclosing_mount(null);
+                if (mount != null)
+                    return mount;
+            } catch (Error error) {}
+        }
+
+        return null;
+    }
+
+    private string? get_port_path(string port) {
+        // Accepted format is usb:001,005
+        return port.has_prefix("usb:") ? 
+            "/dev/bus/usb/%s".printf(port.substring(4).replace(",", "/")) : null;
+    }
+ 
+}
+
+
diff --git a/src/camera/GPhoto.vala b/src/camera/GPhoto.vala
index 9bcb151..702f307 100644
--- a/src/camera/GPhoto.vala
+++ b/src/camera/GPhoto.vala
@@ -93,7 +93,7 @@ namespace GPhoto {
     }
 
     // For CameraFileInfoFile, CameraFileInfoPreview, and CameraStorageInformation.  See:
-    // http://redmine.yorba.org/issues/1851
+    // https://bugzilla.gnome.org/show_bug.cgi?id=716252
     // https://bugzilla.redhat.com/show_bug.cgi?id=585676
     // https://sourceforge.net/tracker/?func=detail&aid=3000198&group_id=8874&atid=108874
     public const int MAX_FILENAME_LENGTH = 63;
@@ -129,11 +129,10 @@ namespace GPhoto {
 
     // Libgphoto will in some instances refuse to get metadata from a camera, but the camera is accessible as a
     // filesystem.  In these cases shotwell can access the file directly. See:
-    // http://redmine.yorba.org/issues/2959
+    // https://bugzilla.gnome.org/show_bug.cgi?id=716915
     public PhotoMetadata? get_fallback_metadata(Camera camera, Context context, string folder, string filename) {
         // Fixme: Why do we need to query get_storageinfo here first?
         GPhoto.CameraStorageInformation[] sifs = null;
-        int count = 0;
         camera.get_storageinfo(out sifs, context);
         
         GPhoto.PortInfo port_info;
diff --git a/src/camera/ImportPage.vala b/src/camera/ImportPage.vala
index 84d7cbe..a5d3b4e 100644
--- a/src/camera/ImportPage.vala
+++ b/src/camera/ImportPage.vala
@@ -21,13 +21,13 @@ abstract class ImportSource : ThumbnailSource, Indexable {
     private string folder;
     private string filename;
     private ulong file_size;
-    private time_t modification_time;
+    private DateTime modification_time;
     private Gdk.Pixbuf? preview = null;
     private string? indexable_keywords = null;
     
     protected ImportSource(string camera_name, GPhoto.Camera camera, int fsid, string folder,
-        string filename, ulong file_size, time_t modification_time) {
-        this.camera_name = camera_name;
+        string filename, ulong file_size, DateTime modification_time) {
+        this.camera_name =camera_name;
         this.camera = camera;
         this.fsid = fsid;
         this.folder = folder;
@@ -65,7 +65,7 @@ abstract class ImportSource : ThumbnailSource, Indexable {
         return file_size;
     }
     
-    public time_t get_modification_time() {
+    public DateTime get_modification_time() {
         return modification_time;
     }
     
@@ -73,7 +73,7 @@ abstract class ImportSource : ThumbnailSource, Indexable {
         return preview;
     }
 
-    public virtual time_t get_exposure_time() {
+    public virtual DateTime get_exposure_time() {
         return get_modification_time();
     }
 
@@ -110,7 +110,7 @@ abstract class ImportSource : ThumbnailSource, Indexable {
 
 class VideoImportSource : ImportSource {
     public VideoImportSource(string camera_name, GPhoto.Camera camera, int fsid, string folder, 
-        string filename, ulong file_size, time_t modification_time) {
+        string filename, ulong file_size, DateTime modification_time) {
         base(camera_name, camera, fsid, folder, filename, file_size, modification_time);
     }
     
@@ -159,7 +159,7 @@ class PhotoImportSource : ImportSource {
     private PhotoImportSource? associated = null; // JPEG source for RAW+JPEG
     
     public PhotoImportSource(string camera_name, GPhoto.Camera camera, int fsid, string folder, 
-        string filename, ulong file_size, time_t modification_time, PhotoFileFormat file_format) {
+        string filename, ulong file_size, DateTime modification_time, PhotoFileFormat file_format) {
         base(camera_name, camera, fsid, folder, filename, file_size, modification_time);
         this.file_format = file_format;
     }
@@ -200,7 +200,7 @@ class PhotoImportSource : ImportSource {
         this.exif_md5 = exif_md5;
     }
 
-    public override time_t get_exposure_time() {
+    public override DateTime get_exposure_time() {
         if (metadata == null)
             return get_modification_time();
         
@@ -340,10 +340,10 @@ class ImportPreview : MediaSourceItem {
                     if (duplicated_photo_id.is_valid()) {
                         // Check exposure timestamp
                         LibraryPhoto duplicated_photo = LibraryPhoto.global.fetch(duplicated_photo_id);
-                        time_t photo_exposure_time = photo_import_source.get_exposure_time();
-                        time_t duplicated_photo_exposure_time = duplicated_photo.get_exposure_time();
+                        DateTime photo_exposure_time = photo_import_source.get_exposure_time();
+                        DateTime duplicated_photo_exposure_time = duplicated_photo.get_exposure_time();
                         
-                        if (photo_exposure_time == duplicated_photo_exposure_time) {
+                        if (photo_exposure_time.equal(duplicated_photo_exposure_time)) {
                             duplicated_file = DuplicatedFile.create_from_photo_id(
                                 LibraryPhoto.global.get_basename_filesize_duplicate(
                                 get_import_source().get_filename(), (int64) filesize));
@@ -485,7 +485,7 @@ public class ImportPage : CheckerboardPage {
         private string filename;
         private uint64 filesize;
         private PhotoMetadata metadata;
-        private time_t exposure_time;
+        private DateTime exposure_time;
         private CameraImportJob? associated = null;
         private BackingPhotoRow? associated_file = null;
         private DuplicatedFile? duplicated_file;
@@ -503,12 +503,13 @@ public class ImportPage : CheckerboardPage {
             assert(fulldir != null);
             filename = import_file.get_filename();
             filesize = import_file.get_filesize();
-            metadata = (import_file is PhotoImportSource) ?
-                (import_file as PhotoImportSource).get_metadata() : null;
+            var photo_import_source = import_file as PhotoImportSource;
+            metadata = (photo_import_source != null) ?
+                photo_import_source.get_metadata() : null;
             exposure_time = import_file.get_exposure_time();
         }
         
-        public time_t get_exposure_time() {
+        public DateTime get_exposure_time() {
             return exposure_time;
         }
         
@@ -516,8 +517,8 @@ public class ImportPage : CheckerboardPage {
             return duplicated_file;
         }
 
-        public override time_t get_exposure_time_override() {
-            return (import_file is VideoImportSource) ? get_exposure_time() : 0;
+        public override DateTime? get_exposure_time_override() {
+            return (import_file is VideoImportSource) ? get_exposure_time() : null;
         }
         
         public override string get_dest_identifier() {
@@ -682,16 +683,13 @@ public class ImportPage : CheckerboardPage {
     private Gtk.Label camera_label = new Gtk.Label(null);
     private Gtk.CheckButton hide_imported;
     private Gtk.ProgressBar progress_bar = new Gtk.ProgressBar();
-    private GPhoto.Camera camera;
-    private string uri;
+    private DiscoveredCamera dcamera;
     private bool busy = false;
     private bool refreshed = false;
     private GPhoto.Result refresh_result = GPhoto.Result.OK;
     private string refresh_error = null;
-    private string camera_name;
     private VolumeMonitor volume_monitor = null;
     private ImportPage? local_ref = null;
-    private string? icon;
     private ImportPageSearchViewFilter search_filter = new ImportPageSearchViewFilter();
     private HideImportedViewFilter hide_imported_filter = new HideImportedViewFilter();
     private CameraViewTracker tracker;
@@ -707,28 +705,15 @@ public class ImportPage : CheckerboardPage {
         LIBRARY_ERROR
     }
     
-    public ImportPage(GPhoto.Camera camera, string uri, string? display_name = null, string? icon = null) {
+    public ImportPage(DiscoveredCamera dcamera) {
         base(_("Camera"));
-        this.camera = camera;
-        this.uri = uri;
-        this.import_sources = new ImportSourceCollection("ImportSources for %s".printf(uri));
-        this.icon = icon;
+        this.dcamera = dcamera;
+        this.import_sources = new ImportSourceCollection("ImportSources for %s".printf(dcamera.uri));
         
         tracker = new CameraViewTracker(get_view());
         
-        // Get camera name.
-        if (null != display_name) {
-            camera_name = display_name;
-        } else {
-            GPhoto.CameraAbilities abilities;
-            GPhoto.Result res = camera.get_abilities(out abilities);
-            if (res != GPhoto.Result.OK) {
-                debug("Unable to get camera abilities: %s", res.to_full_string());
-                camera_name = _("Camera");
-            }
-        }
-        camera_label.set_text(camera_name);
-        set_page_name(camera_name);
+        camera_label.set_text(dcamera.display_name);
+        set_page_name(dcamera.display_name);
         
         // Mount.unmounted signal is *only* fired when a VolumeMonitor has been instantiated.
         this.volume_monitor = VolumeMonitor.get();
@@ -846,6 +831,14 @@ public class ImportPage : CheckerboardPage {
         return tracker;
     }
 
+    protected override string get_view_empty_icon() {
+        if (this.dcamera.icon != null) {
+            return this.dcamera.icon;
+        }
+
+        return "camera-photo-symbolic";
+    }
+
     protected override string get_view_empty_message() {
         return _("The camera seems to be empty. No photos/videos found to import");
     }
@@ -855,8 +848,8 @@ public class ImportPage : CheckerboardPage {
     }
 
     private static int64 preview_comparator(void *a, void *b) {
-        return ((ImportPreview *) a)->get_import_source().get_exposure_time()
-            - ((ImportPreview *) b)->get_import_source().get_exposure_time();
+        return nullsafe_date_time_comperator(((ImportPreview *) a)->get_import_source().get_exposure_time(),
+        ((ImportPreview *) b)->get_import_source().get_exposure_time());
     }
     
     private static bool preview_comparator_predicate(DataObject object, Alteration alteration) {
@@ -864,7 +857,7 @@ public class ImportPage : CheckerboardPage {
     }
     
     private int64 import_job_comparator(void *a, void *b) {
-        return ((CameraImportJob *) a)->get_exposure_time() - ((CameraImportJob *) b)->get_exposure_time();
+        return nullsafe_date_time_comperator(((CameraImportJob *) a)->get_exposure_time(), ((CameraImportJob *) b)->get_exposure_time());
     }
     
     protected override void init_collect_ui_filenames(Gee.List<string> ui_filenames) {
@@ -896,11 +889,11 @@ public class ImportPage : CheckerboardPage {
     }
 
     public GPhoto.Camera get_camera() {
-        return camera;
+        return dcamera.gcamera;
     }
     
     public string get_uri() {
-        return uri;
+        return dcamera.uri;
     }
     
     public bool is_busy() {
@@ -998,27 +991,9 @@ public class ImportPage : CheckerboardPage {
                 }
                 
                 // if locked because it's mounted, offer to unmount
-                debug("Checking if %s is mounted…", uri);
+                debug("Checking if %s is mounted…", dcamera.uri);
 
-                File uri = File.new_for_uri(uri);
-
-                Mount mount = null;
-                try {
-                    mount = uri.find_enclosing_mount(null);
-                } catch (Error err) {
-                    // error means not mounted
-                }
-
-                // Could not find mount for gphoto2://, re-try with mtp://
-                // It seems some devices are mounted using MTP and not gphoto2 daemon
-                if (mount == null && this.uri.has_prefix("gphoto2")) {
-                    uri = File.new_for_uri("mtp" + this.uri.substring(7));
-                    try {
-                        mount = uri.find_enclosing_mount(null);
-                    } catch (Error err) {
-                        // error means not mounted
-                    }
-                }
+                var mount = dcamera.get_mount();
                 
                 if (mount != null) {
                     // it's mounted, offer to unmount for the user
@@ -1128,7 +1103,7 @@ public class ImportPage : CheckerboardPage {
      * @param search_target The name of the directory to look for.
      */
     private bool check_directory_exists(int fsid, string dir, string search_target) {
-        string? fulldir = get_fulldir(camera, camera_name, fsid, dir);
+        string? fulldir = get_fulldir(dcamera.gcamera, dcamera.display_name, fsid, dir);
         GPhoto.Result result;
         GPhoto.CameraList folders;
 
@@ -1138,7 +1113,7 @@ public class ImportPage : CheckerboardPage {
             return false;
         }
 
-        result = camera.list_folders(fulldir, folders, spin_idle_context.context);
+        result = dcamera.gcamera.list_folders(fulldir, folders, spin_idle_context.context);
         if (result != GPhoto.Result.OK) {
             // fetching the list failed - can't determine whether specified dir is present
             return false;
@@ -1167,7 +1142,7 @@ public class ImportPage : CheckerboardPage {
         update_status(busy, false);
         
         refresh_error = null;
-        refresh_result = camera.init(spin_idle_context.context);
+        refresh_result = dcamera.gcamera.init(spin_idle_context.context);
 
         // If we fail to claim the device, we might have run into a conflict
         // with gvfs-gphoto2-volume-monitor. Back off, try again after
@@ -1209,7 +1184,7 @@ public class ImportPage : CheckerboardPage {
         Gee.ArrayList<ImportSource> import_list = new Gee.ArrayList<ImportSource>();
         
         GPhoto.CameraStorageInformation[] sifs = null;
-        refresh_result = camera.get_storageinfo(out sifs, spin_idle_context.context);
+        refresh_result = dcamera.gcamera.get_storageinfo(out sifs, spin_idle_context.context);
         if (refresh_result == GPhoto.Result.OK) {
             for (int fsid = 0; fsid < sifs.length; fsid++) {
                 // Check well-known video and image paths first to prevent accidental
@@ -1302,7 +1277,7 @@ public class ImportPage : CheckerboardPage {
         progress_bar.set_text("");
         progress_bar.set_fraction(0.0);
         
-        GPhoto.Result res = camera.exit(spin_idle_context.context);
+        GPhoto.Result res = dcamera.gcamera.exit(spin_idle_context.context);
         if (res != GPhoto.Result.OK) {
             // log but don't fail
             warning("Unable to unlock camera: %s", res.to_full_string());
@@ -1386,7 +1361,7 @@ public class ImportPage : CheckerboardPage {
     }
 
     private bool enumerate_files(int fsid, string dir, Gee.ArrayList<ImportSource> import_list) {
-        string? fulldir = get_fulldir(camera, camera_name, fsid, dir);
+        string? fulldir = get_fulldir(dcamera.gcamera, dcamera.display_name, fsid, dir);
         if (fulldir == null) {
             warning("Skipping enumerating %s: invalid folder name", dir);
             
@@ -1401,7 +1376,7 @@ public class ImportPage : CheckerboardPage {
             return false;
         }
         
-        refresh_result = camera.list_files(fulldir, files, spin_idle_context.context);
+        refresh_result = dcamera.gcamera.list_files(fulldir, files, spin_idle_context.context);
         if (refresh_result != GPhoto.Result.OK) {
             warning("Unable to list files in %s: %s", fulldir, refresh_result.to_full_string());
             
@@ -1424,7 +1399,7 @@ public class ImportPage : CheckerboardPage {
             
             try {
                 GPhoto.CameraFileInfo info;
-                if (!GPhoto.get_info(spin_idle_context.context, camera, fulldir, filename, out info)) {
+                if (!GPhoto.get_info(spin_idle_context.context, dcamera.gcamera, fulldir, filename, out info)) {
                     warning("Skipping import of %s/%s: name too long", fulldir, filename);
                     
                     continue;
@@ -1438,8 +1413,8 @@ public class ImportPage : CheckerboardPage {
                 }
                 
                 if (VideoReader.is_supported_video_filename(filename)) {
-                    VideoImportSource video_source = new VideoImportSource(camera_name, camera,
-                        fsid, dir, filename, info.file.size, info.file.mtime);
+                    VideoImportSource video_source = new VideoImportSource(dcamera.display_name, dcamera.gcamera,
+                        fsid, dir, filename, info.file.size, new DateTime.from_unix_utc(info.file.mtime));
                     import_list.add(video_source);
                 } else {
                     // determine file format from type, and then from file extension
@@ -1454,8 +1429,8 @@ public class ImportPage : CheckerboardPage {
                             continue;
                         }
                     }
-                    import_list.add(new PhotoImportSource(camera_name, camera, fsid, dir, filename,
-                        info.file.size, info.file.mtime, file_format));
+                    import_list.add(new PhotoImportSource(dcamera.display_name, dcamera.gcamera, fsid, dir, filename,
+                        info.file.size, new DateTime.from_unix_utc(info.file.mtime), file_format));
                 }
                 
                 progress_bar.pulse();
@@ -1479,7 +1454,7 @@ public class ImportPage : CheckerboardPage {
             return false;
         }
         
-        refresh_result = camera.list_folders(fulldir, folders, spin_idle_context.context);
+        refresh_result = dcamera.gcamera.list_folders(fulldir, folders, spin_idle_context.context);
         if (refresh_result != GPhoto.Result.OK) {
             warning("Unable to list folders in %s: %s", fulldir, refresh_result.to_full_string());
             
@@ -1498,8 +1473,12 @@ public class ImportPage : CheckerboardPage {
                 return false;
             }
             
-            if (!enumerate_files(fsid, append_path(dir, subdir), import_list))
-                return false;
+            if (subdir.has_prefix(".")) {
+                debug("Skipping hidden sub-folder %s in %s", subdir, dir);
+            } else {
+                if (!enumerate_files(fsid, append_path(dir, subdir), import_list))
+                    return false;
+            }
         }
         
         return true;
@@ -1575,7 +1554,7 @@ public class ImportPage : CheckerboardPage {
             PhotoMetadata? metadata = null;
             if (!VideoReader.is_supported_video_filename(filename)) {
                 try {
-                    metadata = GPhoto.load_metadata(spin_idle_context.context, camera, fulldir,
+                    metadata = GPhoto.load_metadata(spin_idle_context.context, dcamera.gcamera, fulldir,
                         filename);
                 } catch (Error err) {
                     warning("Unable to fetch metadata for %s/%s: %s", fulldir, filename,
@@ -1604,7 +1583,7 @@ public class ImportPage : CheckerboardPage {
                     preview_fulldir = associated.get_fulldir();
                     preview_filename = associated.get_filename();
                 }
-                preview = GPhoto.load_preview(spin_idle_context.context, camera, preview_fulldir,
+                preview = GPhoto.load_preview(spin_idle_context.context, dcamera.gcamera, preview_fulldir,
                     preview_filename, out preview_md5);
             } catch (Error err) {
                 // only issue the warning message if we're not reading a video. GPhoto is capable
@@ -1621,17 +1600,18 @@ public class ImportPage : CheckerboardPage {
             debug("camera MD5 %s: exif=%s preview=%s", filename, exif_only_md5, preview_md5);
 #endif
 
-            if (import_source is VideoImportSource)
-                (import_source as VideoImportSource).update(preview);
+            var video_import_source = import_source as VideoImportSource;
+            if (video_import_source != null)
+                video_import_source.update(preview);
 
-            if (import_source is PhotoImportSource)
-                (import_source as PhotoImportSource).update(preview, preview_md5, metadata,
-                    exif_only_md5);
+            var photo_import_source = import_source as PhotoImportSource;
+            if (photo_import_source != null)
+                photo_import_source.update(preview, preview_md5, metadata, exif_only_md5);
             
             if (associated != null) {
                 try {
                     PhotoMetadata? associated_metadata = GPhoto.load_metadata(spin_idle_context.context, 
-                        camera, associated.get_fulldir(), associated.get_filename());
+                        dcamera.gcamera, associated.get_fulldir(), associated.get_filename());
                     associated.update(preview, preview_md5, associated_metadata, null);
                 } catch (Error err) {
                     warning("Unable to fetch metadata for %s/%s: %s",  associated.get_fulldir(),
@@ -1671,7 +1651,7 @@ public class ImportPage : CheckerboardPage {
     }
     
     private void import(Gee.Iterable<DataObject> items) {
-        GPhoto.Result res = camera.init(spin_idle_context.context);
+        GPhoto.Result res = dcamera.gcamera.init(spin_idle_context.context);
         if (res != GPhoto.Result.OK) {
             AppWindow.error_message(_("Unable to lock camera: %s").printf(res.to_full_string()));
             
@@ -1712,14 +1692,14 @@ public class ImportPage : CheckerboardPage {
             jobs.add(import_job);
         }
         
-        debug("Importing %d files from %s", jobs.size, camera_name);
+        debug("Importing %d files from %s", jobs.size, dcamera.display_name);
         
         if (jobs.size > 0) {
             // see import_reporter() to see why this is held during the duration of the import
             assert(local_ref == null);
             local_ref = this;
             
-            BatchImport batch_import = new BatchImport(jobs, camera_name, import_reporter,
+            BatchImport batch_import = new BatchImport(jobs, dcamera.display_name, import_reporter,
                 null, already_imported);
             batch_import.import_job_failed.connect(on_import_job_failed);
             batch_import.import_complete.connect(close_import);
@@ -1811,7 +1791,7 @@ public class ImportPage : CheckerboardPage {
     }
 
     private void close_import() {
-        GPhoto.Result res = camera.exit(spin_idle_context.context);
+        GPhoto.Result res = dcamera.gcamera.exit(spin_idle_context.context);
         if (res != GPhoto.Result.OK) {
             // log but don't fail
             message("Unable to unlock camera: %s", res.to_full_string());
diff --git a/src/config/Config.vala b/src/config/Config.vala
index 0e2798a..3081ff0 100644
--- a/src/config/Config.vala
+++ b/src/config/Config.vala
@@ -26,7 +26,7 @@ public class Facade : ConfigurationFacade {
     public signal void colors_changed();
 
     private Facade() {
-        base(new GSettingsConfigurationEngine());
+        base(new GSettingsConfigurationEngine(Shotwell.ProfileManager.get_instance().id()));
 
         transparent_background_type_changed.connect(on_color_name_changed);
         transparent_background_color_changed.connect(on_color_name_changed);
diff --git a/src/config/ConfigurationInterfaces.vala b/src/config/ConfigurationInterfaces.vala
index a8d8192..12c7da1 100644
--- a/src/config/ConfigurationInterfaces.vala
+++ b/src/config/ConfigurationInterfaces.vala
@@ -39,6 +39,7 @@ public enum ConfigurableProperty {
     DISPLAY_EXTENDED_PROPERTIES,
     DISPLAY_SIDEBAR,
     DISPLAY_TOOLBAR,
+    DISPLAY_MAP_WIDGET,
     DISPLAY_SEARCH_BAR,
     DISPLAY_PHOTO_RATINGS,
     DISPLAY_PHOTO_TAGS,
@@ -149,7 +150,10 @@ public enum ConfigurableProperty {
 
             case DISPLAY_TOOLBAR:
                 return "DISPLAY_TOOLBAR";
-                
+
+            case DISPLAY_MAP_WIDGET:
+                return "DISPLAY_MAP_WIDGET";
+
             case DISPLAY_SEARCH_BAR:
                 return "DISPLAY_SEARCH_BAR";
                 
@@ -400,6 +404,9 @@ public abstract class ConfigurationFacade : Object {
             case ConfigurableProperty.IMPORT_DIR:
                 import_directory_changed();
             break;
+            default:
+                // We do not support notification for the rest of the properties
+            break;
         }
     }
 
@@ -718,7 +725,6 @@ public abstract class ConfigurationFacade : Object {
             on_configuration_error(err);
         }
     }
-    
 
     //
     // display toolbar
@@ -742,6 +748,26 @@ public abstract class ConfigurationFacade : Object {
     }
 
     //
+    // display map widget
+    //
+    public virtual bool get_display_map_widget() {
+        try {
+            return get_engine().get_bool_property(ConfigurableProperty.DISPLAY_MAP_WIDGET);
+        } catch (ConfigurationError err) {
+            on_configuration_error(err);
+
+            return false;
+        }
+    }
+    public virtual void set_display_map_widget(bool display) {
+        try {
+            get_engine().set_bool_property(ConfigurableProperty.DISPLAY_MAP_WIDGET, display);
+        } catch (ConfigurationError err) {
+            on_configuration_error(err);
+        }
+    }
+
+    //
     // display search & filter toolbar
     //
     public virtual bool get_display_search_bar() {
diff --git a/src/config/GSettingsEngine.vala b/src/config/GSettingsEngine.vala
index d35eb93..d4d95c6 100644
--- a/src/config/GSettingsEngine.vala
+++ b/src/config/GSettingsEngine.vala
@@ -5,7 +5,7 @@
  */
 
 public class GSettingsConfigurationEngine : ConfigurationEngine, GLib.Object {
-    private const string ROOT_SCHEMA_NAME = "org.yorba.shotwell";
+    private const string ROOT_SCHEMA_NAME = "org.gnome.shotwell";
     private const string PREFS_SCHEMA_NAME = ROOT_SCHEMA_NAME + ".preferences";
     private const string UI_PREFS_SCHEMA_NAME = PREFS_SCHEMA_NAME + ".ui";
     private const string SLIDESHOW_PREFS_SCHEMA_NAME = PREFS_SCHEMA_NAME + ".slideshow";
@@ -25,8 +25,11 @@ public class GSettingsConfigurationEngine : ConfigurationEngine, GLib.Object {
     private string[] schema_names;
     private string[] key_names;
     private Gee.HashMap<string, Settings> settings_cache = new Gee.HashMap<string, Settings>();
-    
-    public GSettingsConfigurationEngine() {
+
+    private string profile = "";
+
+    public GSettingsConfigurationEngine(string? profile) {
+        this.profile = profile == null ? "" : profile;
         schema_names = new string[ConfigurableProperty.NUM_PROPERTIES];
 
         schema_names[ConfigurableProperty.AUTO_IMPORT_FROM_LIBRARY] = FILES_PREFS_SCHEMA_NAME;
@@ -47,6 +50,7 @@ public class GSettingsConfigurationEngine : ConfigurationEngine, GLib.Object {
         schema_names[ConfigurableProperty.DISPLAY_EXTENDED_PROPERTIES] = UI_PREFS_SCHEMA_NAME;
         schema_names[ConfigurableProperty.DISPLAY_SIDEBAR] = UI_PREFS_SCHEMA_NAME;
         schema_names[ConfigurableProperty.DISPLAY_TOOLBAR] = UI_PREFS_SCHEMA_NAME;
+        schema_names[ConfigurableProperty.DISPLAY_MAP_WIDGET] = UI_PREFS_SCHEMA_NAME;
         schema_names[ConfigurableProperty.DISPLAY_SEARCH_BAR] = UI_PREFS_SCHEMA_NAME;
         schema_names[ConfigurableProperty.DISPLAY_PHOTO_RATINGS] = UI_PREFS_SCHEMA_NAME;
         schema_names[ConfigurableProperty.DISPLAY_PHOTO_TAGS] = UI_PREFS_SCHEMA_NAME;
@@ -120,6 +124,7 @@ public class GSettingsConfigurationEngine : ConfigurationEngine, GLib.Object {
         key_names[ConfigurableProperty.DISPLAY_EXTENDED_PROPERTIES] = "display-extended-properties";
         key_names[ConfigurableProperty.DISPLAY_SIDEBAR] = "display-sidebar";
         key_names[ConfigurableProperty.DISPLAY_TOOLBAR] = "display-toolbar";
+        key_names[ConfigurableProperty.DISPLAY_MAP_WIDGET] = "display-map-widget";
         key_names[ConfigurableProperty.DISPLAY_SEARCH_BAR] = "display-search-bar";
         key_names[ConfigurableProperty.DISPLAY_PHOTO_RATINGS] = "display-photo-ratings";
         key_names[ConfigurableProperty.DISPLAY_PHOTO_TAGS] = "display-photo-tags";
@@ -176,7 +181,14 @@ public class GSettingsConfigurationEngine : ConfigurationEngine, GLib.Object {
 
     private Settings get_settings(string schema) {
         if (!this.settings_cache.has_key(schema)) {
-            this.settings_cache[schema] = new Settings(schema);
+            if (schema.has_prefix (ROOT_SCHEMA_NAME)) {
+                var path = schema.replace(ROOT_SCHEMA_NAME, "");
+                path = "/org/gnome/shotwell/%s%s/".printf(profile == "" ? "" : "profiles/" + profile, path.replace(".", "/"));
+                path = path.replace("//", "/");
+                this.settings_cache[schema] = new Settings.with_path (schema, path);
+            } else {
+                this.settings_cache[schema] = new Settings(schema);
+            }
         }
 
         return this.settings_cache[schema];
@@ -229,7 +241,9 @@ public class GSettingsConfigurationEngine : ConfigurationEngine, GLib.Object {
 
         Settings schema_object = get_settings(schema);
 
-        return schema_object.get_int(key);
+        var v = schema_object.get_int(key);
+
+        return v;
     }
     
     private void set_gs_int(string schema, string key, int value) throws ConfigurationError {
@@ -292,7 +306,7 @@ public class GSettingsConfigurationEngine : ConfigurationEngine, GLib.Object {
         if (cleaned_id == null)
             cleaned_id = "default";
 
-        cleaned_id = cleaned_id.replace("org.yorba.shotwell.", "");
+        cleaned_id = cleaned_id.replace("org.gnome.shotwell.", "");
         cleaned_id = cleaned_id.replace(".", "-");
         
         return cleaned_id;
@@ -304,7 +318,7 @@ public class GSettingsConfigurationEngine : ConfigurationEngine, GLib.Object {
             cleaned_id = "default";
         cleaned_id = cleaned_id.replace(".", "-");
         
-        return "org.yorba.shotwell.%s.%s".printf(domain, cleaned_id);
+        return "org.gnome.shotwell.%s.%s".printf(domain, cleaned_id);
     }
     
     private static string make_gsettings_key(string gconf_key) {
@@ -513,4 +527,64 @@ public class GSettingsConfigurationEngine : ConfigurationEngine, GLib.Object {
         }
     }
 
+    /*! @brief Migrates settings data over from old-style /org/yorba/ paths to /org/gnome/ ones.
+     *  Should only be called ONCE, during DB upgrading; otherwise, stale data may be copied
+     *  over newer data by accident.
+     */
+    public static void run_gsettings_migrator_v2() {
+        var source = SettingsSchemaSource.get_default();
+        var schema = source.lookup("org.yorba.shotwell", true);
+        var settings = new Settings.full(schema, null, null);
+    
+        copy_schema(settings);
+    
+        Settings.sync();
+    }
+
+    static void copy_schema(Settings settings) {
+        SettingsSchema schema;
+        ((Object)settings).get("settings-schema", out schema, null);
+        var id = schema.get_id();
+        var path = schema.get_path();
+    
+        var new_id = id.replace("org.yorba.shotwell", "org.gnome.shotwell");
+        var new_path = path.replace("/org/yorba/shotwell", "/org/gnome/shotwell");
+    
+        var new_schema = SettingsSchemaSource.get_default().lookup(new_id, true);
+    
+        // If we cannot find this schema, we cannot migrate the keys anyway, so skip it
+        if (new_schema != null) {
+            var new_settings = new Settings.with_path(new_id, new_path);
+            new_settings.delay();
+    
+            foreach (var k in schema.list_keys()) {
+                var key = schema.get_key(k);
+                var default_value = key.get_default_value();
+                var val = settings.get_value(k);
+                if (val.equal(default_value)) {
+                    debug("%s is default value, skipping", k);
+                    continue;
+                }
+
+                if (!new_schema.has_key(k)) {
+                    debug("Cannot migrate %s as it does not exist", k);
+                    continue;
+                }
+
+                debug("Will migrate %s %s @ %s -> %s:%s %s", k, id, path, new_id, new_path, val.print(true));
+                if (!new_settings.set_value(k, val)) {
+                    debug(" Failed...");
+                }
+            }
+            new_settings.apply();
+        }
+        else {
+            debug("%s does not exist, skipping\n", new_id);
+        }
+    
+        foreach (var c in schema.list_children()) {
+            var child = settings.get_child(c);
+            copy_schema(child);
+        }
+    }
 }
diff --git a/src/core/DataCollection.vala b/src/core/DataCollection.vala
index 83a216d..044f7b6 100644
--- a/src/core/DataCollection.vala
+++ b/src/core/DataCollection.vala
@@ -559,7 +559,7 @@ public class DataCollection {
         if (!properties.unset(name))
             return;
         
-        // only notify if the propery was unset (that is, was set to begin with)
+        // only notify if the property was unset (that is, was set to begin with)
         notify_property_cleared(name);
             
         // notify all items
diff --git a/src/core/DataSourceTypes.vala b/src/core/DataSourceTypes.vala
index a79264f..1baf387 100644
--- a/src/core/DataSourceTypes.vala
+++ b/src/core/DataSourceTypes.vala
@@ -72,9 +72,9 @@ public abstract class EventSource : ThumbnailSource {
         base (object_id);
     }
     
-    public abstract time_t get_start_time();
+    public abstract DateTime? get_start_time();
     
-    public abstract time_t get_end_time();
+    public abstract DateTime? get_end_time();
     
     public abstract uint64 get_total_filesize();
     
diff --git a/src/core/SourceInterfaces.vala b/src/core/SourceInterfaces.vala
index 91a8aca..6e0c149 100644
--- a/src/core/SourceInterfaces.vala
+++ b/src/core/SourceInterfaces.vala
@@ -42,3 +42,18 @@ public interface Indexable : DataSource {
     }
 }
 
+// Positionable DataSources provide a globally locatable point in longitude and latitude degrees
+
+public struct GpsCoords {
+    public int has_gps;
+    public double latitude;
+    public double longitude;
+    public bool equals(ref GpsCoords gps) {
+        return (has_gps == 0 && gps.has_gps == 0) || (latitude == gps.latitude && longitude == gps.longitude);
+    }
+}
+
+public interface Positionable : DataSource {
+    public abstract GpsCoords get_gps_coords();
+    public abstract void set_gps_coords(GpsCoords gps_coords);
+}
diff --git a/src/core/util.vala b/src/core/util.vala
index 9507895..461d2c0 100644
--- a/src/core/util.vala
+++ b/src/core/util.vala
@@ -190,7 +190,12 @@ public bool null_progress_monitor(uint64 count, uint64 total) {
     return true;
 }
 
+public static int64 nullsafe_date_time_comperator(DateTime? time_a, DateTime? time_b) {
+    if (time_a == null && time_b == null) return 0;
 
-double degrees_to_radians(double theta) {
-    return (theta * (GLib.Math.PI / 180.0));
-}
+    if (time_a == null && time_b != null) return -1;
+    if (time_a != null && time_b == null) return 1;
+
+    return time_a.compare(time_b);
+
+}
\ No newline at end of file
diff --git a/src/data_imports/DataImportJob.vala b/src/data_imports/DataImportJob.vala
index 4035ae6..eeaec40 100644
--- a/src/data_imports/DataImportJob.vala
+++ b/src/data_imports/DataImportJob.vala
@@ -13,7 +13,7 @@ public class DataImportJob : BatchImportJob {
     private DataImportSource import_source;
     private File? src_file;
     private uint64 filesize;
-    private time_t exposure_time;
+    private DateTime? exposure_time;
     private DataImportJob? associated = null;
     private HierarchicalTagIndex? detected_htags = null;
     
@@ -48,7 +48,7 @@ public class DataImportJob : BatchImportJob {
         return (detected_htags.size > 0) ? HierarchicalTagIndex.from_paths(detected_htags) : null;
     }
     
-    public time_t get_exposure_time() {
+    public DateTime get_exposure_time() {
         return exposure_time;
     }
     
@@ -158,7 +158,7 @@ public class DataImportJob : BatchImportJob {
         if (title != null)
             photo.set_title(title);
         // exposure time
-        time_t? date_time = src_photo.get_exposure_time();
+        var date_time = src_photo.get_exposure_time();
         if (date_time != null)
             photo.set_exposure_time(date_time);
         // import ID
diff --git a/src/data_imports/DataImportSource.vala b/src/data_imports/DataImportSource.vala
index ba00be3..012abdc 100644
--- a/src/data_imports/DataImportSource.vala
+++ b/src/data_imports/DataImportSource.vala
@@ -20,7 +20,7 @@ public class DataImportSource {
     private string? title = null;
     private string? preview_md5 = null;
     private uint64 file_size;
-    private time_t modification_time;
+    private DateTime modification_time;
     private MetadataDateTime? exposure_time;
     
     public DataImportSource(ImportableMediaItem db_photo) {
@@ -52,7 +52,7 @@ public class DataImportSource {
             if (title == null) {
                 title = (metadata != null) ? metadata.get_title() : null;
             }
-            time_t? date_time = db_photo.get_exposure_time();
+            var date_time = db_photo.get_exposure_time();
             if (date_time != null) {
                 exposure_time = new MetadataDateTime(date_time);
             } else {
@@ -110,7 +110,7 @@ public class DataImportSource {
         return get_name();
     }
     
-    public time_t get_exposure_time() {
+    public DateTime get_exposure_time() {
         return (exposure_time != null) ? exposure_time.get_timestamp() : modification_time;
     }
     
diff --git a/src/data_imports/DataImports.vala b/src/data_imports/DataImports.vala
index a98c91b..258a653 100644
--- a/src/data_imports/DataImports.vala
+++ b/src/data_imports/DataImports.vala
@@ -17,7 +17,7 @@ namespace DataImports {
 
 public void init() throws Error {
     string[] core_ids = new string[0];
-    core_ids += "org.yorba.shotwell.dataimports.fspot";
+    core_ids += "org.gnome.shotwell.dataimports.fspot";
     
     Plugins.register_extension_point(typeof(Spit.DataImports.Service), _("Data Imports"),
         Resources.IMPORT, core_ids);
diff --git a/src/data_imports/DataImportsPluginHost.vala b/src/data_imports/DataImportsPluginHost.vala
index 158b8f4..46cfa46 100644
--- a/src/data_imports/DataImportsPluginHost.vala
+++ b/src/data_imports/DataImportsPluginHost.vala
@@ -474,8 +474,9 @@ private void data_import_reporter(ImportManifest manifest, BatchImportRoll impor
 }
 
 private int64 import_job_comparator(void *a, void *b) {
-    return ((DataImportJob *) a)->get_exposure_time()
-        - ((DataImportJob *) b)->get_exposure_time();
+
+    return nullsafe_date_time_comperator(((DataImportJob *) a)->get_exposure_time(),
+        ((DataImportJob *) b)->get_exposure_time());
 }
 
 }
diff --git a/src/data_imports/DataImportsUI.vala b/src/data_imports/DataImportsUI.vala
index 29791a4..6fb7158 100644
--- a/src/data_imports/DataImportsUI.vala
+++ b/src/data_imports/DataImportsUI.vala
@@ -34,7 +34,7 @@ public class ConcreteDialogPane : Spit.DataImports.DialogPane, GLib.Object {
 public class StaticMessagePane : ConcreteDialogPane {
     public StaticMessagePane(string message_string) {
         Gtk.Label message_label = new Gtk.Label(message_string);
-        (get_widget() as Gtk.Box).pack_start(message_label, true, true, 0);
+        ((Gtk.Box) get_widget()).pack_start(message_label, true, true, 0);
     }
     
     public StaticMessagePane.with_pango(string msg) {
@@ -42,7 +42,7 @@ public class StaticMessagePane : ConcreteDialogPane {
         label.set_markup(msg);
         label.set_line_wrap(true);
         
-        (get_widget() as Gtk.Box).pack_start(label, true, true, 0);
+        ((Gtk.Box) get_widget()).pack_start(label, true, true, 0);
     }
 }
 
@@ -123,7 +123,7 @@ public class LibrarySelectionPane : ConcreteDialogPane {
         button_box.add(import_button);
         content_box.pack_end(button_box, true, false, 6);
         
-        (get_widget() as Gtk.Box).pack_start(content_box, true, true, 0);
+        ((Gtk.Box) get_widget()).pack_start(content_box, true, true, 0);
         
         set_import_button_sensitivity();
     }
@@ -177,7 +177,7 @@ public class ProgressPane : ConcreteDialogPane {
         progress_label = new Gtk.Label("");
         content_box.pack_start(progress_label, false, true, 6);
         
-        (get_widget() as Gtk.Container).add(content_box);
+        ((Gtk.Container) get_widget()).add(content_box);
     }
     
     public void update_progress(double progress, string? progress_message) {
@@ -285,7 +285,7 @@ public class DataImportsDialog : Gtk.Dialog {
             }
         }
         
-        // Intall the central area in all cases
+        // Install the central area in all cases
         central_area_layouter = new Gtk.Box(Gtk.Orientation.VERTICAL, 0);
         ((Gtk.Box) get_content_area()).pack_start(central_area_layouter, true, true, 0);
         
diff --git a/src/db/DatabaseTable.vala b/src/db/DatabaseTable.vala
index 5ec5be1..dea797a 100644
--- a/src/db/DatabaseTable.vala
+++ b/src/db/DatabaseTable.vala
@@ -21,12 +21,12 @@ public abstract class DatabaseTable {
      * tables are created on demand and tables and columns are easily ignored when already present.
      * However, the change should be noted in upgrade_database() as a comment.
      ***/
-    public const int SCHEMA_VERSION = 20;
-    
+    public const int SCHEMA_VERSION = 24;
+
     protected static Sqlite.Database db;
-    
+
     private static int in_transaction = 0;
-    
+
     public string table_name = null;
 
     private static void prepare_db(string filename) {
@@ -287,7 +287,19 @@ public abstract class DatabaseTable {
         if (res != Sqlite.DONE)
             throw_error("DatabaseTable.update_int64_by_id_2 %s.%s".printf(table_name, column), res);
     }
-    
+
+    protected void update_double_by_id_2(int64 id, string column, double value) throws DatabaseError {
+        Sqlite.Statement stmt;
+        prepare_update_by_id(id, column, out stmt);
+
+        int res = stmt.bind_double(1, value);
+        assert(res == Sqlite.OK);
+
+        res = stmt.step();
+        if (res != Sqlite.DONE)
+            throw_error("DatabaseTable.update_double_by_id_2 %s.%s".printf(table_name, column), res);
+    }
+
     protected void delete_by_id(int64 id) throws DatabaseError {
         Sqlite.Statement stmt;
         int res = db.prepare_v2("DELETE FROM %s WHERE id=?".printf(table_name), -1, out stmt);
diff --git a/src/db/Db.vala b/src/db/Db.vala
index 3eca8ce..5072967 100644
--- a/src/db/Db.vala
+++ b/src/db/Db.vala
@@ -293,7 +293,7 @@ private VerifyResult upgrade_database(int input_version) {
     }
     
     version = 16;
-    
+
     //
     // Version 17:
     // * Added comment column to PhotoTable and VideoTable
@@ -349,11 +349,72 @@ private VerifyResult upgrade_database(int input_version) {
     //
     
     version = 20;
+
     
     //
-    // Finalize the upgrade process
+    // Version 21:
+    // * Add has_gps, gps_lat and gps_lon columns to PhotoTable
+
+    if (!DatabaseTable.ensure_column("PhotoTable", "has_gps", "INTEGER DEFAULT -1",
+        "upgrade_database: adding gps_lat column to PhotoTable")
+        || !DatabaseTable.ensure_column("PhotoTable", "gps_lat", "REAL",
+        "upgrade_database: adding gps_lat column to PhotoTable")
+        || !DatabaseTable.ensure_column("PhotoTable", "gps_lon", "REAL",
+        "upgrade_database: adding gps_lon column to PhotoTable")) {
+        return VerifyResult.UPGRADE_ERROR;
+    }
+
+    version = 21;
+
+    //
+    // Version 22:
+    // * Create face detection tables even if feasture is not enabled
+    // * Added face pixels column to FaceLocationTable
+    // * Added face vector column to FaceTable
     //
+    FaceTable.get_instance();
+    FaceLocationTable.get_instance();
+    if (!DatabaseTable.has_column("FaceLocationTable", "vec")) {
+        message("upgrade_database: adding vec column to FaceLocationTable");
+        if (!DatabaseTable.add_column("FaceLocationTable", "vec", "TEXT"))
+            return VerifyResult.UPGRADE_ERROR;
+    }
+    if (!DatabaseTable.has_column("FaceLocationTable", "guess")) {
+        message("upgrade_database: adding guess column to FaceLocationTable");
+        if (!DatabaseTable.add_column("FaceLocationTable", "guess", "INTEGER DEFAULT 0"))
+            return VerifyResult.UPGRADE_ERROR;
+    }
+    if (!DatabaseTable.has_column("FaceTable", "ref")) {
+        message("upgrade_database: adding ref column to FaceTable");
+        if (!DatabaseTable.add_column("FaceTable", "ref", "INTEGER DEFAULT -1"))
+            return VerifyResult.UPGRADE_ERROR;
+    }
     
+    version = 22;
+
+    //
+    // Finalize the upgrade process
+    //
+
+    if (input_version < 23) {
+        // Run the settings migrator to copy settings data from /org/yorba/shotwell to /org/gnome/shotwell
+        GSettingsConfigurationEngine.run_gsettings_migrator_v2();
+    }
+
+    version = 23;
+
+    if (input_version < 24) {
+        // Convert timestamp 0 to NULL to represent unset date and free 0 to be 1.1.1970 00:00
+        message("upgrade_database: Shifting times from 0 to null for unset times");
+        try {
+            PhotoTable.upgrade_for_unset_timestamp();
+            VideoTable.upgrade_for_unset_timestamp();
+            version = 24;
+        } catch (DatabaseError err) {
+            critical("Failed to upgrade database to version 24: %s", err.message);
+        }
+    }
+
     assert(version == DatabaseTable.SCHEMA_VERSION);
     VersionTable.get_instance().update_version(version, Resources.APP_VERSION);
     
diff --git a/src/db/EventTable.vala b/src/db/EventTable.vala
index 593d51c..3b7df17 100644
--- a/src/db/EventTable.vala
+++ b/src/db/EventTable.vala
@@ -25,7 +25,7 @@ public struct EventID {
 public class EventRow {
     public EventID event_id;
     public string? name;
-    public time_t time_created;
+    public int64 time_created;
     public string? primary_source_id;
     public string? comment;
 }
@@ -80,7 +80,7 @@ public class EventTable : DatabaseTable {
             -1, out stmt);
         assert(res == Sqlite.OK);
         
-        time_t time_created = (time_t) now_sec();
+        int64 time_created = now_sec();
         
         res = stmt.bind_text(1, primary_source_id);
         assert(res == Sqlite.OK);
@@ -151,7 +151,7 @@ public class EventTable : DatabaseTable {
         if (row.name != null && row.name.length == 0)
             row.name = null;
         row.primary_source_id = source_id_upgrade(stmt.column_int64(1), stmt.column_text(2));
-        row.time_created = (time_t) stmt.column_int64(3);
+        row.time_created = stmt.column_int64(3);
         row.comment = stmt.column_text(4);
         
         return row;
@@ -183,7 +183,7 @@ public class EventTable : DatabaseTable {
             row.event_id = EventID(stmt.column_int64(0));
             row.name = stmt.column_text(1);
             row.primary_source_id = source_id_upgrade(stmt.column_int64(2), stmt.column_text(3));
-            row.time_created = (time_t) stmt.column_int64(4);            
+            row.time_created = stmt.column_int64(4);            
             row.comment = stmt.column_text(5);
 
             event_rows.add(row);
@@ -218,12 +218,12 @@ public class EventTable : DatabaseTable {
         return update_text_by_id(event_id.id, "primary_source_id", primary_source_id);
     }
     
-    public time_t get_time_created(EventID event_id) {
+    public DateTime? get_time_created(EventID event_id) {
         Sqlite.Statement stmt;
         if (!select_by_id(event_id.id, "time_created", out stmt))
-            return 0;
+            return null;
         
-        return (time_t) stmt.column_int64(0);
+        return new DateTime.from_unix_utc(stmt.column_int64(0));
     }
 
     public bool set_comment(EventID event_id, string new_comment) {
diff --git a/src/db/FaceLocationTable.vala b/src/db/FaceLocationTable.vala
index 8398616..f4c88d7 100644
--- a/src/db/FaceLocationTable.vala
+++ b/src/db/FaceLocationTable.vala
@@ -27,6 +27,7 @@ public class FaceLocationRow {
     public FaceID face_id;
     public PhotoID photo_id;
     public string geometry;
+    public string vec;
 }
 
 public class FaceLocationTable : DatabaseTable {
@@ -42,7 +43,9 @@ public class FaceLocationTable : DatabaseTable {
             + "id INTEGER NOT NULL PRIMARY KEY, "
             + "face_id INTEGER NOT NULL, "
             + "photo_id INTEGER NOT NULL, "
-            + "geometry TEXT"
+            + "geometry TEXT, "
+            + "vec TEXT, "
+            + "guess INTEGER DEFAULT 0"
             + ")", -1, out stmt);
         assert(res == Sqlite.OK);
         
@@ -58,10 +61,10 @@ public class FaceLocationTable : DatabaseTable {
         return instance;
     }
  
-    public FaceLocationRow add(FaceID face_id, PhotoID photo_id, string geometry) throws DatabaseError {
+    public FaceLocationRow add(FaceID face_id, PhotoID photo_id, string geometry, string? vec = null) throws DatabaseError {
         Sqlite.Statement stmt;
         int res = db.prepare_v2(
-            "INSERT INTO FaceLocationTable (face_id, photo_id, geometry) VALUES (?, ?, ?)",
+            "INSERT INTO FaceLocationTable (face_id, photo_id, geometry, vec) VALUES (?, ?, ?, ?)",
              -1, out stmt);
         assert(res == Sqlite.OK);
         
@@ -71,6 +74,9 @@ public class FaceLocationTable : DatabaseTable {
         assert(res == Sqlite.OK);
         res = stmt.bind_text(3, geometry);
         assert(res == Sqlite.OK);
+	if (vec == null) vec = "";
+        res = stmt.bind_text(4, vec);
+        assert(res == Sqlite.OK);
         
         res = stmt.step();
         if (res != Sqlite.DONE)
@@ -81,6 +87,7 @@ public class FaceLocationTable : DatabaseTable {
         row.face_id = face_id;
         row.photo_id = photo_id;
         row.geometry = geometry;
+        row.vec = vec;
         
         return row;
     }
@@ -88,7 +95,7 @@ public class FaceLocationTable : DatabaseTable {
     public Gee.List<FaceLocationRow?> get_all_rows() throws DatabaseError {
         Sqlite.Statement stmt;
         int res = db.prepare_v2(
-            "SELECT id, face_id, photo_id, geometry FROM FaceLocationTable",
+            "SELECT id, face_id, photo_id, geometry, vec FROM FaceLocationTable",
             -1, out stmt);
         assert(res == Sqlite.OK);
         
@@ -107,6 +114,7 @@ public class FaceLocationTable : DatabaseTable {
             row.face_id = FaceID(stmt.column_int64(1));
             row.photo_id = PhotoID(stmt.column_int64(2));
             row.geometry = stmt.column_text(3);
+            row.vec = stmt.column_text(4);
             
             rows.add(row);
         }
@@ -195,4 +203,63 @@ public class FaceLocationTable : DatabaseTable {
         if (res != Sqlite.DONE)
             throw_error("FaceLocationTable.update_face_location_serialized_geometry", res);
     }
+
+    public void update_face_location_face_data(FaceLocation face_location)
+        throws DatabaseError {
+        Sqlite.Statement stmt;
+        int res = db.prepare_v2("UPDATE FaceLocationTable SET geometry=?, vec=? WHERE id=?", -1, out stmt);
+        assert(res == Sqlite.OK);
+
+        FaceLocationData face_data = face_location.get_face_data();
+        res = stmt.bind_text(1, face_data.geometry);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_text(2, face_data.vec);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_int64(3, face_location.get_face_location_id().id);
+        assert(res == Sqlite.OK);
+        
+        res = stmt.step();
+        if (res != Sqlite.DONE)
+            throw_error("FaceLocationTable.update_face_location_serialized_geometry", res);
+    }
+    public Gee.List<FaceLocationRow?> get_face_ref_vecs(Gee.List<FaceRow?> face_rows)
+        throws DatabaseError {
+        Sqlite.Statement stmt;
+
+        string[] where_in = {};
+        foreach (var r in face_rows) {
+            if (r != null) where_in += "?";
+        }
+        int res = db.prepare_v2(
+            "SELECT id, face_id, photo_id, geometry, vec FROM FaceLocationTable WHERE photo_id IN (%s)"
+                    .printf(string.joinv(",", where_in)),
+            -1, out stmt);
+        assert(res == Sqlite.OK);
+        int c = 1;
+        foreach (var r in face_rows) {
+            if (r != null) { 
+                res = stmt.bind_int64(c, r.ref.id);
+                assert(res == Sqlite.OK);
+            }
+            c++;
+        }
+        
+        Gee.List<FaceLocationRow?> rows = new Gee.ArrayList<FaceLocationRow?>();
+        for (;;) {
+            res = stmt.step();
+            if (res == Sqlite.DONE)
+                break;
+            else if (res != Sqlite.ROW)
+                throw_error("FaceLocationTable.get_face_ref_vecs", res);
+            
+            FaceLocationRow row = new FaceLocationRow();
+            row.face_location_id = FaceLocationID(stmt.column_int64(0));
+            row.face_id = FaceID(stmt.column_int64(1));
+            row.photo_id = PhotoID(stmt.column_int64(2));
+            row.geometry = stmt.column_text(3);
+            row.vec = stmt.column_text(4);
+            rows.add(row);
+        }
+        return rows;
+    }
 }
diff --git a/src/db/FaceTable.vala b/src/db/FaceTable.vala
index 4836910..e799f97 100644
--- a/src/db/FaceTable.vala
+++ b/src/db/FaceTable.vala
@@ -25,7 +25,9 @@ public struct FaceID {
 public class FaceRow {
     public FaceID face_id;
     public string name;
-    public time_t time_created;
+    public int64 time_created;
+    public PhotoID ref;
+    public string vec;
 }
 
 public class FaceTable : DatabaseTable {
@@ -40,7 +42,8 @@ public class FaceTable : DatabaseTable {
             + "("
             + "id INTEGER NOT NULL PRIMARY KEY, "
             + "name TEXT NOT NULL, "
-            + "time_created TIMESTAMP"
+            + "time_created TIMESTAMP, "
+            + "ref INTEGER DEFAULT -1"
             + ")", -1, out stmt);
         assert(res == Sqlite.OK);
         
@@ -62,7 +65,7 @@ public class FaceTable : DatabaseTable {
             out stmt);
         assert(res == Sqlite.OK);
         
-        time_t time_created = (time_t) now_sec();
+        var time_created = now_sec();
         
         res = stmt.bind_text(1, name);
         assert(res == Sqlite.OK);
@@ -129,7 +132,7 @@ public class FaceTable : DatabaseTable {
         FaceRow row = new FaceRow();
         row.face_id = face_id;
         row.name = stmt.column_text(0);
-        row.time_created = (time_t) stmt.column_int64(1);
+        row.time_created = stmt.column_int64(1);
         
         return row;
     }
@@ -153,7 +156,7 @@ public class FaceTable : DatabaseTable {
             FaceRow row = new FaceRow();
             row.face_id = FaceID(stmt.column_int64(0));
             row.name = stmt.column_text(1);
-            row.time_created = (time_t) stmt.column_int64(2);
+            row.time_created = stmt.column_int64(2);
             
             rows.add(row);
         }
@@ -164,4 +167,47 @@ public class FaceTable : DatabaseTable {
     public void rename(FaceID face_id, string new_name) throws DatabaseError {
         update_text_by_id_2(face_id.id, "name", new_name);
     }
+
+    public void set_reference(FaceID face_id, PhotoID photo_id)
+        throws DatabaseError {
+        Sqlite.Statement stmt;
+        int res = db.prepare_v2("UPDATE FaceTable SET ref=? WHERE id=?", -1, out stmt);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_int64(1, photo_id.id);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_int64(2, face_id.id);
+        assert(res == Sqlite.OK);
+        
+        res = stmt.step();
+        if (res != Sqlite.DONE)
+            throw_error("FaceTable.set_reference", res);
+    }
+
+    public Gee.List<FaceRow?> get_ref_rows() throws DatabaseError {
+        Sqlite.Statement stmt;
+        int res = db.prepare_v2("SELECT id, name, time_created, ref FROM FaceTable WHERE ref != -1", -1,
+            out stmt);
+        assert(res == Sqlite.OK);
+        
+        Gee.List<FaceRow?> rows = new Gee.ArrayList<FaceRow?>();
+        
+        for (;;) {
+            res = stmt.step();
+            if (res == Sqlite.DONE)
+                break;
+            else if (res != Sqlite.ROW)
+                throw_error("FaceTable.get_all_rows", res);
+            
+            // res == Sqlite.ROW
+            FaceRow row = new FaceRow();
+            row.face_id = FaceID(stmt.column_int64(0));
+            row.name = stmt.column_text(1);
+            row.time_created = stmt.column_int64(2);
+            row.ref = PhotoID(stmt.column_int64(3));
+            
+            rows.add(row);
+        }
+        
+        return rows;
+    }
 }
diff --git a/src/db/PhotoTable.vala b/src/db/PhotoTable.vala
index 24cec86..4e3f672 100644
--- a/src/db/PhotoTable.vala
+++ b/src/db/PhotoTable.vala
@@ -44,9 +44,7 @@ public struct ImportID {
     }
     
     public static ImportID generate() {
-        TimeVal timestamp = TimeVal();
-        timestamp.get_current_time();
-        int64 id = timestamp.tv_sec;
+        int64 id = GLib.get_real_time () / Util.USEC_PER_SEC;
         
         return ImportID(id);
     }
@@ -72,7 +70,7 @@ public struct ImportID {
 public class PhotoRow {
     public PhotoID photo_id;
     public BackingPhotoRow master;
-    public time_t exposure_time;
+    public DateTime? exposure_time;
     public ImportID import_id;
     public EventID event_id;
     public Orientation orientation;
@@ -80,13 +78,14 @@ public class PhotoRow {
     public string md5;
     public string thumbnail_md5;
     public string exif_md5;
-    public time_t time_created;
+    public int64 time_created;
     public uint64 flags;
     public Rating rating;
     public string title;
+    public GpsCoords gps_coords;
     public string comment;
     public string? backlinks;
-    public time_t time_reimported;
+    public int64 time_reimported;
     public BackingPhotoID editable_id;
     public bool metadata_dirty;
     
@@ -103,6 +102,10 @@ public class PhotoRow {
         development_ids = new BackingPhotoID[RawDeveloper.as_array().length];
         foreach (RawDeveloper d in RawDeveloper.as_array())
             development_ids[d] = BackingPhotoID();
+        gps_coords = GpsCoords();
+        development_ids = new BackingPhotoID[RawDeveloper.as_array().length];
+        foreach (RawDeveloper d in RawDeveloper.as_array())
+            development_ids[d] = BackingPhotoID();
     }
 }
 
@@ -140,6 +143,9 @@ public class PhotoTable : DatabaseTable {
             + "develop_shotwell_id INTEGER DEFAULT -1, "
             + "develop_camera_id INTEGER DEFAULT -1, "
             + "develop_embedded_id INTEGER DEFAULT -1, "
+            + "has_gps INTEGER DEFAULT -1, "
+            + "gps_lat REAL, "
+            + "gps_lon REAL, "
             + "comment TEXT"
             + ")", -1, out stmt);
         assert(res == Sqlite.OK);
@@ -209,12 +215,12 @@ public class PhotoTable : DatabaseTable {
         int res = db.prepare_v2(
             "INSERT INTO PhotoTable (filename, width, height, filesize, timestamp, exposure_time, "
             + "orientation, original_orientation, import_id, event_id, md5, thumbnail_md5, "
-            + "exif_md5, time_created, file_format, title, rating, editable_id, developer, comment) "
-            + "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+            + "exif_md5, time_created, file_format, title, rating, editable_id, developer, has_gps, gps_lat, gps_lon, comment) "
+            + "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
             -1, out stmt);
         assert(res == Sqlite.OK);
         
-        ulong time_created = now_sec();
+        var time_created = now_sec();
         
         res = stmt.bind_text(1, photo_row.master.filepath);
         assert(res == Sqlite.OK);
@@ -224,9 +230,17 @@ public class PhotoTable : DatabaseTable {
         assert(res == Sqlite.OK);
         res = stmt.bind_int64(4, photo_row.master.filesize);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(5, photo_row.master.timestamp);
+        if (photo_row.master.timestamp == null) {
+            res = stmt.bind_null(5);
+        } else {
+            res = stmt.bind_int64(5, photo_row.master.timestamp.to_unix());
+        }
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(6, photo_row.exposure_time);
+        if (photo_row.exposure_time == null) {
+            res = stmt.bind_null(6);
+        } else {
+            res = stmt.bind_int64(6, photo_row.exposure_time.to_unix());
+        }
         assert(res == Sqlite.OK);
         res = stmt.bind_int(7, photo_row.master.original_orientation);
         assert(res == Sqlite.OK);
@@ -254,7 +268,13 @@ public class PhotoTable : DatabaseTable {
         assert(res == Sqlite.OK);
         res = stmt.bind_text(19, photo_row.developer.to_string());
         assert(res == Sqlite.OK);
-        res = stmt.bind_text(20, photo_row.comment);
+        res = stmt.bind_int(20, photo_row.gps_coords.has_gps);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_double(21, photo_row.gps_coords.latitude);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_double(22, photo_row.gps_coords.longitude);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_text(23, photo_row.comment);
         assert(res == Sqlite.OK);
         
         res = stmt.step();
@@ -269,7 +289,7 @@ public class PhotoTable : DatabaseTable {
         photo_row.photo_id = PhotoID(db.last_insert_rowid());
         photo_row.orientation = photo_row.master.original_orientation;
         photo_row.event_id = EventID();
-        photo_row.time_created = (time_t) time_created;
+        photo_row.time_created = time_created;
         photo_row.flags = 0;
         
         return photo_row.photo_id;
@@ -285,11 +305,12 @@ public class PhotoTable : DatabaseTable {
         int res = db.prepare_v2(
             "UPDATE PhotoTable SET width = ?, height = ?, filesize = ?, timestamp = ?, "
             + "exposure_time = ?, orientation = ?, original_orientation = ?, md5 = ?, " 
-            + "exif_md5 = ?, thumbnail_md5 = ?, file_format = ?, title = ?, time_reimported = ? "
+            + "exif_md5 = ?, thumbnail_md5 = ?, file_format = ?, title = ?, "
+            + "has_gps = ?, gps_lat = ?, gps_lon = ?, time_reimported = ? "
             + "WHERE id = ?", -1, out stmt);
         assert(res == Sqlite.OK);
         
-        time_t time_reimported = (time_t) now_sec();
+        var time_reimported = now_sec();
         
         res = stmt.bind_int(1, row.master.dim.width);
         assert(res == Sqlite.OK);
@@ -297,9 +318,13 @@ public class PhotoTable : DatabaseTable {
         assert(res == Sqlite.OK);
         res = stmt.bind_int64(3, row.master.filesize);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(4, row.master.timestamp);
+        res = stmt.bind_int64(4, row.master.timestamp.to_unix());
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(5, row.exposure_time);
+        if (row.exposure_time == null) {
+            res = stmt.bind_null(5);
+        } else {
+            res = stmt.bind_int64(5, row.exposure_time.to_unix());
+        }
         assert(res == Sqlite.OK);
         res = stmt.bind_int(6, row.master.original_orientation);
         assert(res == Sqlite.OK);
@@ -315,9 +340,15 @@ public class PhotoTable : DatabaseTable {
         assert(res == Sqlite.OK);
         res = stmt.bind_text(12, row.title);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(13, time_reimported);
+        res = stmt.bind_int(13, row.gps_coords.has_gps);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_double(14, row.gps_coords.latitude);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_double(15, row.gps_coords.longitude);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_int64(16, time_reimported);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(14, row.photo_id.id);
+        res = stmt.bind_int64(17, row.photo_id.id);
         assert(res == Sqlite.OK);
         
         res = stmt.step();
@@ -328,7 +359,7 @@ public class PhotoTable : DatabaseTable {
         row.orientation = row.master.original_orientation;
     }
 
-    public bool master_exif_updated(PhotoID photoID, int64 filesize, long timestamp, 
+    public bool master_exif_updated(PhotoID photoID, int64 filesize, DateTime timestamp, 
         string md5, string? exif_md5, string? thumbnail_md5, PhotoRow row) {
         Sqlite.Statement stmt;
         int res = db.prepare_v2(
@@ -338,7 +369,7 @@ public class PhotoTable : DatabaseTable {
         
         res = stmt.bind_int64(1, filesize);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(2, timestamp);
+        res = stmt.bind_int64(2, timestamp.to_unix());
         assert(res == Sqlite.OK);
         res = stmt.bind_text(3, md5);
         assert(res == Sqlite.OK);
@@ -372,7 +403,7 @@ public class PhotoTable : DatabaseTable {
     // the DB as a zero due to Vala 0.14 breaking the way it handled
     // objects passed as 'ref' arguments to methods. 
     // 
-    // For further details, please see http://redmine.yorba.org/issues/4354 and 
+    // For further details, please see https://bugzilla.gnome.org/show_bug.cgi?id=718194 and
     // https://bugzilla.gnome.org/show_bug.cgi?id=663818 .
     private void validate_orientation(PhotoRow row) {
         if ((row.orientation < Orientation.MIN) ||
@@ -390,7 +421,7 @@ public class PhotoTable : DatabaseTable {
             + "original_orientation, import_id, event_id, transformations, md5, thumbnail_md5, "
             + "exif_md5, time_created, flags, rating, file_format, title, backlinks, "
             + "time_reimported, editable_id, metadata_dirty, developer, develop_shotwell_id, "
-            + "develop_camera_id, develop_embedded_id, comment "
+            + "develop_camera_id, develop_embedded_id, has_gps, gps_lat, gps_lon, comment "
             + "FROM PhotoTable WHERE id=?", 
             -1, out stmt);
         assert(res == Sqlite.OK);
@@ -406,8 +437,12 @@ public class PhotoTable : DatabaseTable {
         row.master.filepath = stmt.column_text(0);
         row.master.dim = Dimensions(stmt.column_int(1), stmt.column_int(2));
         row.master.filesize = stmt.column_int64(3);
-        row.master.timestamp = (time_t) stmt.column_int64(4);
-        row.exposure_time = (time_t) stmt.column_int64(5);
+        row.master.timestamp = new DateTime.from_unix_utc(stmt.column_int64(4));
+        if (stmt.column_type(5) == Sqlite.NULL) {
+            row.exposure_time = null;
+        } else {
+            row.exposure_time = new DateTime.from_unix_utc(stmt.column_int64(5));
+        }
         row.orientation = (Orientation) stmt.column_int(6);
         row.master.original_orientation = (Orientation) stmt.column_int(7);
         row.import_id.id = stmt.column_int64(8);
@@ -416,13 +451,13 @@ public class PhotoTable : DatabaseTable {
         row.md5 = stmt.column_text(11);
         row.thumbnail_md5 = stmt.column_text(12);
         row.exif_md5 = stmt.column_text(13);
-        row.time_created = (time_t) stmt.column_int64(14);
+        row.time_created = stmt.column_int64(14);
         row.flags = stmt.column_int64(15);
         row.rating = Rating.unserialize(stmt.column_int(16));
         row.master.file_format = PhotoFileFormat.unserialize(stmt.column_int(17));
         row.title = stmt.column_text(18);
         row.backlinks = stmt.column_text(19);
-        row.time_reimported = (time_t) stmt.column_int64(20);
+        row.time_reimported = stmt.column_int64(20);
         row.editable_id = BackingPhotoID(stmt.column_int64(21));
         row.metadata_dirty = stmt.column_int(22) != 0;
         row.developer = stmt.column_text(23) != null ? RawDeveloper.from_string(stmt.column_text(23)) :
@@ -430,7 +465,10 @@ public class PhotoTable : DatabaseTable {
         row.development_ids[RawDeveloper.SHOTWELL] = BackingPhotoID(stmt.column_int64(24));
         row.development_ids[RawDeveloper.CAMERA] = BackingPhotoID(stmt.column_int64(25));
         row.development_ids[RawDeveloper.EMBEDDED] = BackingPhotoID(stmt.column_int64(26));
-        row.comment = stmt.column_text(27);
+        row.gps_coords.has_gps = stmt.column_int(27);
+        row.gps_coords.latitude = stmt.column_double(28);
+        row.gps_coords.longitude = stmt.column_double(29);
+        row.comment = stmt.column_text(30);
         
         return row;
     }
@@ -442,7 +480,7 @@ public class PhotoTable : DatabaseTable {
             + "original_orientation, import_id, event_id, transformations, md5, thumbnail_md5, "
             + "exif_md5, time_created, flags, rating, file_format, title, backlinks, time_reimported, "
             + "editable_id, metadata_dirty, developer, develop_shotwell_id, develop_camera_id, " 
-            + "develop_embedded_id, comment FROM PhotoTable", 
+            + "develop_embedded_id, has_gps, gps_lat, gps_lon, comment FROM PhotoTable",
             -1, out stmt);
         assert(res == Sqlite.OK);
         
@@ -454,8 +492,12 @@ public class PhotoTable : DatabaseTable {
             row.master.filepath = stmt.column_text(1);
             row.master.dim = Dimensions(stmt.column_int(2), stmt.column_int(3));
             row.master.filesize = stmt.column_int64(4);
-            row.master.timestamp = (time_t) stmt.column_int64(5);
-            row.exposure_time = (time_t) stmt.column_int64(6);
+            row.master.timestamp = new DateTime.from_unix_utc(stmt.column_int64(5));
+            if (stmt.column_type(6) == Sqlite.NULL) {
+                row.exposure_time = null;
+            } else {
+                row.exposure_time = new DateTime.from_unix_utc(stmt.column_int64(6));
+            }    
             row.orientation = (Orientation) stmt.column_int(7);
             row.master.original_orientation = (Orientation) stmt.column_int(8);
             row.import_id.id = stmt.column_int64(9);
@@ -464,13 +506,13 @@ public class PhotoTable : DatabaseTable {
             row.md5 = stmt.column_text(12);
             row.thumbnail_md5 = stmt.column_text(13);
             row.exif_md5 = stmt.column_text(14);
-            row.time_created = (time_t) stmt.column_int64(15);
+            row.time_created = stmt.column_int64(15);
             row.flags = stmt.column_int64(16);
             row.rating = Rating.unserialize(stmt.column_int(17));
             row.master.file_format = PhotoFileFormat.unserialize(stmt.column_int(18));
             row.title = stmt.column_text(19);
             row.backlinks = stmt.column_text(20);
-            row.time_reimported = (time_t) stmt.column_int64(21);
+            row.time_reimported = stmt.column_int64(21);
             row.editable_id = BackingPhotoID(stmt.column_int64(22));
             row.metadata_dirty = stmt.column_int(23) != 0;
             row.developer = stmt.column_text(24) != null ? RawDeveloper.from_string(stmt.column_text(24)) :
@@ -478,7 +520,10 @@ public class PhotoTable : DatabaseTable {
             row.development_ids[RawDeveloper.SHOTWELL] = BackingPhotoID(stmt.column_int64(25));
             row.development_ids[RawDeveloper.CAMERA] = BackingPhotoID(stmt.column_int64(26));
             row.development_ids[RawDeveloper.EMBEDDED] = BackingPhotoID(stmt.column_int64(27));
-            row.comment = stmt.column_text(28);
+            row.gps_coords.has_gps = stmt.column_int(28);
+            row.gps_coords.latitude = stmt.column_double(29);
+            row.gps_coords.longitude = stmt.column_double(30);
+            row.comment = stmt.column_text(31);
             
             validate_orientation(row);
             
@@ -500,9 +545,9 @@ public class PhotoTable : DatabaseTable {
         int res = db.prepare_v2("INSERT INTO PhotoTable (filename, width, height, filesize, "
             + "timestamp, exposure_time, orientation, original_orientation, import_id, event_id, "
             + "transformations, md5, thumbnail_md5, exif_md5, time_created, flags, rating, "
-            + "file_format, title, editable_id, developer, develop_shotwell_id, develop_camera_id, "
-            + "develop_embedded_id, comment) "
-            + "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+            + "file_format, title, has_gps, gps_lat, gps_lon, editable_id, developer, "
+            + "develop_shotwell_id, develop_camera_id, develop_embedded_id, comment) "
+            + "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
             -1, out stmt);
         assert(res == Sqlite.OK);
         
@@ -514,9 +559,13 @@ public class PhotoTable : DatabaseTable {
         assert(res == Sqlite.OK);
         res = stmt.bind_int64(4, original.master.filesize);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(5, original.master.timestamp);
+        res = stmt.bind_int64(5, original.master.timestamp.to_unix());
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(6, original.exposure_time);
+        if (original.exposure_time == null) { 
+            res = stmt.bind_null(6);
+        } else {
+            res = stmt.bind_int64(6, original.exposure_time.to_unix());
+        }
         assert(res == Sqlite.OK);
         res = stmt.bind_int(7, original.orientation);
         assert(res == Sqlite.OK);
@@ -544,18 +593,23 @@ public class PhotoTable : DatabaseTable {
         assert(res == Sqlite.OK);
         res = stmt.bind_text(19, original.title);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(20, editable_id.id);
+        res = stmt.bind_int(20, original.gps_coords.has_gps);
         assert(res == Sqlite.OK);
-        
-        res = stmt.bind_text(21, original.developer.to_string());
+        res = stmt.bind_double(21, original.gps_coords.latitude);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(22, develop_shotwell.id);
+        res = stmt.bind_double(22, original.gps_coords.longitude);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(23, develop_camera_id.id);
+        res = stmt.bind_int64(23, editable_id.id);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(24, develop_embedded_id.id);
+        res = stmt.bind_text(24, original.developer.to_string());
         assert(res == Sqlite.OK);
-        res = stmt.bind_text(25, original.comment);
+        res = stmt.bind_int64(25, develop_shotwell.id);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_int64(26, develop_camera_id.id);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_int64(27, develop_embedded_id.id);
+        assert(res == Sqlite.OK);
+        res = stmt.bind_text(28, original.comment);
         assert(res == Sqlite.OK);
         
         res = stmt.step();
@@ -572,7 +626,15 @@ public class PhotoTable : DatabaseTable {
     public bool set_title(PhotoID photo_id, string? new_title) {
        return update_text_by_id(photo_id.id, "title", new_title != null ? new_title : "");
     }
-    
+
+    public void set_gps_coords(PhotoID photo_id, GpsCoords new_gps_coords) throws DatabaseError {
+        update_int_by_id_2(photo_id.id, "has_gps", new_gps_coords.has_gps);
+        if (new_gps_coords.has_gps > 0) {
+            update_double_by_id_2(photo_id.id, "gps_lat", new_gps_coords.latitude);
+            update_double_by_id_2(photo_id.id, "gps_lon", new_gps_coords.longitude);
+        }
+    }
+
     public bool set_comment(PhotoID photo_id, string? new_comment) {
        return update_text_by_id(photo_id.id, "comment", new_comment != null ? new_comment : "");
     }
@@ -581,12 +643,12 @@ public class PhotoTable : DatabaseTable {
         update_text_by_id_2(photo_id.id, "filename", filepath);
     }
     
-    public void update_timestamp(PhotoID photo_id, time_t timestamp) throws DatabaseError {
-        update_int64_by_id_2(photo_id.id, "timestamp", timestamp);
+    public void update_timestamp(PhotoID photo_id, DateTime timestamp) throws DatabaseError {
+        update_int64_by_id_2(photo_id.id, "timestamp", timestamp.to_unix());
     }
     
-    public bool set_exposure_time(PhotoID photo_id, time_t time) {
-        return update_int64_by_id(photo_id.id, "exposure_time", (int64) time);
+    public bool set_exposure_time(PhotoID photo_id, DateTime time) {
+        return update_int64_by_id(photo_id.id, "exposure_time", time.to_unix());
     }
     
     public void set_import_id(PhotoID photo_id, ImportID import_id) throws DatabaseError {
@@ -1051,6 +1113,16 @@ public class PhotoTable : DatabaseTable {
     public void remove_development(PhotoRow row, RawDeveloper rd) throws DatabaseError {
         update_raw_development(row, rd, BackingPhotoID());
     }
+
+    public static void upgrade_for_unset_timestamp() throws DatabaseError {
+        Sqlite.Statement stmt;
+        int res = db.prepare_v2("UPDATE PhotoTable SET exposure_time = NULL WHERE exposure_time = '0'", -1, out stmt);
+        assert(res == Sqlite.OK);
+        res = stmt.step();
+        if (res != Sqlite.DONE) {
+            throw_error("PhotoTable.upgrade_for_unset_timestamp", res);
+        }
+    }
     
 }
 
@@ -1084,10 +1156,10 @@ public struct BackingPhotoID {
 
 public class BackingPhotoRow {
     public BackingPhotoID id;
-    public time_t time_created;
+    public int64 time_created;
     public string? filepath = null;
     public int64 filesize;
-    public time_t timestamp;
+    public DateTime? timestamp;
     public PhotoFileFormat file_format;
     public Dimensions dim;
     public Orientation original_orientation;
@@ -1095,15 +1167,21 @@ public class BackingPhotoRow {
     public bool matches_file_info(FileInfo info) {
         if (filesize != info.get_size())
             return false;
+
+        if (timestamp == null)
+            return false;
         
-        return timestamp == info.get_modification_time().tv_sec;
+        return timestamp.equal(info.get_modification_date_time());
     }
     
     public bool is_touched(FileInfo info) {
         if (filesize != info.get_size())
             return false;
+
+        if (timestamp == null)
+            return true;
         
-        return timestamp != info.get_modification_time().tv_sec;
+        return !timestamp.equal(info.get_modification_date_time());
     }
     
     // Copies another backing photo row into this one.
@@ -1162,11 +1240,11 @@ public class BackingPhotoTable : DatabaseTable {
             -1, out stmt);
         assert(res == Sqlite.OK);
         
-        time_t time_created = (time_t) now_sec();
+        var time_created = now_sec();
         
         res = stmt.bind_text(1, state.filepath);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(2, state.timestamp);
+        res = stmt.bind_int64(2, state.timestamp.to_unix());
         assert(res == Sqlite.OK);
         res = stmt.bind_int64(3, state.filesize);
         assert(res == Sqlite.OK);
@@ -1208,12 +1286,12 @@ public class BackingPhotoTable : DatabaseTable {
         BackingPhotoRow row = new BackingPhotoRow();
         row.id = id;
         row.filepath = stmt.column_text(0);
-        row.timestamp = (time_t) stmt.column_int64(1);
+        row.timestamp = new DateTime.from_unix_utc(stmt.column_int64(1));
         row.filesize = stmt.column_int64(2);
         row.dim = Dimensions(stmt.column_int(3), stmt.column_int(4));
         row.original_orientation = (Orientation) stmt.column_int(5);
         row.file_format = PhotoFileFormat.unserialize(stmt.column_int(6));
-        row.time_created = (time_t) stmt.column_int64(7);
+        row.time_created = stmt.column_int64(7);
         
         return row;
     }
@@ -1227,7 +1305,7 @@ public class BackingPhotoTable : DatabaseTable {
             -1, out stmt);
         assert(res == Sqlite.OK);
         
-        res = stmt.bind_int64(1, row.timestamp);
+        res = stmt.bind_int64(1, row.timestamp.to_unix());
         assert(res == Sqlite.OK);
         res = stmt.bind_int64(2, row.filesize);
         assert(res == Sqlite.OK);
@@ -1247,13 +1325,13 @@ public class BackingPhotoTable : DatabaseTable {
             throw_error("BackingPhotoTable.update", res);
     }
     
-    public void update_attributes(BackingPhotoID id, time_t timestamp, int64 filesize) throws DatabaseError {
+    public void update_attributes(BackingPhotoID id, DateTime timestamp, int64 filesize) throws DatabaseError {
         Sqlite.Statement stmt;
         int res = db.prepare_v2("UPDATE BackingPhotoTable SET timestamp=?, filesize=? WHERE id=?",
             -1, out stmt);
         assert(res == Sqlite.OK);
         
-        res = stmt.bind_int64(1, timestamp);
+        res = stmt.bind_int64(1, timestamp.to_unix());
         assert(res == Sqlite.OK);
         res = stmt.bind_int64(2, filesize);
         assert(res == Sqlite.OK);
@@ -1273,8 +1351,8 @@ public class BackingPhotoTable : DatabaseTable {
         update_text_by_id_2(id.id, "filepath", filepath);
     }
     
-    public void update_timestamp(BackingPhotoID id, time_t timestamp) throws DatabaseError {
-        update_int64_by_id_2(id.id, "timestamp", timestamp);
+    public void update_timestamp(BackingPhotoID id, DateTime timestamp) throws DatabaseError {
+        update_int64_by_id_2(id.id, "timestamp", timestamp.to_unix());
     }
 }
 
diff --git a/src/db/TagTable.vala b/src/db/TagTable.vala
index d650641..ce191c1 100644
--- a/src/db/TagTable.vala
+++ b/src/db/TagTable.vala
@@ -26,7 +26,7 @@ public class TagRow {
     public TagID tag_id;
     public string name;
     public Gee.Set<string>? source_id_list;
-    public time_t time_created;
+    public int64 time_created;
 }
 
 public class TagTable : DatabaseTable {
@@ -79,7 +79,7 @@ public class TagTable : DatabaseTable {
             out stmt);
         assert(res == Sqlite.OK);
         
-        time_t time_created = (time_t) now_sec();
+        var time_created = now_sec();
         
         res = stmt.bind_text(1, name);
         assert(res == Sqlite.OK);
@@ -151,7 +151,7 @@ public class TagTable : DatabaseTable {
         row.tag_id = tag_id;
         row.name = stmt.column_text(0);
         row.source_id_list = unserialize_source_ids(stmt.column_text(1));
-        row.time_created = (time_t) stmt.column_int64(2);
+        row.time_created = stmt.column_int64(2);
         
         return row;
     }
@@ -176,7 +176,7 @@ public class TagTable : DatabaseTable {
             row.tag_id = TagID(stmt.column_int64(0));
             row.name = stmt.column_text(1);
             row.source_id_list = unserialize_source_ids(stmt.column_text(2));
-            row.time_created = (time_t) stmt.column_int64(3);
+            row.time_created = stmt.column_int64(3);
             
             rows.add(row);
         }
diff --git a/src/db/TombstoneTable.vala b/src/db/TombstoneTable.vala
index 892198f..5c19c5c 100644
--- a/src/db/TombstoneTable.vala
+++ b/src/db/TombstoneTable.vala
@@ -27,7 +27,7 @@ public class TombstoneRow {
     public string filepath;
     public int64 filesize;
     public string? md5;
-    public time_t time_created;
+    public int64 time_created;
     public Tombstone.Reason reason;
 } 
 
@@ -71,7 +71,7 @@ public class TombstoneTable : DatabaseTable {
             -1, out stmt);
         assert(res == Sqlite.OK);
         
-        time_t time_created = (time_t) now_sec();
+        var time_created = now_sec();
         
         res = stmt.bind_text(1, filepath);
         assert(res == Sqlite.OK);
@@ -124,7 +124,7 @@ public class TombstoneTable : DatabaseTable {
             row.filepath = stmt.column_text(1);
             row.filesize = stmt.column_int64(2);
             row.md5 = stmt.column_text(3);
-            row.time_created = (time_t) stmt.column_int64(4);
+            row.time_created = stmt.column_int64(4);
             row.reason = Tombstone.Reason.unserialize(stmt.column_int(5));
             
             rows[index++] = row;
diff --git a/src/db/VideoTable.vala b/src/db/VideoTable.vala
index 7bd1bb7..8af1278 100644
--- a/src/db/VideoTable.vala
+++ b/src/db/VideoTable.vala
@@ -38,20 +38,20 @@ public class VideoRow {
     public VideoID video_id;
     public string filepath;
     public int64 filesize;
-    public time_t timestamp;
+    public DateTime timestamp;
     public int width;
     public int height;
     public double clip_duration;
     public bool is_interpretable;
-    public time_t exposure_time;
+    public DateTime? exposure_time;
     public ImportID import_id;
     public EventID event_id;
     public string md5;
-    public time_t time_created;
+    public int64 time_created;
     public Rating rating;
     public string title;
     public string? backlinks;
-    public time_t time_reimported;
+    public int64 time_reimported;
     public uint64 flags;
     public string comment;
 }
@@ -119,7 +119,7 @@ public class VideoTable : DatabaseTable {
             -1, out stmt);
         assert(res == Sqlite.OK);
         
-        ulong time_created = now_sec();
+        var time_created = now_sec();
         
         res = stmt.bind_text(1, video_row.filepath);
         assert(res == Sqlite.OK);
@@ -133,9 +133,13 @@ public class VideoTable : DatabaseTable {
         assert(res == Sqlite.OK);       
         res = stmt.bind_int64(6, video_row.filesize);
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(7, video_row.timestamp);
+        res = stmt.bind_int64(7, video_row.timestamp.to_unix());
         assert(res == Sqlite.OK);
-        res = stmt.bind_int64(8, video_row.exposure_time);
+        if (video_row.exposure_time == null) {
+            stmt.bind_null(8);
+        } else {
+            res = stmt.bind_int64(8, video_row.exposure_time.to_unix());
+        }
         assert(res == Sqlite.OK);
         res = stmt.bind_int64(9, video_row.import_id.id);
         assert(res == Sqlite.OK);
@@ -159,7 +163,7 @@ public class VideoTable : DatabaseTable {
         // fill in ignored fields with database values
         video_row.video_id = VideoID(db.last_insert_rowid());
         video_row.event_id = EventID();
-        video_row.time_created = (time_t) time_created;
+        video_row.time_created = time_created;
         video_row.flags = 0;
         
         return video_row.video_id;
@@ -208,16 +212,19 @@ public class VideoTable : DatabaseTable {
         row.clip_duration = stmt.column_double(3);
         row.is_interpretable = (stmt.column_int(4) == 1);
         row.filesize = stmt.column_int64(5);
-        row.timestamp = (time_t) stmt.column_int64(6);
-        row.exposure_time = (time_t) stmt.column_int64(7);
+        if (stmt.column_type(6) == Sqlite.NULL) {
+            row.exposure_time = null;
+        } else {
+            row.exposure_time = new DateTime.from_unix_utc(stmt.column_int64(6));
+        }
         row.import_id.id = stmt.column_int64(8);
         row.event_id.id = stmt.column_int64(9);
         row.md5 = stmt.column_text(10);
-        row.time_created = (time_t) stmt.column_int64(11);
+        row.time_created = stmt.column_int64(11);
         row.rating = Rating.unserialize(stmt.column_int(12));
         row.title = stmt.column_text(13);
         row.backlinks = stmt.column_text(14);
-        row.time_reimported = (time_t) stmt.column_int64(15);
+        row.time_reimported = stmt.column_int64(15);
         row.flags = stmt.column_int64(16);
         row.comment = stmt.column_text(17);
         
@@ -244,16 +251,20 @@ public class VideoTable : DatabaseTable {
             row.clip_duration = stmt.column_double(4);
             row.is_interpretable = (stmt.column_int(5) == 1);
             row.filesize = stmt.column_int64(6);
-            row.timestamp = (time_t) stmt.column_int64(7);
-            row.exposure_time = (time_t) stmt.column_int64(8);
-            row.import_id.id = stmt.column_int64(9);
+            row.timestamp = new DateTime.from_unix_utc(stmt.column_int64(7));
+            if (stmt.column_type(8) == Sqlite.NULL) {
+                row.exposure_time = null;
+            } else {
+                row.exposure_time = new DateTime.from_unix_utc(stmt.column_int64(8));
+            }
+                row.import_id.id = stmt.column_int64(9);
             row.event_id.id = stmt.column_int64(10);
             row.md5 = stmt.column_text(11);
-            row.time_created = (time_t) stmt.column_int64(12);
+            row.time_created = stmt.column_int64(12);
             row.rating = Rating.unserialize(stmt.column_int(13));
             row.title = stmt.column_text(14);
             row.backlinks = stmt.column_text(15);
-            row.time_reimported = (time_t) stmt.column_int64(16);
+            row.time_reimported = stmt.column_int64(16);
             row.flags = stmt.column_int64(17);
             row.comment = stmt.column_text(18);
             
@@ -275,8 +286,8 @@ public class VideoTable : DatabaseTable {
        update_text_by_id_2(video_id.id, "comment", new_comment != null ? new_comment : "");
     }
     
-    public void set_exposure_time(VideoID video_id, time_t time) throws DatabaseError {
-        update_int64_by_id_2(video_id.id, "exposure_time", (int64) time);
+    public void set_exposure_time(VideoID video_id, DateTime time) throws DatabaseError {
+        update_int64_by_id_2(video_id.id, "exposure_time", time.to_unix());
     }
 
     public void set_rating(VideoID video_id, Rating rating) throws DatabaseError {
@@ -455,8 +466,19 @@ public class VideoTable : DatabaseTable {
         return result;
     }
     
-    public void set_timestamp(VideoID video_id, time_t timestamp) throws DatabaseError {
-        update_int64_by_id_2(video_id.id, "timestamp", (int64) timestamp);
+    public void set_timestamp(VideoID video_id, DateTime timestamp) throws DatabaseError {
+        update_int64_by_id_2(video_id.id, "timestamp", timestamp.to_unix());
     }
+
+    public static void upgrade_for_unset_timestamp() throws DatabaseError {
+        Sqlite.Statement stmt;
+        int res = db.prepare_v2("UPDATE VideoTable SET exposure_time = NULL WHERE exposure_time = '0'", -1, out stmt);
+        assert(res == Sqlite.OK);
+        res = stmt.step();
+        if (res != Sqlite.DONE) {
+            throw_error("VideoTable.upgrade_for_unset_timestamp", res);
+        }
+    }
+
 }
 
diff --git a/src/dialogs/AdjustDateTimeDialog.vala b/src/dialogs/AdjustDateTimeDialog.vala
index fc08a3f..f475773 100644
--- a/src/dialogs/AdjustDateTimeDialog.vala
+++ b/src/dialogs/AdjustDateTimeDialog.vala
@@ -14,7 +14,7 @@ public class AdjustDateTimeDialog : Gtk.Dialog {
 
     private const int CALENDAR_THUMBNAIL_SCALE = 1;
 
-    time_t original_time;
+    DateTime? original_time;
     Gtk.Label original_time_label;
     Gtk.Calendar calendar;
     Gtk.SpinButton hour;
@@ -182,32 +182,33 @@ public class AdjustDateTimeDialog : Gtk.Dialog {
 
         original_time = source.get_exposure_time();
 
-        if (original_time == 0) {
-            original_time = time_t();
+        if (original_time == null) {
+            // This came from 
+            original_time = new DateTime.now_utc();
             no_original_time = true;
         }
 
-        set_time(Time.local(original_time));
+        set_time(original_time.to_local());
         set_original_time_label(Config.Facade.get_instance().get_use_24_hour_time());
     }
 
-    private void set_time(Time time) {
-        calendar.select_month(time.month, time.year + YEAR_OFFSET);
-        calendar.select_day(time.day);
+    private void set_time(DateTime time) {
+        calendar.select_month(time.get_month() - 1, time.get_year());
+        calendar.select_day(time.get_day_of_month());
         calendar.notify_property("year");
         calendar.notify_property("month");
 
         if (Config.Facade.get_instance().get_use_24_hour_time()) {
             system.set_active(TimeSystem.24HR);
-            hour.set_value(time.hour);
+            hour.set_value(time.get_hour());
         } else {
-            int AMPM_hour = time.hour % 12;
+            int AMPM_hour = time.get_hour() % 12;
             hour.set_value((AMPM_hour == 0) ? 12 : AMPM_hour);
-            system.set_active((time.hour >= 12) ? TimeSystem.PM : TimeSystem.AM);
+            system.set_active((time.get_hour() >= 12) ? TimeSystem.PM : TimeSystem.AM);
         }
 
-        minute.set_value(time.minute);
-        second.set_value(time.second);
+        minute.set_value(time.get_minute());
+        second.set_value(time.get_second());
 
         previous_time_system = (TimeSystem) system.get_active();
     }
@@ -217,43 +218,35 @@ public class AdjustDateTimeDialog : Gtk.Dialog {
             return;
 
         original_time_label.set_text(_("Original: ") +
-            Time.local(original_time).format(use_24_hr_format ? _("%m/%d/%Y, %H:%M:%S") :
+            original_time.to_local().format(use_24_hr_format ? _("%m/%d/%Y, %H:%M:%S") :
             _("%m/%d/%Y, %I:%M:%S %p")));
     }
 
-    private time_t get_time() {
-        Time time = Time();
-
-        time.second = (int) second.get_value();
-        time.minute = (int) minute.get_value();
-
+    private DateTime get_time() {
         // convert to 24 hr
         int hour = (int) hour.get_value();
-        time.hour = (hour == 12 && system.get_active() != TimeSystem.24HR) ? 0 : hour;
-        time.hour += ((system.get_active() == TimeSystem.PM) ? 12 : 0);
+        hour = (hour == 12 && system.get_active() != TimeSystem.24HR) ? 0 : hour;
+        hour += ((system.get_active() == TimeSystem.PM) ? 12 : 0);
 
         uint year, month, day;
         calendar.get_date(out year, out month, out day);
-        time.year = ((int) year) - YEAR_OFFSET;
-        time.month = (int) month;
-        time.day = (int) day;
 
-        time.isdst = -1;
-
-        return time.mktime();
+        return new DateTime.local((int)year, (int)month + 1, (int)day, hour, (int)minute.get_value(), (int)second.get_value());
     }
 
-    public bool execute(out int64 time_shift, out bool keep_relativity,
+    public bool execute(out TimeSpan time_shift, out bool keep_relativity,
         out bool modify_originals) {
         show_all();
 
         bool response = false;
 
         if (run() == Gtk.ResponseType.OK) {
-            if (no_original_time)
-                time_shift = (int64) get_time();
-            else
-                time_shift = (int64) (get_time() - original_time);
+            // Difference returns microseconds, so divide by 1000000, we need seconds
+            if (no_original_time) {
+                time_shift = get_time().difference(new DateTime.from_unix_utc(0)) / 1000 / 1000;
+            } else {
+                time_shift = (get_time().difference(original_time)) / 1000 / 1000;
+            }
 
             keep_relativity = relativity_radio_button.get_active();
 
@@ -286,7 +279,7 @@ public class AdjustDateTimeDialog : Gtk.Dialog {
     }
 
     private void on_time_changed() {
-        int64 time_shift = ((int64) get_time() - (int64) original_time);
+        var time_shift = get_time().difference (original_time);
         calendar.notify_property("year");
         calendar.notify_property("month");
 
@@ -301,12 +294,12 @@ public class AdjustDateTimeDialog : Gtk.Dialog {
 
             time_shift = time_shift.abs();
 
-            days = (int) (time_shift / SECONDS_IN_DAY);
-            time_shift = time_shift % SECONDS_IN_DAY;
-            hours = (int) (time_shift / SECONDS_IN_HOUR);
-            time_shift = time_shift % SECONDS_IN_HOUR;
-            minutes = (int) (time_shift / SECONDS_IN_MINUTE);
-            seconds = (int) (time_shift % SECONDS_IN_MINUTE);
+            days = (int) (time_shift / TimeSpan.DAY);
+            time_shift = time_shift % TimeSpan.DAY;
+            hours = (int) (time_shift / TimeSpan.HOUR);
+            time_shift = time_shift % TimeSpan.HOUR;
+            minutes = (int) (time_shift / TimeSpan.MINUTE);
+            seconds = (int) ((time_shift % TimeSpan.MINUTE) / TimeSpan.SECOND);
 
             string shift_status = (forward) ?
                 _("Exposure time will be shifted forward by\n%d %s, %d %s, %d %s, and %d %s.") :
diff --git a/src/dialogs/MultiTextEntryDialog.vala b/src/dialogs/MultiTextEntryDialog.vala
index 42e5318..ddbd59b 100644
--- a/src/dialogs/MultiTextEntryDialog.vala
+++ b/src/dialogs/MultiTextEntryDialog.vala
@@ -11,7 +11,7 @@ public class MultiTextEntryDialog : Gtk.Dialog {
 
     private unowned OnModifyValidateType on_modify_validate;
     [GtkChild]
-    private Gtk.TextView entry;
+    private unowned Gtk.TextView entry;
 
     public MultiTextEntryDialog() {
         Object (use_header_bar: Resources.use_header_bar());
diff --git a/src/dialogs/Preferences.vala b/src/dialogs/Preferences.vala
index 17b16cf..efd9589 100644
--- a/src/dialogs/Preferences.vala
+++ b/src/dialogs/Preferences.vala
@@ -19,49 +19,49 @@ public class PreferencesDialog : Gtk.Dialog {
     private static PreferencesDialog preferences_dialog;
 
     [GtkChild]
-    private Gtk.Switch switch_dark;
+    private unowned Gtk.Switch switch_dark;
 
     [GtkChild]
-    private Gtk.ComboBox photo_editor_combo;
+    private unowned Gtk.ComboBox photo_editor_combo;
     [GtkChild]
-    private Gtk.ComboBox raw_editor_combo;
+    private unowned Gtk.ComboBox raw_editor_combo;
     private SortedList<AppInfo> external_raw_apps;
     private SortedList<AppInfo> external_photo_apps;
     [GtkChild]
-    private Gtk.FileChooserButton library_dir_button;
+    private unowned Gtk.FileChooserButton library_dir_button;
     [GtkChild]
-    private Gtk.ComboBoxText dir_pattern_combo;
+    private unowned Gtk.ComboBoxText dir_pattern_combo;
     [GtkChild]
-    private Gtk.Entry dir_pattern_entry;
+    private unowned Gtk.Entry dir_pattern_entry;
     [GtkChild]
-    private Gtk.Label dir_pattern_example;
+    private unowned Gtk.Label dir_pattern_example;
     private bool allow_closing = false;
     private string? lib_dir = null;
     private Gee.ArrayList<PathFormat> path_formats = new Gee.ArrayList<PathFormat>();
     private GLib.DateTime example_date = new GLib.DateTime.local(2009, 3, 10, 18, 16, 11);
     [GtkChild]
-    private Gtk.CheckButton lowercase;
+    private unowned Gtk.CheckButton lowercase;
     private Plugins.ManifestWidgetMediator plugins_mediator = new Plugins.ManifestWidgetMediator();
     [GtkChild]
-    private Gtk.ComboBoxText default_raw_developer_combo;
+    private unowned Gtk.ComboBoxText default_raw_developer_combo;
 
     [GtkChild]
-    private Gtk.CheckButton autoimport;
+    private unowned Gtk.CheckButton autoimport;
     [GtkChild]
-    private Gtk.CheckButton write_metadata;
+    private unowned Gtk.CheckButton write_metadata;
     [GtkChild]
-    private Gtk.Label pattern_help;
+    private unowned Gtk.Label pattern_help;
     [GtkChild]
-    private Gtk.Notebook preferences_notebook;
+    private unowned Gtk.Stack preferences_stack;
 
     [GtkChild]
-    private Gtk.RadioButton transparent_checker_radio;
+    private unowned Gtk.RadioButton transparent_checker_radio;
     [GtkChild]
-    private Gtk.RadioButton transparent_solid_radio;
+    private unowned Gtk.RadioButton transparent_solid_radio;
     [GtkChild]
-    private Gtk.ColorButton transparent_solid_color;
+    private unowned Gtk.ColorButton transparent_solid_color;
     [GtkChild]
-    private Gtk.RadioButton transparent_none_radio;
+    private unowned Gtk.RadioButton transparent_none_radio;
 
     private PreferencesDialog() {
         Object (use_header_bar: Resources.use_header_bar());
@@ -81,7 +81,7 @@ public class PreferencesDialog : Gtk.Dialog {
 
         Gdk.RGBA color = Gdk.RGBA();
         color.parse(Config.Facade.get_instance().get_transparent_background_color());
-        (transparent_solid_color as Gtk.ColorChooser).rgba = color;
+        ((Gtk.ColorChooser) transparent_solid_color).rgba = color;
         transparent_solid_color.color_set.connect(on_color_changed);
 
         switch (Config.Facade.get_instance().get_transparent_background_type()) {
@@ -105,11 +105,11 @@ public class PreferencesDialog : Gtk.Dialog {
 
         if (help_path == null) {
             // We're installed system-wide, so use the system help.
-            pattern_help.set_markup("<a href=\"" + Resources.DIR_PATTERN_URI_SYSWIDE + "\">" + _("(Help)") + "</a>");
+	    pattern_help.set_markup("<a href=\"%s\">%s</a>".printf(Resources.DIR_PATTERN_URI_SYSWIDE,  _("(Help)")));
         } else {
             // We're being run from the build directory; we'll have to handle clicks to this
             // link manually ourselves, due to a limitation of help: URIs.
-            pattern_help.set_markup("<a href=\"dummy:\">" + _("(Help)") + "</a>");
+	    pattern_help.set_markup("<a href=\"dummy:\">%s</a>".printf(_("(Help)")));
             pattern_help.activate_link.connect(on_local_pattern_help);
         }
 
@@ -126,7 +126,9 @@ public class PreferencesDialog : Gtk.Dialog {
 
         lowercase.toggled.connect(on_lowercase_toggled);
 
-        (preferences_notebook.get_nth_page (2) as Gtk.Container).add (plugins_mediator);
+        ((Gtk.Box)preferences_stack.get_child_by_name("plugins")).add(plugins_mediator);
+        ((Gtk.Box)preferences_stack.get_child_by_name("profiles")).add(new Shotwell.ProfileBrowser());
+
 
         populate_preference_options();
 
@@ -177,7 +179,7 @@ public class PreferencesDialog : Gtk.Dialog {
     }
 
     private void on_color_changed() {
-        var color = (transparent_solid_color as Gtk.ColorChooser).rgba.to_string();
+        var color = ((Gtk.ColorChooser) transparent_solid_color).rgba.to_string();
         Config.Facade.get_instance().set_transparent_background_color(color);
     }
 
diff --git a/src/dialogs/SetBackground.vala b/src/dialogs/SetBackground.vala
index d9a77c4..ec56502 100644
--- a/src/dialogs/SetBackground.vala
+++ b/src/dialogs/SetBackground.vala
@@ -8,9 +8,9 @@
 [GtkTemplate (ui = "/org/gnome/Shotwell/ui/set_background_dialog.ui")]
 public class SetBackgroundPhotoDialog : Gtk.Dialog {
     [GtkChild]
-    private Gtk.CheckButton desktop_background_checkbox;
+    private unowned Gtk.CheckButton desktop_background_checkbox;
     [GtkChild]
-    private Gtk.CheckButton screensaver_checkbox;
+    private unowned Gtk.CheckButton screensaver_checkbox;
 
     public SetBackgroundPhotoDialog() {
         Object(use_header_bar: Resources.use_header_bar());
diff --git a/src/dialogs/SetBackgroundSlideshow.vala b/src/dialogs/SetBackgroundSlideshow.vala
index 914af76..479b0c7 100644
--- a/src/dialogs/SetBackgroundSlideshow.vala
+++ b/src/dialogs/SetBackgroundSlideshow.vala
@@ -8,13 +8,13 @@
 [GtkTemplate (ui = "/org/gnome/Shotwell/ui/set_background_slideshow_dialog.ui")]
 public class SetBackgroundSlideshowDialog : Gtk.Dialog {
     [GtkChild]
-    private Gtk.CheckButton desktop_background_checkbox;
+    private unowned Gtk.CheckButton desktop_background_checkbox;
     [GtkChild]
-    private Gtk.CheckButton screensaver_checkbox;
+    private unowned Gtk.CheckButton screensaver_checkbox;
     [GtkChild]
-    private Gtk.Scale delay_scale;
+    private unowned Gtk.Scale delay_scale;
     [GtkChild]
-    private Gtk.Label delay_value_label;
+    private unowned Gtk.Label delay_value_label;
 
     private int delay_value = 0;
 
diff --git a/src/dialogs/TextEntry.vala b/src/dialogs/TextEntry.vala
index d82fdbd..a2e4653 100644
--- a/src/dialogs/TextEntry.vala
+++ b/src/dialogs/TextEntry.vala
@@ -12,10 +12,10 @@ public class TextEntryDialog : Gtk.Dialog {
     private unowned OnModifyValidateType on_modify_validate;
 
     [GtkChild]
-    private Gtk.Entry entry;
+    private unowned Gtk.Entry entry;
 
     [GtkChild]
-    private Gtk.Label label;
+    private unowned Gtk.Label label;
 
     public TextEntryDialog() {
         Object (use_header_bar: Resources.use_header_bar());
diff --git a/src/dialogs/WelcomeDialog.vala b/src/dialogs/WelcomeDialog.vala
index e40686d..7fa0b7c 100644
--- a/src/dialogs/WelcomeDialog.vala
+++ b/src/dialogs/WelcomeDialog.vala
@@ -60,11 +60,9 @@ public class WelcomeDialog : Gtk.Dialog {
         Gtk.Label instructions = new Gtk.Label("");
         string indent_prefix = "   "; // we can't tell what the indent prefix is going to be so assume we need one
 
-        string arrow_glyph = (get_direction() == Gtk.TextDirection.RTL) ? "◂" : "▸";
-
         instructions.set_markup(((indent_prefix + "&#8226; %s\n") + (indent_prefix + "&#8226; %s\n")
             + (indent_prefix + "&#8226; %s")).printf(
-            _("Choose <span weight=\"bold\">File %s Import From Folder</span>").printf(arrow_glyph),
+            _("Choose “Import From Folder” from the File menu"),
             _("Drag and drop photos onto the Shotwell window"),
             _("Connect a camera to your computer and import")));
         instructions.xalign = 0.0f;
diff --git a/src/direct/DirectPhotoPage.vala b/src/direct/DirectPhotoPage.vala
index 39a87f1..cc7186c 100644
--- a/src/direct/DirectPhotoPage.vala
+++ b/src/direct/DirectPhotoPage.vala
@@ -219,8 +219,9 @@ public class DirectPhotoPage : EditingHostPage {
             
             return true;
         } else {
-            if (get_container() is DirectWindow) {
-                (get_container() as DirectWindow).do_fullscreen();
+            var direct_window = get_container() as DirectWindow;
+            if (direct_window != null) {
+                direct_window.do_fullscreen();
 
                 return true;
             }
diff --git a/src/editing_tools/EditingTools.vala b/src/editing_tools/EditingTools.vala
index 02e366a..0042d57 100644
--- a/src/editing_tools/EditingTools.vala
+++ b/src/editing_tools/EditingTools.vala
@@ -87,7 +87,8 @@ public abstract class EditingToolWindow : Gtk.Window {
     }
 
     public override void realize() {
-        (this as Gtk.Widget).set_opacity(Resources.TRANSIENT_WINDOW_OPACITY);
+        // Force the use of gtk_widget_set_opacity; gtk_window_set_opacity is deprecated
+        ((Gtk.Widget) this).set_opacity(Resources.TRANSIENT_WINDOW_OPACITY);
         
         base.realize();
     }
@@ -381,12 +382,13 @@ public abstract class PhotoCanvas {
     }
 
     public void erase_horizontal_line(int x, int y, int width) {
+        var scale = Application.get_scale();
         default_ctx.save();
 
         default_ctx.set_operator(Cairo.Operator.SOURCE);
         default_ctx.set_source_surface(scaled, scaled_position.x, scaled_position.y);
         default_ctx.rectangle(scaled_position.x + x, scaled_position.y + y,
-            width - 1, 1);
+            width - 1, 1 * scale);
         default_ctx.fill();
 
         default_ctx.restore();
@@ -404,6 +406,8 @@ public abstract class PhotoCanvas {
     public void erase_vertical_line(int x, int y, int height) {
         default_ctx.save();
 
+        var scale = Application.get_scale();
+
         // Ticket #3146 - artifacting when moving the crop box or
         // enlarging it from the lower right.
         // We now no longer subtract one from the height before choosing
@@ -411,7 +415,7 @@ public abstract class PhotoCanvas {
         default_ctx.set_operator(Cairo.Operator.SOURCE);
         default_ctx.set_source_surface(scaled, scaled_position.x, scaled_position.y);
         default_ctx.rectangle(scaled_position.x + x, scaled_position.y + y,
-            1, height);
+            1 * scale, height);
         default_ctx.fill();
 
         default_ctx.restore();
@@ -427,12 +431,19 @@ public abstract class PhotoCanvas {
 
     public void invalidate_area(Box area) {
         Gdk.Rectangle rect = area.get_rectangle();
+
         rect.x += scaled_position.x;
         rect.y += scaled_position.y;
 
         drawing_window.invalidate_rect(rect, false);
     }
 
+    public void set_cursor(Gdk.CursorType cursor_type) {
+        var display = get_drawing_window().get_display();
+        var cursor = new Gdk.Cursor.for_display (display, cursor_type);
+        get_drawing_window().set_cursor(cursor);
+    }
+
     private Cairo.Surface pixbuf_to_surface(Cairo.Context default_ctx, Gdk.Pixbuf pixbuf,
         Gdk.Rectangle pos) {
         Cairo.Surface surface = new Cairo.Surface.similar(default_ctx.get_target(),
@@ -1220,11 +1231,7 @@ public class CropTool : EditingTool {
 
         // make sure the cursor isn't set to a modify indicator
         if (canvas != null) {
-            var drawing_window = canvas.get_drawing_window ();
-            var display = drawing_window.get_display ();
-            var cursor = new Gdk.Cursor.for_display (display,
-                                                     Gdk.CursorType.LEFT_PTR);
-            drawing_window.set_cursor (cursor);
+            canvas.set_cursor (Gdk.CursorType.LEFT_PTR);
         }
 
         crop_surface = null;
@@ -1244,20 +1251,22 @@ public class CropTool : EditingTool {
     }
 
     private void prepare_ctx(Cairo.Context ctx, Dimensions dim) {
+        var scale = Application.get_scale();
         wide_black_ctx = new Cairo.Context(ctx.get_target());
         set_source_color_from_string(wide_black_ctx, "#000");
-        wide_black_ctx.set_line_width(1);
+        wide_black_ctx.set_line_width(1 * scale);
 
         wide_white_ctx = new Cairo.Context(ctx.get_target());
         set_source_color_from_string(wide_white_ctx, "#FFF");
-        wide_white_ctx.set_line_width(1);
+        wide_white_ctx.set_line_width(1 * scale);
 
         thin_white_ctx = new Cairo.Context(ctx.get_target());
         set_source_color_from_string(thin_white_ctx, "#FFF");
-        thin_white_ctx.set_line_width(0.5);
+        thin_white_ctx.set_line_width(0.5 * scale);
 
         text_ctx = new Cairo.Context(ctx.get_target());
         text_ctx.select_font_face("Sans", Cairo.FontSlant.NORMAL, Cairo.FontWeight.NORMAL);
+        text_ctx.set_font_size(10.0 * scale);
     }
 
     private void on_resized_pixbuf(Dimensions old_dim, Gdk.Pixbuf scaled, Gdk.Rectangle scaled_position) {
@@ -1286,7 +1295,8 @@ public class CropTool : EditingTool {
         Box offset_scaled_crop = scaled_crop.get_offset(scaled_pixbuf_pos.x, scaled_pixbuf_pos.y);
 
         // determine where the mouse down landed and store for future events
-        in_manipulation = offset_scaled_crop.approx_location(x, y);
+        in_manipulation = offset_scaled_crop.approx_location((int)Math.lround(x * Application.get_scale()),
+        (int)Math.lround(y * Application.get_scale()));
         last_grab_x = x -= scaled_pixbuf_pos.x;
         last_grab_y = y -= scaled_pixbuf_pos.y;
 
@@ -1314,19 +1324,21 @@ public class CropTool : EditingTool {
         // only deal with manipulating the crop tool when click-and-dragging one of the edges
         // or the interior
         if (in_manipulation != BoxLocation.OUTSIDE)
-            on_canvas_manipulation(x, y);
+            on_canvas_manipulation((int)Math.lround(x * Application.get_scale()),
+            (int)Math.lround(y * Application.get_scale()));
 
         update_cursor(x, y);
         canvas.repaint();
     }
 
     public override void paint(Cairo.Context default_ctx) {
+        var scale = Application.get_scale();
         // fill region behind the crop surface with neutral color
         int w = canvas.get_drawing_window().get_width();
         int h = canvas.get_drawing_window().get_height();
 
         default_ctx.set_source_rgba(0.0, 0.0, 0.0, 1.0);
-        default_ctx.rectangle(0, 0, w, h);
+        default_ctx.rectangle(0, 0, w * scale, h * scale);
         default_ctx.fill();
         default_ctx.paint();
 
@@ -1376,7 +1388,8 @@ public class CropTool : EditingTool {
         Box offset_scaled_crop = scaled_crop.get_offset(scaled_pos.x, scaled_pos.y);
 
         Gdk.CursorType cursor_type = Gdk.CursorType.LEFT_PTR;
-        switch (offset_scaled_crop.approx_location(x, y)) {
+        switch (offset_scaled_crop.approx_location((int)Math.lround(x * Application.get_scale()),
+        (int)Math.lround(y * Application.get_scale()))) {
             case BoxLocation.LEFT_SIDE:
                 cursor_type = Gdk.CursorType.LEFT_SIDE;
             break;
@@ -1419,10 +1432,7 @@ public class CropTool : EditingTool {
         }
 
         if (cursor_type != current_cursor_type) {
-            var drawing_window = canvas.get_drawing_window ();
-            var display = drawing_window.get_display ();
-            var cursor = new Gdk.Cursor.for_display (display, cursor_type);
-            drawing_window.set_cursor (cursor);
+            canvas.set_cursor(cursor_type);
             current_cursor_type = cursor_type;
         }
     }
@@ -1893,8 +1903,6 @@ public class RedeyeTool : EditingTool {
     private bool is_reticle_move_in_progress = false;
     private Gdk.Point reticle_move_mouse_start_point;
     private Gdk.Point reticle_move_anchor;
-    private Gdk.Cursor cached_arrow_cursor;
-    private Gdk.Cursor cached_grab_cursor;
     private Gdk.Rectangle old_scaled_pixbuf_position;
     private Gdk.Pixbuf current_pixbuf = null;
 
@@ -1928,13 +1936,14 @@ public class RedeyeTool : EditingTool {
     }
 
     private void prepare_ctx(Cairo.Context ctx, Dimensions dim) {
+        var scale = Application.get_scale();
         wider_gray_ctx = new Cairo.Context(ctx.get_target());
         set_source_color_from_string(wider_gray_ctx, "#111");
-        wider_gray_ctx.set_line_width(3);
+        wider_gray_ctx.set_line_width(3 * scale);
 
         thin_white_ctx = new Cairo.Context(ctx.get_target());
         set_source_color_from_string(thin_white_ctx, "#FFF");
-        thin_white_ctx.set_line_width(1);
+        thin_white_ctx.set_line_width(1 * scale);
     }
 
     private void draw_redeye_instance(RedeyeInstance inst) {
@@ -2044,10 +2053,6 @@ public class RedeyeTool : EditingTool {
 
         bind_window_handlers();
 
-        var display = canvas.get_drawing_window().get_display();
-        cached_arrow_cursor = new Gdk.Cursor.for_display(display, Gdk.CursorType.LEFT_PTR);
-        cached_grab_cursor = new Gdk.Cursor.for_display(display, Gdk.CursorType.FLEUR);
-
         DataCollection? owner = canvas.get_photo().get_membership();
         if (owner != null)
             owner.items_altered.connect(on_photos_altered);
@@ -2112,13 +2117,17 @@ public class RedeyeTool : EditingTool {
     }
 
     public override void on_left_click(int x, int y) {
+        var scale = Application.get_scale();
+
         Gdk.Rectangle bounds_rect =
             RedeyeInstance.to_bounds_rect(user_interaction_instance);
 
-        if (coord_in_rectangle(x, y, bounds_rect)) {
+
+        if (coord_in_rectangle((int)Math.lround(x * scale), (int)Math.lround(y * scale), bounds_rect)) {
+            print("Motion in progress!!\n");
             is_reticle_move_in_progress = true;
-            reticle_move_mouse_start_point.x = x;
-            reticle_move_mouse_start_point.y = y;
+            reticle_move_mouse_start_point.x = (int)Math.lround(x * scale);
+            reticle_move_mouse_start_point.y = (int)Math.lround(y * scale);
             reticle_move_anchor = user_interaction_instance.center;
         }
     }
@@ -2128,6 +2137,8 @@ public class RedeyeTool : EditingTool {
     }
 
     public override void on_motion(int x, int y, Gdk.ModifierType mask) {
+        var scale = Application.get_scale();
+
         if (is_reticle_move_in_progress) {
 
             Gdk.Rectangle active_region_rect =
@@ -2144,8 +2155,8 @@ public class RedeyeTool : EditingTool {
                 active_region_rect.y + active_region_rect.height -
                 user_interaction_instance.radius - 1;
 
-            int delta_x = x - reticle_move_mouse_start_point.x;
-            int delta_y = y - reticle_move_mouse_start_point.y;
+            int delta_x = (int)Math.lround(x * scale) - reticle_move_mouse_start_point.x;
+            int delta_y = (int)Math.lround(y * scale) - reticle_move_mouse_start_point.y;
 
             user_interaction_instance.center.x = reticle_move_anchor.x +
                 delta_x;
@@ -2164,10 +2175,10 @@ public class RedeyeTool : EditingTool {
             Gdk.Rectangle bounds =
                 RedeyeInstance.to_bounds_rect(user_interaction_instance);
 
-            if (coord_in_rectangle(x, y, bounds)) {
-                canvas.get_drawing_window().set_cursor(cached_grab_cursor);
+            if (coord_in_rectangle((int)Math.lround(x * scale), (int)Math.lround(y * scale), bounds)) {
+                canvas.set_cursor(Gdk.CursorType.FLEUR);
             } else {
-                canvas.get_drawing_window().set_cursor(cached_arrow_cursor);
+                canvas.set_cursor(Gdk.CursorType.LEFT_PTR);
             }
         }
     }
@@ -2251,7 +2262,7 @@ public class AdjustTool : EditingTool {
             slider_organizer.attach(saturation_label, 0, 2, 1, 1);
             slider_organizer.attach(saturation_slider, 1, 2, 1, 1);
             saturation_slider.set_size_request(SLIDER_WIDTH, -1);
-            saturation_slider.set_draw_value(false);
+            saturation_slider.set_value_pos(Gtk.PositionType.RIGHT);
             saturation_slider.set_margin_end(0);
 
             Gtk.Label tint_label = new Gtk.Label.with_mnemonic(_("Tint:"));
diff --git a/src/editing_tools/StraightenTool.vala b/src/editing_tools/StraightenTool.vala
index f427b99..2b0591a 100644
--- a/src/editing_tools/StraightenTool.vala
+++ b/src/editing_tools/StraightenTool.vala
@@ -80,13 +80,13 @@ public class StraightenTool : EditingTool {
             // different backgrounds.
             ctx.set_source_rgba(0.0, 0.0, 0.0, alpha);
             ctx.set_dash(GUIDE_DASH,  GUIDE_DASH[0] / 2);
-            ctx.move_to(x[0] + 0.5, y[0] + 0.5);
-            ctx.line_to(x[1] + 0.5, y[1] + 0.5);
+            ctx.move_to(x[0] * Application.get_scale() + 0.5, y[0]* Application.get_scale() + 0.5);
+            ctx.line_to(x[1] * Application.get_scale()+ 0.5, y[1]* Application.get_scale() + 0.5);
             ctx.stroke();
             ctx.set_dash(GUIDE_DASH, -GUIDE_DASH[0] / 2);
             ctx.set_source_rgba(1.0, 1.0, 1.0, alpha); 
-            ctx.move_to(x[0] + 0.5, y[0] + 0.5);
-            ctx.line_to(x[1] + 0.5, y[1] + 0.5);
+            ctx.move_to(x[0] * Application.get_scale()+ 0.5, y[0]* Application.get_scale() + 0.5);
+            ctx.line_to(x[1] * Application.get_scale()+ 0.5, y[1] * Application.get_scale()+ 0.5);
             ctx.stroke();
         }
     }
@@ -456,7 +456,7 @@ public class StraightenTool : EditingTool {
      */
     private void update_rotated_surface() {        
         draw_rotated_source(photo_surf, rotate_ctx, view_width, view_height, photo_angle);
-        rotate_ctx.set_line_width(1.0);
+        rotate_ctx.set_line_width(1.0 * Application.get_scale());
         draw_superimposed_grid(rotate_ctx, view_width, view_height);
     }
 
@@ -468,8 +468,8 @@ public class StraightenTool : EditingTool {
      *      it's not used.
      */
     public override void paint(Cairo.Context ctx) {
-        int w = canvas.get_drawing_window().get_width();
-        int h = canvas.get_drawing_window().get_height();
+        var w = canvas.get_drawing_window().get_width() * Application.get_scale();
+        var h = canvas.get_drawing_window().get_height() * Application.get_scale();
 
         // fill region behind the rotation surface with neutral color.
         canvas.get_default_ctx().identity_matrix();
diff --git a/src/events/EventDirectoryItem.vala b/src/events/EventDirectoryItem.vala
index 5b177fb..dbab1b1 100644
--- a/src/events/EventDirectoryItem.vala
+++ b/src/events/EventDirectoryItem.vala
@@ -60,7 +60,7 @@ class EventDirectoryItem : CheckerboardItem {
             pixbuf = media.get_preview_pixbuf(squared_scaling);
         } catch (Error error) {
             ThumbnailCache.fetch_async_scaled(media, ThumbnailCache.Size.BIG,
-                                             new Dimensions(ThumbnailCache.Size.BIG, ThumbnailCache.Size.BIG),
+                                              Dimensions(ThumbnailCache.Size.BIG, ThumbnailCache.Size.BIG),
                                              ThumbnailCache.DEFAULT_INTERP, () => {});
             if (media is LibraryPhoto) {
                 LibraryPhoto photo = (LibraryPhoto) media;
diff --git a/src/events/EventsBranch.vala b/src/events/EventsBranch.vala
index 097a664..0550eb7 100644
--- a/src/events/EventsBranch.vala
+++ b/src/events/EventsBranch.vala
@@ -133,8 +133,8 @@ public class Events.Branch : Sidebar.Branch {
             b = swap;
         }
         
-        int64 result = ((Events.EventEntry) a).get_event().get_start_time() 
-            - ((Events.EventEntry) b).get_event().get_start_time();
+        int64 result = nullsafe_date_time_comperator(((Events.EventEntry) a).get_event().get_start_time(),
+            ((Events.EventEntry) b).get_event().get_start_time());
         
         // to stabilize sort (events with the same start time are allowed)
         if (result == 0) {
@@ -215,14 +215,14 @@ public class Events.Branch : Sidebar.Branch {
     }
     
     private void add_event(Event event) {
-        time_t event_time = event.get_start_time();
-        if (event_time == 0) {
+        DateTime? event_time = event.get_start_time();
+        if (event_time == null) {
             add_undated_event(event);
             
             return;
         }
         
-        Time event_tm = Time.local(event_time);
+        var event_tm = event_time.to_local();
         
         Sidebar.Entry? year;
         Sidebar.Entry? month = find_event_month(event, event_tm, out year);
@@ -246,14 +246,14 @@ public class Events.Branch : Sidebar.Branch {
     }
     
     private void move_event(Event event) {
-        time_t event_time = event.get_start_time();
-        if (event_time == 0) {
+        DateTime? event_time = event.get_start_time();
+        if (event_time == null) {
             move_to_undated_event(event);
             
             return;
         }
         
-        Time event_tm = Time.local(event_time);
+        var event_tm = event_time.to_local();
         
         Sidebar.Entry? year;
         Sidebar.Entry? month = find_event_month(event, event_tm, out year);
@@ -296,13 +296,13 @@ public class Events.Branch : Sidebar.Branch {
         }
     }
     
-    private Sidebar.Entry? find_event_month(Event event, Time event_tm, out Sidebar.Entry found_year) {
+    private Sidebar.Entry? find_event_month(Event event, DateTime event_tm, out Sidebar.Entry found_year) {
         // find the year first
         found_year = find_event_year(event, event_tm);
         if (found_year == null)
             return null;
         
-        int event_month = event_tm.month + 1;
+        int event_month = event_tm.get_month();
         
         // found the year, traverse the months
         return find_first_child(found_year, (entry) => {
@@ -310,8 +310,8 @@ public class Events.Branch : Sidebar.Branch {
         });
     }
     
-    private Sidebar.Entry? find_event_year(Event event, Time event_tm) {
-        int event_year = event_tm.year + 1900;
+    private Sidebar.Entry? find_event_year(Event event, DateTime event_tm) {
+        int event_year = event_tm.get_year();
         
         return find_first_child(get_root(), (entry) => {
             if ((entry is Events.UndatedDirectoryEntry) || (entry is Events.NoEventEntry) || 
@@ -400,9 +400,9 @@ public class Events.MasterDirectoryEntry : Events.DirectoryEntry {
 
 public class Events.YearDirectoryEntry : Events.DirectoryEntry {
     private string name;
-    private Time tm;
+    private DateTime tm;
     
-    public YearDirectoryEntry(string name, Time tm) {
+    public YearDirectoryEntry(string name, DateTime tm) {
         this.name = name;
         this.tm = tm;
     }
@@ -412,7 +412,7 @@ public class Events.YearDirectoryEntry : Events.DirectoryEntry {
     }
     
     public int get_year() {
-        return tm.year + 1900;
+        return tm.get_year();
     }
     
     protected override Page create_page() {
@@ -422,9 +422,9 @@ public class Events.YearDirectoryEntry : Events.DirectoryEntry {
 
 public class Events.MonthDirectoryEntry : Events.DirectoryEntry {
     private string name;
-    private Time tm;
+    private DateTime tm;
     
-    public MonthDirectoryEntry(string name, Time tm) {
+    public MonthDirectoryEntry(string name, DateTime tm) {
         this.name = name;
         this.tm = tm;
     }
@@ -434,11 +434,11 @@ public class Events.MonthDirectoryEntry : Events.DirectoryEntry {
     }
     
     public int get_year() {
-        return tm.year + 1900;
+        return tm.get_year();
     }
     
     public int get_month() {
-        return tm.month + 1;
+        return tm.get_month();
     }
     
     protected override Page create_page() {
@@ -456,7 +456,7 @@ public class Events.UndatedDirectoryEntry : Events.DirectoryEntry {
     
     protected override Page create_page() {
         return new SubEventsDirectoryPage(SubEventsDirectoryPage.DirectoryType.UNDATED,
-            Time.local(0));
+            new DateTime.now_local());
     }
 }
 
diff --git a/src/events/EventsDirectoryPage.vala b/src/events/EventsDirectoryPage.vala
index 7ead1a0..c00e4bf 100644
--- a/src/events/EventsDirectoryPage.vala
+++ b/src/events/EventsDirectoryPage.vala
@@ -88,10 +88,10 @@ public abstract class EventsDirectoryPage : CheckerboardPage {
     }
     
     private static int64 event_ascending_comparator(void *a, void *b) {
-        time_t start_a = ((EventDirectoryItem *) a)->event.get_start_time();
-        time_t start_b = ((EventDirectoryItem *) b)->event.get_start_time();
+        DateTime start_a = ((EventDirectoryItem *) a)->event.get_start_time();
+        DateTime start_b = ((EventDirectoryItem *) b)->event.get_start_time();
         
-        return start_a - start_b;
+        return start_a.compare(start_b);
     }
     
     private static int64 event_descending_comparator(void *a, void *b) {
@@ -239,21 +239,21 @@ public class SubEventsDirectoryPage : EventsDirectoryPage {
     }
     
     public const string UNDATED_PAGE_NAME = _("Undated");
-    public const string YEAR_FORMAT = _("%Y");
-    public const string MONTH_FORMAT = _("%B");
+    public const string YEAR_FORMAT = "%Y";
+    public const string MONTH_FORMAT = "%0B";
     
     private class SubEventDirectoryManager : EventsDirectoryPage.EventDirectoryManager {
         private int month = 0;
         private int year = 0;
         DirectoryType type;
 
-        public SubEventDirectoryManager(DirectoryType type, Time time) {
+        public SubEventDirectoryManager(DirectoryType type, DateTime time) {
             base();
             
             if (type == DirectoryType.MONTH)
-                month = time.month;
+                month = time.get_month();
             this.type = type;
-            year = time.year; 
+            year = time.get_year(); 
         }
 
         public override bool include_in_view(DataSource source) {
@@ -261,10 +261,10 @@ public class SubEventsDirectoryPage : EventsDirectoryPage {
                 return false;
             
             EventSource event = (EventSource) source;
-            Time event_time = Time.local(event.get_start_time());
-            if (event_time.year == year) {
+            var event_time = event.get_start_time().to_local();
+            if (event_time.get_year() == year) {
                 if (type == DirectoryType.MONTH) {
-                    return (event_time.month == month);
+                    return (event_time.get_month() == month);
                 }
                 return true;
             }
@@ -284,12 +284,26 @@ public class SubEventsDirectoryPage : EventsDirectoryPage {
         }
     }
 
-    public SubEventsDirectoryPage(DirectoryType type, Time time) {
+    public SubEventsDirectoryPage(DirectoryType type, DateTime time) {
         string page_name;
         if (type == SubEventsDirectoryPage.DirectoryType.UNDATED) {
             page_name = UNDATED_PAGE_NAME;
         } else {
-            page_name = time.format((type == DirectoryType.YEAR) ? YEAR_FORMAT : MONTH_FORMAT);
+            switch (type) {
+                case DirectoryType.MONTH: {
+                    page_name = time.format(MONTH_FORMAT);
+                    if (page_name.index_of("%0B") != -1) {
+                        page_name = time.format("%B");
+                    }
+                }
+                break;
+                case DirectoryType.YEAR: {
+                    page_name = time.format(YEAR_FORMAT);
+                }
+                break;
+                default:
+                    assert_not_reached();
+            }
         }
 
         base(page_name, new SubEventDirectoryManager(type, time), null); 
diff --git a/src/faces/Face.vala b/src/faces/Face.vala
index 9304023..cdccc1b 100644
--- a/src/faces/Face.vala
+++ b/src/faces/Face.vala
@@ -345,9 +345,19 @@ public class Face : DataSource, ContainerSource, Proxyable, Indexable {
         // add them all at once to the SourceCollection
         global.add_many(faces);
         global.init_add_many_unlinked(unlinked);
+
+#if ENABLE_FACE_DETECTION
+        // Start the face detection background process
+        // FaceTool talks to it over DBus
+        start_facedetect_process();
+#endif
     }
     
     public static void terminate() {
+        try {
+            if (FaceDetect.face_detect_proxy != null)
+                FaceDetect.face_detect_proxy.terminate();
+        } catch(Error e) {}
     }
     
     public static int compare_names(void *a, void *b) {
@@ -365,6 +375,14 @@ public class Face : DataSource, ContainerSource, Proxyable, Indexable {
     public static bool equal_name_strings(void *a, void *b) {
         return String.collated_equals(a, b);
     }
+
+#if ENABLE_FACE_DETECTION
+    private static void start_facedetect_process() {
+        message("Launching facedetect process: %s", AppDirs.get_facedetect_bin().get_path());
+        // Start the watcher, process started via DBus service
+        FaceDetect.init(AppDirs.get_openface_dnn_system_dir().get_path() + ":" + AppDirs.get_openface_dnn_dir().get_path());
+    }
+#endif
     
     // Returns a Face for the name, creating a new empty one if it does not already exist.
     // name should have already been prepared by prep_face_name.
@@ -387,7 +405,7 @@ public class Face : DataSource, ContainerSource, Proxyable, Indexable {
         
         return face;
     }
-    
+
     // Utility function to cleanup a face name that comes from user input and prepare it for use
     // in the system and storage in the database.  Returns null if the name is unacceptable.
     public static string? prep_face_name(string name) {
@@ -574,6 +592,16 @@ public class Face : DataSource, ContainerSource, Proxyable, Indexable {
         
         return true;
     }
+
+    public bool set_reference(FaceLocation face_loc) {
+        try {
+            FaceTable.get_instance().set_reference(row.face_id, face_loc.get_photo_id());
+        } catch (DatabaseError err) {
+            AppWindow.database_error(err);
+            return false;
+        }
+        return true;
+    }
     
     public bool contains(MediaSource source) {
         return media_views.has_view_for_source(source);
diff --git a/src/faces/FaceDetect.vala b/src/faces/FaceDetect.vala
new file mode 100644
index 0000000..83caa4d
--- /dev/null
+++ b/src/faces/FaceDetect.vala
@@ -0,0 +1,146 @@
+/**
+ * Face detection and recognition functions
+ * Copyright 2018 Narendra A (narendra_m_a(at)yahoo(dot)com)
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+// DBus face_detect_proxy definition
+public struct FaceRect {
+    public double x;
+    public double y;
+    public double width;
+    public double height;
+    public double[] vec;
+}
+
+[DBus (name = "org.gnome.Shotwell.Faces1")]
+public interface FaceDetectInterface : DBusProxy {
+    public abstract FaceRect[] detect_faces(string inputName, string cascadeName, double scale, bool infer)
+        throws IOError, DBusError;
+    public abstract bool load_net(string netFile)
+        throws IOError, DBusError;
+    public abstract void terminate() throws IOError, DBusError;
+}
+
+// Class to communicate with facedetect process over DBus
+public class FaceDetect {
+    public const string DBUS_NAME = "org.gnome.Shotwell.Faces1";
+    public const string DBUS_PATH = "/org/gnome/shotwell/faces";
+    public static bool connected = false;
+    public static string net_file;
+    public const string ERROR_MESSAGE = "Unable to connect to facedetect service";
+    
+    public static FaceDetectInterface face_detect_proxy;
+
+#if FACEDETECT_BUS_PRIVATE
+    private static GLib.DBusServer dbus_server;
+    private static Subprocess process;
+#endif
+
+    public static void create_face_detect_proxy(DBusConnection connection, string bus_name, string owner) {
+        if (bus_name == DBUS_NAME) {
+            message("Dbus name %s available", bus_name);
+
+            try {
+                // Service file should automatically run the facedetect binary
+                face_detect_proxy = Bus.get_proxy_sync (BusType.SESSION, DBUS_NAME, DBUS_PATH);
+                face_detect_proxy.load_net(net_file);
+                connected = true;
+            } catch(IOError e) {
+                AppWindow.error_message(ERROR_MESSAGE);
+            } catch(DBusError e) {
+                AppWindow.error_message(ERROR_MESSAGE);
+            }
+        }
+    }
+
+    public static void interface_gone(DBusConnection connection, string bus_name) {
+        message("Dbus name %s gone", bus_name);
+        connected = false;
+        face_detect_proxy = null;
+    }
+
+#if FACEDETECT_BUS_PRIVATE
+    private static bool on_new_connection(DBusServer server, DBusConnection connection) {
+        try {
+            face_detect_proxy = connection.get_proxy_sync(null, DBUS_PATH,
+                                                  DBusProxyFlags.DO_NOT_LOAD_PROPERTIES
+                                                  | DBusProxyFlags.DO_NOT_CONNECT_SIGNALS,
+                                                  null);
+            Idle.add(() => {
+                try {
+                    face_detect_proxy.load_net(net_file);
+                    connected = true;
+                } catch (Error error) {
+                    critical("Failed to call load_net: %s", error.message);
+                    AppWindow.error_message(ERROR_MESSAGE);
+                }
+                return false;
+            });
+
+            return true;
+        } catch (Error error) {
+            critical("Failed to create face_detect_proxy for face detect: %s", error.message);
+            AppWindow.error_message(ERROR_MESSAGE);
+
+            return false;
+        }
+    }
+#endif
+    
+    public static void init(string net_file) {
+        FaceDetect.net_file = net_file;
+#if FACEDETECT_BUS_PRIVATE
+        var address = "unix:tmpdir=%s".printf(Environment.get_tmp_dir());
+        var observer = new DBusAuthObserver();
+        observer.authorize_authenticated_peer.connect((stream, credentials) => {
+            debug("Observer trying to authorize for %s", credentials.to_string());
+            if (credentials == null)
+                return false;
+
+            try {
+                if (!credentials.is_same_user(new Credentials()))
+                    return false;
+                return true;
+            } catch (Error error) {
+                return false;
+            }
+        });
+
+        try {
+            dbus_server = new GLib.DBusServer.sync(address, DBusServerFlags.NONE, DBus.generate_guid(), observer, null);
+            dbus_server.new_connection.connect(on_new_connection);
+            dbus_server.start();
+            process = new Subprocess(SubprocessFlags.NONE, AppDirs.get_facedetect_bin().get_path(),
+            "--address=" + dbus_server.get_client_address());
+
+        } catch (Error error) {
+            warning("Failed to create private DBus server: %s", error.message);
+            AppWindow.error_message(ERROR_MESSAGE);
+        }
+#else
+        Bus.watch_name(BusType.SESSION, DBUS_NAME, BusNameWatcherFlags.NONE,
+                       create_face_detect_proxy, interface_gone);
+#endif
+    }
+
+}
diff --git a/src/faces/FaceLocation.vala b/src/faces/FaceLocation.vala
index e143b2e..0f4e383 100644
--- a/src/faces/FaceLocation.vala
+++ b/src/faces/FaceLocation.vala
@@ -4,6 +4,11 @@
  * (version 2.1 or later).  See the COPYING file in this distribution.
  */
 
+// Encapsulate geometry and pixels of a Face
+public struct FaceLocationData {
+    public string geometry;
+    public string vec;
+}
 public class FaceLocation : Object {
     
     private static Gee.Map<FaceID?, Gee.Map<PhotoID?, FaceLocation>> face_photos_map;
@@ -12,17 +17,17 @@ public class FaceLocation : Object {
     private FaceLocationID face_location_id;
     private FaceID face_id;
     private PhotoID photo_id;
-    private string geometry;
-    
+    private FaceLocationData face_data;
+
     private FaceLocation(FaceLocationID face_location_id, FaceID face_id, PhotoID photo_id,
-    string geometry) {
+            FaceLocationData face_data) {
         this.face_location_id = face_location_id;
         this.face_id = face_id;
         this.photo_id = photo_id;
-        this.geometry = geometry;
+        this.face_data = face_data;
     }
     
-    public static FaceLocation create(FaceID face_id, PhotoID photo_id, string geometry) {
+    public static FaceLocation create(FaceID face_id, PhotoID photo_id, FaceLocationData face_data) {
         FaceLocation face_location = null;
         
         // Test if that FaceLocation already exists (that face in that photo) ...
@@ -33,12 +38,11 @@ public class FaceLocation : Object {
             
             face_location = faces_map.get(face_id);
             
-            if (face_location.get_serialized_geometry() != geometry) {
-                face_location.set_serialized_geometry(geometry);
+            if (face_location.get_serialized_geometry() != face_data.geometry) {
+                face_location.set_face_data(face_data);
                 
                 try {
-                    FaceLocationTable.get_instance().update_face_location_serialized_geometry(
-                        face_location);
+                    FaceLocationTable.get_instance().update_face_location_face_data(face_location);
                 } catch (DatabaseError err) {
                     AppWindow.database_error(err);
                 }
@@ -51,7 +55,7 @@ public class FaceLocation : Object {
         try {
             face_location =
                 FaceLocation.add_from_row(
-                    FaceLocationTable.get_instance().add(face_id, photo_id, geometry));
+                    FaceLocationTable.get_instance().add(face_id, photo_id, face_data.geometry, face_data.vec));
         } catch (DatabaseError err) {
             AppWindow.database_error(err);
         }
@@ -84,7 +88,8 @@ public class FaceLocation : Object {
     public static FaceLocation add_from_row(FaceLocationRow row) {
         
         FaceLocation face_location =
-            new FaceLocation(row.face_location_id, row.face_id, row.photo_id, row.geometry);
+            new FaceLocation(row.face_location_id, row.face_id, row.photo_id,
+                { row.geometry, row.vec });
         
         Gee.Map<PhotoID?, FaceLocation> photos_map = face_photos_map.get(row.face_id);
         if (photos_map == null) {photos_map = new Gee.HashMap<PhotoID?, FaceLocation>
@@ -196,10 +201,22 @@ public class FaceLocation : Object {
     }
     
     public string get_serialized_geometry() {
-        return geometry;
+        return face_data.geometry;
+    }
+
+    public string get_serialized_vec() {
+        return face_data.vec;
+    }
+
+    public FaceLocationData get_face_data() {
+        return face_data;
+    }
+
+    public PhotoID get_photo_id() {
+        return photo_id;
     }
     
-    private void set_serialized_geometry(string geometry) {
-        this.geometry = geometry;
+    private void set_face_data(FaceLocationData face_data) {
+        this.face_data = face_data;
     }
 }
diff --git a/src/faces/FacePage.vala b/src/faces/FacePage.vala
index f2512d5..1766b91 100644
--- a/src/faces/FacePage.vala
+++ b/src/faces/FacePage.vala
@@ -44,6 +44,7 @@ public class FacePage : CollectionPage {
         { "DeleteFace", on_delete_face },
         { "RenameFace", on_rename_face },
         { "RemoveFaceFromPhotos", on_remove_face_from_photos },
+        { "SetFaceRefFromPhoto", on_set_face_ref },
         { "DeleteFaceSidebar", on_delete_face },
         { "RenameFaceSidebar", on_rename_face }
     };
@@ -74,6 +75,7 @@ public class FacePage : CollectionPage {
        
         menuFaces.add_menu_item(Resources.remove_face_from_photos_menu(this.face.get_name(), get_view().get_count()), "RemoveFaceFromPhotos", "<Primary>r");
         menuFaces.add_menu_item(Resources.rename_face_menu(this.face.get_name()), "RenameFace", "<Primary>e");
+        menuFaces.add_menu_item(Resources.set_face_from_photo_menu(this.face.get_name()), "SetFaceRefFromPhoto", null);
         menuFaces.add_menu_item(Resources.delete_face_menu(this.face.get_name()), "DeleteFace", "<Primary>t");
         
         return menuFaces;
@@ -102,6 +104,11 @@ public class FacePage : CollectionPage {
             null,
             selected_count > 0);
         
+        set_action_details("SetFaceRefFromPhoto",
+            Resources.set_face_from_photo_menu(face.get_name()),
+            null,
+            selected_count == 1);
+            
         base.update_actions(selected_count, count);
     }
     
@@ -120,4 +127,11 @@ public class FacePage : CollectionPage {
                 (Gee.Collection<MediaSource>) get_view().get_selected_sources()));
         }
     }
+
+    private void on_set_face_ref() {
+        if (get_view().get_selected_count() == 1) {
+            get_command_manager().execute(new SetFaceRefCommand(face,
+                            (MediaSource) get_view().get_selected_at(0).get_source()));
+        }
+    }
 }
diff --git a/src/faces/FaceShape.vala b/src/faces/FaceShape.vala
index 1ff01fd..f90f254 100644
--- a/src/faces/FaceShape.vala
+++ b/src/faces/FaceShape.vala
@@ -18,14 +18,16 @@ public abstract class FaceShape : Object {
     protected Gdk.CursorType current_cursor_type = Gdk.CursorType.BOTTOM_RIGHT_CORNER;
     protected EditingTools.PhotoCanvas canvas;
     protected string serialized = null;
+    protected double[] face_vec;
     
     private bool editable = true;
     private bool visible = true;
     private bool known = true;
+    private double guess = 0.0;
     
     private weak FacesTool.FaceWidget face_widget = null;
     
-    protected FaceShape(EditingTools.PhotoCanvas canvas) {
+    protected FaceShape(EditingTools.PhotoCanvas canvas, double[] vec) {
         this.canvas = canvas;
         this.canvas.new_surface.connect(prepare_ctx);
         
@@ -37,19 +39,21 @@ public abstract class FaceShape : Object {
         face_window.show_all();
         face_window.hide();
         
-        this.canvas.get_drawing_window().set_cursor(new Gdk.Cursor(current_cursor_type));
+        this.face_vec = vec;
+        this.canvas.set_cursor(current_cursor_type);
     }
     
     ~FaceShape() {
-        if (visible)
+        if (visible) {
             erase();
+        }
         
         face_window.destroy();
         
         canvas.new_surface.disconnect(prepare_ctx);
         
         // make sure the cursor isn't set to a modify indicator
-        canvas.get_drawing_window().set_cursor(new Gdk.Cursor(Gdk.CursorType.LEFT_PTR));
+        canvas.set_cursor(Gdk.CursorType.LEFT_PTR);
     }
     
     public static FaceShape from_serialized(EditingTools.PhotoCanvas canvas, string serialized)
@@ -88,7 +92,15 @@ public abstract class FaceShape : Object {
     public bool get_known() {
         return known;
     }
+
+    public void set_guess(double guess) {
+        this.guess = guess;
+    }
     
+    public double get_guess() {
+        return guess;
+    }
+
     public void set_widget(FacesTool.FaceWidget face_widget) {
         this.face_widget = face_widget;
     }
@@ -107,7 +119,7 @@ public abstract class FaceShape : Object {
             face_window.hide();
         
         // make sure the cursor isn't set to a modify indicator
-        canvas.get_drawing_window().set_cursor(new Gdk.Cursor(Gdk.CursorType.LEFT_PTR));
+        canvas.set_cursor(Gdk.CursorType.LEFT_PTR);
     }
     
     public void show() {
@@ -160,7 +172,7 @@ public abstract class FaceShape : Object {
         return true;
     }
     
-    public abstract string serialize();
+    public abstract string serialize(bool geometry_only = false);
     public abstract void update_face_window_position();
     public abstract void prepare_ctx(Cairo.Context ctx, Dimensions dim);
     public abstract void on_resized_pixbuf(Dimensions old_dim, Gdk.Pixbuf scaled);
@@ -170,6 +182,7 @@ public abstract class FaceShape : Object {
     public abstract bool cursor_is_over(int x, int y);
     public abstract bool equals(FaceShape face_shape);
     public abstract double get_distance(int x, int y);
+    public abstract double[] get_face_vec();
     
     protected abstract void paint();
     protected abstract void erase();
@@ -186,13 +199,17 @@ public class FaceRectangle : FaceShape {
     private BoxLocation in_manipulation = BoxLocation.OUTSIDE;
     private Cairo.Context wide_black_ctx = null;
     private Cairo.Context wide_white_ctx = null;
-    private Cairo.Context thin_white_ctx = null;
     private int last_grab_x = -1;
     private int last_grab_y = -1;
     
     public FaceRectangle(EditingTools.PhotoCanvas canvas, int x, int y,
-        int half_width = NULL_SIZE, int half_height = NULL_SIZE) {
-        base(canvas);
+        int half_width = NULL_SIZE, int half_height = NULL_SIZE, double[] vec = {}) {
+	double[] int_vec;
+	if (vec.length == 0)
+	   int_vec = create_empty_vec();
+	else
+	   int_vec = vec;
+        base(canvas, int_vec);
         
         Gdk.Rectangle scaled_pixbuf_pos = canvas.get_scaled_pixbuf_position();
         x -= scaled_pixbuf_pos.x;
@@ -219,6 +236,14 @@ public class FaceRectangle : FaceShape {
         if (!is_editable())
             erase_label();
     }
+
+    public static double[] create_empty_vec() {
+        double[] empty_vec = new double[128];
+        for (int i = 0; i < 128; i++) {
+            empty_vec[i] = 0;
+	}
+	return empty_vec;
+    }
     
     public static new FaceRectangle from_serialized(EditingTools.PhotoCanvas canvas, string[] args)
         throws FaceShapeError {
@@ -226,7 +251,9 @@ public class FaceRectangle : FaceShape {
         
         Photo photo = canvas.get_photo();
         Dimensions raw_dim = photo.get_raw_dimensions();
-        
+
+        // 1, 2 is the center of the rectangle, 3, 4 is the half width / height of the rectangle,
+        // normalized
         int x = (int) (raw_dim.width * double.parse(args[1]));
         int y = (int) (raw_dim.height * double.parse(args[2]));
         int half_width = (int) (raw_dim.width * double.parse(args[3]));
@@ -265,9 +292,21 @@ public class FaceRectangle : FaceShape {
         
         if (half_width < FACE_MIN_SIZE || half_height < FACE_MIN_SIZE)
             throw new FaceShapeError.CANT_CREATE("FaceShape is out of cropped photo area");
-        
+
+        string[] vec_str;
+        if (args.length == 6)
+            vec_str = args[5].split(",");
+        else
+            vec_str = {};
+        double[] vec = new double[128];
+        for (int i = 0; i < 128; i++) {
+            if (vec_str.length > i)
+                vec[i] = double.parse(vec_str[i]);
+            else
+                vec[i] = 0;
+        }
         return new FaceRectangle(canvas, box.left + half_width, box.top + half_height,
-            half_width, half_height);
+            half_width, half_height, vec);
     }
     
     public override void update_face_window_position() {
@@ -283,32 +322,35 @@ public class FaceRectangle : FaceShape {
         
         face_window.get_allocation(out face_window_alloc);
         
-        x += scaled_pixbuf_pos.x + box.left + ((box.get_width() - face_window_alloc.width) >> 1);
-        y += scaled_pixbuf_pos.y + box.bottom + FACE_WINDOW_MARGIN;
+        var scale = Application.get_scale();
+        var left = (int)Math.lround((scaled_pixbuf_pos.x + box.left) / scale);
+        var width = (int)Math.lround(box.get_width() / scale);
+        var top = (int)Math.lround((scaled_pixbuf_pos.y + box.bottom) / scale);
+        x += (left  + ((width - face_window_alloc.width) >> 1));
+        y += top + FACE_WINDOW_MARGIN;
         
         face_window.move(x, y);
     }
     
     protected override void paint() {
+        // The box is in image coordinates. Need to scale down to device coordinates
         canvas.draw_box(wide_black_ctx, box);
         canvas.draw_box(wide_white_ctx, box.get_reduced(1));
         canvas.draw_box(wide_white_ctx, box.get_reduced(2));
         
-        canvas.invalidate_area(box);
+        //canvas.invalidate_area(box);
         
         if (!is_editable())
             paint_label();
     }
     
     protected override void erase() {
-        canvas.erase_box(box);
-        canvas.erase_box(box.get_reduced(1));
-        canvas.erase_box(box.get_reduced(2));
-        
         canvas.invalidate_area(box);
         
         if (!is_editable())
             erase_label();
+
+//        canvas.repaint();
     }
     
     private void paint_label() {
@@ -317,6 +359,9 @@ public class FaceRectangle : FaceShape {
         
         ctx.save();
         
+        ctx.select_font_face("Sans", Cairo.FontSlant.NORMAL, Cairo.FontWeight.NORMAL);
+        ctx.set_font_size(10.0 * Application.get_scale());
+
         Cairo.TextExtents text_extents = Cairo.TextExtents();
         ctx.text_extents(get_name(), out text_extents);
         
@@ -368,7 +413,7 @@ public class FaceRectangle : FaceShape {
         ctx.restore();
     }
     
-    public override string serialize() {
+    public override string serialize(bool geometry_only = false) {
         if (serialized != null)
             return serialized;
         
@@ -378,10 +423,15 @@ public class FaceRectangle : FaceShape {
         double half_height;
         
         get_geometry(out x, out y, out half_width, out half_height);
-        
-        serialized = "%s;%s;%s;%s;%s".printf(SHAPE_TYPE, x.to_string(),
+        serialized = "%s;%s;%s;%s;%s;".printf(SHAPE_TYPE, x.to_string(),
             y.to_string(), half_width.to_string(), half_height.to_string());
-        
+        if (!geometry_only) {
+            string face_vec_str = "";
+            foreach (var d in face_vec[0:-2])
+                face_vec_str += d.to_string() + ",";
+            face_vec_str += face_vec[-1].to_string();
+            serialized += face_vec_str;
+        }
         return serialized;
     }
     
@@ -425,23 +475,23 @@ public class FaceRectangle : FaceShape {
         half_width = (width_right_end - width_left_end) / 2;
         half_height = (height_bottom_end - height_top_end) / 2;
     }
+
+    public override double[] get_face_vec() {
+        return face_vec;
+    }
     
     public override bool equals(FaceShape face_shape) {
-        return serialize() == face_shape.serialize();
+        return serialize(true) == face_shape.serialize(true);
     }
     
     public override void prepare_ctx(Cairo.Context ctx, Dimensions dim) {
         wide_black_ctx = new Cairo.Context(ctx.get_target());
         set_source_color_from_string(wide_black_ctx, "#000");
-        wide_black_ctx.set_line_width(1);
+        wide_black_ctx.set_line_width(1 * Application.get_scale());
         
         wide_white_ctx = new Cairo.Context(ctx.get_target());
-        set_source_color_from_string(wide_black_ctx, "#FFF");
-        wide_white_ctx.set_line_width(1);
-        
-        thin_white_ctx = new Cairo.Context(ctx.get_target());
-        set_source_color_from_string(wide_black_ctx, "#FFF");
-        thin_white_ctx.set_line_width(0.5);
+        set_source_color_from_string(wide_white_ctx, "#FFF");
+        wide_white_ctx.set_line_width(1 * Application.get_scale());
     }
     
     private bool on_canvas_manipulation(int x, int y) {
@@ -620,17 +670,20 @@ public class FaceRectangle : FaceShape {
         Box new_box = Box(left, top, right, bottom);
         
         if (!box.equals(new_box)) {
-            erase();
+            canvas.invalidate_area(box);
             
             if (in_manipulation != BoxLocation.INSIDE)
                 check_resized_box(new_box);
             
             box = new_box;
             paint();
+            canvas.invalidate_area(new_box);
         }
         
         if (is_editable())
             update_face_window_position();
+
+            canvas.repaint();
         
         serialized = null;
         
@@ -698,8 +751,7 @@ public class FaceRectangle : FaceShape {
         }
         
         if (cursor_type != current_cursor_type) {
-            Gdk.Cursor cursor = new Gdk.Cursor(cursor_type);
-            canvas.get_drawing_window().set_cursor(cursor);
+            canvas.set_cursor(cursor_type);
             current_cursor_type = cursor_type;
         }
     }
diff --git a/src/faces/FacesTool.vala b/src/faces/FacesTool.vala
index 9803787..d399b38 100644
--- a/src/faces/FacesTool.vala
+++ b/src/faces/FacesTool.vala
@@ -119,7 +119,7 @@ public class FacesTool : EditingTools.EditingTool {
         private EditingPhase editing_phase = EditingPhase.NOT_EDITING;
         private Gtk.Box help_layout = null;
         private Gtk.Box response_layout = null;
-        private Gtk.HSeparator buttons_text_separator = null;
+        private Gtk.Separator buttons_text_separator = null;
         private Gtk.Label help_text = null;
         private Gtk.Box face_widgets_layout = null;
         private Gtk.Box layout = null;
@@ -163,7 +163,7 @@ public class FacesTool : EditingTools.EditingTool {
             layout = new Gtk.Box(Gtk.Orientation.VERTICAL, CONTROL_SPACING);
             layout.pack_start(face_widgets_layout, false);
             layout.pack_start(help_layout, false);
-            layout.pack_start(new Gtk.HSeparator(), false);
+            layout.pack_start(new Gtk.Separator(Gtk.Orientation.HORIZONTAL), false);
             layout.pack_start(response_layout, false);
 
             add(layout);
@@ -178,7 +178,7 @@ public class FacesTool : EditingTools.EditingTool {
                 case EditingPhase.CLICK_TO_EDIT:
                     assert(face_shape != null);
 
-                    help_text.set_markup(Markup.printf_escaped(_("Click to edit face <i>%s</i>"),
+                    help_text.set_markup(Markup.printf_escaped(_("Click to edit face “%s”"),
                         face_shape.get_name()));
 
                     break;
@@ -254,7 +254,7 @@ public class FacesTool : EditingTools.EditingTool {
             face_widgets_layout.pack_start(event_box, false);
 
             if (buttons_text_separator == null) {
-                buttons_text_separator = new Gtk.HSeparator();
+                buttons_text_separator = new Gtk.Separator(Gtk.Orientation.HORIZONTAL);
                 face_widgets_layout.pack_end(buttons_text_separator, false);
             }
 
@@ -315,121 +315,49 @@ public class FacesTool : EditingTools.EditingTool {
     private class FaceDetectionJob : BackgroundJob {
         private Gee.Queue<string> faces = null;
         private string image_path;
-        private string output;
-        public SpawnError? spawnError;
+        private float scale;
+        public string? spawnError;
 
-        public FaceDetectionJob(FacesToolWindow owner, string image_path,
+        public FaceDetectionJob(FacesToolWindow owner, string image_path, float scale,
             CompletionCallback completion_callback, Cancellable cancellable,
             CancellationCallback cancellation_callback) {
             base(owner, completion_callback, cancellable, cancellation_callback);
 
             this.image_path = image_path;
+            this.scale = scale;
         }
 
         public override void execute() {
+            if (!FaceDetect.connected) {
+                spawnError = "Face detect process not connected!\n";
+                return;
+            }
+            FaceRect[] rects;
             try {
-                string[] argv = {
-                    AppDirs.get_facedetect_bin().get_path(),
-                    "--cascade=" + AppDirs.get_haarcascade_file().get_path(),
-                    "--scale=1.2",
-                    image_path
-                };
-                Process.spawn_sync(null, argv, null, SpawnFlags.STDERR_TO_DEV_NULL, null, out output);
-
-            } catch (SpawnError e) {
-                spawnError = e;
-                critical(e.message);
-
+                rects = FaceDetect.face_detect_proxy.detect_faces(image_path,
+                                                          AppDirs.get_haarcascade_file().get_path(), scale, true);
+            } catch(Error e) {
+                spawnError = "DBus error: " + e.message + "!\n";
                 return;
             }
-
             faces = new Gee.PriorityQueue<string>();
-            string[] lines = output.split("\n");
-            foreach (string line in lines) {
-                if (line.length == 0)
-                    continue;
-
-                debug("shotwell-facedetect: %s", line);
-
-                string[] type_and_serialized = line.split(";");
-                if (type_and_serialized.length != 2) {
-                    // Pass on external helper log output as our debug log
-                    continue;
-                }
-
-                switch (type_and_serialized[0]) {
-                    case "face":
-                        StringBuilder serialized_geometry = new StringBuilder();
-                        serialized_geometry.append(FaceRectangle.SHAPE_TYPE);
-                        serialized_geometry.append(";");
-                        serialized_geometry.append(parse_serialized_geometry(type_and_serialized[1]));
-
-                        faces.add(serialized_geometry.str);
-                        break;
-
-                    case "warning":
-                        warning("%s\n", type_and_serialized[1]);
-                        break;
-
-                    case "error":
-                        critical("%s\n", type_and_serialized[1]);
-                        assert_not_reached();
-
-                    default:
-                        break;
+            for (int i = 0; i < rects.length; i++) {
+                double rect_x, rect_y, rect_w, rect_h;
+                string face_vec_str = "";
+                rect_w = rects[i].width / 2;
+                rect_h = rects[i].height / 2;
+                rect_x = rects[i].x + rect_w;
+                rect_y = rects[i].y + rect_h;
+                if (rects[i].vec != null) {
+                    foreach (var d in rects[i].vec) { face_vec_str += d.to_string() + ","; }
                 }
+                string serialized = "%s;%f;%f;%f;%f;%s".printf(FaceRectangle.SHAPE_TYPE,
+                                                                                rect_x, rect_y, rect_w, rect_h,
+                                                                                face_vec_str);
+                faces.add(serialized);
             }
         }
 
-        private string parse_serialized_geometry(string serialized_geometry) {
-            string[] serialized_geometry_pieces = serialized_geometry.split("&");
-            if (serialized_geometry_pieces.length != 4) {
-                critical("Wrong serialized line in face detection program output.");
-                assert_not_reached();
-            }
-
-            double x = 0;
-            double y = 0;
-            double width = 0;
-            double height = 0;
-            foreach (string piece in serialized_geometry_pieces) {
-
-                string[] name_and_value = piece.split("=");
-                if (name_and_value.length != 2) {
-                    critical("Wrong serialized line in face detection program output.");
-                    assert_not_reached();
-                }
-
-                switch (name_and_value[0]) {
-                    case "x":
-                        x = name_and_value[1].to_double();
-                        break;
-
-                    case "y":
-                        y = name_and_value[1].to_double();
-                        break;
-
-                    case "width":
-                        width = name_and_value[1].to_double();
-                        break;
-
-                    case "height":
-                        height = name_and_value[1].to_double();
-                        break;
-
-                    default:
-                        critical("Wrong serialized line in face detection program output.");
-                        assert_not_reached();
-                }
-            }
-
-            double half_width = width / 2;
-            double half_height = height / 2;
-
-            return "%s;%s;%s;%s".printf((x + half_width).to_string(), (y + half_height).to_string(),
-                half_width.to_string(), half_height.to_string());
-        }
-
         public string? get_next() {
             if (faces == null)
                 return null;
@@ -450,6 +378,7 @@ public class FacesTool : EditingTools.EditingTool {
     private Workers workers;
     private FaceShape editing_face_shape = null;
     private FacesToolWindow faces_tool_window = null;
+    private const int FACE_DETECT_MAX_WIDTH = 1200;
 
     private FacesTool() {
         base("FacesTool");
@@ -481,8 +410,10 @@ public class FacesTool : EditingTools.EditingTool {
             foreach (Gee.Map.Entry<FaceID?, FaceLocation> entry in face_locations.entries) {
                 FaceShape new_face_shape;
                 string serialized_geometry = entry.value.get_serialized_geometry();
+                string serialized_vec = entry.value.get_serialized_vec();
+                string face_shape_str = serialized_geometry + ";" + serialized_vec;
                 try {
-                    new_face_shape = FaceShape.from_serialized(canvas, serialized_geometry);
+                    new_face_shape = FaceShape.from_serialized(canvas, face_shape_str);
                 } catch (FaceShapeError e) {
                     if (e is FaceShapeError.CANT_CREATE)
                         continue;
@@ -502,9 +433,12 @@ public class FacesTool : EditingTools.EditingTool {
 
         face_detection_cancellable = new Cancellable();
         workers = new Workers(1, false);
+        Dimensions dimensions = canvas.get_photo().get_dimensions();
+        float scale_factor = (float)dimensions.width / FACE_DETECT_MAX_WIDTH;
         face_detection = new FaceDetectionJob(faces_tool_window,
-            canvas.get_photo().get_file().get_path(), on_faces_detected,
-            face_detection_cancellable, on_detection_cancelled);
+                                              canvas.get_photo().get_file().get_path(), scale_factor,
+                                              on_faces_detected,
+                                              face_detection_cancellable, on_detection_cancelled);
 
         bind_window_handlers();
 
@@ -591,6 +525,10 @@ public class FacesTool : EditingTools.EditingTool {
     }
 
     public override void on_left_click(int x, int y) {
+        var scale = Application.get_scale();
+        x = (int) Math.lround(x * scale);
+        y = (int) Math.lround(y * scale);
+        
         if (editing_face_shape != null && editing_face_shape.on_left_click(x, y))
             return;
 
@@ -607,6 +545,10 @@ public class FacesTool : EditingTools.EditingTool {
     }
 
     public override void on_left_released(int x, int y) {
+        var scale = Application.get_scale();
+        x = (int) Math.lround(x * scale);
+        y = (int) Math.lround(y * scale);
+
         if (editing_face_shape != null) {
             editing_face_shape.on_left_released(x, y);
 
@@ -616,6 +558,10 @@ public class FacesTool : EditingTools.EditingTool {
     }
 
     public override void on_motion(int x, int y, Gdk.ModifierType mask) {
+        var scale = Application.get_scale();
+        x = (int) Math.lround(x * scale);
+        y = (int) Math.lround(y * scale);
+        
         if (editing_face_shape == null) {
             FaceShape to_show = null;
             double distance = 0;
@@ -784,14 +730,21 @@ public class FacesTool : EditingTools.EditingTool {
         if (face_shapes == null)
             return;
 
-        Gee.Map<Face, string> new_faces = new Gee.HashMap<Face, string>();
+        Gee.Map<Face, FaceLocationData?> new_faces = new Gee.HashMap<Face, FaceLocationData?>();
         foreach (FaceShape face_shape in face_shapes.values) {
             if (!face_shape.get_known())
                 continue;
 
             Face new_face = Face.for_name(face_shape.get_name());
-
-            new_faces.set(new_face, face_shape.serialize());
+            string[] face_string = face_shape.serialize().split(";");
+            string face_vec_str, face_geometry;
+            face_geometry = string.joinv(";", face_string[0:5]);
+            face_vec_str = face_string[5];
+            FaceLocationData face_data =
+                {
+                 face_geometry, face_vec_str
+                };
+            new_faces.set(new_face, face_data);
         }
 
         ModifyFacesCommand command = new ModifyFacesCommand(canvas.get_photo(), new_faces);
@@ -848,7 +801,7 @@ public class FacesTool : EditingTools.EditingTool {
     private void delete_face(string face_name) {
         face_shapes.unset(face_name);
 
-        // It is posible to have two visible faces at the same time, this happens
+        // It is possible to have two visible faces at the same time, this happens
         // if you are editing one face and you move the pointer around the
         // FaceWidgets area in FacesToolWindow. And you can delete one of that
         // faces, so the other visible face must be repainted.
@@ -908,7 +861,6 @@ public class FacesTool : EditingTools.EditingTool {
     private void detect_faces() {
         faces_tool_window.detection_button.set_sensitive(false);
         faces_tool_window.set_editing_phase(EditingPhase.DETECTING_FACES);
-
         workers.enqueue(face_detection);
     }
 
@@ -945,19 +897,71 @@ public class FacesTool : EditingTools.EditingTool {
                 continue;
 
             c++;
+            // Reference faces to match with
+            Face? guess = get_face_match(face_shape, 0.7);
 
-            face_shape.set_name("Unknown face #%d".printf(c));
-            face_shape.set_known(false);
+            if (guess == null) {
+                face_shape.set_name("Unknown face #%d".printf(c));
+                face_shape.set_known(false);
+            } else {
+                string name_str;
+                name_str = "%s (%0.2f%%)".printf(guess.get_name(), face_shape.get_guess() * 100);
+                face_shape.set_name(name_str);
+                face_shape.set_known(true);
+            }
             add_face(face_shape);
         }
     }
 
+    private double dot_product(double[] vec1, double[] vec2) {
+        if (vec1.length != vec2.length) {
+            return 0;
+        }
+
+        double ret = 0;
+        for (var i = 0; i < vec1.length; i++) {
+            ret += vec1[i] * vec2[i];
+        }
+        return ret;
+    }
+
+    private Face? get_face_match(FaceShape face_shape, double threshold) {
+        Gee.List<FaceLocationRow?> face_vecs;
+        try {
+            Gee.List<FaceRow?> face_rows = FaceTable.get_instance().get_ref_rows();
+            face_vecs = FaceLocationTable.get_instance().get_face_ref_vecs(face_rows);
+        } catch(DatabaseError err) {
+            warning("Cannot get reference faces from DB");
+            return null;
+        }
+        FaceID? guess_id = null;
+        double max_product = threshold;
+        foreach (var row in face_vecs) {
+            string[] vec_str = row.vec.split(",");
+            double[] vec = {};
+            foreach (var d in vec_str) vec += double.parse(d);
+            double product = dot_product(face_shape.get_face_vec(), vec[0:128]);
+            if (product > max_product) {
+                max_product = product;
+                guess_id = row.face_id;
+            }
+        }
+
+        Face? face = null;
+        if (guess_id != null) {
+            face = Face.global.fetch(guess_id);
+            face_shape.set_guess(max_product);
+            assert(face != null);
+        }
+        return face;
+    }
+    
     private void on_faces_detected() {
         face_detection_cancellable.reset();
         
         if (face_detection.spawnError != null){
             string spawnErrorMessage = _("Error trying to spawn face detection program:\n");
-            AppWindow.error_message(spawnErrorMessage + face_detection.spawnError.message + "\n");
+            AppWindow.error_message(spawnErrorMessage + face_detection.spawnError + "\n");
             faces_tool_window.set_editing_phase(EditingPhase.DETECTING_FACES_FINISHED);
         } else
             pick_faces_from_autodetected();
diff --git a/src/import-roll/ImportRollBranch.vala b/src/import-roll/ImportRollBranch.vala
index 32337cc..0c582ac 100644
--- a/src/import-roll/ImportRollBranch.vala
+++ b/src/import-roll/ImportRollBranch.vala
@@ -6,8 +6,7 @@ public class ImportRoll.Branch : Sidebar.Branch {
               Sidebar.Branch.Options.HIDE_IF_EMPTY,
               ImportRoll.Branch.comparator);
 
-        this.entries = new Gee.HashMap<int64?, ImportRoll.SidebarEntry>((Gee.HashDataFunc<int64?>)GLib.int64_hash,
-        (Gee.EqualDataFunc<int64?>)GLib.int64_equal);
+        this.entries = new Gee.HashMap<int64?, ImportRoll.SidebarEntry>(int64_hash, int64_equal);
 
         foreach (var source in MediaCollectionRegistry.get_instance().get_all()) {
             on_import_rolls_altered(source);
diff --git a/src/library/BackgroundProgressBar.vala b/src/library/BackgroundProgressBar.vala
new file mode 100644
index 0000000..8ad7185
--- /dev/null
+++ b/src/library/BackgroundProgressBar.vala
@@ -0,0 +1,109 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later).  See the COPYING file in this distribution.
+ */
+
+internal class BackgroundProgressBar : Gtk.ProgressBar {
+    public enum Priority {
+        NONE = 0,
+        STARTUP_SCAN = 35,
+        REALTIME_UPDATE = 40,
+        REALTIME_IMPORT = 50,
+        METADATA_WRITER = 30
+    }
+
+    public bool should_be_visible { get; private set; default = false; }
+
+#if UNITY_SUPPORT
+    // UnityProgressBar: init
+    private UnityProgressBar uniprobar = UnityProgressBar.get_instance();
+#endif
+
+    private const int PULSE_MSEC = 250;
+
+    public BackgroundProgressBar() {
+        Object(show_text: true);
+    }
+
+    private Priority current_priority = Priority.NONE;
+    private uint pulse_id = 0;
+
+    public void start(string label, Priority priority) {
+        if (priority < current_priority)
+            return;
+
+        stop(priority, false);
+
+        current_priority = priority;
+        set_text(label);
+        pulse();
+        should_be_visible = true;
+        pulse_id = Timeout.add(PULSE_MSEC, on_pulse_timeout);
+    }
+
+    public void stop(Priority priority, bool clear) {
+        if (priority < current_priority)
+            return;
+
+        if (pulse_id != 0) {
+            Source.remove(pulse_id);
+            pulse_id = 0;
+        }
+
+        if (clear)
+            this.clear(priority);
+    }
+
+    public bool update(string label, Priority priority, double count, double total) {
+        if (priority < current_priority)
+            return false;
+
+        stop(priority, false);
+
+        if (count <= 0.0 || total <= 0.0 || count >= total) {
+            clear(priority);
+
+            return false;
+        }
+
+        current_priority = priority;
+
+        double fraction = count / total;
+        set_fraction(fraction);
+        set_text(_("%s (%d%%)").printf(label, (int) (fraction * 100.0)));
+        should_be_visible = true;
+
+#if UNITY_SUPPORT
+        // UnityProgressBar: try to draw & set progress
+        uniprobar.set_visible(true);
+        uniprobar.set_progress(fraction);
+#endif
+
+        return true;
+    }
+
+    public void clear(Priority priority) {
+        if (priority < current_priority)
+            return;
+
+        stop(priority, false);
+
+        current_priority = 0;
+
+        set_fraction(0.0);
+        set_text("");
+        should_be_visible = false;
+
+#if UNITY_SUPPORT
+        // UnityProgressBar: reset
+        uniprobar.reset();
+#endif
+    }
+
+    private bool on_pulse_timeout() {
+        pulse();
+
+        return true;
+    }
+}
diff --git a/src/library/LibraryWindow.vala b/src/library/LibraryWindow.vala
index 53b3a7b..849ae2e 100644
--- a/src/library/LibraryWindow.vala
+++ b/src/library/LibraryWindow.vala
@@ -24,18 +24,10 @@ public class LibraryWindow : AppWindow {
         "mtp:"
     };
     
-    private const int BACKGROUND_PROGRESS_PULSE_MSEC = 250;
 
     // If we're not operating on at least this many files, don't display the progress
     // bar at all; otherwise, it'll go by too quickly, giving the appearance of a glitch.
-    const int MIN_PROGRESS_BAR_FILES = 20;
-    
-    // these values reflect the priority various background operations have when reporting
-    // progress to the LibraryWindow progress bar ... higher values give priority to those reports
-    private const int STARTUP_SCAN_PROGRESS_PRIORITY =      35;
-    private const int REALTIME_UPDATE_PROGRESS_PRIORITY =   40;
-    private const int REALTIME_IMPORT_PROGRESS_PRIORITY =   50;
-    private const int METADATA_WRITER_PROGRESS_PRIORITY =   30;
+    const int MIN_PROGRESS_BAR_FILES = 1;
     
     // This lists the order of the toplevel items in the sidebar.  New toplevel items should be
     // added here in the position they should appear in the sidebar.  To re-order, simply move
@@ -136,11 +128,12 @@ public class LibraryWindow : AppWindow {
     private SearchFilterToolbar search_toolbar;
     
     private Gtk.Box top_section = new Gtk.Box(Gtk.Orientation.VERTICAL, 0);
-    private Gtk.Frame background_progress_frame = new Gtk.Frame(null);
-    private Gtk.ProgressBar background_progress_bar = new Gtk.ProgressBar();
-    private bool background_progress_displayed = false;
+    private Gtk.Revealer background_progress_frame = new Gtk.Revealer();
+    private BackgroundProgressBar background_progress_bar = new BackgroundProgressBar();
     
-    private BasicProperties basic_properties = new BasicProperties();
+    // Instantiate later in constructor because the map support loads its icons in there and we need
+    // to have the global app instance available for that
+    private BasicProperties basic_properties;
     private ExtendedProperties extended_properties = new ExtendedProperties();
     private Gtk.Revealer extended_properties_revealer = new Gtk.Revealer();
     
@@ -149,14 +142,6 @@ public class LibraryWindow : AppWindow {
     private Gtk.Box right_vbox;
     private Gtk.Revealer toolbar_revealer = new Gtk.Revealer ();
     
-    private int current_progress_priority = 0;
-    private uint background_progress_pulse_id = 0;
-    
-#if UNITY_SUPPORT
-    //UnityProgressBar: init
-    UnityProgressBar uniprobar = UnityProgressBar.get_instance();
-#endif
-    
     public LibraryWindow(ProgressMonitor progress_monitor) {
         base();
 
@@ -180,11 +165,12 @@ public class LibraryWindow : AppWindow {
         
         properties_scheduler = new OneShotScheduler("LibraryWindow properties",
             on_update_properties_now);
-        
+
         // setup search bar and add its accelerators to the window
         search_toolbar = new SearchFilterToolbar(search_actions);
 
         // create the main layout & start at the Library page
+        basic_properties = new BasicProperties();
         create_layout(library_branch.photos_entry.get_page());
         
         // settings that should persist between sessions
@@ -217,8 +203,6 @@ public class LibraryWindow : AppWindow {
         
         CameraTable.get_instance().camera_added.connect(on_camera_added);
         
-        background_progress_bar.set_show_text(true);
-
         // Need to re-install F8 here as it will overwrite the binding created
         // by the menu
         const string[] accels = { "<Primary>f", "F8", null };
@@ -282,7 +266,7 @@ public class LibraryWindow : AppWindow {
         { "CommonFind", on_find },
         { "CommonNewSearch", on_new_search },
 
-        // Toogle actions
+        // Toggle actions
         { "CommonDisplayBasicProperties", on_action_toggle, null, "false", on_display_basic_properties },
         { "CommonDisplayExtendedProperties", on_action_toggle, null, "false", on_display_extended_properties },
 
@@ -770,7 +754,7 @@ public class LibraryWindow : AppWindow {
         if (AppDirs.get_import_dir().get_path() == Environment.get_home_dir() && notify_library_is_home_dir) {
             Gtk.ResponseType response = AppWindow.affirm_cancel_question(
                 _("Shotwell is configured to import photos to your home directory.\n" + 
-                "We recommend changing this in <span weight=\"bold\">Edit %s Preferences</span>.\n" + 
+                "We recommend changing this in Edit %s Preferences.\n" + 
                 "Do you want to continue importing photos?").printf("▸"),
                 _("_Import"), _("Library Location"), AppWindow.get_instance());
             
@@ -949,15 +933,9 @@ public class LibraryWindow : AppWindow {
             return;
         
         ImportPage page = (ImportPage) entry.get_page();
-        File uri_file = File.new_for_uri(camera.uri);
         
         // find the VFS mount point
-        Mount mount = null;
-        try {
-            mount = uri_file.find_enclosing_mount(null);
-        } catch (Error err) {
-            // error means not mounted
-        }
+        var mount = camera.get_mount();
         
         // don't unmount mass storage cameras, as they are then unavailable to gPhoto
         if (mount != null && !camera.uri.has_prefix("file://")) {
@@ -1012,135 +990,40 @@ public class LibraryWindow : AppWindow {
         
         sort_events_action.change_state (event_sort_val);
     }
-    
-    private void start_pulse_background_progress_bar(string label, int priority) {
-        if (priority < current_progress_priority)
-            return;
-        
-        stop_pulse_background_progress_bar(priority, false);
-        
-        current_progress_priority = priority;
-        
-        background_progress_bar.set_text(label);
-        background_progress_bar.pulse();
-        show_background_progress_bar();
-        
-        background_progress_pulse_id = Timeout.add(BACKGROUND_PROGRESS_PULSE_MSEC,
-            on_pulse_background_progress_bar);
-    }
-    
-    private bool on_pulse_background_progress_bar() {
-        background_progress_bar.pulse();
-        
-        return true;
-    }
-    
-    private void stop_pulse_background_progress_bar(int priority, bool clear) {
-        if (priority < current_progress_priority)
-            return;
-        
-        if (background_progress_pulse_id != 0) {
-            Source.remove(background_progress_pulse_id);
-            background_progress_pulse_id = 0;
-        }
-        
-        if (clear)
-            clear_background_progress_bar(priority);
-    }
-    
-    private void update_background_progress_bar(string label, int priority, double count,
-        double total) {
-        if (priority < current_progress_priority)
-            return;
-        
-        stop_pulse_background_progress_bar(priority, false);
-        
-        if (count <= 0.0 || total <= 0.0 || count >= total) {
-            clear_background_progress_bar(priority);
-            
-            return;
-        }
-        
-        current_progress_priority = priority;
-        
-        double fraction = count / total;
-        background_progress_bar.set_fraction(fraction);
-        background_progress_bar.set_text(_("%s (%d%%)").printf(label, (int) (fraction * 100.0)));
-        show_background_progress_bar();
-        
-#if UNITY_SUPPORT
-        //UnityProgressBar: try to draw & set progress
-        uniprobar.set_visible(true);
-        uniprobar.set_progress(fraction);
-#endif
-    }
-    
-    private void clear_background_progress_bar(int priority) {
-        if (priority < current_progress_priority)
-            return;
-        
-        stop_pulse_background_progress_bar(priority, false);
-        
-        current_progress_priority = 0;
-        
-        background_progress_bar.set_fraction(0.0);
-        background_progress_bar.set_text("");
-        hide_background_progress_bar();
-        
-#if UNITY_SUPPORT
-        //UnityProgressBar: reset
-        uniprobar.reset();
-#endif
-    }
-    
-    private void show_background_progress_bar() {
-        if (!background_progress_displayed) {
-            top_section.pack_end(background_progress_frame, false, false, 0);
-            background_progress_frame.show_all();
-            background_progress_displayed = true;
-        }
-    }
-    
-    private void hide_background_progress_bar() {
-        if (background_progress_displayed) {
-            top_section.remove(background_progress_frame);
-            background_progress_displayed = false;
-        }
-    }
-    
+
     private void on_library_monitor_discovery_started() {
-        start_pulse_background_progress_bar(_("Updating library…"), STARTUP_SCAN_PROGRESS_PRIORITY);
+        background_progress_bar.start(_("Updating library…"), BackgroundProgressBar.Priority.STARTUP_SCAN);
     }
     
     private void on_library_monitor_discovery_completed() {
-        stop_pulse_background_progress_bar(STARTUP_SCAN_PROGRESS_PRIORITY, true);
+        background_progress_bar.stop(BackgroundProgressBar.Priority.STARTUP_SCAN, true);
     }
     
     private void on_library_monitor_auto_update_progress(int completed_files, int total_files) {
         if (total_files < MIN_PROGRESS_BAR_FILES)
-            clear_background_progress_bar(REALTIME_UPDATE_PROGRESS_PRIORITY);
+            background_progress_bar.clear(BackgroundProgressBar.Priority.REALTIME_UPDATE);
         else {
-            update_background_progress_bar(_("Updating library…"), REALTIME_UPDATE_PROGRESS_PRIORITY,
+            background_progress_bar.update(_("Updating library…"), BackgroundProgressBar.Priority.REALTIME_UPDATE,
                 completed_files, total_files);
         }
     }
     
     private void on_library_monitor_auto_import_preparing() {
-        start_pulse_background_progress_bar(_("Preparing to auto-import photos…"),
-            REALTIME_IMPORT_PROGRESS_PRIORITY);
+        background_progress_bar.start(_("Preparing to auto-import photos…"),
+            BackgroundProgressBar.Priority.REALTIME_UPDATE);
     }
     
     private void on_library_monitor_auto_import_progress(uint64 completed_bytes, uint64 total_bytes) {
-        update_background_progress_bar(_("Auto-importing photos…"),
-            REALTIME_IMPORT_PROGRESS_PRIORITY, completed_bytes, total_bytes);
+        background_progress_bar.update(_("Auto-importing photos…"),
+            BackgroundProgressBar.Priority.REALTIME_UPDATE, completed_bytes, total_bytes);
     }
     
     private void on_metadata_writer_progress(uint completed, uint total) {
         if (total < MIN_PROGRESS_BAR_FILES)
-            clear_background_progress_bar(METADATA_WRITER_PROGRESS_PRIORITY);
+            background_progress_bar.clear(BackgroundProgressBar.Priority.METADATA_WRITER);
         else {
-            update_background_progress_bar(_("Writing metadata to files…"),
-                METADATA_WRITER_PROGRESS_PRIORITY, completed, total);
+            background_progress_bar.update(_("Writing metadata to files…"),
+                BackgroundProgressBar.Priority.METADATA_WRITER, completed, total);
         }
     }
     
@@ -1153,17 +1036,22 @@ public class LibraryWindow : AppWindow {
         
         background_progress_frame.set_border_width(2);
         background_progress_frame.add(background_progress_bar);
-        background_progress_frame.get_style_context().remove_class("frame");
+        background_progress_frame.set_transition_type(Gtk.RevealerTransitionType.SLIDE_UP);
+        background_progress_frame.halign = Gtk.Align.FILL;
+        background_progress_frame.valign = Gtk.Align.END;
+        background_progress_frame.vexpand = false;
+        background_progress_frame.hexpand = true;
+        background_progress_bar.bind_property("should-be-visible", background_progress_frame, "reveal-child", GLib.BindingFlags.DEFAULT);
 
         // pad the bottom frame (properties)
         basic_properties.halign = Gtk.Align.FILL;
         basic_properties.valign = Gtk.Align.CENTER;
         basic_properties.hexpand = true;
-        basic_properties.vexpand = false;
+        basic_properties.vexpand = true;
         basic_properties.margin_top = 10;
         basic_properties.margin_bottom = 10;
         basic_properties.margin_start = 6;
-        basic_properties.margin_end = 0;
+        basic_properties.margin_end = 6;
 
         bottom_frame.add(basic_properties);
         bottom_frame.get_style_context().remove_class("frame");
@@ -1171,6 +1059,7 @@ public class LibraryWindow : AppWindow {
         // "attach" the progress bar to the sidebar tree, so the movable ridge is to resize the
         // top two and the basic information pane
         top_section.pack_start(scrolled_sidebar, true, true, 0);
+        top_section.pack_end(background_progress_frame, false, false, 0);
 
         sidebar_paned.pack1(top_section, true, false);
         sidebar_paned.pack2(bottom_frame, false, false);
diff --git a/src/library/TrashPage.vala b/src/library/TrashPage.vala
index 35dee4e..1e72f07 100644
--- a/src/library/TrashPage.vala
+++ b/src/library/TrashPage.vala
@@ -105,6 +105,10 @@ public class TrashPage : CheckerboardPage {
     protected override string get_view_empty_message() {
         return _("Trash is empty");
     }
+
+    protected override string get_view_empty_icon() {
+        return "user-trash-symbolic";
+    }
     
     private void on_delete() {
         remove_from_app((Gee.Collection<MediaSource>) get_view().get_selected_sources(), _("Delete"), 
diff --git a/src/libshotwell.deps b/src/libshotwell.deps
deleted file mode 100644
index 62f5abe..0000000
--- a/src/libshotwell.deps
+++ /dev/null
@@ -1,20 +0,0 @@
-atk
-gdk-3.0
-gee-0.8
-gexiv2
-gio-unix-2.0
-glib-2.0
-gmodule-2.0
-gnome-vfs-2.0
-gstreamer-0.10
-gstreamer-base-0.10
-gtk+-3.0
-gudev-1.0
-libexif
-libraw
-libgphoto2
-libsoup-2.4
-libxml-2.0
-sqlite3
-unique-1.0
-webkit-1.0
diff --git a/src/main.vala b/src/main.vala
index d0cb246..cdc9b27 100644
--- a/src/main.vala
+++ b/src/main.vala
@@ -72,6 +72,10 @@ void library_exec(string[] mounts) {
                 result.to_string());
         break;
     }
+
+    // Need to set this before anything else, but _after_ setting the profile
+    var use_dark = Config.Facade.get_instance().get_gtk_theme_variant();
+    Gtk.Settings.get_default().gtk_application_prefer_dark_theme = use_dark;
     
     if (errormsg != null) {
         Gtk.MessageDialog dialog = new Gtk.MessageDialog(null, Gtk.DialogFlags.MODAL, 
@@ -107,7 +111,7 @@ void library_exec(string[] mounts) {
             progress_dialog.update_display_every(100);
             progress_dialog.set_minimum_on_screen_time_msec(250);
             try {
-                progress_dialog.icon = new Gdk.Pixbuf.from_resource("/org/gnome/Shotwell/icons/shotwell.svg");
+                progress_dialog.icon = new Gdk.Pixbuf.from_resource("/org/gnome/Shotwell/icons/hicolor/scalable/org.gnome.Shotwell.svg");
             } catch (Error err) {
                 debug("Warning - could not load application icon for loading window: %s", err.message);
             }
@@ -253,13 +257,43 @@ private void report_system_pictures_import(ImportManifest manifest, BatchImportR
     ImportUI.report_manifest(manifest, true);
 }
 
+void dump_tags (GExiv2.Metadata metadata, string[] tags) throws Error {
+    foreach (string tag in tags) {
+        try {
+            print("%-64s%s\n",
+                tag,
+                metadata.try_get_tag_interpreted_string (tag));
+        } catch (Error err) {
+            print("Failed to get tag %s: %s\n", tag, err.message);
+        }
+    }
+}
+
+void dump_metadata (string filename) {
+    try {
+        var metadata = new GExiv2.Metadata();
+        var file = File.new_for_commandline_arg(filename);
+        metadata.from_stream (file.read());
+
+        dump_tags(metadata, metadata.get_exif_tags());
+        dump_tags(metadata, metadata.get_iptc_tags());
+        dump_tags(metadata, metadata.get_xmp_tags());
+    } catch (Error err) {
+        stderr.printf("Unable to dump metadata for %s: %s\n", filename, err.message);
+    }
+}
+
 void editing_exec(string filename, bool fullscreen) {
     File initial_file = File.new_for_commandline_arg(filename);
     
     // preconfigure units
     Direct.preconfigure(initial_file);
     Db.preconfigure(null);
-    
+
+    // Need to set this before anything else, but _after_ setting the profile
+    var use_dark = Config.Facade.get_instance().get_gtk_theme_variant();
+    Gtk.Settings.get_default().gtk_application_prefer_dark_theme = use_dark;
+
     // initialize units for direct-edit mode
     try {
         Direct.app_init();
@@ -278,6 +312,7 @@ void editing_exec(string filename, bool fullscreen) {
     
     DirectWindow direct_window = new DirectWindow(initial_file);
     direct_window.show_all();
+    direct_window.maximize();
     
     debug("%lf seconds to Gtk.main()", startup_timer.elapsed());
 
@@ -299,43 +334,29 @@ void editing_exec(string filename, bool fullscreen) {
 namespace CommandlineOptions {
 
 bool no_startup_progress = false;
-string data_dir = null;
+string? data_dir = null;
 bool show_version = false;
 bool no_runtime_monitoring = false;
 bool fullscreen = false;
-
-private OptionEntry[]? entries = null;
-
-public OptionEntry[] get_options() {
-    if (entries != null)
-        return entries;
-    
-    OptionEntry datadir = { "datadir", 'd', 0, OptionArg.FILENAME, &data_dir,
-        _("Path to Shotwell’s private data"), _("DIRECTORY") };
-    entries += datadir;
-    
-    OptionEntry no_monitoring = { "no-runtime-monitoring", 0, 0, OptionArg.NONE, &no_runtime_monitoring,
-        _("Do not monitor library directory at runtime for changes"), null };
-    entries += no_monitoring;
-    
-    OptionEntry no_startup = { "no-startup-progress", 0, 0, OptionArg.NONE, &no_startup_progress,
-        _("Don’t display startup progress meter"), null };
-    entries += no_startup;
-    
-    OptionEntry version = { "version", 'V', 0, OptionArg.NONE, &show_version, 
-        _("Show the application’s version"), null };
-    entries += version;
-
-    OptionEntry fullscreen = { "fullscreen", 'f', 0, OptionArg.NONE,
-        &fullscreen, _("Start the application in fullscreen mode"), null };
-    entries += fullscreen;
-    
-    OptionEntry terminator = { null, 0, 0, 0, null, null, null };
-    entries += terminator;
-    
-    return entries;
-}
-
+bool show_metadata = false;
+string? profile = null;
+bool create_profile = false;
+bool list_profiles = false;
+bool browse_profiles = false;
+
+const OptionEntry[] entries = {
+    { "datadir", 'd', 0, OptionArg.FILENAME, ref data_dir, N_("Path to Shotwell’s private data"), N_("DIRECTORY") },
+    { "no-runtime-monitoring", 0, 0, OptionArg.NONE, ref no_runtime_monitoring, N_("Do not monitor library directory at runtime for changes"), null },
+    { "no-startup-progress", 0, 0, OptionArg.NONE, ref no_startup_progress, N_("Don’t display startup progress meter"), null },
+    { "version", 'V', 0, OptionArg.NONE, ref show_version, N_("Show the application’s version") },
+    { "fullscreen", 'f', 0, OptionArg.NONE, ref fullscreen, N_("Start the application in fullscreen mode"), null },
+    { "show-metadata", 'p', 0, OptionArg.NONE, ref show_metadata, N_("Print the metadata of the image file"), null },
+    { "profile", 'i', 0, OptionArg.STRING, ref profile, N_("Name for a custom profile"), N_("PROFILE") },
+    { "profile-browser", 'b', 0, OptionArg.NONE, ref browse_profiles, N_("Start with a browser of available profiles"), null },
+    { "create", 'c', 0, OptionArg.NONE, ref create_profile, N_("If PROFILE given with --profile does not exist, create it"), null },
+    { "list-profiles", 'l', 0, OptionArg.NONE, ref list_profiles, N_("Show available profiles"), null },
+    { null, 0, 0, 0, null, null, null }
+};
 }
 
 void main(string[] args) {
@@ -345,7 +366,7 @@ void main(string[] args) {
 
     // This has to be done before the AppWindow is created in order to ensure the XMP
     // parser is initialized in a thread-safe fashion; please see 
-    // http://redmine.yorba.org/issues/4120 for details.
+    // https://bugzilla.gnome.org/show_bug.cgi?id=717931 for details.
     GExiv2.initialize();
     GExiv2.log_use_glib_logging();
 
@@ -353,22 +374,30 @@ void main(string[] args) {
     // logging mechanisms
     GExiv2.log_set_level(GExiv2.LogLevel.DEBUG);
 
+    // If set to non-empty, initialize GdkPixbuf with an additional loader path
+    if (Resources.PIXBUF_LOADER_PATH != "") {
+        debug("Trying to set module path to %s", Resources.PIXBUF_LOADER_PATH);
+        try {
+            Gdk.Pixbuf.init_modules(Resources.PIXBUF_LOADER_PATH);
+        } catch (Error err) {
+            message("Failed to set additional pixbuf loader path: %s", err.message);
+        }
+    }
+
     // following the GIO programming guidelines at http://developer.gnome.org/gio/2.26/ch03.html,
     // set the GSETTINGS_SCHEMA_DIR environment variable to allow us to load GSettings schemas from 
     // the build directory. this allows us to access local GSettings schemas without having to
     // muck with the user's XDG_... directories, which is seriously frowned upon
     if (AppDirs.get_install_dir() == null) {
         GLib.Environment.set_variable("GSETTINGS_SCHEMA_DIR", AppDirs.get_lib_dir().get_path() +
-            "/misc", true);
+            "/data/gsettings", true);
     }
-    
+
     // init GTK (valac has already called g_threads_init())
     try {
-        Gtk.init_with_args(ref args, _("[FILE]"), CommandlineOptions.get_options(),
+        Gtk.init_with_args(ref args, _("[FILE]"), CommandlineOptions.entries,
             Resources.APP_GETTEXT_PACKAGE);
 
-        var use_dark = Config.Facade.get_instance().get_gtk_theme_variant();
-        Gtk.Settings.get_default().gtk_application_prefer_dark_theme = use_dark;
     } catch (Error e) {
         print(e.message + "\n");
         print(_("Run “%s --help” to see a full list of available command line options.\n"), args[0]);
@@ -376,6 +405,41 @@ void main(string[] args) {
         return;
     }
 
+    if (CommandlineOptions.browse_profiles) {
+        var window = new Gtk.Dialog();
+        window.set_title (_("Choose Shotwell's profile"));
+        var browser = new Shotwell.ProfileBrowser();
+        browser.profile_activated.connect((profile) => {
+            CommandlineOptions.profile = profile;
+            window.response(Gtk.ResponseType.OK);
+        });
+        window.get_content_area().add(browser);
+        window.set_size_request(430, 560);
+        var response = window.run();
+        window.destroy();
+        // Anything else than selecting an entry in the list will stop shotwell from starting
+        if (response != Gtk.ResponseType.OK) {
+            return;
+        }
+    }
+
+    // Setup profile manager
+    if (CommandlineOptions.profile != null) {
+        var manager = Shotwell.ProfileManager.get_instance();
+        if (!manager.has_profile (CommandlineOptions.profile)) {
+             if (!CommandlineOptions.create_profile) {
+                print(_("Profile %s does not exist. Did you mean to pass --create as well?"),
+                      CommandlineOptions.profile);
+                AppDirs.terminate();
+                return;
+             }
+        }
+        manager.set_profile(CommandlineOptions.profile);
+        CommandlineOptions.data_dir = manager.derive_data_dir(CommandlineOptions.data_dir);
+    } else {
+        message("Starting session with system profile");
+    }
+
     if (CommandlineOptions.show_version) {
         if (Resources.GIT_VERSION != "")
             print("%s %s (%s)\n", Resources.APP_TITLE, Resources.APP_VERSION, Resources.GIT_VERSION);
@@ -386,7 +450,16 @@ void main(string[] args) {
         
         return;
     }
-    
+
+    if (CommandlineOptions.list_profiles) {
+        var manager  = Shotwell.ProfileManager.get_instance();
+        manager.print_profiles();
+
+        AppDirs.terminate();
+
+        return;
+    }
+
     // init debug prior to anything else (except Gtk, which it relies on, and AppDirs, which needs
     // to be set ASAP) ... since we need to know what mode we're in, examine the command-line
     // first
@@ -397,15 +470,21 @@ void main(string[] args) {
     string[] mounts = new string[0];
     string filename = null;
 
-    for (int ctr = 1; ctr < args.length; ctr++) {
-        string arg = args[ctr];
-        
+    foreach (var arg in args[1:args.length]) {
         if (LibraryWindow.is_mount_uri_supported(arg)) {
             mounts += arg;
         } else if (is_string_empty(filename) && !arg.contains("://")) {
             filename = arg;
         }
     }
+
+    if (CommandlineOptions.show_metadata) {
+        dump_metadata (filename);
+
+        AppDirs.terminate();
+
+        return;
+    }
     
     Debug.init(is_string_empty(filename) ? Debug.LIBRARY_PREFIX : Debug.VIEWER_PREFIX);
 
diff --git a/src/meson.build b/src/meson.build
index cc99f56..460092e 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -17,235 +17,272 @@ processor = executable('shotwell-graphics-processor',
                        dependencies: [gio, gdk, gee],
                        link_with: sw_graphics_processor)
 
+shotwell_deps = [gio, gee, sqlite, gtk, sqlite, posix, gphoto2,
+                 gstreamer_pbu, gudev, gexiv2, gmodule,
+                 libraw, libexif, sw_plugin]
+
+shotwell_libs = [sw_graphics_processor]
+
 face_sources = (['faces/FacesBranch.vala',
-                     'faces/FaceLocation.vala',
                      'faces/FacePage.vala',
                      'faces/FaceShape.vala',
+                     'faces/FaceDetect.vala',
                      'faces/Faces.vala',
-                     'faces/Face.vala',
-                     'db/FaceLocationTable.vala',
-                     'db/FaceTable.vala',
                      'faces/FacesTool.vala'])
 
 shotwell_deps = [gio, gee, sqlite, gtk, sqlite, posix, gphoto2,
-                 gstreamer_pbu, gio_unix, gudev, gexiv2, gmodule,
-                 libraw, libexif, sw_plugin, gdk, version]
-if unity_available
-    shotwell_deps += [unity]
-endif
-executable('shotwell',
-           ['unit/Unit.vala',
-            'util/Util.vala',
-            'util/file.vala',
-            'util/image.vala',
-            'util/misc.vala',
-            'util/string.vala',
-            'util/system.vala',
-            'util/ui.vala',
-            'threads/Threads.vala',
-            'threads/Workers.vala',
-            'threads/BackgroundJob.vala',
-            'threads/Semaphore.vala',
-            'db/Db.vala',
-            'db/DatabaseTable.vala',
-            'db/PhotoTable.vala',
-            'db/EventTable.vala',
-            'db/TagTable.vala',
-            'db/TombstoneTable.vala',
-            'db/VideoTable.vala',
-            'db/VersionTable.vala',
-            'db/SavedSearchDBTable.vala',
-            'editing_tools/EditingTools.vala',
-            'editing_tools/RGBHistogramManipulator.vala',
-            'editing_tools/StraightenTool.vala',
-            'slideshow/Slideshow.vala',
-            'slideshow/TransitionEffects.vala',
-            'photos/Photos.vala',
-            'photos/PhotoFileAdapter.vala',
-            'photos/PhotoFileFormat.vala',
-            'photos/PhotoFileSniffer.vala',
-            'photos/PhotoMetadata.vala',
-            'photos/GRaw.vala',
-            'photos/GdkSupport.vala',
-            'photos/GifSupport.vala',
-            'photos/JfifSupport.vala',
-            'photos/BmpSupport.vala',
-            'photos/RawSupport.vala',
-            'photos/PngSupport.vala',
-            'photos/TiffSupport.vala',
-            'plugins/Plugins.vala',
-            'plugins/StandardHostInterface.vala',
-            'plugins/ManifestWidget.vala',
-            'publishing/Publishing.vala',
-            'publishing/PublishingUI.vala',
-            'publishing/PublishingPluginHost.vala',
-            'publishing/APIGlue.vala',
-            'library/Library.vala',
-            'library/LibraryWindow.vala',
-            'library/LibraryBranch.vala',
-            'library/TrashSidebarEntry.vala',
-            'library/OfflineSidebarEntry.vala',
-            'library/FlaggedSidebarEntry.vala',
-            'library/LastImportSidebarEntry.vala',
-            'library/ImportQueueSidebarEntry.vala',
-            'library/FlaggedPage.vala',
-            'library/ImportQueuePage.vala',
-            'library/LastImportPage.vala',
-            'library/OfflinePage.vala',
-            'library/TrashPage.vala',
-            'direct/Direct.vala',
-            'direct/DirectWindow.vala',
-            'direct/DirectPhoto.vala',
-            'direct/DirectPhotoPage.vala',
-            'direct/DirectView.vala',
-            'core/Core.vala',
-            'core/DataCollection.vala',
-            'core/DataSet.vala',
-            'core/util.vala',
-            'core/SourceCollection.vala',
-            'core/SourceHoldingTank.vala',
-            'core/DatabaseSourceCollection.vala',
-            'core/ContainerSourceCollection.vala',
-            'core/ViewCollection.vala',
-            'core/DataObject.vala',
-            'core/Alteration.vala',
-            'core/DataSource.vala',
-            'core/DataSourceTypes.vala',
-            'core/DataView.vala',
-            'core/DataViewTypes.vala',
-            'core/Tracker.vala',
-            'core/SourceInterfaces.vala',
-            'sidebar/Sidebar.vala',
-            'sidebar/Branch.vala',
-            'sidebar/Entry.vala',
-            'sidebar/Tree.vala',
-            'sidebar/common.vala',
-            'events/Events.vala',
-            'events/EventsBranch.vala',
-            'events/EventsDirectoryPage.vala',
-            'events/EventPage.vala',
-            'events/EventDirectoryItem.vala',
-            'tags/Tags.vala',
-            'tags/TagsBranch.vala',
-            'tags/TagPage.vala',
-            'tags/HierarchicalTagIndex.vala',
-            'tags/HierarchicalTagUtilities.vala',
-            'camera/Camera.vala',
-            'camera/CameraBranch.vala',
-            'camera/CameraTable.vala',
-            'camera/GPhoto.vala',
-            'camera/ImportPage.vala',
-            'searches/Searches.vala',
-            'searches/SearchesBranch.vala',
-            'searches/SearchBoolean.vala',
-            'searches/SavedSearchPage.vala',
-            'searches/SavedSearchDialog.vala',
-            'config/Config.vala',
-            'config/ConfigurationInterfaces.vala',
-            'config/GSettingsEngine.vala',
-            'data_imports/DataImports.vala',
-            'data_imports/DataImportsPluginHost.vala',
-            'data_imports/DataImportsUI.vala',
-            'data_imports/DataImportJob.vala',
-            'data_imports/DataImportSource.vala',
-            'folders/Folders.vala',
-            'folders/FoldersBranch.vala',
-            'folders/FoldersPage.vala',
-            'import-roll/ImportRollBranch.vala',
-            'import-roll/ImportRollEntry.vala',
-            'main.vala',
-            'AppWindow.vala',
-            'CollectionPage.vala',
-            'NaturalCollate.vala',
-            'Thumbnail.vala',
-            'ThumbnailCache.vala',
-            'CheckerboardLayout.vala',
-            'PhotoPage.vala',
-            'Page.vala',
-            'SortedList.vala',
-            'Dimensions.vala',
-            'Box.vala',
-            'Photo.vala',
-            'Orientation.vala',
-            'BatchImport.vala',
-            'Dialogs.vala',
-            'Resources.vala',
-            'Debug.vala',
-            'Properties.vala',
-            'Event.vala',
-            'International.vala',
-            'AppDirs.vala',
-            'PixbufCache.vala',
-            'CommandManager.vala',
-            'Commands.vala',
-            'SlideshowPage.vala',
-            'LibraryFiles.vala',
-            'Printing.vala',
-            'Tag.vala',
-            'Screensaver.vala',
-            'Exporter.vala',
-            'DirectoryMonitor.vala',
-            'LibraryMonitor.vala',
-            'VideoSupport.vala',
-            'Tombstone.vala',
-            'MetadataWriter.vala',
-            'Application.vala',
-            'TimedQueue.vala',
-            'MediaPage.vala',
-            'MediaDataRepresentation.vala',
-            'DesktopIntegration.vala',
-        'Portal.vala',
-            'MediaInterfaces.vala',
-            'MediaMetadata.vala',
-            'VideoMetadata.vala',
-            'MediaMonitor.vala',
-            'PhotoMonitor.vala',
-            'VideoMonitor.vala',
-            'SearchFilter.vala',
-            'MediaViewTracker.vala',
-            'UnityProgressBar.vala',
-            'Upgrades.vala',
-            'dialogs/AdjustDateTimeDialog.vala',
-            'dialogs/EntryMultiCompletion.vala',
-            'dialogs/ExportDialog.vala',
-            'dialogs/MultiTextEntryDialog.vala',
-            'dialogs/Preferences.vala',
-            'dialogs/ProgressDialog.vala',
-            'dialogs/SetBackgroundSlideshow.vala',
-            'dialogs/SetBackground.vala',
-            'dialogs/TextEntry.vala',
-            'dialogs/WelcomeDialog.vala',
-            '.unitize/_UnitInternals.vala',
-            '.unitize/_UtilInternals.vala',
-            '.unitize/_ThreadsInternals.vala',
-            '.unitize/_DbInternals.vala',
-            '.unitize/_EditingToolsInternals.vala',
-            '.unitize/_PluginsInternals.vala',
-            '.unitize/_SlideshowInternals.vala',
-            '.unitize/_PhotosInternals.vala',
-            '.unitize/_PublishingInternals.vala',
-            '.unitize/_LibraryInternals.vala',
-            '.unitize/_DirectInternals.vala',
-            '.unitize/_CoreInternals.vala',
-            '.unitize/_SidebarInternals.vala',
-            '.unitize/_EventsInternals.vala',
-            '.unitize/_TagsInternals.vala',
-            '.unitize/_CameraInternals.vala',
-            '.unitize/_SearchesInternals.vala',
-            '.unitize/_ConfigInternals.vala',
-            '.unitize/_DataImportsInternals.vala',
-            '.unitize/_FoldersInternals.vala',
-            '.unitize/_Library_unitize_entry.vala',
-            '.unitize/_Direct_unitize_entry.vala'] + shotwell_resources + face_sources,
-           include_directories : vapi_incdir,
-           dependencies : shotwell_deps,
-           vala_args : ['--pkg', 'libgphoto2',
-                        '--pkg', 'libraw',
-                        '--pkg', 'libexif',
-                        '--pkg', 'version',
-                        '--gresources',
-                        join_paths(meson.source_root(),
-                          'org.gnome.Shotwell.gresource.xml')
-                       ],
-           link_with: [sw_graphics_processor],
-           install : true)
+                 gstreamer_pbu, gudev, gexiv2, gmodule, unity,
+                 libraw, libexif, sw_plugin, webpdemux, webp, version,
+                 portal]
+
+subdir('metadata')
+subdir('publishing')
+subdir('video-support')
+
+executable(
+    'shotwell',
+    [
+        'unit/Unit.vala',
+        'util/Util.vala',
+        'util/file.vala',
+        'util/image.vala',
+        'util/misc.vala',
+        'util/string.vala',
+        'util/system.vala',
+        'util/ui.vala',
+        'threads/Threads.vala',
+        'threads/Workers.vala',
+        'threads/BackgroundJob.vala',
+        'threads/Semaphore.vala',
+        'db/Db.vala',
+        'db/DatabaseTable.vala',
+        'db/PhotoTable.vala',
+        'db/EventTable.vala',
+        'db/FaceLocationTable.vala',
+        'db/FaceTable.vala',
+        'db/TagTable.vala',
+        'db/TombstoneTable.vala',
+        'db/VideoTable.vala',
+        'db/VersionTable.vala',
+        'db/SavedSearchDBTable.vala',
+        'editing_tools/EditingTools.vala',
+        'editing_tools/RGBHistogramManipulator.vala',
+        'editing_tools/StraightenTool.vala',
+        'faces/Face.vala',
+        'faces/FaceLocation.vala',
+        'slideshow/Slideshow.vala',
+        'slideshow/TransitionEffects.vala',
+        'photos/Photos.vala',
+        'photos/PhotoFileAdapter.vala',
+        'photos/PhotoFileFormat.vala',
+        'photos/PhotoFileSniffer.vala',
+        'photos/PhotoMetadata.vala',
+        'photos/GRaw.vala',
+        'photos/GdkSupport.vala',
+        'photos/GifSupport.vala',
+        'photos/JfifSupport.vala',
+        'photos/BmpSupport.vala',
+        'photos/RawSupport.vala',
+        'photos/PngSupport.vala',
+        'photos/TiffSupport.vala',
+        'photos/WebPSupport.vala',
+        'photos/AvifSupport.vala',
+        'photos/HeifSupport.vala',
+        'photos/JpegXLSupport.vala',
+        'plugins/Plugins.vala',
+        'plugins/StandardHostInterface.vala',
+        'plugins/ManifestWidget.vala',
+        'publishing/Publishing.vala',
+        'publishing/PublishingUI.vala',
+        'publishing/PublishingPluginHost.vala',
+        'publishing/APIGlue.vala',
+            'library/BackgroundProgressBar.vala',
+        'library/Library.vala',
+        'library/LibraryWindow.vala',
+        'library/LibraryBranch.vala',
+        'library/TrashSidebarEntry.vala',
+        'library/OfflineSidebarEntry.vala',
+        'library/FlaggedSidebarEntry.vala',
+        'library/LastImportSidebarEntry.vala',
+        'library/ImportQueueSidebarEntry.vala',
+        'library/FlaggedPage.vala',
+        'library/ImportQueuePage.vala',
+        'library/LastImportPage.vala',
+        'library/OfflinePage.vala',
+        'library/TrashPage.vala',
+        'direct/Direct.vala',
+        'direct/DirectWindow.vala',
+        'direct/DirectPhoto.vala',
+        'direct/DirectPhotoPage.vala',
+        'direct/DirectView.vala',
+        'core/Core.vala',
+        'core/DataCollection.vala',
+        'core/DataSet.vala',
+        'core/util.vala',
+        'core/SourceCollection.vala',
+        'core/SourceHoldingTank.vala',
+        'core/DatabaseSourceCollection.vala',
+        'core/ContainerSourceCollection.vala',
+        'core/ViewCollection.vala',
+        'core/DataObject.vala',
+        'core/Alteration.vala',
+        'core/DataSource.vala',
+        'core/DataSourceTypes.vala',
+        'core/DataView.vala',
+        'core/DataViewTypes.vala',
+        'core/Tracker.vala',
+        'core/SourceInterfaces.vala',
+        'sidebar/Sidebar.vala',
+        'sidebar/Branch.vala',
+        'sidebar/Entry.vala',
+        'sidebar/Tree.vala',
+        'sidebar/common.vala',
+        'events/Events.vala',
+        'events/EventsBranch.vala',
+        'events/EventsDirectoryPage.vala',
+        'events/EventPage.vala',
+        'events/EventDirectoryItem.vala',
+        'tags/Tags.vala',
+        'tags/TagsBranch.vala',
+        'tags/TagPage.vala',
+        'tags/HierarchicalTagIndex.vala',
+        'tags/HierarchicalTagUtilities.vala',
+        'camera/Camera.vala',
+        'camera/CameraBranch.vala',
+        'camera/CameraTable.vala',
+            'camera/DiscoveredCamera.vala',
+        'camera/GPhoto.vala',
+        'camera/ImportPage.vala',
+        'searches/Searches.vala',
+        'searches/SearchesBranch.vala',
+        'searches/SearchBoolean.vala',
+        'searches/SavedSearchPage.vala',
+        'searches/SavedSearchDialog.vala',
+        'config/Config.vala',
+        'config/ConfigurationInterfaces.vala',
+        'config/GSettingsEngine.vala',
+        'data_imports/DataImports.vala',
+        'data_imports/DataImportsPluginHost.vala',
+        'data_imports/DataImportsUI.vala',
+        'data_imports/DataImportJob.vala',
+        'data_imports/DataImportSource.vala',
+        'folders/Folders.vala',
+        'folders/FoldersBranch.vala',
+        'folders/FoldersPage.vala',
+        'import-roll/ImportRollBranch.vala',
+        'import-roll/ImportRollEntry.vala',
+        'main.vala',
+        'AppWindow.vala',
+        'CollectionPage.vala',
+        'NaturalCollate.vala',
+        'Thumbnail.vala',
+        'ThumbnailCache.vala',
+        'CheckerboardItem.vala',
+        'CheckerboardItemText.vala',
+        'CheckerboardLayout.vala',
+        'PhotoPage.vala',
+        'Page.vala',
+        'SinglePhotoPage.vala',
+        'CheckerboardPage.vala',
+        'DragAndDropHandler.vala',
+        'PageMessagePane.vala',
+        'SortedList.vala',
+        'Dimensions.vala',
+        'Box.vala',
+        'Photo.vala',
+        'Orientation.vala',
+        'BatchImport.vala',
+        'Dialogs.vala',
+        'Resources.vala',
+        'Debug.vala',
+        'Properties.vala',
+        'Event.vala',
+        'International.vala',
+        'AppDirs.vala',
+        'PixbufCache.vala',
+        'CommandManager.vala',
+        'Commands.vala',
+        'SlideshowPage.vala',
+        'LibraryFiles.vala',
+        'Printing.vala',
+        'Tag.vala',
+        'Screensaver.vala',
+        'Exporter.vala',
+        'DirectoryMonitor.vala',
+        'LibraryMonitor.vala',
+        'Tombstone.vala',
+        'MetadataWriter.vala',
+        'Application.vala',
+        'TimedQueue.vala',
+        'MediaPage.vala',
+        'MediaDataRepresentation.vala',
+        'DesktopIntegration.vala',
+        'MediaInterfaces.vala',
+        'MediaMonitor.vala',
+        'PhotoMonitor.vala',
+        'VideoMonitor.vala',
+        'SearchFilter.vala',
+        'MediaViewTracker.vala',
+        'UnityProgressBar.vala',
+        'Upgrades.vala',
+        'dialogs/AdjustDateTimeDialog.vala',
+        'dialogs/EntryMultiCompletion.vala',
+        'dialogs/ExportDialog.vala',
+        'dialogs/MultiTextEntryDialog.vala',
+        'dialogs/Preferences.vala',
+        'dialogs/ProgressDialog.vala',
+        'dialogs/SetBackgroundSlideshow.vala',
+        'dialogs/SetBackground.vala',
+        'dialogs/TextEntry.vala',
+        'dialogs/WelcomeDialog.vala',
+        'Profiles.vala',
+        'ProfileBrowser.vala',
+        '.unitize/_UnitInternals.vala',
+        '.unitize/_UtilInternals.vala',
+        '.unitize/_ThreadsInternals.vala',
+        '.unitize/_DbInternals.vala',
+        '.unitize/_EditingToolsInternals.vala',
+        '.unitize/_PluginsInternals.vala',
+        '.unitize/_SlideshowInternals.vala',
+        '.unitize/_PhotosInternals.vala',
+        '.unitize/_PublishingInternals.vala',
+        '.unitize/_LibraryInternals.vala',
+        '.unitize/_DirectInternals.vala',
+        '.unitize/_CoreInternals.vala',
+        '.unitize/_SidebarInternals.vala',
+        '.unitize/_EventsInternals.vala',
+        '.unitize/_TagsInternals.vala',
+        '.unitize/_CameraInternals.vala',
+        '.unitize/_SearchesInternals.vala',
+        '.unitize/_ConfigInternals.vala',
+        '.unitize/_DataImportsInternals.vala',
+        '.unitize/_FoldersInternals.vala',
+        '.unitize/_Library_unitize_entry.vala',
+        '.unitize/_Direct_unitize_entry.vala',
+        'video-support/VideoReader.vala',
+        'video-support/VideoImportParams.vala',
+        'video-support/Video.vala',
+        'video-support/VideoSourceCollection.vala',
+        'video-support/VideoMetadata.vala'
+    ] + shotwell_resources + face_sources,
+    include_directories : vapi_incdir,
+    dependencies : [
+        shotwell_deps,
+        sw_publishing_gui,
+        metadata,
+        metadata_handling
+    ],
+    vala_args : [
+        '--pkg', 'libgphoto2',
+        '--pkg', 'libraw',
+        '--pkg', 'libexif',
+        '--pkg', 'version',
+        '--gresources',
+        join_paths(meson.project_source_root(), 'data',
+        'org.gnome.Shotwell.gresource.xml')
+    ],
+    link_with: [
+        sw_graphics_processor
+    ],
+    install : true
+)
diff --git a/src/metadata/MediaMetadata.vala b/src/metadata/MediaMetadata.vala
new file mode 100644
index 0000000..a329cb1
--- /dev/null
+++ b/src/metadata/MediaMetadata.vala
@@ -0,0 +1,15 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later).  See the COPYING file in this distribution.
+ */
+
+public abstract class MediaMetadata {
+    public abstract void read_from_file(File file) throws Error;
+
+    public abstract MetadataDateTime? get_creation_date_time();
+
+    public abstract string? get_title();
+
+    public abstract string? get_comment();
+}
diff --git a/src/metadata/MetadataDateTime.vala b/src/metadata/MetadataDateTime.vala
new file mode 100644
index 0000000..9dae99b
--- /dev/null
+++ b/src/metadata/MetadataDateTime.vala
@@ -0,0 +1,78 @@
+public errordomain MetadataDateTimeError {
+    INVALID_FORMAT,
+    UNSUPPORTED_FORMAT
+}
+
+public class MetadataDateTime {
+
+    private DateTime timestamp;
+
+    public MetadataDateTime(DateTime timestamp) {
+        this.timestamp = timestamp;
+    }
+
+    public MetadataDateTime.from_exif(string label) throws MetadataDateTimeError {
+        if (!from_exif_date_time(label, out timestamp))
+            throw new MetadataDateTimeError.INVALID_FORMAT("%s is not EXIF format date/time", label);
+    }
+
+    public MetadataDateTime.from_iptc(string date, string time) throws MetadataDateTimeError {
+        // TODO: Support IPTC date/time format
+        throw new MetadataDateTimeError.UNSUPPORTED_FORMAT("IPTC date/time format not currently supported");
+    }
+
+    public MetadataDateTime.from_xmp(string label) throws MetadataDateTimeError {
+        var dt = new DateTime.from_iso8601(label, null);
+        if (dt == null)
+            throw new MetadataDateTimeError.INVALID_FORMAT("%s is not XMP format date/time", label);
+
+        timestamp = dt;
+    }
+
+    public DateTime? get_timestamp() {
+        return timestamp;
+    }
+
+    public string get_exif_label() {
+        return to_exif_date_time(timestamp);
+    }
+
+    // TODO: get_iptc_date() and get_iptc_time()
+
+    public string get_xmp_label() {
+        return timestamp.format_iso8601();
+    }
+
+    public static bool from_exif_date_time(string date_time, out DateTime? timestamp) {
+        timestamp = null;
+
+        Time tm = Time();
+
+        // Check standard EXIF format
+        if (date_time.scanf("%d:%d:%d %d:%d:%d",
+                            &tm.year, &tm.month, &tm.day, &tm.hour, &tm.minute, &tm.second) != 6) {
+            // Fallback in a more generic format
+            string tmp = date_time.dup();
+            tmp.canon("0123456789", ' ');
+            if (tmp.scanf("%4d%2d%2d%2d%2d%2d",
+                          &tm.year, &tm.month, &tm.day, &tm.hour, &tm.minute,&tm.second) != 6)
+                return false;
+        }
+
+        // watch for bogosity
+        if (tm.year <= 1900 || tm.month <= 0 || tm.day < 0 || tm.hour < 0 || tm.minute < 0 || tm.second < 0)
+            return false;
+
+        timestamp = new DateTime.local(tm.year, tm.month, tm.day, tm.hour, tm.minute, tm.second);
+
+        return true;
+    }
+
+    public static string to_exif_date_time(DateTime timestamp) {
+        return timestamp.to_local().format("%Y:%m:%d %H:%M:%S");
+    }
+
+    public string to_string() {
+        return to_exif_date_time(timestamp);
+    }
+}
diff --git a/src/metadata/MetadataRational.vala b/src/metadata/MetadataRational.vala
new file mode 100644
index 0000000..ec3ac17
--- /dev/null
+++ b/src/metadata/MetadataRational.vala
@@ -0,0 +1,26 @@
+public struct MetadataRational {
+    public int numerator;
+    public int denominator;
+
+    public MetadataRational.invalid() {
+        this.numerator = -1;
+        this.denominator = -1;
+    }
+
+    public MetadataRational(int numerator, int denominator) {
+        this.numerator = numerator;
+        this.denominator = denominator;
+    }
+
+    private bool is_component_valid(int component) {
+        return (component >= 0) && (component <= 1000000);
+    }
+
+    public bool is_valid() {
+        return (is_component_valid(numerator) && is_component_valid(denominator));
+    }
+
+    public string to_string() {
+        return (is_valid()) ? ("%d/%d".printf(numerator, denominator)) : "";
+    }
+}
diff --git a/src/metadata/meson.build b/src/metadata/meson.build
new file mode 100644
index 0000000..7f322ca
--- /dev/null
+++ b/src/metadata/meson.build
@@ -0,0 +1,16 @@
+libmetadata = static_library(
+    'metadata',
+    [
+        'MediaMetadata.vala',
+        'MetadataDateTime.vala',
+        'MetadataRational.vala'
+    ],
+    dependencies : [
+        gio
+    ]
+)
+
+metadata = declare_dependency(
+    include_directories : include_directories('.'),
+    link_with : libmetadata
+)
diff --git a/src/photos/AvifSupport.vala b/src/photos/AvifSupport.vala
new file mode 100644
index 0000000..842f0fc
--- /dev/null
+++ b/src/photos/AvifSupport.vala
@@ -0,0 +1,140 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+class AvifFileFormatProperties : PhotoFileFormatProperties {
+    private static string[] KNOWN_EXTENSIONS = { "avif" };
+    private static string[] KNOWN_MIME_TYPES = { "image/avif" };
+
+    private static AvifFileFormatProperties instance = null;
+
+    public static void init() {
+        instance = new AvifFileFormatProperties();
+    }
+    
+    public static AvifFileFormatProperties get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormat get_file_format() {
+        return PhotoFileFormat.AVIF;
+    }
+    
+    public override PhotoFileFormatFlags get_flags() {
+        return PhotoFileFormatFlags.NONE;
+    }
+
+    public override string get_user_visible_name() {
+        return _("AVIF");
+    }
+
+    public override string get_default_extension() {
+        return KNOWN_EXTENSIONS[0];
+    }
+    
+    public override string[] get_known_extensions() {
+        return KNOWN_EXTENSIONS;
+    }
+    
+    public override string get_default_mime_type() {
+        return KNOWN_MIME_TYPES[0];
+    }
+    
+    public override string[] get_mime_types() {
+        return KNOWN_MIME_TYPES;
+    }
+}
+
+public class AvifSniffer : GdkSniffer {
+    public AvifSniffer(File file, PhotoFileSniffer.Options options) {
+        base (file, options);
+    }
+
+    public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
+        // Rely on GdkSniffer to detect corruption
+        is_corrupted = false;
+        
+        if (!is_supported_bmff_with_variants(file, {"avif", "avis"}))
+            return null;
+        
+        DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
+        if (detected == null)
+            return null;
+        
+        return (detected.file_format == PhotoFileFormat.AVIF) ? detected : null;
+    }
+}
+
+public class AvifReader : GdkReader {
+    public AvifReader(string filepath) {
+        base (filepath, PhotoFileFormat.AVIF);
+    }
+}
+
+public class AvifWriter : PhotoFileWriter {
+    public AvifWriter(string filepath) {
+        base (filepath, PhotoFileFormat.AVIF);
+    }
+    
+    public override void write(Gdk.Pixbuf pixbuf, Jpeg.Quality quality) throws Error {
+        pixbuf.save(get_filepath(), "avif", "quality", "90", null);
+    }
+}
+
+public class AvifMetadataWriter : PhotoFileMetadataWriter {
+    public AvifMetadataWriter(string filepath) {
+        base (filepath, PhotoFileFormat.AVIF);
+    }
+    
+    public override void write_metadata(PhotoMetadata metadata) throws Error {
+        metadata.write_to_file(get_file());
+    }
+}
+
+public class AvifFileFormatDriver : PhotoFileFormatDriver {
+    private static AvifFileFormatDriver instance = null;
+    
+    public static void init() {
+        instance = new AvifFileFormatDriver();
+        AvifFileFormatProperties.init();
+    }
+    
+    public static AvifFileFormatDriver get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormatProperties get_properties() {
+        return AvifFileFormatProperties.get_instance();
+    }
+    
+    public override PhotoFileReader create_reader(string filepath) {
+        return new AvifReader(filepath);
+    }
+    
+    public override bool can_write_image() {
+        return true;
+    }
+    
+    public override bool can_write_metadata() {
+        return true;
+    }
+    
+    public override PhotoFileWriter? create_writer(string filepath) {
+        return new AvifWriter(filepath);
+    }
+    
+    public override PhotoFileMetadataWriter? create_metadata_writer(string filepath) {
+        return new AvifMetadataWriter(filepath);
+    }
+    
+    public override PhotoFileSniffer create_sniffer(File file, PhotoFileSniffer.Options options) {
+        return new AvifSniffer(file, options);
+    }
+    
+    public override PhotoMetadata create_metadata() {
+        return new PhotoMetadata();
+    }
+}
+
diff --git a/src/photos/BmpSupport.vala b/src/photos/BmpSupport.vala
index a59a4d9..26ec911 100644
--- a/src/photos/BmpSupport.vala
+++ b/src/photos/BmpSupport.vala
@@ -90,33 +90,6 @@ public class BmpReader : GdkReader {
     public BmpReader(string filepath) {
         base (filepath, PhotoFileFormat.BMP);
     }
-    
-    public override Gdk.Pixbuf scaled_read(Dimensions full, Dimensions scaled) throws Error {
-        Gdk.Pixbuf result = null;
-        /* if we encounter a situation where there are two orders of magnitude or more of
-           difference between the full image size and the scaled size, and if the full image
-           size has five or more decimal digits of precision, Gdk.Pixbuf.from_file_at_scale( ) can
-           fail due to what appear to be floating-point round-off issues. This isn't surprising,
-           since 32-bit floats only have 6-7 decimal digits of precision in their mantissa. In
-           this case, we prefetch the image at a larger scale and then downsample it to the
-           desired scale as a post-process step. This short-circuits Gdk.Pixbuf's buggy
-           scaling code. */
-        if (((full.width > 9999) || (full.height > 9999)) && ((scaled.width < 100) ||
-             (scaled.height < 100))) {
-            Dimensions prefetch_dimensions = full.get_scaled_by_constraint(1000,
-                ScaleConstraint.DIMENSIONS);
-                                  
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), prefetch_dimensions.width,
-                prefetch_dimensions.height, false);
-
-            result = result.scale_simple(scaled.width, scaled.height, Gdk.InterpType.HYPER);
-        } else {
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width,
-                scaled.height, false);
-        }
-
-        return result;
-    }
 }
 
 public class BmpWriter : PhotoFileWriter {
diff --git a/src/photos/GdkSupport.vala b/src/photos/GdkSupport.vala
index f7e18d5..64a08d6 100644
--- a/src/photos/GdkSupport.vala
+++ b/src/photos/GdkSupport.vala
@@ -21,7 +21,30 @@ public abstract class GdkReader : PhotoFileReader {
     }
     
     public override Gdk.Pixbuf scaled_read(Dimensions full, Dimensions scaled) throws Error {
-        return new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width, scaled.height, false);
+        Gdk.Pixbuf result = null;
+        /* if we encounter a situation where there are two orders of magnitude or more of
+           difference between the full image size and the scaled size, and if the full image
+           size has five or more decimal digits of precision, Gdk.Pixbuf.from_file_at_scale( ) can
+           fail due to what appear to be floating-point round-off issues. This isn't surprising,
+           since 32-bit floats only have 6-7 decimal digits of precision in their mantissa. In
+           this case, we prefetch the image at a larger scale and then downsample it to the
+           desired scale as a post-process step. This short-circuits Gdk.Pixbuf's buggy
+           scaling code. */
+        if (((full.width > 9999) || (full.height > 9999)) && ((scaled.width < 100) ||
+             (scaled.height < 100))) {
+            Dimensions prefetch_dimensions = full.get_scaled_by_constraint(1000,
+                ScaleConstraint.DIMENSIONS);
+                                  
+            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), prefetch_dimensions.width,
+                prefetch_dimensions.height, false);
+
+            result = result.scale_simple(scaled.width, scaled.height, Gdk.InterpType.HYPER);
+        } else {
+            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width,
+                scaled.height, false);
+        }
+
+        return result;
     }
 }
 
@@ -112,13 +135,14 @@ public abstract class GdkSniffer : PhotoFileSniffer {
         Gdk.Pixbuf? pixbuf = pixbuf_loader.get_pixbuf();
         if (pixbuf == null)
             return;
-        
+
         detected.colorspace = pixbuf.get_colorspace();
         detected.channels = pixbuf.get_n_channels();
         detected.bits_per_channel = pixbuf.get_bits_per_sample();
         
         unowned Gdk.PixbufFormat format = pixbuf_loader.get_format();
         detected.format_name = format.get_name();
+        debug("Pixbuf detected format name: %s", detected.format_name);
         detected.file_format = PhotoFileFormat.from_pixbuf_name(detected.format_name);
         
         area_prepared = true;
diff --git a/src/photos/GifSupport.vala b/src/photos/GifSupport.vala
index bd6ef6a..b49b4f2 100644
--- a/src/photos/GifSupport.vala
+++ b/src/photos/GifSupport.vala
@@ -86,33 +86,6 @@ public class GifReader : GdkReader {
     public GifReader(string filepath) {
         base (filepath, PhotoFileFormat.PNG);
     }
-
-    public override Gdk.Pixbuf scaled_read(Dimensions full, Dimensions scaled) throws Error {
-        Gdk.Pixbuf result = null;
-        /* if we encounter a situation where there are two orders of magnitude or more of
-           difference between the full image size and the scaled size, and if the full image
-           size has five or more decimal digits of precision, Gdk.Pixbuf.from_file_at_scale( ) can
-           fail due to what appear to be floating-point round-off issues. This isn't surprising,
-           since 32-bit floats only have 6-7 decimal digits of precision in their mantissa. In
-           this case, we prefetch the image at a larger scale and then downsample it to the
-           desired scale as a post-process step. This short-circuits Gdk.Pixbuf's buggy
-           scaling code. */
-        if (((full.width > 9999) || (full.height > 9999)) && ((scaled.width < 100) ||
-             (scaled.height < 100))) {
-            Dimensions prefetch_dimensions = full.get_scaled_by_constraint(1000,
-                ScaleConstraint.DIMENSIONS);
-
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), prefetch_dimensions.width,
-                prefetch_dimensions.height, false);
-
-            result = result.scale_simple(scaled.width, scaled.height, Gdk.InterpType.HYPER);
-        } else {
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width,
-                scaled.height, false);
-        }
-
-        return result;
-    }
 }
 
 public class GifMetadataWriter : PhotoFileMetadataWriter {
diff --git a/src/photos/HeifSupport.vala b/src/photos/HeifSupport.vala
new file mode 100644
index 0000000..0c05e02
--- /dev/null
+++ b/src/photos/HeifSupport.vala
@@ -0,0 +1,150 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+class HeifFileFormatProperties : PhotoFileFormatProperties {
+    private static string[] KNOWN_EXTENSIONS = { "heif", "heic" };
+    private static string[] KNOWN_MIME_TYPES = { "image/heif" };
+
+    private static HeifFileFormatProperties instance = null;
+
+    public static void init() {
+        instance = new HeifFileFormatProperties();
+    }
+    
+    public static HeifFileFormatProperties get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormat get_file_format() {
+        return PhotoFileFormat.HEIF;
+    }
+    
+    public override PhotoFileFormatFlags get_flags() {
+        return PhotoFileFormatFlags.NONE;
+    }
+
+    public override string get_user_visible_name() {
+        return _("HEIF");
+    }
+
+    public override string get_default_extension() {
+        return KNOWN_EXTENSIONS[0];
+    }
+    
+    public override string[] get_known_extensions() {
+        return KNOWN_EXTENSIONS;
+    }
+    
+    public override string get_default_mime_type() {
+        return KNOWN_MIME_TYPES[0];
+    }
+    
+    public override string[] get_mime_types() {
+        return KNOWN_MIME_TYPES;
+    }
+}
+
+public class HeifSniffer : GdkSniffer {
+    private const string[] MAGIC_SEQUENCES = { "heic", "heix", "hevc", "heim", "heis", "hevm", "hevs", "mif1", "msf1"};
+
+    public HeifSniffer(File file, PhotoFileSniffer.Options options) {
+        base (file, options);
+    }
+
+    public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
+        // Rely on GdkSniffer to detect corruption
+        is_corrupted = false;
+        
+        if (!is_supported_bmff_with_variants(file, MAGIC_SEQUENCES))
+            return null;
+        
+        DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
+        if (detected == null)
+            return null;
+
+        if (detected.file_format == PhotoFileFormat.AVIF)
+            detected.file_format = PhotoFileFormat.HEIF;
+
+        // Heif contains its own rotation information, so we need to ignore the EXIF rotation+
+        if (detected.metadata != null) {
+            detected.metadata.set_orientation(Orientation.TOP_LEFT);
+        }
+
+        return (detected.file_format == PhotoFileFormat.HEIF) ? detected : null;
+    }
+
+}
+
+public class HeifReader : GdkReader {
+    public HeifReader(string filepath) {
+        base (filepath, PhotoFileFormat.HEIF);
+    }
+
+    public override PhotoMetadata read_metadata() throws Error {
+        PhotoMetadata metadata = new PhotoMetadata();
+        metadata.read_from_file(get_file());
+        // Heif contains its own rotation information, so we need to ignore the EXIF rotation
+        metadata.set_orientation(Orientation.TOP_LEFT);
+        return metadata;
+    }
+
+}
+
+public class HeifMetadataWriter : PhotoFileMetadataWriter {
+    public HeifMetadataWriter(string filepath) {
+        base (filepath, PhotoFileFormat.HEIF);
+    }
+    
+    public override void write_metadata(PhotoMetadata metadata) throws Error {
+        metadata.write_to_file(get_file());
+    }
+}
+
+public class HeifFileFormatDriver : PhotoFileFormatDriver {
+    private static HeifFileFormatDriver instance = null;
+    
+    public static void init() {
+        instance = new HeifFileFormatDriver();
+        HeifFileFormatProperties.init();
+    }
+    
+    public static HeifFileFormatDriver get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormatProperties get_properties() {
+        return HeifFileFormatProperties.get_instance();
+    }
+    
+    public override PhotoFileReader create_reader(string filepath) {
+        return new HeifReader(filepath);
+    }
+    
+    public override bool can_write_image() {
+        return false;
+    }
+    
+    public override bool can_write_metadata() {
+        return true;
+    }
+    
+    public override PhotoFileWriter? create_writer(string filepath) {
+        return null;
+    }
+    
+    public override PhotoFileMetadataWriter? create_metadata_writer(string filepath) {
+        return new HeifMetadataWriter(filepath);
+    }
+    
+    public override PhotoFileSniffer create_sniffer(File file, PhotoFileSniffer.Options options) {
+        return new HeifSniffer(file, options);
+    }
+    
+    public override PhotoMetadata create_metadata() {
+        return new PhotoMetadata();
+    }
+}
+
diff --git a/src/photos/JfifSupport.vala b/src/photos/JfifSupport.vala
index 5ea64a5..0de45f8 100644
--- a/src/photos/JfifSupport.vala
+++ b/src/photos/JfifSupport.vala
@@ -103,17 +103,78 @@ public class JfifSniffer : GdkSniffer {
     }
     
     public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
-        // Rely on GdkSniffer to detect corruption
         is_corrupted = false;
-        
-        if (!Jpeg.is_jpeg(file))
-            return null;
-        
-        DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
-        if (detected == null)
+        if (!calc_md5) {
+            return fast_sniff (out is_corrupted);
+        } else {
+            if (!Jpeg.is_jpeg(file)) {
+                return null;
+            }
+
+            // Rely on GdkSniffer to detect corruption
+
+            DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
+            if (detected == null)
+                return null;
+
+            return (detected.file_format == PhotoFileFormat.JFIF) ? detected : null;
+        }
+    }
+
+    private DetectedPhotoInformation? fast_sniff(out bool is_corrupted) throws Error {
+        is_corrupted = false;
+        var detected = new DetectedPhotoInformation();
+
+        detected.metadata = new PhotoMetadata();
+        try {
+            detected.metadata.read_from_file(file);
+        } catch (Error err) {
+            // no metadata detected
+            detected.metadata = null;
+        }
+
+        var fins = file.read(null);
+        var dins = new DataInputStream(fins);
+        dins.set_byte_order(DataStreamByteOrder.BIG_ENDIAN);
+        var seekable = (Seekable) dins;
+
+        var marker = Jpeg.Marker.INVALID;
+        var length = Jpeg.read_marker_2(dins, out marker);
+
+        if (marker != Jpeg.Marker.SOI) {
             return null;
-        
-        return (detected.file_format == PhotoFileFormat.JFIF) ? detected : null;
+        }
+
+        length = Jpeg.read_marker_2(dins, out marker);
+        while (!marker.is_sof() && length > 0) {
+            seekable.seek(length, SeekType.CUR, null);
+            length = Jpeg.read_marker_2(dins, out marker);
+        }
+
+        if (marker.is_sof()) {
+            if (length < 6) {
+                is_corrupted = true;
+                return null;
+            }
+
+            // Skip precision
+            dins.read_byte();
+
+            // Next two 16 bytes are image dimensions
+            uint16 height = dins.read_uint16();
+            uint16 width = dins.read_uint16();
+
+            detected.image_dim = Dimensions(width, height);
+            detected.colorspace = Gdk.Colorspace.RGB;
+            detected.channels = 3;
+            detected.bits_per_channel = 8;
+            detected.format_name = "jpeg";
+            detected.file_format = PhotoFileFormat.from_pixbuf_name(detected.format_name);
+        } else {
+            is_corrupted = true;
+        }
+
+        return detected;
     }
 }
 
@@ -159,6 +220,16 @@ namespace Jpeg {
         public uint8 get_byte() {
             return (uint8) this;
         }
+
+        public bool is_sof() {
+            // FFCn is SOF unless n is a multiple of 4 > 0 (FFC4, FFC8, FFCC)
+            if ((this & 0xC0) != 0xC0) {
+                return false;
+            }
+
+            var variant = this & 0x0F;
+            return variant == 0 || variant % 4 != 0;
+        }
     }
     
     public enum Quality {
@@ -219,12 +290,9 @@ namespace Jpeg {
         return is_jpeg_stream(mins);
     }
 
-    private int read_marker(InputStream fins, out Jpeg.Marker marker) throws Error {
+    private int32 read_marker_2(DataInputStream dins, out Jpeg.Marker marker) throws Error {
         marker = Jpeg.Marker.INVALID;
-        
-        DataInputStream dins = new DataInputStream(fins);
-        dins.set_byte_order(DataStreamByteOrder.BIG_ENDIAN);
-        
+
         if (dins.read_byte() != Jpeg.MARKER_PREFIX)
             return -1;
         
@@ -235,9 +303,10 @@ namespace Jpeg {
         }
         
         uint16 length = dins.read_uint16();
-        if (length < 2 && fins is Seekable) {
+        var seekable = dins as Seekable;
+        if (length < 2 && dins != null) {
             debug("Invalid length %Xh at ofs %" + int64.FORMAT + "Xh", length,
-                    (fins as Seekable).tell() - 2);
+                    seekable.tell() - 2);
             
             return -1;
         }
@@ -245,5 +314,12 @@ namespace Jpeg {
         // account for two length bytes already read
         return length - 2;
     }
+
+    private int read_marker(InputStream fins, out Jpeg.Marker marker) throws Error {
+        DataInputStream dins = new DataInputStream(fins);
+        dins.set_byte_order(DataStreamByteOrder.BIG_ENDIAN);
+
+        return read_marker_2(dins, out marker);
+    }
 }
 
diff --git a/src/photos/JpegXLSupport.vala b/src/photos/JpegXLSupport.vala
new file mode 100644
index 0000000..eed220c
--- /dev/null
+++ b/src/photos/JpegXLSupport.vala
@@ -0,0 +1,149 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+class JpegXLFileFormatProperties : PhotoFileFormatProperties {
+    private static string[] KNOWN_EXTENSIONS = { "jxl", "jpegxl" };
+    private static string[] KNOWN_MIME_TYPES = { "image/jxl" };
+
+    private static JpegXLFileFormatProperties instance = null;
+
+    public static void init() {
+        instance = new JpegXLFileFormatProperties();
+    }
+    
+    public static JpegXLFileFormatProperties get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormat get_file_format() {
+        return PhotoFileFormat.JPEGXL;
+    }
+    
+    public override PhotoFileFormatFlags get_flags() {
+        return PhotoFileFormatFlags.NONE;
+    }
+
+    public override string get_user_visible_name() {
+        return _("JPEGXL");
+    }
+
+    public override string get_default_extension() {
+        return KNOWN_EXTENSIONS[0];
+    }
+    
+    public override string[] get_known_extensions() {
+        return KNOWN_EXTENSIONS;
+    }
+    
+    public override string get_default_mime_type() {
+        return KNOWN_MIME_TYPES[0];
+    }
+    
+    public override string[] get_mime_types() {
+        return KNOWN_MIME_TYPES;
+    }
+}
+
+public class JpegXLSniffer : GdkSniffer {
+    // See https://github.com/ImageMagick/jpeg-xl/blob/main/doc/format_overview.md#file-format
+    private const uint8[] CODESTREAM_MAGIC_SEQUENCE = { 0xff, 0x0a };
+    private const uint8[] BMFF_MAGIC_SEQUENCE = {0x00, 0x00, 0x00, 0x0C, 0x4A, 0x58, 0x4C, 0x20, 0x0D, 0x0A, 0x87, 0x0A};
+
+
+    public JpegXLSniffer(File file, PhotoFileSniffer.Options options) {
+        base (file, options);
+    }
+
+    private static bool is_jpegxl_file(File file) throws Error {
+        FileInputStream instream = file.read(null);
+
+        // Read out first four bytes
+        uint8[] file_lead_sequence = new uint8[BMFF_MAGIC_SEQUENCE.length];
+
+        var size = instream.read(file_lead_sequence, null);
+
+        return size == BMFF_MAGIC_SEQUENCE.length && (Memory.cmp(CODESTREAM_MAGIC_SEQUENCE, file_lead_sequence, CODESTREAM_MAGIC_SEQUENCE.length) == 0 ||
+                Memory.cmp(BMFF_MAGIC_SEQUENCE, file_lead_sequence, BMFF_MAGIC_SEQUENCE.length) == 0);
+
+    }
+
+    public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
+        // Rely on GdkSniffer to detect corruption
+        is_corrupted = false;
+        
+        if (!is_jpegxl_file(file))
+            return null;
+        
+        DetectedPhotoInformation? detected = base.sniff(out is_corrupted);
+        if (detected == null)
+            return null;
+
+        return (detected.file_format == PhotoFileFormat.JPEGXL) ? detected : null;
+    }
+
+}
+
+public class JpegXLReader : GdkReader {
+    public JpegXLReader(string filepath) {
+        base (filepath, PhotoFileFormat.JPEGXL);
+    }
+}
+
+public class JpegXLMetadataWriter : PhotoFileMetadataWriter {
+    public JpegXLMetadataWriter(string filepath) {
+        base (filepath, PhotoFileFormat.JPEGXL);
+    }
+    
+    public override void write_metadata(PhotoMetadata metadata) throws Error {
+        metadata.write_to_file(get_file());
+    }
+}
+
+public class JpegXLFileFormatDriver : PhotoFileFormatDriver {
+    private static JpegXLFileFormatDriver instance = null;
+    
+    public static void init() {
+        instance = new JpegXLFileFormatDriver();
+        JpegXLFileFormatProperties.init();
+    }
+    
+    public static JpegXLFileFormatDriver get_instance() {
+        return instance;
+    }
+    
+    public override PhotoFileFormatProperties get_properties() {
+        return JpegXLFileFormatProperties.get_instance();
+    }
+    
+    public override PhotoFileReader create_reader(string filepath) {
+        return new JpegXLReader(filepath);
+    }
+    
+    public override bool can_write_image() {
+        return false;
+    }
+    
+    public override bool can_write_metadata() {
+        return true;
+    }
+    
+    public override PhotoFileWriter? create_writer(string filepath) {
+        return null;
+    }
+    
+    public override PhotoFileMetadataWriter? create_metadata_writer(string filepath) {
+        return new JpegXLMetadataWriter(filepath);
+    }
+    
+    public override PhotoFileSniffer create_sniffer(File file, PhotoFileSniffer.Options options) {
+        return new JpegXLSniffer(file, options);
+    }
+    
+    public override PhotoMetadata create_metadata() {
+        return new PhotoMetadata();
+    }
+}
+
diff --git a/src/photos/PhotoFileFormat.vala b/src/photos/PhotoFileFormat.vala
index e642008..4c69de3 100644
--- a/src/photos/PhotoFileFormat.vala
+++ b/src/photos/PhotoFileFormat.vala
@@ -58,12 +58,16 @@ public enum PhotoFileFormat {
     TIFF,
     BMP,
     GIF,
+    WEBP,
+    AVIF,
+    HEIF,
+    JPEGXL,
     UNKNOWN;
     
     // This is currently listed in the order of detection, that is, the file is examined from
     // left to right.  (See PhotoFileInterrogator.)
     public static PhotoFileFormat[] get_supported() {
-        return { JFIF, RAW, PNG, TIFF, BMP, GIF };
+        return { JFIF, RAW, PNG, TIFF, BMP, GIF, WEBP, AVIF, HEIF, JPEGXL };
     }
     
     public static PhotoFileFormat[] get_writeable() {
@@ -141,7 +145,19 @@ public enum PhotoFileFormat {
 
             case GIF:
                 return 5;
-            
+
+            case WEBP:
+                return 6;
+
+            case AVIF:
+                return 7;
+
+            case HEIF:
+                return 8;
+
+            case JPEGXL:
+                return 9;
+
             case UNKNOWN:
             default:
                 return -1;
@@ -169,6 +185,18 @@ public enum PhotoFileFormat {
             case 5:
                 return GIF;
                             
+            case 6:
+                return WEBP;
+
+            case 7:
+                return AVIF;
+
+            case 8:
+                return HEIF;
+
+            case 9:
+                return JPEGXL;
+
             default:
                 return UNKNOWN;
         }
@@ -217,7 +245,17 @@ public enum PhotoFileFormat {
 
             case "gif":
                 return PhotoFileFormat.GIF;
-            
+
+            case "heif/avif":
+            case "avif":
+                return PhotoFileFormat.AVIF;
+
+            case "heif":
+                return PhotoFileFormat.HEIF;
+
+            case "jxl":
+                return PhotoFileFormat.JPEGXL;
+
             default:
                 return PhotoFileFormat.UNKNOWN;
         }
@@ -249,6 +287,22 @@ public enum PhotoFileFormat {
                 Photos.GifFileFormatDriver.init();
                 break;
 
+            case WEBP:
+                Photos.WebpFileFormatDriver.init();
+                break;
+
+            case AVIF:
+                AvifFileFormatDriver.init();
+                break;
+
+            case HEIF:
+                HeifFileFormatDriver.init();
+                break;
+
+            case JPEGXL:
+                JpegXLFileFormatDriver.init();
+                break;
+
             default:
                 error("Unsupported file format %s", this.to_string());
         }
@@ -274,6 +328,18 @@ public enum PhotoFileFormat {
             case GIF:
                 return Photos.GifFileFormatDriver.get_instance();
 
+            case WEBP:
+                return Photos.WebpFileFormatDriver.get_instance();
+
+            case AVIF:
+                return AvifFileFormatDriver.get_instance();
+
+            case HEIF:
+                return HeifFileFormatDriver.get_instance();
+
+            case JPEGXL:
+                return JpegXLFileFormatDriver.get_instance();
+
             default:
                 error("Unsupported file format %s", this.to_string());
         }
diff --git a/src/photos/PhotoFileSniffer.vala b/src/photos/PhotoFileSniffer.vala
index 7442fde..6358920 100644
--- a/src/photos/PhotoFileSniffer.vala
+++ b/src/photos/PhotoFileSniffer.vala
@@ -47,6 +47,34 @@ public abstract class PhotoFileSniffer {
     }
     
     public abstract DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error;
+
+    protected static bool is_supported_bmff_with_variants(File file, string[] variants) throws Error {
+        
+        FileInputStream instream = file.read(null);
+
+        // Skip the first four bytes
+        if (instream.skip(4) != 4) {
+            return false;
+        }
+
+        // The next four bytes need to be ftyp
+        var buf = new uint8[4];
+        if (instream.read(buf, null) != 4) {
+            return false;
+        }
+
+        if (Memory.cmp("ftyp".data, buf, 4) != 0) {
+            return false;
+        }
+
+        if (instream.read(buf, null) != 4) {
+            return false;
+        }
+
+        buf += '\0';
+
+        return (string)buf in variants;
+    }
 }
 
 //
diff --git a/src/photos/PhotoMetadata.vala b/src/photos/PhotoMetadata.vala
index a9b7457..3bf77d6 100644
--- a/src/photos/PhotoMetadata.vala
+++ b/src/photos/PhotoMetadata.vala
@@ -241,9 +241,13 @@ public class PhotoMetadata : MediaMetadata {
         public override Bytes flatten() throws Error {
             unowned GExiv2.PreviewProperties?[] props = owner.exiv2.get_preview_properties();
             assert(props != null && props.length > number);
-            
-            return new
-                Bytes(owner.exiv2.get_preview_image(props[number]).get_data());
+           
+            try {
+                return new
+                    Bytes(owner.exiv2.try_get_preview_image(props[number]).get_data());
+            } catch (Error err) {
+                return new Bytes(null);
+            }
         }
     }
     
@@ -278,12 +282,8 @@ public class PhotoMetadata : MediaMetadata {
         exiv2 = new GExiv2.Metadata();
         exif = null;
         
-#if NEW_GEXIV2_API
         exiv2.open_buf(buffer[0:length]);
-#else
-        exiv2.open_buf(buffer, length);
-#endif
-        exif = Exif.Data.new_from_data(buffer);
+        exif = Exif.Data.new_from_data(buffer[0:length]);
         source_name = "<memory buffer %d bytes>".printf(length);
     }
     
@@ -291,11 +291,8 @@ public class PhotoMetadata : MediaMetadata {
         exiv2 = new GExiv2.Metadata();
         exif = null;
         
-#if NEW_GEXIV2_API
         exiv2.from_app1_segment(buffer.get_data());
-#else
         exif = Exif.Data.new_from_data(buffer.get_data());
-#endif
         source_name = "<app1 segment %zu bytes>".printf(buffer.get_size());
     }
     
@@ -371,7 +368,11 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public bool has_tag(string tag) {
-        return exiv2.has_tag(tag);
+        try {
+            return exiv2.try_has_tag(tag);
+        } catch (Error error) {
+            return false;
+        }
     }
     
     private Gee.Set<string> create_string_set(owned CompareDataFunc<string>? compare_func) {
@@ -397,6 +398,9 @@ public class PhotoMetadata : MediaMetadata {
             case MetadataDomain.IPTC:
                 tags = exiv2.get_iptc_tags();
             break;
+            default:
+            // Just ignore any other unknown tags
+            break;
         }
         
         if (tags == null || tags.length == 0)
@@ -429,19 +433,35 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public string? get_tag_label(string tag) {
-        return GExiv2.Metadata.get_tag_label(tag);
+        try {
+            return GExiv2.Metadata.try_get_tag_label(tag);
+        } catch (Error error) {
+            return null;
+        }
     }
     
     public string? get_tag_description(string tag) {
-        return GExiv2.Metadata.get_tag_description(tag);
+        try {
+            return GExiv2.Metadata.try_get_tag_description(tag);
+        } catch (Error error) {
+            return null;
+        }
     }
     
     public string? get_string(string tag, PrepareInputTextOptions options = PREPARE_STRING_OPTIONS) {
-        return prepare_input_text(exiv2.get_tag_string(tag), options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+        try {
+            return prepare_input_text(exiv2.try_get_tag_string(tag), options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+        } catch (Error error) {
+            return null;
+        }
     }
     
     public string? get_string_interpreted(string tag, PrepareInputTextOptions options = PREPARE_STRING_OPTIONS) {
-        return prepare_input_text(exiv2.get_tag_interpreted_string(tag), options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+        try {
+            return prepare_input_text(exiv2.try_get_tag_interpreted_string(tag), options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+        } catch (Error error) {
+            return null;
+        }
     }
     
     public string? get_first_string(string[] tags) {
@@ -469,26 +489,30 @@ public class PhotoMetadata : MediaMetadata {
     // NOTE: get_tag_multiple() in gexiv2 currently does not work with EXIF tags (as EXIF can 
     // never return a list of strings).  It will quietly return NULL if attempted.  Until fixed
     // (there or here), don't use this function to access EXIF.  See:
-    // http://trac.yorba.org/ticket/2966
+    // https://gitlab.gnome.org/GNOME/gexiv2/issues/10
     public Gee.List<string>? get_string_multiple(string tag) {
-        string[] values = exiv2.get_tag_multiple(tag);
-        if (values == null || values.length == 0)
-            return null;
-        
-        Gee.List<string> list = new Gee.ArrayList<string>();
-        
-        Gee.HashSet<string> collection = new Gee.HashSet<string>();
-        foreach (string value in values) {
-            string? prepped = prepare_input_text(value, PREPARE_STRING_OPTIONS,
-                DEFAULT_USER_TEXT_INPUT_LENGTH);
-                
-            if (prepped != null && !collection.contains(prepped)) {
-                list.add(prepped);
-                collection.add(prepped);
+        try {
+            string[] values = exiv2.try_get_tag_multiple(tag);
+            if (values == null || values.length == 0)
+                return null;
+            
+            Gee.List<string> list = new Gee.ArrayList<string>();
+            
+            Gee.HashSet<string> collection = new Gee.HashSet<string>();
+            foreach (string value in values) {
+                string? prepped = prepare_input_text(value, PREPARE_STRING_OPTIONS,
+                    DEFAULT_USER_TEXT_INPUT_LENGTH);
+                    
+                if (prepped != null && !collection.contains(prepped)) {
+                    list.add(prepped);
+                    collection.add(prepped);
+                }
             }
+            
+            return list.size > 0 ? list : null;
+        } catch (Error error) {
+            return null;
         }
-        
-        return list.size > 0 ? list : null;
     }
     
     // Returns a List that has been filtered through a Set, so no duplicates will be found.
@@ -496,7 +520,7 @@ public class PhotoMetadata : MediaMetadata {
     // NOTE: get_tag_multiple() in gexiv2 currently does not work with EXIF tags (as EXIF can 
     // never return a list of strings).  It will quietly return NULL if attempted.  Until fixed
     // (there or here), don't use this function to access EXIF.  See:
-    // http://trac.yorba.org/ticket/2966
+    // https://gitlab.gnome.org/GNOME/gexiv2/issues/10
     public Gee.List<string>? get_first_string_multiple(string[] tags) {
         foreach (string tag in tags) {
             Gee.List<string>? values = get_string_multiple(tag);
@@ -507,16 +531,20 @@ public class PhotoMetadata : MediaMetadata {
         return null;
     }
     
-    public void set_string(string tag, string value, PrepareInputTextOptions options = PREPARE_STRING_OPTIONS) {
-        string? prepped = prepare_input_text(value, options, DEFAULT_USER_TEXT_INPUT_LENGTH);
+    public void set_string(string tag, string value, PrepareInputTextOptions options = PREPARE_STRING_OPTIONS,
+                           int length = DEFAULT_USER_TEXT_INPUT_LENGTH) {
+        string? prepped = prepare_input_text(value, options, length);
         if (prepped == null) {
             warning("Not setting tag %s to string %s: invalid UTF-8", tag, value);
             
             return;
         }
         
-        if (!exiv2.set_tag_string(tag, prepped))
-            warning("Unable to set tag %s to string %s from source %s", tag, value, source_name);
+        try {
+            exiv2.try_set_tag_string(tag, prepped);
+        } catch (Error error) {
+            warning("Unable to set tag %s to string %s from source %s: %s", tag, value, source_name, error.message);
+        }
     }
     
     private delegate void SetGenericValue(string tag);
@@ -562,13 +590,16 @@ public class PhotoMetadata : MediaMetadata {
             return;
 
         // append a null pointer to the end of the string array -- this is a necessary
-        // workaround for http://trac.yorba.org/ticket/3264. See also
-        // http://trac.yorba.org/ticket/3257, which describes the user-visible behavior
-        // seen in the Flickr Connector as a result of the former bug.
+        // workaround for https://bugzilla.gnome.org/show_bug.cgi?id=712479. See also
+        // https://bugzilla.gnome.org/show_bug.cgi?id=717438, which describes the
+        // user-visible behavior seen in the Flickr Connector as a result of the former bug.
         values += null;
         
-        if (!exiv2.set_tag_multiple(tag, values))
-            warning("Unable to set %d strings to tag %s from source %s", values.length, tag, source_name);
+        try {
+            exiv2.try_set_tag_multiple(tag, values);
+        } catch (Error err) {
+            warning("Unable to set %d strings to tag %s from source %s: %s", values.length, tag, source_name, err.message);
+        }
     }
     
     public void set_all_string_multiple(string[] tags, Gee.Collection<string> values, SetOption option) {
@@ -576,13 +607,16 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public bool get_long(string tag, out long value) {
+        value = 0;
         if (!has_tag(tag)) {
-            value = 0;
-            
             return false;
         }
         
-        value = exiv2.get_tag_long(tag);
+        try {
+            value = exiv2.try_get_tag_long(tag);
+        } catch (Error error) {
+            return false;
+        }
         
         return true;
     }
@@ -599,8 +633,11 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public void set_long(string tag, long value) {
-        if (!exiv2.set_tag_long(tag, value))
-            warning("Unable to set tag %s to long %ld from source %s", tag, value, source_name);
+        try {
+            exiv2.try_set_tag_long(tag, value);
+        } catch (Error err) {
+            warning("Unable to set tag %s to long %ld from source %s: %s", tag, value, source_name, err.message);
+        }
     }
     
     public void set_all_long(string[] tags, long value, SetOption option) {
@@ -609,11 +646,19 @@ public class PhotoMetadata : MediaMetadata {
     
     public bool get_rational(string tag, out MetadataRational rational) {
         int numerator, denominator;
-        bool result = exiv2.get_exif_tag_rational(tag, out numerator, out denominator);
-        
-        rational = MetadataRational(numerator, denominator);
-        
-        return result;
+        try {
+            if (exiv2.try_get_exif_tag_rational(tag, out numerator, out denominator)) {
+                rational = MetadataRational(numerator, denominator);
+            } else {
+                rational = MetadataRational.invalid();
+                return false;
+            }
+        } catch (Error error) {
+            rational = MetadataRational.invalid();
+            return false;
+        }
+
+        return true;
     }
     
     public bool get_first_rational(string[] tags, out MetadataRational rational) {
@@ -628,9 +673,11 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public void set_rational(string tag, MetadataRational rational) {
-        if (!exiv2.set_exif_tag_rational(tag, rational.numerator, rational.denominator)) {
-            warning("Unable to set tag %s to rational %s from source %s", tag, rational.to_string(),
-                source_name);
+        try {
+            exiv2.try_set_exif_tag_rational(tag, rational.numerator, rational.denominator);
+        } catch (Error err) {
+            warning("Unable to set tag %s to rational %s from source %s: %s", tag, rational.to_string(),
+                source_name, err.message);
         }
     }
     
@@ -769,7 +816,10 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public void remove_exif_thumbnail() {
-        exiv2.erase_exif_thumbnail();
+        try {
+            exiv2.try_erase_exif_thumbnail();
+        } catch (Error err) { }
+
         if (exif != null) {
             Exif.Mem.new_default().free(exif.data);
             exif.data = null;
@@ -778,7 +828,9 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public void remove_tag(string tag) {
-        exiv2.clear_tag(tag);
+        try {
+            exiv2.try_clear_tag(tag);
+        } catch (Error err){}
     }
     
     public void remove_tags(string[] tags) {
@@ -799,6 +851,9 @@ public class PhotoMetadata : MediaMetadata {
             case MetadataDomain.IPTC:
                 exiv2.clear_iptc();
             break;
+            default:
+                // Just ignore any unknown tags
+            break;
         }
     }
     
@@ -881,7 +936,7 @@ public class PhotoMetadata : MediaMetadata {
     public static string[] HEIGHT_TAGS = {
         "Exif.Photo.PixelYDimension",
         "Xmp.exif.PixelYDimension",
-        "Xmp.tiff.ImageHeight",
+        "Xmp.tiff.ImageLength",
         "Xmp.exif.PixelYDimension"
     };
     
@@ -923,7 +978,7 @@ public class PhotoMetadata : MediaMetadata {
     // (sometimes) appropriate tag for the description.  And there's general confusion about
     // whether Exif.Image.ImageDescription is a description (which is what the tag name
     // suggests) or a title (which is what the specification states).
-    // See: http://trac.yorba.org/wiki/PhotoTags
+    // See: https://wiki.gnome.org/Apps/Shotwell/PhotoTags
     //
     // Hence, the following logic tries to do the right thing in most of these cases.  If
     // the iPhoto title tag is detected, it and the iPhoto description tag are used.  Otherwise,
@@ -997,8 +1052,9 @@ public class PhotoMetadata : MediaMetadata {
          * newlines from comments */
         if (!is_string_empty(comment))
             set_all_generic(COMMENT_TAGS, option, (tag) => {
+                // 4095 is coming from acdsee.notes which is limited to that
                 set_string(tag, comment, PREPARE_STRING_OPTIONS &
-                        ~PrepareInputTextOptions.STRIP_CRLF);
+                        ~PrepareInputTextOptions.STRIP_CRLF, 4095);
             });
         else
             remove_tags(COMMENT_TAGS);
@@ -1139,24 +1195,37 @@ public class PhotoMetadata : MediaMetadata {
     }
     
     public bool has_orientation() {
-        return exiv2.get_orientation() == GExiv2.Orientation.UNSPECIFIED;
+        try {
+            return exiv2.try_get_orientation() == GExiv2.Orientation.UNSPECIFIED;
+        } catch (Error err) {
+            debug("Failed to get orientation: %s", err.message);
+            return false;
+        }
     }
     
     // If not present, returns Orientation.TOP_LEFT.
     public Orientation get_orientation() {
         // GExiv2.Orientation is the same value-wise as Orientation, with one exception:
         // GExiv2.Orientation.UNSPECIFIED must be handled
-        GExiv2.Orientation orientation = exiv2.get_orientation();
-        if (orientation ==  GExiv2.Orientation.UNSPECIFIED || orientation < Orientation.MIN ||
-            orientation > Orientation.MAX)
+        try {
+            GExiv2.Orientation orientation = exiv2.try_get_orientation();
+            if (orientation ==  GExiv2.Orientation.UNSPECIFIED || orientation < Orientation.MIN ||
+                orientation > Orientation.MAX)
+                return Orientation.TOP_LEFT;
+            else
+                return (Orientation) orientation;
+        } catch (Error error) {
             return Orientation.TOP_LEFT;
-        else
-            return (Orientation) orientation;
+        }
     }
     
     public void set_orientation(Orientation orientation) {
         // GExiv2.Orientation is the same value-wise as Orientation
-        exiv2.set_orientation((GExiv2.Orientation) orientation);
+        try {
+            exiv2.try_set_orientation((GExiv2.Orientation) orientation);
+        } catch (Error err) {
+            debug("Failed to set the orientation: %s", err.message);
+        }
     }
     
     public bool get_gps(out double longitude, out string long_ref, out double latitude, out string lat_ref,
@@ -1164,14 +1233,22 @@ public class PhotoMetadata : MediaMetadata {
         longitude = 0.0;
         latitude = 0.0;
         altitude = 0.0;
-        if (!exiv2.get_gps_longitude(out longitude) || !exiv2.get_gps_latitude(out latitude)) {
-            long_ref = null;
-            lat_ref = null;
-            
-            return false;
+        try {
+            if (!exiv2.try_get_gps_longitude(out longitude) || !exiv2.try_get_gps_latitude(out latitude)) {
+                long_ref = null;
+                lat_ref = null;
+                
+                return false;
+            }
+        } catch (Error err) {
+            debug("Failed to get GPS lon/lat: %s", err.message);
         }
 
-        exiv2.get_gps_altitude(out altitude);
+        try {
+            exiv2.try_get_gps_altitude(out altitude);
+        } catch (Error err) {
+            debug("Failed to get GPS altitude: %s", err.message);
+        }
         
         long_ref = get_string("Exif.GPSInfo.GPSLongitudeRef");
         lat_ref = get_string("Exif.GPSInfo.GPSLatitudeRef");
@@ -1179,6 +1256,37 @@ public class PhotoMetadata : MediaMetadata {
         return true;
     }
 
+    public GpsCoords get_gps_coords() {
+        GpsCoords gps_coords = GpsCoords();
+        try {
+            double altitude;
+            gps_coords.has_gps = exiv2.try_get_gps_info(out gps_coords.longitude, out gps_coords.latitude, out altitude) ? 1 : 0;
+            if (gps_coords.has_gps > 0) {
+                if (get_string("Exif.GPSInfo.GPSLongitudeRef") == "W" && gps_coords.longitude > 0)
+                    gps_coords.longitude = -gps_coords.longitude;
+                if (get_string("Exif.GPSInfo.GPSLatitudeRef") == "S" && gps_coords.latitude > 0)
+                    gps_coords.latitude = -gps_coords.latitude;
+            }
+        } catch (Error err) {
+            gps_coords.has_gps = 0;
+        }
+
+        return gps_coords;
+    }
+
+    public void set_gps_coords(GpsCoords gps_coords) {
+        try {
+            if (gps_coords.has_gps > 0) {
+                var altitude = 0.0;
+                exiv2.try_get_gps_altitude(out altitude);
+                exiv2.try_set_gps_info(gps_coords.longitude, gps_coords.latitude, altitude);
+            } else
+                exiv2.try_delete_gps_info();
+        } catch (Error err) {
+            debug("Failed to set or remove GPS info: %s", err.message);
+        }
+    }
+
     public bool get_exposure(out MetadataRational exposure) {
         return get_rational("Exif.Photo.ExposureTime", out exposure);
     }
@@ -1326,7 +1434,7 @@ public class PhotoMetadata : MediaMetadata {
     // Other photo managers, notably F-Spot, take hints from Urgency fields about what the rating
     // of an imported photo should be, and we have decided to do as well. Xmp.xmp.Rating is the only 
     // field we've seen photo manages export ratings to, while Urgency fields seem to have a fundamentally
-    // different meaning. See http://trac.yorba.org/wiki/PhotoTags#Rating for more information.
+    // different meaning. See https://wiki.gnome.org/Apps/Shotwell/PhotoTags#Rating for more information.
     public void set_rating(Rating rating) {
         int int_rating = rating.serialize();
         set_string("Xmp.xmp.Rating", int_rating.to_string());
diff --git a/src/photos/PngSupport.vala b/src/photos/PngSupport.vala
index c891136..e154fc4 100644
--- a/src/photos/PngSupport.vala
+++ b/src/photos/PngSupport.vala
@@ -88,33 +88,6 @@ public class PngReader : GdkReader {
     public PngReader(string filepath) {
         base (filepath, PhotoFileFormat.PNG);
     }
-    
-    public override Gdk.Pixbuf scaled_read(Dimensions full, Dimensions scaled) throws Error {
-        Gdk.Pixbuf result = null;
-        /* if we encounter a situation where there are two orders of magnitude or more of
-           difference between the full image size and the scaled size, and if the full image
-           size has five or more decimal digits of precision, Gdk.Pixbuf.from_file_at_scale( ) can
-           fail due to what appear to be floating-point round-off issues. This isn't surprising,
-           since 32-bit floats only have 6-7 decimal digits of precision in their mantissa. In
-           this case, we prefetch the image at a larger scale and then downsample it to the
-           desired scale as a post-process step. This short-circuits Gdk.Pixbuf's buggy
-           scaling code. */
-        if (((full.width > 9999) || (full.height > 9999)) && ((scaled.width < 100) ||
-             (scaled.height < 100))) {
-            Dimensions prefetch_dimensions = full.get_scaled_by_constraint(1000,
-                ScaleConstraint.DIMENSIONS);
-                                  
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), prefetch_dimensions.width,
-                prefetch_dimensions.height, false);
-
-            result = result.scale_simple(scaled.width, scaled.height, Gdk.InterpType.HYPER);
-        } else {
-            result = new Gdk.Pixbuf.from_file_at_scale(get_filepath(), scaled.width,
-                scaled.height, false);
-        }
-
-        return result;
-    }
 }
 
 public class PngWriter : PhotoFileWriter {
diff --git a/src/photos/RawSupport.vala b/src/photos/RawSupport.vala
index 8c23826..538c949 100644
--- a/src/photos/RawSupport.vala
+++ b/src/photos/RawSupport.vala
@@ -51,7 +51,7 @@ public class RawFileFormatDriver : PhotoFileFormatDriver {
 
 public class RawFileFormatProperties : PhotoFileFormatProperties {
     private static string[] KNOWN_EXTENSIONS = {
-        "3fr", "arw", "srf", "sr2", "bay", "crw", "cr2", "cap", "iiq", "eip", "dcs", "dcr", "drf",
+        "3fr", "arw", "srf", "sr2", "bay", "crw", "cr2", "cr3", "cap", "iiq", "eip", "dcs", "dcr", "drf",
         "k25", "kdc", "dng", "erf", "fff", "mef", "mos", "mrw", "nef", "nrw", "orf", "ptx", "pef",
         "pxn", "r3d", "raf", "raw", "rw2", "raw", "rwl", "rwz", "x3f", "srw"
     };
@@ -63,6 +63,7 @@ public class RawFileFormatProperties : PhotoFileFormatProperties {
     
         /* manufacturer blessed MIME types */
         "image/x-canon-cr2",
+        "image/x-canon-cr3",
         "image/x-canon-crw",
         "image/x-fuji-raf",
         "image/x-adobe-dng",
@@ -85,6 +86,7 @@ public class RawFileFormatProperties : PhotoFileFormatProperties {
         "image/x-bay",
         "image/x-crw",
         "image/x-cr2",
+        "image/x-cr3",
         "image/x-cap",
         "image/x-iiq",
         "image/x-eip",
@@ -174,7 +176,6 @@ public class RawSniffer : PhotoFileSniffer {
         
         try {
             processor.open_file(file.get_path());
-            processor.unpack();
             processor.adjust_sizes_info_only();
         } catch (GRaw.Exception exception) {
             if (exception is GRaw.Exception.UNSUPPORTED_FILE)
@@ -195,7 +196,7 @@ public class RawSniffer : PhotoFileSniffer {
             // ignored
         }
         
-        if (detected.metadata != null) {
+        if (calc_md5 && detected.metadata != null) {
             detected.exif_md5 = detected.metadata.exif_hash();
             detected.thumbnail_md5 = detected.metadata.thumbnail_hash();
         }
@@ -211,15 +212,19 @@ public class RawSniffer : PhotoFileSniffer {
 }
 
 public class RawReader : PhotoFileReader {
+    private PhotoMetadata? cached_metadata = null;
+
     public RawReader(string filepath) {
         base (filepath, PhotoFileFormat.RAW);
     }
     
     public override PhotoMetadata read_metadata() throws Error {
-        PhotoMetadata metadata = new PhotoMetadata();
-        metadata.read_from_file(get_file());
-        
-        return metadata;
+        if (cached_metadata == null) {
+            PhotoMetadata metadata = new PhotoMetadata();
+            metadata.read_from_file(get_file());
+            cached_metadata = metadata;
+        }
+        return cached_metadata;
     }
     
     public override Gdk.Pixbuf unscaled_read() throws Error {
diff --git a/src/photos/TiffSupport.vala b/src/photos/TiffSupport.vala
index 7ed8b98..cadcd0e 100644
--- a/src/photos/TiffSupport.vala
+++ b/src/photos/TiffSupport.vala
@@ -151,6 +151,9 @@ private class TiffMetadataWriter : PhotoFileMetadataWriter {
     }
 }
 
+private const uint16 FILE_MARKER_TIFF = 42;
+private const uint16 FILE_MARKER_BIGTIFF = 43;
+
 public bool is_tiff(File file, Cancellable? cancellable = null) throws Error {
     DataInputStream dins = new DataInputStream(file.read());
     
@@ -173,8 +176,9 @@ public bool is_tiff(File file, Cancellable? cancellable = null) throws Error {
     
     // second two bytes: some random number
     uint16 lue = dins.read_uint16(cancellable);
-    if (lue != 42)
+    if (lue != FILE_MARKER_TIFF && lue != FILE_MARKER_BIGTIFF) {
         return false;
+    }
     
     // remaining bytes are offset of first IFD, which doesn't matter for our purposes
     return true;
diff --git a/src/photos/WebPSupport.vala b/src/photos/WebPSupport.vala
new file mode 100644
index 0000000..2f4723c
--- /dev/null
+++ b/src/photos/WebPSupport.vala
@@ -0,0 +1,240 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+namespace Photos {
+
+public class WebpFileFormatDriver : PhotoFileFormatDriver {
+    private static WebpFileFormatDriver instance = null;
+
+    public static void init() {
+        instance = new WebpFileFormatDriver();
+        WebpFileFormatProperties.init();
+    }
+
+    public static WebpFileFormatDriver get_instance() {
+        return instance;
+    }
+
+    public override PhotoFileFormatProperties get_properties() {
+        return WebpFileFormatProperties.get_instance();
+    }
+
+    public override PhotoFileReader create_reader(string filepath) {
+        return new WebpReader(filepath);
+    }
+
+    public override PhotoMetadata create_metadata() {
+        return new PhotoMetadata();
+    }
+
+    public override bool can_write_image() {
+        return false;
+    }
+
+    public override bool can_write_metadata() {
+        return true;
+    }
+
+    public override PhotoFileWriter? create_writer(string filepath) {
+        return null;
+    }
+
+    public override PhotoFileMetadataWriter? create_metadata_writer(string filepath) {
+        return new WebpMetadataWriter(filepath);
+    }
+
+    public override PhotoFileSniffer create_sniffer(File file, PhotoFileSniffer.Options options) {
+        return new WebpSniffer(file, options);
+    }
+}
+
+private class WebpFileFormatProperties : PhotoFileFormatProperties {
+    private static string[] KNOWN_EXTENSIONS = {
+        "webp"
+    };
+
+    private static string[] KNOWN_MIME_TYPES = {
+        "image/webp"
+    };
+
+    private static WebpFileFormatProperties instance = null;
+
+    public static void init() {
+        instance = new WebpFileFormatProperties();
+    }
+
+    public static WebpFileFormatProperties get_instance() {
+        return instance;
+    }
+
+    public override PhotoFileFormat get_file_format() {
+        return PhotoFileFormat.WEBP;
+    }
+
+    public override PhotoFileFormatFlags get_flags() {
+        return PhotoFileFormatFlags.NONE;
+    }
+
+    public override string get_default_extension() {
+        return "webp";
+    }
+
+    public override string get_user_visible_name() {
+        return _("WebP");
+    }
+
+    public override string[] get_known_extensions() {
+        return KNOWN_EXTENSIONS;
+    }
+
+    public override string get_default_mime_type() {
+        return KNOWN_MIME_TYPES[0];
+    }
+
+    public override string[] get_mime_types() {
+        return KNOWN_MIME_TYPES;
+    }
+}
+
+private class WebpSniffer : PhotoFileSniffer {
+    private DetectedPhotoInformation detected = null;
+
+    public WebpSniffer(File file, PhotoFileSniffer.Options options) {
+        base (file, options);
+        detected = new DetectedPhotoInformation();
+    }
+
+    public override DetectedPhotoInformation? sniff(out bool is_corrupted) throws Error {
+        is_corrupted = false;
+
+        if (!is_webp(file))
+            return null;
+
+         // valac chokes on the ternary operator here
+        Checksum? md5_checksum = null;
+        if (calc_md5)
+            md5_checksum = new Checksum(ChecksumType.MD5);
+
+        detected.metadata = new PhotoMetadata();
+        try {
+            detected.metadata.read_from_file(file);
+        } catch (Error err) {
+            debug("Failed to load meta-data from file: %s", err.message);
+            // no metadata detected
+            detected.metadata = null;
+        }
+
+        if (calc_md5 && detected.metadata != null) {
+            detected.exif_md5 = detected.metadata.exif_hash();
+            detected.thumbnail_md5 = detected.metadata.thumbnail_hash();
+        }
+
+        // if no MD5, don't read as much, as the needed info will probably be gleaned
+        // in the first 8K to 16K
+        uint8[] buffer = calc_md5 ? new uint8[64 * 1024] : new uint8[8 * 1024];
+        size_t count = 0;
+
+        // loop through until all conditions we're searching for are met
+        FileInputStream fins = file.read(null);
+        var ba = new ByteArray();
+        for (;;) {
+            size_t bytes_read = fins.read(buffer, null);
+            if (bytes_read <= 0)
+                break;
+
+            ba.append(buffer[0:bytes_read]);
+
+            count += bytes_read;
+
+            if (calc_md5)
+                md5_checksum.update(buffer, bytes_read);
+
+            WebP.Data d = WebP.Data();
+            d.bytes = ba.data;
+
+            WebP.ParsingState state;
+            var demux = new WebP.Demuxer.partial(d, out state);
+
+            if (state == WebP.ParsingState.PARSE_ERROR) {
+                is_corrupted = true;
+                break;
+            }
+
+            if (state > WebP.ParsingState.PARSED_HEADER) {
+                detected.file_format = PhotoFileFormat.WEBP;
+                detected.format_name = "WebP";
+                detected.channels = 4;
+                detected.bits_per_channel = 8;
+                detected.image_dim.width = (int) demux.get(WebP.FormatFeature.CANVAS_WIDTH);
+                detected.image_dim.height = (int) demux.get(WebP.FormatFeature.CANVAS_HEIGHT);
+
+                // if not searching for anything else, exit
+                if (!calc_md5)
+                    break;
+            }
+        }
+
+        if (fins != null)
+            fins.close(null);
+
+        if (calc_md5)
+            detected.md5 = md5_checksum.get_string();
+
+        return detected;
+    }
+}
+
+private class WebpReader : PhotoFileReader {
+    public WebpReader(string filepath) {
+        base (filepath, PhotoFileFormat.WEBP);
+    }
+
+    public override PhotoMetadata read_metadata() throws Error {
+        PhotoMetadata metadata = new PhotoMetadata();
+        metadata.read_from_file(get_file());
+
+        return metadata;
+    }
+
+    public override Gdk.Pixbuf unscaled_read() throws Error {
+        uint8[] buffer;
+
+        FileUtils.get_data(this.get_filepath(), out buffer);
+        int width, height;
+        var pixdata = WebP.DecodeRGBA(buffer, out width, out height);
+        pixdata.length = width * height * 4;
+
+        return new Gdk.Pixbuf.from_data(pixdata, Gdk.Colorspace.RGB, true, 8, width, height, width * 4);
+    }
+}
+
+private class WebpMetadataWriter : PhotoFileMetadataWriter {
+    public WebpMetadataWriter(string filepath) {
+        base (filepath, PhotoFileFormat.WEBP);
+    }
+
+    public override void write_metadata(PhotoMetadata metadata) throws Error {
+        metadata.write_to_file(get_file());
+    }
+}
+
+public bool is_webp(File file, Cancellable? cancellable = null) throws Error {
+    var ins = file.read();
+
+    uint8 buffer[12];
+    try {
+        ins.read(buffer, null);
+        if (buffer[0] == 'R' && buffer[1] == 'I' && buffer[2] == 'F' && buffer[3] == 'F' &&
+            buffer[8] == 'W' && buffer[9] == 'E' && buffer[10] == 'B' && buffer[11] == 'P')
+            return true;
+    } catch (Error error) {
+        debug ("Failed to read from file %s: %s", file.get_path (), error.message);
+    }
+
+    return false;
+}
+
+}
diff --git a/src/plugins/DataImportsInterfaces.vala b/src/plugins/DataImportsInterfaces.vala
index f2c8a53..518f8d0 100644
--- a/src/plugins/DataImportsInterfaces.vala
+++ b/src/plugins/DataImportsInterfaces.vala
@@ -120,7 +120,7 @@ public interface ImportableMediaItem : GLib.Object {
     
     public abstract string get_filename();
 
-    public abstract time_t? get_exposure_time();
+    public abstract DateTime? get_exposure_time();
 }
 
 /**
@@ -416,7 +416,7 @@ public interface PluginHost : GLib.Object, Spit.HostInterface {
      * @param host_progress_delta the amount of progress the host should update
      * the progress bar during import preparation. Plugins should ensure that
      * a proportion of progress for each media item is set aside for the host
-     * in oder to ensure a smoother update to the progress bar.
+     * in order to ensure a smoother update to the progress bar.
      *
      * @param progress_message the text to be displayed below the progress bar. If that
      * parameter is null, the message will be left unchanged.
diff --git a/src/plugins/ManifestWidget.vala b/src/plugins/ManifestWidget.vala
index 8fb0ba2..55ccdc3 100644
--- a/src/plugins/ManifestWidget.vala
+++ b/src/plugins/ManifestWidget.vala
@@ -10,10 +10,7 @@ namespace Plugins {
 [GtkTemplate (ui = "/org/gnome/Shotwell/ui/manifest_widget.ui")]
 public class ManifestWidgetMediator : Gtk.Box {
     [GtkChild]
-    private Gtk.Button about_button;
-    
-    [GtkChild]
-    private Gtk.ScrolledWindow list_bin;
+    private unowned Gtk.ScrolledWindow list_bin;
     
     private ManifestListView list = new ManifestListView();
     
@@ -21,247 +18,212 @@ public class ManifestWidgetMediator : Gtk.Box {
         Object();
 
         list_bin.add(list);
-        
-        about_button.clicked.connect(on_about);
-        list.get_selection().changed.connect(on_selection_changed);
-        
-        set_about_button_sensitivity();
+    }    
+}
+
+private class CollectionModel<G> : GLib.ListModel, Object {
+    private Gee.Collection<G> target;
+    private unowned Gee.List<G>? as_list = null;
+
+    public CollectionModel(Gee.Collection<G> target) {
+        Object();
+        this.target = target.read_only_view;
+        if (this.target is Gee.List) {
+            this.as_list = (Gee.List<G>)this.target;
+        }
     }
-    
-    private void on_about() {
-        string[] ids = list.get_selected_ids();
-        if (ids.length == 0)
-            return;
-        
-        string id = ids[0];
-        
-        Spit.PluggableInfo info = Spit.PluggableInfo();
-        if (!get_pluggable_info(id, ref info)) {
-            warning("Unable to retrieve information for plugin %s", id);
-            
-            return;
+
+    GLib.Object? get_item(uint position) {
+        if (position >= this.target.size) {
+            return null;
         }
-        
-        // prepare authors names (which are comma-delimited by the plugin) for the about box
-        // (which wants an array of names)
-        string[]? authors = null;
-        if (info.authors != null) {
-            string[] split = info.authors.split(",");
-            for (int ctr = 0; ctr < split.length; ctr++) {
-                string stripped = split[ctr].strip();
-                if (!is_string_empty(stripped)) {
-                    if (authors == null)
-                        authors = new string[0];
-                    
-                    authors += stripped;
-                }
+
+        if (this.as_list != null) {
+            return (GLib.Object) this.as_list.@get((int) position);
+        }
+
+        var count = 0U;
+        foreach (var g in this.target) {
+            if (count == position) {
+                return (GLib.Object)g;
             }
+            count++;
         }
-        
-        Gtk.AboutDialog about_dialog = new Gtk.AboutDialog();
-        about_dialog.authors = authors;
-        about_dialog.comments = info.brief_description;
-        about_dialog.copyright = info.copyright;
-        about_dialog.license = info.license;
-        about_dialog.wrap_license = info.is_license_wordwrapped;
-        about_dialog.logo = (info.icons != null && info.icons.length > 0) ? info.icons[0] :
-            Resources.get_icon(Resources.ICON_GENERIC_PLUGIN);
-        about_dialog.program_name = get_pluggable_name(id);
-        about_dialog.translator_credits = info.translators;
-        about_dialog.version = info.version;
-        about_dialog.website = info.website_url;
-        about_dialog.website_label = info.website_name;
-        
-        about_dialog.run();
-        
-        about_dialog.destroy();
+
+        return null;
     }
-    
-    private void on_selection_changed() {
-        set_about_button_sensitivity();
+
+    GLib.Type get_item_type() {
+        return typeof(G);
     }
-    
-    private void set_about_button_sensitivity() {
-        // have to get the array and then get its length rather than do so in one call due to a 
-        // bug in Vala 0.10:
-        //     list.get_selected_ids().length -> uninitialized value
-        // this appears to be fixed in Vala 0.11
-        string[] ids = list.get_selected_ids();
-        about_button.sensitive = (ids.length == 1);
+
+    uint get_n_items() {
+        return this.target.size;
     }
+
 }
 
-private class ManifestListView : Gtk.TreeView {
-    private const int ICON_SIZE = 24;
-    private const int ICON_X_PADDING = 6;
-    private const int ICON_Y_PADDING = 2;
-    
-    private enum Column {
-        ENABLED,
-        CAN_ENABLE,
-        ICON,
-        NAME,
-        ID,
-        N_COLUMNS
+private class Selection : Object {
+    public signal void changed();
+}
+
+private class PluggableRow : Gtk.Box {
+    public Spit.Pluggable pluggable { get; construct; }
+    public bool enabled {get; construct; }
+
+    public PluggableRow(Spit.Pluggable pluggable_, bool enable_) {
+        Object(orientation: Gtk.Orientation.VERTICAL, pluggable: pluggable_,
+            enabled: enable_, margin_top: 6, margin_bottom:6, margin_start:6, margin_end:6);
     }
-    
-    private Gtk.TreeStore store = new Gtk.TreeStore(Column.N_COLUMNS,
-        typeof(bool),       // ENABLED
-        typeof(bool),       // CAN_ENABLE
-        typeof(Gdk.Pixbuf), // ICON
-        typeof(string),     // NAME
-        typeof(string)      // ID
-    );
-    
-    public ManifestListView() {
-        set_model(store);
-        
-        Gtk.CellRendererToggle checkbox_renderer = new Gtk.CellRendererToggle();
-        checkbox_renderer.radio = false;
-        checkbox_renderer.activatable = true;
-        
-        Gtk.CellRendererPixbuf icon_renderer = new Gtk.CellRendererPixbuf();
-        icon_renderer.stock_size = Gtk.IconSize.MENU;
-        icon_renderer.xpad = ICON_X_PADDING;
-        icon_renderer.ypad = ICON_Y_PADDING;
-        
-        Gtk.CellRendererText text_renderer = new Gtk.CellRendererText();
-        
-        Gtk.TreeViewColumn column = new Gtk.TreeViewColumn();
-        column.set_sizing(Gtk.TreeViewColumnSizing.AUTOSIZE);
-        column.pack_start(checkbox_renderer, false);
-        column.pack_start(icon_renderer, false);
-        column.pack_end(text_renderer, true);
-        
-        column.add_attribute(checkbox_renderer, "active", Column.ENABLED);
-        column.add_attribute(checkbox_renderer, "visible", Column.CAN_ENABLE);
-        column.add_attribute(icon_renderer, "pixbuf", Column.ICON);
-        column.add_attribute(text_renderer, "text", Column.NAME);
-        
-        append_column(column);
+
+    public override void constructed() {
+        base.constructed();
+        var content = new Gtk.Box(Gtk.Orientation.HORIZONTAL, 6);
+        pack_start(content, true);
+
+        var revealer = new Gtk.Revealer();
+        revealer.margin_top = 6;
+        pack_end(revealer, true);
         
-        set_headers_visible(false);
-        set_enable_search(false);
-        set_show_expanders(true);
-        set_reorderable(false);
-        set_enable_tree_lines(false);
-        set_grid_lines(Gtk.TreeViewGridLines.NONE);
-        get_selection().set_mode(Gtk.SelectionMode.BROWSE);
+        var info = pluggable.get_info();
         
-        Gtk.IconTheme icon_theme = Resources.get_icon_theme_engine();
+        var image = new Gtk.Image.from_icon_name(info.icon_name, Gtk.IconSize.BUTTON);
+        content.pack_start(image, false, false, 6);
+        image.hexpand = false;
+
+        var label = new Gtk.Label(pluggable.get_pluggable_name());
+        label.halign = Gtk.Align.START;
+        content.pack_start(label, true, true, 6);
+
+        var button = new Gtk.ToggleButton();
+        button.get_style_context().add_class("flat");
+        content.pack_end(button, false, false, 6);
+        button.bind_property("active", revealer, "reveal-child", BindingFlags.DEFAULT);
+        image = new Gtk.Image.from_icon_name("go-down-symbolic", Gtk.IconSize.SMALL_TOOLBAR);
+        button.add(image);
+
+        var plugin_enabled = new Gtk.Switch();
+        plugin_enabled.hexpand = false;
+        plugin_enabled.vexpand = false;
+        plugin_enabled.valign = Gtk.Align.CENTER;
+        plugin_enabled.set_active(enabled);
+
+        content.pack_end(plugin_enabled, false, false, 6);
+        plugin_enabled.notify["active"].connect(() => {
+            var id = pluggable.get_id();
+            set_pluggable_enabled(id, plugin_enabled.active);
+        });
+
+        if (pluggable is Spit.Publishing.Service) {
+#if 0
+            var manage = new Gtk.Button.from_icon_name("avatar-default-symbolic", Gtk.IconSize.SMALL_TOOLBAR);
+            manage.get_style_context().add_class("flat");
+            // TRANSLATORS: %s is the name of an online service such as YouTube, Mastodon, ...
+            manage.set_tooltip_text(_("Manage accounts for %s").printf(pluggable.get_pluggable_name()));
+            content.pack_start(manage, false, false, 6);
+#endif
+        }
+
+        var grid = new Gtk.Grid();
+        grid.get_style_context().add_class("content");
+        grid.set_row_spacing(12);
+        grid.set_column_spacing(6);
+        revealer.add(grid);
+        label = new Gtk.Label(info.copyright);
+        label.hexpand = true;
+        label.halign = Gtk.Align.START;
+        grid.attach(label, 0, 0, 2, 1);
+        label = new Gtk.Label(_("Authors"));
+        label.get_style_context().add_class("dim-label");
+        label.halign = Gtk.Align.END;
+        label.margin_start = 12;
+        grid.attach(label, 0, 1, 1, 1);
+        label = new Gtk.Label(info.authors);
+        label.halign = Gtk.Align.START;
+        label.hexpand = true;
+        grid.attach(label, 1, 1, 1, 1);
+
+        label = new Gtk.Label(_("Version"));
+        label.get_style_context().add_class("dim-label");
+        label.halign = Gtk.Align.END;
+        label.margin_start = 12;
+        grid.attach(label, 0, 2, 1, 1);
+        label = new Gtk.Label(info.version);
+        label.halign = Gtk.Align.START;
+        label.hexpand = true;
+        grid.attach(label, 1, 2, 1, 1);
+
+        label = new Gtk.Label(_("License"));
+        label.get_style_context().add_class("dim-label");
+        label.halign = Gtk.Align.END;
+        label.margin_start = 12;
+        grid.attach(label, 0, 3, 1, 1);
+        var link = new Gtk.LinkButton.with_label(info.license_url, info.license_blurp);
+        link.halign = Gtk.Align.START;
+        // remove the annoying padding around the link
+        link.get_style_context().remove_class("text-button");
+        link.get_style_context().add_class("shotwell-plain-link");
+        grid.attach(link, 1, 3, 1, 1);
+
+        label = new Gtk.Label(_("Website"));
+        label.get_style_context().add_class("dim-label");
+        label.halign = Gtk.Align.END;
+        label.margin_start = 12;
+        grid.attach(label, 0, 4, 1, 1);
+        link = new Gtk.LinkButton.with_label(info.website_url, info.website_name);
+        link.halign = Gtk.Align.START;
+        // remove the annoying padding around the link
+        link.get_style_context().remove_class("text-button");
+        link.get_style_context().add_class("shotwell-plain-link");
+        grid.attach(link, 1, 4, 1, 1);
         
-        // create a list of plugins (sorted by name) that are separated by extension points (sorted
-        // by name)
-        foreach (ExtensionPoint extension_point in get_extension_points(compare_extension_point_names)) {
-            Gtk.TreeIter category_iter;
-            store.append(out category_iter, null);
-            
-            Gdk.Pixbuf? icon = null;
-            if (extension_point.icon_name != null) {
-                Gtk.IconInfo? icon_info = icon_theme.lookup_by_gicon(
-                    new ThemedIcon(extension_point.icon_name), ICON_SIZE, 0);
-                if (icon_info != null) {
-                    try {
-                        icon = icon_info.load_icon();
-                    } catch (Error err) {
-                        warning("Unable to load icon %s: %s", extension_point.icon_name, err.message);
-                    }
-                }
-            }
-            
-            store.set(category_iter, Column.NAME, extension_point.name, Column.CAN_ENABLE, false,
-                Column.ICON, icon);
-            
-            Gee.Collection<Spit.Pluggable> pluggables = get_pluggables_for_type(
-                extension_point.pluggable_type, compare_pluggable_names, true);
-            foreach (Spit.Pluggable pluggable in pluggables) {
+    }
+}
+
+private class ManifestListView : Gtk.Box {
+    public ManifestListView() {
+        Object(orientation: Gtk.Orientation.VERTICAL, spacing: 6);
+    }
+
+    public signal void row_selected(Spit.Pluggable? pluggable);
+
+    public override void constructed() {
+        base.constructed();
+
+        foreach (var extension_point in get_extension_points(compare_extension_point_names)) {
+            var label = new Gtk.Label(null);
+            label.set_markup("<span weight=\"bold\">%s</span>".printf(extension_point.name));
+            label.halign = Gtk.Align.START;
+            label.hexpand = true;
+            add(label);
+
+            var pluggables = get_pluggables_for_type(extension_point.pluggable_type, compare_pluggable_names, true);
+            var box = new Gtk.ListBox();
+            box.set_selection_mode(Gtk.SelectionMode.NONE);
+            box.hexpand = true;
+            box.margin_start = 12;
+            box.margin_end = 12;
+
+            var added = 0;
+            foreach (var pluggable in pluggables) {
                 bool enabled;
+
                 if (!get_pluggable_enabled(pluggable.get_id(), out enabled))
                     continue;
-                
-                Spit.PluggableInfo info = Spit.PluggableInfo();
-                pluggable.get_info(ref info);
-                
-                icon = (info.icons != null && info.icons.length > 0) 
-                    ? info.icons[0]
-                    : Resources.get_icon(Resources.ICON_GENERIC_PLUGIN, ICON_SIZE);
-                
-                Gtk.TreeIter plugin_iter;
-                store.append(out plugin_iter, category_iter);
-                
-                store.set(plugin_iter, Column.ENABLED, enabled, Column.NAME, pluggable.get_pluggable_name(),
-                    Column.ID, pluggable.get_id(), Column.CAN_ENABLE, true, Column.ICON, icon);
+
+                var pluggable_row = new PluggableRow(pluggable, enabled);
+
+                added++;
+                box.insert(pluggable_row, -1);
+            }
+            if (added > 0) {
+                add(box);
             }
         }
-        
-        expand_all();
-    }
-    
-    public string[] get_selected_ids() {
-        string[] ids = new string[0];
-        
-        List<Gtk.TreePath> selected = get_selection().get_selected_rows(null);
-        foreach (Gtk.TreePath path in selected) {
-            Gtk.TreeIter iter;
-            string? id = get_id_at_path(path, out iter);
-            if (id != null)
-                ids += id;
-        }
-        
-        return ids;
-    }
-    
-    private string? get_id_at_path(Gtk.TreePath path, out Gtk.TreeIter iter) {
-        if (!store.get_iter(out iter, path))
-            return null;
-        
-        unowned string id;
-        store.get(iter, Column.ID, out id);
-        
-        return id;
-    }
 
-    // Because we want each row to left-align and not for each column to line up in a grid
-    // (otherwise the checkboxes -- hidden or not -- would cause the rest of the row to line up
-    // along the icon's left edge), we put all the renderers into a single column.  However, the
-    // checkbox renderer then triggers its "toggle" signal any time the row is single-clicked,
-    // whether or not the actual checkbox hit-tests.
-    //
-    // The only way found to work around this is to capture the button-down event and do our own
-    // hit-testing.
-    public override bool button_press_event(Gdk.EventButton event) {
-        Gtk.TreePath path;
-        Gtk.TreeViewColumn col;
-        int cellx;
-        int celly;
-        if (!get_path_at_pos((int) event.x, (int) event.y, out path, out col, out cellx,
-            out celly))
-            return base.button_press_event(event);
-        
-        // Perform custom hit testing as described above. The first cell in the column is offset
-        // from the left edge by whatever size the group description icon is allocated (including
-        // padding).
-        if (cellx < (ICON_SIZE + ICON_X_PADDING) || cellx > (2 * (ICON_X_PADDING + ICON_SIZE)))
-            return base.button_press_event(event);
-
-        Gtk.TreeIter iter;
-        string? id = get_id_at_path(path, out iter);
-        if (id == null)
-            return base.button_press_event(event);
-        
-        bool enabled;
-        if (!get_pluggable_enabled(id, out enabled))
-            return base.button_press_event(event);
-        
-        // toggle and set
-        enabled = !enabled;
-        set_pluggable_enabled(id, enabled);
-        
-        store.set(iter, Column.ENABLED, enabled);
-        
-        return true;
+        show_all();
     }
-}
+} 
 
 }
 
diff --git a/src/plugins/Plugins.vala b/src/plugins/Plugins.vala
index 6aff461..cfab7e8 100644
--- a/src/plugins/Plugins.vala
+++ b/src/plugins/Plugins.vala
@@ -6,10 +6,6 @@
 
 namespace Plugins {
 
-// GModule doesn't have a truly generic way to determine if a file is a shared library by extension,
-// so these are hard-coded
-private const string[] SHARED_LIB_EXTS = { "so", "la" };
-
 // Although not expecting this system to last very long, these ranges declare what versions of this
 // interface are supported by the current implementation.
 private const int MIN_SPIT_INTERFACE = 0;
@@ -39,8 +35,12 @@ private class ModuleRep {
     
     private ModuleRep(File file) {
         this.file = file;
-        
+
+#if VALA_0_46
+        module = Module.open(file.get_path(), ModuleFlags.LAZY);
+#else
         module = Module.open(file.get_path(), ModuleFlags.BIND_LAZY);
+#endif
     }
     
     ~ModuleRep() {
@@ -221,7 +221,7 @@ public string? get_pluggable_module_id(Spit.Pluggable needle) {
     return (module_rep != null) ? module_rep.spit_module.get_id() : null;
 }
 
-public Gee.Collection<ExtensionPoint> get_extension_points(owned CompareDataFunc? compare_func = null) {
+public Gee.Collection<ExtensionPoint> get_extension_points(owned CompareDataFunc<ExtensionPoint>? compare_func = null) {
     Gee.Collection<ExtensionPoint> sorted = new Gee.TreeSet<ExtensionPoint>((owned) compare_func);
     sorted.add_all(extension_points.values);
     
@@ -229,7 +229,7 @@ public Gee.Collection<ExtensionPoint> get_extension_points(owned CompareDataFunc
 }
 
 public Gee.Collection<Spit.Pluggable> get_pluggables_for_type(Type type,
-    owned CompareDataFunc? compare_func = null, bool include_disabled = false) {
+    owned CompareDataFunc<Spit.Pluggable>? compare_func = null, bool include_disabled = false) {
     // if this triggers it means the extension point didn't register itself at init() time
     assert(extension_points.has_key(type));
     
@@ -252,12 +252,14 @@ public string? get_pluggable_name(string id) {
         ? pluggable_rep.pluggable.get_pluggable_name() : null;
 }
 
-public bool get_pluggable_info(string id, ref Spit.PluggableInfo info) {
+public bool get_pluggable_info(string id, out Spit.PluggableInfo info) {
     PluggableRep? pluggable_rep = pluggable_table.get(id);
-    if (pluggable_rep == null || !pluggable_rep.activated)
+    if (pluggable_rep == null || !pluggable_rep.activated) {
+        info = null;
         return false;
+    }
     
-    pluggable_rep.pluggable.get_info(ref info);
+    info = pluggable_rep.pluggable.get_info();
     
     return true;
 }
@@ -290,30 +292,19 @@ public File get_pluggable_module_file(Spit.Pluggable pluggable) {
     return (module_rep != null) ? module_rep.file : null;
 }
 
-public int compare_pluggable_names(void *a, void *b) {
-    Spit.Pluggable *apluggable = (Spit.Pluggable *) a;
-    Spit.Pluggable *bpluggable = (Spit.Pluggable *) b;
-    
-    return apluggable->get_pluggable_name().collate(bpluggable->get_pluggable_name());
+public int compare_pluggable_names(Spit.Pluggable a, Spit.Pluggable b) {
+    return a.get_pluggable_name().collate(b.get_pluggable_name());
 }
 
-public int compare_extension_point_names(void *a, void *b) {
-    ExtensionPoint *apoint = (ExtensionPoint *) a;
-    ExtensionPoint *bpoint = (ExtensionPoint *) b;
-    
-    return apoint->name.collate(bpoint->name);
+public int compare_extension_point_names(ExtensionPoint a, ExtensionPoint b) {
+    return a.name.collate(b.name);
 }
 
 private bool is_shared_library(File file) {
     string name, ext;
     disassemble_filename(file.get_basename(), out name, out ext);
-    
-    foreach (string shared_ext in SHARED_LIB_EXTS) {
-        if (ext == shared_ext)
-            return true;
-    }
-    
-    return false;
+
+    return ext == Module.SUFFIX;
 }
 
 private void search_for_plugins(File dir) throws Error {
diff --git a/src/plugins/PublishingInterfaces.vala b/src/plugins/PublishingInterfaces.vala
index 6518142..05b161f 100644
--- a/src/plugins/PublishingInterfaces.vala
+++ b/src/plugins/PublishingInterfaces.vala
@@ -9,7 +9,7 @@
  *
  * The Shotwell Pluggable Publishing API allows you to write plugins that upload
  * photos and videos to web services. The Shotwell distribution includes publishing
- * support for four core services: Facebook, Flickr, Picasa Web Albums, and YouTube.
+ * support for three core services: Flickr, Google Photos, and YouTube.
  * To enable Shotwell to connect to additional services, developers like you write
  * publishing plugins, dynamically-loadable shared objects that are linked into the
  * Shotwell process at runtime. Publishing plugins are just one of several kinds of
@@ -87,7 +87,7 @@ public errordomain PublishingError {
     /**
      * Indicates that a secure connection to the remote host cannot be
      * established. This might have various reasons such as expired
-     * certificats, invalid certificates, self-signed certificates...
+     * certificates, invalid certificates, self-signed certificates...
      */
     SSL_FAILED
 }
@@ -268,6 +268,8 @@ public interface PluginHost : GLib.Object, Spit.HostInterface {
         CANCEL = 1
     }
 
+    public abstract string get_current_profile_id();
+
     /**
      * Notifies the user that an unrecoverable publishing error has occurred and halts
      * the publishing process.
@@ -367,7 +369,7 @@ public interface PluginHost : GLib.Object, Spit.HostInterface {
      * The text displayed depends on the type of media the current publishing service
      * supports. To provide visual consistency across publishing services and to allow
      * Shotwell to handle internationalization, always use this convenience method; don’t
-     * contruct and install success panes manually.
+     * construct and install success panes manually.
      *
      * If an error has posted, the {@link PluginHost} will not honor
      * this request.
@@ -413,7 +415,7 @@ public interface PluginHost : GLib.Object, Spit.HostInterface {
      * the callback 'on_login_clicked'. Every Publisher should provide a welcome pane to
      * introduce the service and explain service-specific features or restrictions. To provide
      * visual consistency across publishing services and to allow Shotwell to handle
-     * internationalization, always use this convenience method; don’t contruct and install
+     * internationalization, always use this convenience method; don’t construct and install
      * welcome panes manually.
      *
      * If an error has posted, the {@link PluginHost} will not honor this request.
@@ -565,6 +567,11 @@ public interface Publishable : GLib.Object {
      */
     public abstract GLib.DateTime get_exposure_date_time();
     
+    /**
+     * Returns the rating on the file.
+     */
+    public abstract uint get_rating();
+
     //
     // For future expansion.
     //
@@ -578,6 +585,17 @@ public interface Publishable : GLib.Object {
     protected virtual void reserved7() {}
 }
 
+public interface Account : Object {
+    public abstract string display_name();
+}
+
+public class DefaultAccount : Spit.Publishing.Account, Object {
+    public string display_name() {
+        return "";
+    }
+}
+
+
 /**
  * Describes the features and capabilities of a remote publishing service.
  *
@@ -590,10 +608,26 @@ public interface Service : Object, Spit.Pluggable {
      */
     public abstract Spit.Publishing.Publisher create_publisher(Spit.Publishing.PluginHost host);
 
+    public virtual Spit.Publishing.Publisher create_publisher_with_account(Spit.Publishing.PluginHost host,
+                                                              Spit.Publishing.Account? account) {
+        return this.create_publisher(host);
+    }
+
     /**
      * Returns the kinds of media that this service can work with.
      */
     public abstract Spit.Publishing.Publisher.MediaType get_supported_media();
+
+    /**
+     * Returns a list of accounts associated with the service
+     * Returns: null if there are no accounts, identifier
+     */
+    public virtual Gee.List<Account>? get_accounts(string profile_id) {
+        var list = new Gee.ArrayList<Account>();
+        list.add(new DefaultAccount());
+
+        return list;
+    }
     
     //
     // For future expansion.
@@ -617,6 +651,8 @@ public interface Authenticator : Object {
     public abstract void logout();
     public abstract void refresh();
 
+    public abstract void set_accountname(string name);
+
     public abstract GLib.HashTable<string, Variant> get_authentication_parameter();
 }
 
diff --git a/src/plugins/SpitInterfaces.vala b/src/plugins/SpitInterfaces.vala
index 3e2c70e..94e6f95 100644
--- a/src/plugins/SpitInterfaces.vala
+++ b/src/plugins/SpitInterfaces.vala
@@ -4,6 +4,8 @@
  * (version 2.1 or later).  See the COPYING file in this distribution.
  */
 
+private extern const string _VERSION;
+
 /**
  * Shotwell Pluggable Interface Technology (SPIT)
  *
@@ -156,27 +158,26 @@ public interface Module : Object {
     protected virtual void reserved7() {}
 }
 
+
 /**
  * A structure holding an assortment of information about a {@link Pluggable}.
  */
-public struct PluggableInfo {
-    public string? version;
-    public string? brief_description;
+public class PluggableInfo : Object {
+    public string? version {get; set; default = _VERSION; }
+    public string? brief_description {get; set; }
     /**
      * A comma-delimited list of the authors of this {@link Pluggable}.
      */
-    public string? authors;
-    public string? copyright;
-    public string? license;
-    public bool is_license_wordwrapped;
-    public string? website_url;
-    public string? website_name;
-    public string? translators;
-    /**
-     * An icon representing this plugin at one or more sizes. Shotwell may select an icon 
-     * according to the size that closest fits the control its being drawn in.
-     */
-    public Gdk.Pixbuf[]? icons;
+    public string? authors { get; set; }
+    public string? copyright {get; set; }
+    public string? license_blurp { get; set; default = _("LGPL v2.1 or later"); }
+    public string? license_url { get; set; default = "https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html"; }
+    public string? website_url {get; set;  default = "https://wiki.gnome.org/Apps/Shotwell";}
+    public string? website_name { get; set;  default = _("Visit the Shotwell home page");}
+    public string? translators {get; set; default = _("translator-credits"); }
+
+    // Name of an icon in the theme, to be set in the Pluggable implementation
+    public string icon_name {get; set; default = "application-x-addon-symbolic"; }
 }
 
 /**
@@ -225,7 +226,7 @@ public interface Pluggable : Object {
     /**
      * Returns extra information about the Pluggable that is used to identify it to the user.
      */
-    public abstract void get_info(ref PluggableInfo info);
+    public abstract PluggableInfo get_info();
     
     /**
      * Called when the Pluggable is enabled (activated) or disabled (deactivated).
diff --git a/src/plugins/StandardHostInterface.vala b/src/plugins/StandardHostInterface.vala
index d0f3ed4..aa012ef 100644
--- a/src/plugins/StandardHostInterface.vala
+++ b/src/plugins/StandardHostInterface.vala
@@ -16,20 +16,17 @@ public class StandardHostInterface : Object, Spit.HostInterface {
         this.config_domain = config_domain;
         config_id = parse_key(pluggable.get_id());
         module_file = get_pluggable_module_file(pluggable);
-        pluggable.get_info(ref info);
+        info = pluggable.get_info();
     }
     
     private static string parse_key(string id) {
         // special case: legacy plugins (Web publishers moved into SPIT) have special names
         // new plugins will use their full ID
         switch (id) {
-            case "org.yorba.shotwell.publishing.facebook":
-                return "facebook";
-            
-            case "org.yorba.shotwell.publishing.flickr":
+            case "org.gnome.shotwell.publishing.flickr":
                 return "flickr";
                 
-            case "org.yorba.shotwell.publishing.youtube":
+            case "org.gnome.shotwell.publishing.youtube":
                 return "youtube";
 
             default:
diff --git a/src/publishing/APIGlue.vala b/src/publishing/APIGlue.vala
index 23c4e8c..56013a2 100644
--- a/src/publishing/APIGlue.vala
+++ b/src/publishing/APIGlue.vala
@@ -126,7 +126,11 @@ public class MediaSourcePublishableWrapper : Spit.Publishing.Publishable, GLib.O
     }
     
     public GLib.DateTime get_exposure_date_time() {
-        return new GLib.DateTime.from_unix_local(wrapped.get_exposure_time());
+        return wrapped.get_exposure_time().to_local();
+    }
+
+    public uint get_rating() {
+        return wrapped.get_rating();
     }
 }
 
diff --git a/src/publishing/LoginWelcomePaneWidget.vala b/src/publishing/LoginWelcomePaneWidget.vala
new file mode 100644
index 0000000..3e9847b
--- /dev/null
+++ b/src/publishing/LoginWelcomePaneWidget.vala
@@ -0,0 +1,45 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ * Copyright 2019 Jens Georg <mail@jensge.org>
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+namespace PublishingUI {
+
+[GtkTemplate (ui = "/org/gnome/Shotwell/ui/login_welcome_pane_widget.ui")]
+public class LoginWelcomePane : Spit.Publishing.DialogPane, Gtk.Box {
+    [GtkChild]
+    private unowned Gtk.Button login_button;
+    [GtkChild]
+    private unowned Gtk.Label not_logged_in_label;
+
+    public Gtk.Widget get_widget() {
+        return this;
+    }
+
+    public Spit.Publishing.DialogPane.GeometryOptions get_preferred_geometry() {
+        return Spit.Publishing.DialogPane.GeometryOptions.NONE;
+    }
+
+    public void on_pane_installed() {
+    }
+
+    public void on_pane_uninstalled() {
+    }
+
+    public signal void login_requested();
+
+    public LoginWelcomePane(string service_welcome_message) {
+        Object();
+
+        login_button.clicked.connect(on_login_clicked);
+        not_logged_in_label.set_use_markup(true);
+        not_logged_in_label.set_markup(service_welcome_message);
+    }
+
+    private void on_login_clicked() {
+        login_requested();
+    }
+}
+} // namespace PublishingUI
diff --git a/src/publishing/ProgressPaneWidget.vala b/src/publishing/ProgressPaneWidget.vala
new file mode 100644
index 0000000..0c89d77
--- /dev/null
+++ b/src/publishing/ProgressPaneWidget.vala
@@ -0,0 +1,44 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ * Copyright 2019 Jens Georg <mail@jensge.org>
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+namespace PublishingUI {
+
+[GtkTemplate (ui = "/org/gnome/Shotwell/ui/progress_pane_widget.ui")]
+public class ProgressPane : Spit.Publishing.DialogPane, Gtk.Box {
+    [GtkChild]
+    private unowned Gtk.ProgressBar progress_bar;
+
+    public Gtk.Widget get_widget() {
+        return this;
+    }
+
+    public Spit.Publishing.DialogPane.GeometryOptions get_preferred_geometry() {
+        return Spit.Publishing.DialogPane.GeometryOptions.NONE;
+    }
+
+    public void on_pane_installed() {
+    }
+
+    public void on_pane_uninstalled() {
+    }
+
+    public void set_text(string text) {
+        progress_bar.set_text(text);
+    }
+
+    public void set_progress(double progress) {
+        progress_bar.set_fraction(progress);
+    }
+
+    public void set_status(string status_text, double progress) {
+        if (status_text != progress_bar.get_text())
+            progress_bar.set_text(status_text);
+
+        set_progress(progress);
+    }
+}
+} // namespace PublishingUI
diff --git a/src/publishing/Publishing.vala b/src/publishing/Publishing.vala
index 455013c..c41e121 100644
--- a/src/publishing/Publishing.vala
+++ b/src/publishing/Publishing.vala
@@ -8,10 +8,9 @@ namespace Publishing {
 
 public void init() throws Error {
     string[] core_ids = new string[0];
-    core_ids += "org.yorba.shotwell.publishing.facebook";
-    core_ids += "org.yorba.shotwell.publishing.flickr";
-    core_ids += "org.yorba.shotwell.publishing.youtube";
-    core_ids += "org.yorba.shotwell.publishing.gnome-photos";
+    core_ids += "org.gnome.shotwell.publishing.flickr";
+    core_ids += "org.gnome.shotwell.publishing.youtube";
+    core_ids += "org.gnome.shotwell.publishing.gnome-photos";
     
     Plugins.register_extension_point(typeof(Spit.Publishing.Service), _("Publishing"),
         Resources.PUBLISH, core_ids);
diff --git a/src/publishing/PublishingPluginHost.vala b/src/publishing/PublishingPluginHost.vala
index ca935ab..7804924 100644
--- a/src/publishing/PublishingPluginHost.vala
+++ b/src/publishing/PublishingPluginHost.vala
@@ -22,7 +22,7 @@ public class ConcretePublishingHost : Plugins.StandardHostInterface,
         Spit.Publishing.Publisher.MediaType.NONE;
     
     public ConcretePublishingHost(Service service, PublishingUI.PublishingDialog dialog,
-        Publishable[] publishables) {
+        Publishable[] publishables, Account account) {
         base(service, "sharing");
         this.dialog = dialog;
         this.publishables = publishables;
@@ -30,7 +30,11 @@ public class ConcretePublishingHost : Plugins.StandardHostInterface,
         foreach (Publishable curr_publishable in publishables)
             this.media_type |= curr_publishable.get_media_type();
         
-        this.active_publisher = service.create_publisher(this);
+        this.active_publisher = service.create_publisher_with_account(this, account);
+    }
+
+    public string get_current_profile_id() {
+        return Shotwell.ProfileManager.get_instance().id();
     }
     
     private void on_login_clicked() {
diff --git a/src/publishing/PublishingUI.vala b/src/publishing/PublishingUI.vala
index d3d4a69..de642a4 100644
--- a/src/publishing/PublishingUI.vala
+++ b/src/publishing/PublishingUI.vala
@@ -6,134 +6,6 @@
 
 namespace PublishingUI {
 
-public class ConcreteDialogPane : Spit.Publishing.DialogPane, GLib.Object {
-    protected Gtk.Box pane_widget = null;
-    protected Gtk.Builder builder = null;
-
-    public ConcreteDialogPane() {
-        builder = AppWindow.create_builder();
-    }
-
-    public Gtk.Widget get_widget() {
-        return pane_widget;
-    }
-
-    public Spit.Publishing.DialogPane.GeometryOptions get_preferred_geometry() {
-        return Spit.Publishing.DialogPane.GeometryOptions.NONE;
-    }
-
-    public void on_pane_installed() {
-    }
-
-    public void on_pane_uninstalled() {
-    }
-}
-
-public class StaticMessagePane : ConcreteDialogPane {
-    private Gtk.Label msg_label = null;
-
-    public StaticMessagePane(string message_string, bool enable_markup = false) {
-        base();
-        msg_label = builder.get_object("static_msg_label") as Gtk.Label;
-        pane_widget = builder.get_object("static_msg_pane_widget") as Gtk.Box;
-
-        if (enable_markup) {
-            msg_label.set_markup(message_string);
-            msg_label.set_line_wrap(true);
-            msg_label.set_use_markup(true);
-        } else {
-            msg_label.set_label(message_string);
-        }
-    }
-}
-
-public class LoginWelcomePane : ConcreteDialogPane {
-    private Gtk.Button login_button = null;
-    private Gtk.Label not_logged_in_label = null;
-
-    public signal void login_requested();
-
-    public LoginWelcomePane(string service_welcome_message) {
-        base();
-        pane_widget = builder.get_object("welcome_pane_widget") as Gtk.Box;
-        login_button = builder.get_object("login_button") as Gtk.Button;
-        not_logged_in_label = builder.get_object("not_logged_in_label") as Gtk.Label;
-
-        login_button.clicked.connect(on_login_clicked);
-        not_logged_in_label.set_use_markup(true);
-        not_logged_in_label.set_markup(service_welcome_message);
-    }
-
-    private void on_login_clicked() {
-        login_requested();
-    }
-}
-
-public class ProgressPane : ConcreteDialogPane {
-    private Gtk.ProgressBar progress_bar = null;
-
-    public ProgressPane() {
-        base();
-        pane_widget = (Gtk.Box) builder.get_object("progress_pane_widget");
-        progress_bar = (Gtk.ProgressBar) builder.get_object("publishing_progress_bar");
-    }
-
-    public void set_text(string text) {
-        progress_bar.set_text(text);
-    }
-
-    public void set_progress(double progress) {
-        progress_bar.set_fraction(progress);
-    }
-
-    public void set_status(string status_text, double progress) {
-        if (status_text != progress_bar.get_text())
-            progress_bar.set_text(status_text);
-
-        set_progress(progress);
-    }
-}
-
-public class SuccessPane : StaticMessagePane {
-    public SuccessPane(Spit.Publishing.Publisher.MediaType published_media, int num_uploaded = 1) {
-        string? message_string = null;
-
-        // Here, we check whether more than one item is being uploaded, and if so, display
-        // an alternate message.
-        if (published_media == Spit.Publishing.Publisher.MediaType.VIDEO) {
-            message_string = ngettext ("The selected video was successfully published.",
-                                       "The selected videos were successfully published.",
-                                       num_uploaded);
-        }
-        else if (published_media == Spit.Publishing.Publisher.MediaType.PHOTO) {
-            message_string = ngettext ("The selected photo was successfully published.",
-                                       "The selected photos were successfully published.",
-                                       num_uploaded);
-        }
-        else if (published_media == (Spit.Publishing.Publisher.MediaType.PHOTO
-                                     | Spit.Publishing.Publisher.MediaType.VIDEO)) {
-            message_string = _("The selected photos/videos were successfully published.");
-        }
-        else {
-            assert_not_reached ();
-        }
-
-        base(message_string);
-    }
-}
-
-public class AccountFetchWaitPane : StaticMessagePane {
-    public AccountFetchWaitPane() {
-        base(_("Fetching account information…"));
-    }
-}
-
-public class LoginWaitPane : StaticMessagePane {
-    public LoginWaitPane() {
-        base(_("Logging in…"));
-    }
-}
-
 public class PublishingDialog : Gtk.Dialog {
     private const int LARGE_WINDOW_WIDTH = 860;
     private const int LARGE_WINDOW_HEIGHT = 688;
@@ -205,12 +77,13 @@ public class PublishingDialog : Gtk.Dialog {
         }
         set_title(title);
 
-        service_selector_box_model = new Gtk.ListStore(2, typeof(Gdk.Pixbuf), typeof(string));
+        service_selector_box_model = new Gtk.ListStore(3, typeof(string), typeof(string),
+            typeof(Spit.Publishing.Account));
         service_selector_box = new Gtk.ComboBox.with_model(service_selector_box_model);
 
         Gtk.CellRendererPixbuf renderer_pix = new Gtk.CellRendererPixbuf();
         service_selector_box.pack_start(renderer_pix,true);
-        service_selector_box.add_attribute(renderer_pix, "pixbuf", 0);
+        service_selector_box.add_attribute(renderer_pix, "icon-name", 0);
 
         Gtk.CellRendererText renderer_text = new Gtk.CellRendererText();
         service_selector_box.pack_start(renderer_text,true);
@@ -226,30 +99,26 @@ public class PublishingDialog : Gtk.Dialog {
         Gtk.TreeIter iter;
 
         foreach (Spit.Publishing.Service service in loaded_services) {
-            service_selector_box_model.append(out iter);
-
             string curr_service_id = service.get_id();
 
-            service.get_info(ref info);
+            info = service.get_info();
 
-            if (null != info.icons && 0 < info.icons.length) {
-                // check if the icons object is set -- if set use that icon
-                service_selector_box_model.set(iter, 0, info.icons[0], 1,
-                    service.get_pluggable_name());
-                
-                // in case the icons object is not set on the next iteration
-                info.icons[0] = Resources.get_icon(Resources.ICON_GENERIC_PLUGIN);
-            } else {
-                // if icons object is null or zero length use a generic icon
-                service_selector_box_model.set(iter, 0, Resources.get_icon(
-                    Resources.ICON_GENERIC_PLUGIN), 1, service.get_pluggable_name());
-            }
-            
-            if (last_used_service == null) {
-                service_selector_box.set_active_iter(iter);
-                last_used_service = service.get_id();
-            } else if (last_used_service == curr_service_id) {
-                service_selector_box.set_active_iter(iter);
+            var accounts = service.get_accounts(Shotwell.ProfileManager.get_instance().id());
+
+            foreach (var account in accounts) {
+                service_selector_box_model.append(out iter);
+
+                var account_name = account.display_name();
+                var display_name = service.get_pluggable_name() + (account_name == "" ? "" : "/" + account_name);
+
+                service_selector_box_model.set(iter, 0, info.icon_name, 1, display_name, 2, account);
+
+                if (last_used_service == null) {
+                    service_selector_box.set_active_iter(iter);
+                    last_used_service = service.get_id();
+                } else if (last_used_service == curr_service_id) {
+                    service_selector_box.set_active_iter(iter);
+                }
             }
         }
 
@@ -373,15 +242,17 @@ public class PublishingDialog : Gtk.Dialog {
         return filtered_services;
     }
 
-    // Because of this bug: http://trac.yorba.org/ticket/3623, we use some extreme measures. The
-    // bug occurs because, in some cases, when publishing is started asynchronous network 
-    // transactions are performed. The mechanism inside libsoup that we use to perform asynchronous
-    // network transactions isn't based on threads but is instead based on the GLib event loop. So
-    // whenever we run a network transaction, the GLib event loop gets spun. One consequence of
-    // this is that PublishingDialog.go( ) can be called multiple times. Note that since events
-    // are processed sequentially, PublishingDialog.go( ) is never called re-entrantly. It just
-    // gets called twice back-to-back in quick succession. So use a timer to do a short circuit
-    // return if this call to go( ) follows immediately on the heels of another call to go( ).
+    // Because of this bug: https://bugzilla.gnome.org/show_bug.cgi?id=717505, we use some
+    // extreme measures. The bug occurs because, in some cases, when publishing is started
+    // asynchronous network transactions are performed. The mechanism inside libsoup that we
+    // use to perform asynchronous network transactions isn't based on threads but is instead
+    // based on the GLib event loop. So whenever we run a network transaction, the GLib event
+    // loop gets spun. One consequence of this is that PublishingDialog.go( ) can be called
+    // multiple times. Note that since events are processed sequentially, PublishingDialog.go()
+    // is never called re-entrantly. It just gets called twice back-to-back in quick
+    // succession. So use a timer to do a short circuit return if this call to go( ) follows
+    // immediately on the heels of another call to go( )
+    // FIXME: Port publising to async libsoup, then there is no nested main loop anymore.
     private static Timer since_last_start = null;
     private static bool elapsed_is_valid = false;
     public static void go(Gee.Collection<MediaSource> to_publish) {
@@ -412,7 +283,7 @@ public class PublishingDialog : Gtk.Dialog {
             // There are no enabled publishing services that accept this media type,
             // warn the user.
             AppWindow.error_message_with_title(_("Unable to publish"),
-                _("Shotwell cannot publish the selected items because you do not have a compatible publishing plugin enabled. To correct this, choose <b>Edit %s Preferences</b> and enable one or more of the publishing plugins on the <b>Plugins</b> tab.").printf("▸"),
+                _("Shotwell cannot publish the selected items because you do not have a compatible publishing plugin enabled. To correct this, choose Edit %s Preferences and enable one or more of the publishing plugins on the <b>Plugins</b> tab.").printf("▸"),
                 null, false);
 
             return;
@@ -458,14 +329,17 @@ public class PublishingDialog : Gtk.Dialog {
         }
         
         Value service_name_val;
+        Value account_val;
         service_selector_box_model.get_value(iter, 1, out service_name_val);
+        service_selector_box_model.get_value(iter, 2, out account_val);
         
         string service_name = (string) service_name_val;
-        
+        var service_account = (Spit.Publishing.Account) account_val;
+       
         Spit.Publishing.Service? selected_service = null;
         Spit.Publishing.Service[] services = load_all_services();
         foreach (Spit.Publishing.Service service in services) {
-            if (service.get_pluggable_name() == service_name) {
+             if (service_name.has_prefix(service.get_pluggable_name())) {
                 selected_service = service;
                 break;
             }
@@ -474,7 +348,7 @@ public class PublishingDialog : Gtk.Dialog {
 
         Config.Facade.get_instance().set_last_used_service(selected_service.get_id());
 
-        host = new Spit.Publishing.ConcretePublishingHost(selected_service, this, publishables);
+        host = new Spit.Publishing.ConcretePublishingHost(selected_service, this, publishables, service_account);
         host.start_publishing();
     }
     
diff --git a/src/publishing/StaticMessagePaneWidget.vala b/src/publishing/StaticMessagePaneWidget.vala
new file mode 100644
index 0000000..5f8de66
--- /dev/null
+++ b/src/publishing/StaticMessagePaneWidget.vala
@@ -0,0 +1,62 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ * Copyright 2019 Jens Georg <mail@jensge.org>
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+namespace PublishingUI {
+
+[GtkTemplate (ui = "/org/gnome/Shotwell/ui/static_message_pane_widget.ui")]
+public class StaticMessagePane : Spit.Publishing.DialogPane, Gtk.Box {
+    public bool show_spinner{get; construct; default=false; }
+
+    [GtkChild]
+    private unowned Gtk.Label static_msg_label;
+
+    [GtkChild]
+    private unowned Gtk.Spinner spinner;
+
+    public Gtk.Widget get_widget() {
+        return this;
+    }
+
+    public Spit.Publishing.DialogPane.GeometryOptions get_preferred_geometry() {
+        return Spit.Publishing.DialogPane.GeometryOptions.NONE;
+    }
+
+    public void on_pane_installed() {
+    }
+
+    public void on_pane_uninstalled() {
+    }
+
+    public StaticMessagePane(string message_string, bool enable_markup = false, bool show_spinner = false) {
+        Object(show_spinner: false);
+
+        spinner.active = show_spinner;
+
+        if (enable_markup) {
+            static_msg_label.set_markup(message_string);
+            static_msg_label.set_line_wrap(true);
+            static_msg_label.set_use_markup(true);
+        } else {
+            static_msg_label.set_label(message_string);
+        }
+    }
+}
+
+public class AccountFetchWaitPane : StaticMessagePane {
+    public AccountFetchWaitPane() {
+        base(_("Fetching account information…"), false, true);
+    }
+}
+
+public class LoginWaitPane : StaticMessagePane {
+    public LoginWaitPane() {
+        base(_("Logging in…"), false, true);
+    }
+}
+
+
+} // namespace PublishingUI
diff --git a/src/publishing/SuccessPaneWidget.vala b/src/publishing/SuccessPaneWidget.vala
new file mode 100644
index 0000000..05b0c16
--- /dev/null
+++ b/src/publishing/SuccessPaneWidget.vala
@@ -0,0 +1,39 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ * Copyright 2019 Jens Georg <mail@jensge.org>
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later).  See the COPYING file in this distribution.
+ */
+
+namespace PublishingUI {
+
+public class SuccessPane : StaticMessagePane {
+    public SuccessPane(Spit.Publishing.Publisher.MediaType published_media, int num_uploaded = 1) {
+        string? message_string = null;
+
+        // Here, we check whether more than one item is being uploaded, and if so, display
+        // an alternate message.
+        if (published_media == Spit.Publishing.Publisher.MediaType.VIDEO) {
+            message_string = ngettext ("The selected video was successfully published.",
+                                       "The selected videos were successfully published.",
+                                       num_uploaded);
+        }
+        else if (published_media == Spit.Publishing.Publisher.MediaType.PHOTO) {
+            message_string = ngettext ("The selected photo was successfully published.",
+                                       "The selected photos were successfully published.",
+                                       num_uploaded);
+        }
+        else if (published_media == (Spit.Publishing.Publisher.MediaType.PHOTO
+                                     | Spit.Publishing.Publisher.MediaType.VIDEO)) {
+            message_string = _("The selected photos/videos were successfully published.");
+        }
+        else {
+            assert_not_reached ();
+        }
+
+        base(message_string);
+    }
+}
+}
+
+
diff --git a/src/publishing/meson.build b/src/publishing/meson.build
new file mode 100644
index 0000000..38178d6
--- /dev/null
+++ b/src/publishing/meson.build
@@ -0,0 +1,27 @@
+libsw_publishing_gui = static_library(
+    'publishing_gui',
+    [
+        'StaticMessagePaneWidget.vala',
+        'ProgressPaneWidget.vala',
+        'SuccessPaneWidget.vala',
+        'LoginWelcomePaneWidget.vala',
+    ],
+    vala_header : 'shotwell-internal-publishing-gui.h',
+    vala_vapi : 'shotwell-internal-publishing-gui.vapi',
+    include_directories : config_incdir,
+    dependencies: [
+        gtk,
+        gee,
+        sw_plugin
+    ],
+    vala_args : [
+        '--gresources',
+        join_paths(meson.project_source_root(), 'data',
+        'org.gnome.Shotwell.gresource.xml')
+    ]
+)
+
+sw_publishing_gui = declare_dependency(
+    include_directories : include_directories('.'),
+    link_with : libsw_publishing_gui
+)
diff --git a/src/searches/SavedSearchDialog.vala b/src/searches/SavedSearchDialog.vala
index 526da35..b08c8a8 100644
--- a/src/searches/SavedSearchDialog.vala
+++ b/src/searches/SavedSearchDialog.vala
@@ -641,18 +641,19 @@ public class SavedSearchDialog : Gtk.Dialog {
     }
     
     [GtkChild]
-    private Gtk.Button add_criteria;
+    private unowned Gtk.Button add_criteria;
     [GtkChild]
-    private Gtk.ComboBoxText operator;
+    private unowned Gtk.ComboBoxText operator;
     [GtkChild]
-    private Gtk.Entry search_title;
+    private unowned Gtk.Entry search_title;
     [GtkChild]
-    private Gtk.ListBox row_listbox;
+    private unowned Gtk.ListBox row_listbox;
 
     private Gee.ArrayList<SearchRowContainer> row_list = new Gee.ArrayList<SearchRowContainer>();
     private bool edit_mode = false;
     private SavedSearch? previous_search = null;
     private bool valid = false;
+    private ulong notify_id = 0;
     
     public SavedSearchDialog() {
         Object (use_header_bar : Resources.use_header_bar());
@@ -701,6 +702,12 @@ public class SavedSearchDialog : Gtk.Dialog {
         add_criteria.clicked.connect(on_add_criteria);
         
         search_title.changed.connect(on_title_changed);
+        if (Resources.use_header_bar() == 1) {
+            var box = search_title.get_parent();
+            box.remove(search_title);
+            box.get_parent().remove(box);
+            ((Gtk.HeaderBar) get_header_bar()).set_custom_title(search_title);
+        }
     }
     
     // Displays the dialog.
@@ -709,9 +716,14 @@ public class SavedSearchDialog : Gtk.Dialog {
         destroy();
     }
     
+    double upper;
     // Adds a row of search criteria.
     private void on_add_criteria() {
+        this.upper = row_listbox.get_adjustment().upper;
+        this.notify_id = row_listbox.get_adjustment().notify["upper"].connect(on_scroll);
         add_text_search();
+        // Wait for upper to change. Then scroll to it, disconnect afterwards
+        // Otherwise the ListBox will randomly scroll to the bottom
     }
     
     private void add_text_search() {
@@ -723,11 +735,26 @@ public class SavedSearchDialog : Gtk.Dialog {
     private void add_row(SearchRowContainer row) {
         if (row_list.size == 1)
             row_list.get(0).allow_removal(true);
-        row_listbox.add(row.get_widget());
+        row_listbox.insert(row.get_widget(), row_list.size);
         row_list.add(row);
         row.remove.connect(on_remove_row);
         row.changed.connect(on_row_changed);
         set_valid(row.is_complete());
+
+    }
+
+    private void on_scroll() {
+        var adj = row_listbox.get_adjustment();
+        if (adj.upper < this.upper) {
+            return;
+        }
+
+        if (this.notify_id != 0) {
+            adj.disconnect(this.notify_id);
+            this.notify_id = 0;
+        }
+
+        adj.value = adj.upper;
     }
     
     // Removes a row of search criteria.
diff --git a/src/searches/SearchBoolean.vala b/src/searches/SearchBoolean.vala
index 5e69e57..fc83e04 100644
--- a/src/searches/SearchBoolean.vala
+++ b/src/searches/SearchBoolean.vala
@@ -776,11 +776,11 @@ public class SearchConditionDate : SearchCondition {
     
     // Determines whether the source is included.
     public override bool predicate(MediaSource source) {
-        time_t exposure_time = source.get_exposure_time();
-        if (exposure_time == 0)
+        var exposure_time = source.get_exposure_time();
+        if (exposure_time == null)
             return context == Context.IS_NOT_SET;
         
-        DateTime dt = new DateTime.from_unix_local(exposure_time);
+        var dt = exposure_time.to_local();
         switch (context) {
             case Context.EXACT:
                 DateTime second = date_one.add_days(1);
diff --git a/src/sidebar/Tree.vala b/src/sidebar/Tree.vala
index ea039ea..aae81a0 100644
--- a/src/sidebar/Tree.vala
+++ b/src/sidebar/Tree.vala
@@ -97,7 +97,6 @@ public class Sidebar.Tree : Gtk.TreeView {
         Gtk.TreeViewColumn text_column = new Gtk.TreeViewColumn();
         text_column.set_expand(true);
         Gtk.CellRendererPixbuf icon_renderer = new Gtk.CellRendererPixbuf();
-        icon_renderer.follow_state = true;
         text_column.pack_start (icon_renderer, false);
         text_column.add_attribute(icon_renderer, "gicon", Columns.ICON);
         text_column.set_cell_data_func(icon_renderer, icon_renderer_function);
@@ -790,17 +789,6 @@ public class Sidebar.Tree : Gtk.TreeView {
         store.set(iter, Columns.ICON, icon);
     }
     
-    private void load_branch_icons(Gtk.TreeIter iter) {
-        load_entry_icons(iter);
-        
-        Gtk.TreeIter child_iter;
-        if (store.iter_children(out child_iter, iter)) {
-            do {
-                load_branch_icons(child_iter);
-            } while (store.iter_next(ref child_iter));
-        }
-    }
-    
     private bool on_selection(Gtk.TreeSelection selection, Gtk.TreeModel model, Gtk.TreePath path,
         bool path_currently_selected) {
         // only allow selection if a page is selectable
diff --git a/src/slideshow/Slideshow.vala b/src/slideshow/Slideshow.vala
index 5d14b64..0ee9392 100644
--- a/src/slideshow/Slideshow.vala
+++ b/src/slideshow/Slideshow.vala
@@ -8,16 +8,16 @@ namespace Slideshow {
 
 public void init() throws Error {
     string[] core_ids = new string[0];
-    core_ids += "org.yorba.shotwell.transitions.crumble";
-    core_ids += "org.yorba.shotwell.transitions.fade";
-    core_ids += "org.yorba.shotwell.transitions.slide";
-    core_ids += "org.yorba.shotwell.transitions.blinds";
-    core_ids += "org.yorba.shotwell.transitions.circle";
-    core_ids += "org.yorba.shotwell.transitions.circles";
-    core_ids += "org.yorba.shotwell.transitions.clock";
-    core_ids += "org.yorba.shotwell.transitions.stripes";
-    core_ids += "org.yorba.shotwell.transitions.squares";
-    core_ids += "org.yorba.shotwell.transitions.chess";
+    core_ids += "org.gnome.shotwell.transitions.crumble";
+    core_ids += "org.gnome.shotwell.transitions.fade";
+    core_ids += "org.gnome.shotwell.transitions.slide";
+    core_ids += "org.gnome.shotwell.transitions.blinds";
+    core_ids += "org.gnome.shotwell.transitions.circle";
+    core_ids += "org.gnome.shotwell.transitions.circles";
+    core_ids += "org.gnome.shotwell.transitions.clock";
+    core_ids += "org.gnome.shotwell.transitions.stripes";
+    core_ids += "org.gnome.shotwell.transitions.squares";
+    core_ids += "org.gnome.shotwell.transitions.chess";
     
     Plugins.register_extension_point(typeof(Spit.Transitions.Descriptor), _("Slideshow Transitions"),
         Resources.ICON_SLIDESHOW_EXTENSION_POINT, core_ids);
diff --git a/src/slideshow/TransitionEffects.vala b/src/slideshow/TransitionEffects.vala
index 5f7dc88..23c666a 100644
--- a/src/slideshow/TransitionEffects.vala
+++ b/src/slideshow/TransitionEffects.vala
@@ -71,7 +71,7 @@ public class TransitionEffectsManager {
         return effects.keys;
     }
     
-    public Gee.Collection<string> get_effect_names(owned CompareDataFunc? comparator = null) {
+    public Gee.Collection<string> get_effect_names(owned CompareDataFunc<string>? comparator = null) {
         Gee.Collection<string> effect_names = new Gee.TreeSet<string>((owned) comparator);
         foreach (Spit.Transitions.Descriptor desc in effects.values)
             effect_names.add(desc.get_pluggable_name());
@@ -273,7 +273,7 @@ public class TransitionClock {
 }
 
 public class NullTransitionDescriptor : Object, Spit.Pluggable, Spit.Transitions.Descriptor {
-    public const string EFFECT_ID = "org.yorba.shotwell.transitions.null";
+    public const string EFFECT_ID = "org.gnome.shotwell.transitions.null";
     
     public int get_pluggable_interface(int min_host_version, int max_host_version) {
         return Spit.Transitions.CURRENT_INTERFACE;
@@ -287,7 +287,8 @@ public class NullTransitionDescriptor : Object, Spit.Pluggable, Spit.Transitions
         return _("None");
     }
     
-    public void get_info(ref Spit.PluggableInfo info) {
+    public Spit.PluggableInfo get_info() {
+        return new Spit.PluggableInfo();
     }
     
     public void activation(bool enabled) {
@@ -325,7 +326,7 @@ public class NullEffect : Object, Spit.Transitions.Effect {
     }
 }
 public class RandomEffectDescriptor : Object, Spit.Pluggable, Spit.Transitions.Descriptor {
-    public const string EFFECT_ID = "org.yorba.shotwell.transitions.random";
+    public const string EFFECT_ID = "org.gnome.shotwell.transitions.random";
 
     public int get_pluggable_interface(int min_host_version, int max_host_version) {
         return Spit.Transitions.CURRENT_INTERFACE;
@@ -339,7 +340,8 @@ public class RandomEffectDescriptor : Object, Spit.Pluggable, Spit.Transitions.D
         return _("Random");
     }
 
-    public void get_info(ref Spit.PluggableInfo info) {
+    public Spit.PluggableInfo get_info() {
+        return new Spit.PluggableInfo();
     }
     
     public void activation(bool enabled) {
diff --git a/src/unit/rc/Unit.m4 b/src/unit/rc/Unit.m4
deleted file mode 100644
index 2665dd6..0000000
--- a/src/unit/rc/Unit.m4
+++ /dev/null
@@ -1,29 +0,0 @@
-/* Copyright 2016 Software Freedom Conservancy Inc.
- *
- * This software is licensed under the GNU Lesser General Public License
- * (version 2.1 or later).  See the COPYING file in this distribution.
- */
-
-/* This file is the master unit file for the _UNIT_NAME_ unit.  It should be edited to include
- * whatever code is deemed necessary.
- *
- * The init() and terminate() methods are mandatory.
- *
- * If the unit needs to be configured prior to initialization, add the proper parameters to
- * the preconfigure() method, implement it, and ensure in init() that it's been called.
- */
-
-namespace _UNIT_NAME_ {
-
-// preconfigure may be deleted if not used.
-public void preconfigure() {
-}
-
-public void init() throws Error {
-}
-
-public void terminate() {
-}
-
-}
-
diff --git a/src/unit/rc/UnitInternals.m4 b/src/unit/rc/UnitInternals.m4
deleted file mode 100644
index 71614d4..0000000
--- a/src/unit/rc/UnitInternals.m4
+++ /dev/null
@@ -1,32 +0,0 @@
-/* Copyright 2016 Software Freedom Conservancy Inc.
- *
- * This software is licensed under the GNU Lesser General Public License
- * (version 2.1 or later).  See the COPYING file in this distribution.
- *
- * Auto-generated file.  Do not modify!
- */
-
-namespace _UNIT_NAME_ {
-
-private int _unit_init_count = 0;
-
-public void init_entry() throws Error {
-    if (_unit_init_count++ != 0)
-        return;
-    
-    _UNIT_USES_INITS_
-    
-    _UNIT_NAME_.init();
-}
-
-public void terminate_entry() {
-    if (_unit_init_count == 0 || --_unit_init_count != 0)
-        return;
-    
-    _UNIT_NAME_.terminate();
-    
-    _UNIT_USES_TERMINATORS_
-}
-
-}
-
diff --git a/src/unit/rc/template.vala b/src/unit/rc/template.vala
deleted file mode 100644
index 31fc93d..0000000
--- a/src/unit/rc/template.vala
+++ /dev/null
@@ -1,7 +0,0 @@
-/* Copyright 2016 Software Freedom Conservancy Inc.
- *
- * This software is licensed under the GNU Lesser General Public License
- * (version 2.1 or later).  See the COPYING file in this distribution.
- */
-
-
diff --git a/src/unit/rc/unitize_entry.m4 b/src/unit/rc/unitize_entry.m4
deleted file mode 100644
index 31602b2..0000000
--- a/src/unit/rc/unitize_entry.m4
+++ /dev/null
@@ -1,19 +0,0 @@
-/* Copyright 2016 Software Freedom Conservancy Inc.
- *
- * This software is licensed under the GNU Lesser General Public License
- * (version 2.1 or later).  See the COPYING file in this distribution.
- *
- * Auto-generated file.  Do not modify!
- */
-
-namespace _APP_UNIT_ {
-
-public void app_init() throws Error {
-    _APP_UNIT_.init_entry();
-}
-
-public void app_terminate() {
-    _APP_UNIT_.terminate_entry();
-}
-
-}
diff --git a/src/util/Util.vala b/src/util/Util.vala
index b87ea3a..45943d7 100644
--- a/src/util/Util.vala
+++ b/src/util/Util.vala
@@ -8,6 +8,8 @@ namespace Util {
     // Use these file attributes when loading file information for a complete FileInfo objects
     public const string FILE_ATTRIBUTES = "standard::*,time::*,id::file,id::filesystem,etag::value";
 
+    public const int64 USEC_PER_SEC = 1000000;
+
     public void init() throws Error {
     }
     
diff --git a/src/util/file.vala b/src/util/file.vala
index c1ee06d..652a141 100644
--- a/src/util/file.vala
+++ b/src/util/file.vala
@@ -31,9 +31,11 @@ public bool claim_file(File file) throws Error {
 // same or similar as what has been requested (adds numerals to the end of the name until a unique
 // one has been found).  The file may exist when this function returns, and it should be
 // overwritten.  It does *not* attempt to create the parent directory, however.
+// The used parameter allows you to pass in a collection of names which should be deemed to be
+// already claimed but which may not yet exist in the file system.
 //
 // This function is thread-safe.
-public File? generate_unique_file(File dir, string basename, out bool collision) throws Error {
+public File? generate_unique_file(File dir, string basename, out bool collision, Gee.Collection<string>? used = null) throws Error {
     // create the file to atomically "claim" it
     File file = dir.get_child(basename);
     if (claim_file(file)) {
@@ -51,7 +53,9 @@ public File? generate_unique_file(File dir, string basename, out bool collision)
     // generate a unique filename
     for (int ctr = 1; ctr < int.MAX; ctr++) {
         string new_name = (ext != null) ? "%s_%d.%s".printf(name, ctr, ext) : "%s_%d".printf(name, ctr);
-        
+        if (used != null && used.contains(new_name)) {
+            continue;
+        }
         file = dir.get_child(new_name);
         if (claim_file(file))
             return file;
@@ -151,11 +155,11 @@ public void delete_all_files(File dir, Gee.Set<string>? exceptions = null, Progr
     }
 }
 
-public time_t query_file_modified(File file) throws Error {
+public DateTime query_file_modified(File file) throws Error {
     FileInfo info = file.query_info(FileAttribute.TIME_MODIFIED, FileQueryInfoFlags.NOFOLLOW_SYMLINKS, 
         null);
 
-    return info.get_modification_time().tv_sec;
+    return info.get_modification_date_time();
 }
 
 public bool query_is_directory(File file) {
@@ -199,20 +203,6 @@ public string? get_file_info_id(FileInfo info) {
     return info.get_attribute_string(FileAttribute.ID_FILE);
 }
 
-// Breaks a uint64 skip amount into several smaller skips.
-public void skip_uint64(InputStream input, uint64 skip_amount) throws GLib.Error {
-    while (skip_amount > 0) {
-        // skip() throws an error if the amount is too large, so check against ssize_t.MAX
-        if (skip_amount >= ssize_t.MAX) {
-            input.skip(ssize_t.MAX);
-            skip_amount -= ssize_t.MAX;
-        } else {
-            input.skip((size_t) skip_amount);
-            skip_amount = 0;
-        }
-    }
-}
-
 // Returns the number of files (and/or directories) within a directory.
 public uint64 count_files_in_directory(File dir) throws GLib.Error {
     if (!query_is_directory(dir))
diff --git a/src/util/image.vala b/src/util/image.vala
index 0a30339..95ac998 100644
--- a/src/util/image.vala
+++ b/src/util/image.vala
@@ -343,7 +343,7 @@ private Cairo.Surface get_background_surface() {
         string color_b;
         var config = Config.Facade.get_instance();
 
-        var type = config.get_transparent_background_type();
+        var type = "checkered"; //config.get_transparent_background_type();
         switch (type) {
             case "checkered":
                 color_a = "#808080";
@@ -386,7 +386,8 @@ public void paint_pixmap_with_background (Cairo.Context ctx, Gdk.Pixbuf pixbuf,
     }
 
     Gdk.cairo_set_source_pixbuf(ctx, pixbuf, x, y);
-    ctx.paint();
+    ctx.rectangle(x, y, pixbuf.width , pixbuf.height);
+    ctx.fill();
 }
 
 // Force an axially-aligned box to be inside a rotated rectangle.
@@ -422,3 +423,6 @@ Box clamp_inside_rotated_image(Box src, int img_w, int img_h, double angle_deg,
                                src.right + right_offset, src.bottom + bottom_offset);
 }
 
+double degrees_to_radians(double theta) {
+    return (theta * (GLib.Math.PI / 180.0));
+}
diff --git a/src/util/misc.vala b/src/util/misc.vala
index 6111ea3..2106621 100644
--- a/src/util/misc.vala
+++ b/src/util/misc.vala
@@ -54,22 +54,12 @@ public bool int_value_equals(Value a, Value b) {
     return (int) a == (int) b;
 }
 
-public ulong timeval_to_ms(TimeVal time_val) {
-    return (((ulong) time_val.tv_sec) * 1000) + (((ulong) time_val.tv_usec) / 1000);
-}
-
 public ulong now_ms() {
-    return timeval_to_ms(TimeVal());
-}
-
-public ulong now_sec() {
-    TimeVal time_val = TimeVal();
-    
-    return time_val.tv_sec;
+    return (ulong) (GLib.get_real_time() / 1000);
 }
 
-public inline time_t now_time_t() {
-    return (time_t) now_sec();
+public int64 now_sec() {
+    return (ulong) (GLib.get_real_time() / Util.USEC_PER_SEC);
 }
 
 public string md5_file(File file) throws Error {
@@ -216,14 +206,16 @@ public Gee.List<MediaSource>? unserialize_media_sources(uchar* serialized, int s
     return list;
 }
 
-public string format_local_datespan(Time from_date, Time to_date) {
+public string format_local_datespan(DateTime from_date, DateTime to_date) {
     string from_format, to_format;
    
     // Ticket #3240 - Change the way date ranges are pretty-
     // printed if the start and end date occur on consecutive days.    
-    if (from_date.year == to_date.year) {
+    if (from_date.get_year() == to_date.get_year()) {
         // are these consecutive dates?
-        if ((from_date.month == to_date.month) && (from_date.day == (to_date.day - 1))) {
+        // get_day_of_year() looks like it saves a bit of code, but then we would
+        // not recognize the change of months
+        if ((from_date.get_month() == to_date.get_month()) && (from_date.get_day_of_month() == (to_date.get_day_of_month() - 1))) {
             // Yes; display like so: Sat, July 4 - 5, 20X6
             from_format =  Resources.get_start_multiday_span_format_string();
             to_format = Resources.get_end_multiday_span_format_string();
@@ -244,7 +236,7 @@ public string format_local_datespan(Time from_date, Time to_date) {
         to_date.format(to_format)));
 }
 
-public string format_local_date(Time date) {
+public string format_local_date(DateTime date) {
     return String.strip_leading_zeroes(date.format(Resources.get_long_date_format_string()));
 }
 
@@ -273,7 +265,9 @@ public class OneShotScheduler {
     }
     
     public void at_idle() {
-        at_priority_idle(Priority.DEFAULT_IDLE);
+        // needs to be lower (higher priority) than Clutter.PRIORITY_REDRAW which is
+        // set at Priority.HIGH_IDLE + 50
+        at_priority_idle(Priority.HIGH_IDLE + 40);
     }
     
     public void at_priority_idle(int priority) {
diff --git a/src/util/string.vala b/src/util/string.vala
index bf7e605..89424d0 100644
--- a/src/util/string.vala
+++ b/src/util/string.vala
@@ -13,13 +13,13 @@ public inline bool is_string_empty(string? s) {
 }
 
 // utf8 case sensitive compare
-public int utf8_cs_compare(void *a, void *b) {
-    return ((string) a).collate((string) b);
+public int utf8_cs_compare(string a, string b) {
+    return a.collate(b);
 }
 
 // utf8 case insensitive compare
-public int utf8_ci_compare(void *a, void *b) {
-    return ((string) a).down().collate(((string) b).down());
+public int utf8_ci_compare(string a, string b) {
+    return a.down().collate(b.down());
 }
 
 // utf8 array to string
@@ -145,7 +145,7 @@ public string? prepare_input_text(string? text, PrepareInputTextOptions options,
     // Using composed form rather than GLib's default (decomposed) as NFC is the preferred form in
     // Linux and WWW.  More importantly, Pango seems to have serious problems displaying decomposed
     // forms of Korean language glyphs (and perhaps others).  See:
-    // http://trac.yorba.org/ticket/2952
+    // https://bugzilla.gnome.org/show_bug.cgi?id=716914
     if ((options & PrepareInputTextOptions.NORMALIZE) != 0)
         prepped = prepped.normalize(-1, NormalizeMode.NFC);
     
@@ -237,6 +237,8 @@ public string remove_diacritics(string istring) {
             case UnicodeType.ENCLOSING_MARK:
             // Ignore those
                 continue;
+            default:
+                break;
         }
         builder.append_unichar(ch);
     }
@@ -255,7 +257,7 @@ public string to_hex_string(string str) {
 
 // A note on the collated_* and precollated_* methods:
 //
-// A bug report (http://trac.yorba.org/ticket/3152) indicated that two different Hirigana characters
+// A bug report (https://bugzilla.gnome.org/show_bug.cgi?id=717135) indicated that two different Hirigana characters
 // as Tag names would trigger an assertion.  Investigation showed that the characters' collation
 // keys computed as equal when the locale was set to anything but the default locale (C) or
 // Japanese.  A related bug was that another hash table was using str_equal, which does not use
diff --git a/src/util/system.vala b/src/util/system.vala
index 1e69304..48e2cc9 100644
--- a/src/util/system.vala
+++ b/src/util/system.vala
@@ -6,7 +6,7 @@
 
 // Return the directory in which Shotwell is installed, or null if uninstalled.
 File? get_sys_install_dir(File exec_dir) {
-    // Assume that if the ui folder lives next to the binary, we runn in-tree
+    // Assume that if the ui folder lives next to the binary, we run in-tree
     File child = exec_dir.get_child("ui");
 
     if (!FileUtils.test(child.get_path(), FileTest.IS_DIR | FileTest.EXISTS)) {
@@ -39,7 +39,8 @@ async void show_file_in_filemanager(File file) throws Error {
                                                                      DBusProxyFlags.DO_NOT_LOAD_PROPERTIES |
                                                                      DBusProxyFlags.DO_NOT_CONNECT_SIGNALS);
         var id = "%s_%s_%d_%s".printf(Environment.get_prgname(), Environment.get_host_name(),
-                                      Posix.getpid(), TimeVal().to_iso8601());
+                                      Posix.getpid(),
+                                      GLib.get_monotonic_time().to_string());
         yield manager.show_items({file.get_uri()}, id);
     } catch (Error e) {
         warning("Failed to launch file manager using DBus, using fall-back: %s", e.message);
diff --git a/src/util/ui.vala b/src/util/ui.vala
index 6d32738..bdc7157 100644
--- a/src/util/ui.vala
+++ b/src/util/ui.vala
@@ -60,7 +60,7 @@ public Gdk.Rectangle get_adjustment_page(Gtk.Adjustment hadj, Gtk.Adjustment vad
 }
 
 // Verifies that only the mask bits are set in the modifier field, disregarding mouse and 
-// key modifers that are not normally of concern (i.e. Num Lock, Caps Lock, etc.).  Mask can be
+// key modifiers that are not normally of concern (i.e. Num Lock, Caps Lock, etc.).  Mask can be
 // one or more bits set, but should only consist of these values:
 // * Gdk.ModifierType.SHIFT_MASK
 // * Gdk.ModifierType.CONTROL_MASK
@@ -87,16 +87,15 @@ public bool has_only_key_modifier(Gdk.ModifierType field, Gdk.ModifierType mask)
 }
 
 bool is_pointer_over(Gdk.Window window) {
-    Gdk.DeviceManager? devmgr = window.get_display().get_device_manager();
-    if (devmgr == null) {
-        debug("No device for display");
+    var seat = window.get_display().get_default_seat();
+    if (seat == null) {
+        debug("No seat for display");
         
         return false;
     }
     
     int x, y;
-    devmgr.get_client_pointer().get_position(null, out x, out y);
-    //gdk_device_get_position(devmgr.get_client_pointer(), null, out x, out y);
+    seat.get_pointer().get_position(null, out x, out y);
     
     return x >= 0 && y >= 0 && x < window.get_width() && y < window.get_height();
 }
diff --git a/src/video-support/AVIChunk.vala b/src/video-support/AVIChunk.vala
new file mode 100644
index 0000000..970f443
--- /dev/null
+++ b/src/video-support/AVIChunk.vala
@@ -0,0 +1,121 @@
+private class AVIChunk {
+    private GLib.File file = null;
+    private string section_name = "";
+    private uint64 section_size = 0;
+    private uint64 section_offset = 0;
+    private GLib.DataInputStream input = null;
+    private AVIChunk? parent = null;
+    private const int MAX_STRING_TO_SECTION_LENGTH = 1024;
+
+    public AVIChunk(GLib.File file) {
+        this.file = file;
+    }
+
+    private AVIChunk.with_input_stream(GLib.DataInputStream input, AVIChunk parent) {
+        this.input = input;
+        this.parent = parent;
+    }
+
+    public void open_file() throws GLib.Error {
+        close_file();
+        input = new GLib.DataInputStream(file.read());
+        input.set_byte_order(DataStreamByteOrder.LITTLE_ENDIAN);
+        section_size = 0;
+        section_offset = 0;
+        section_name = "";
+    }
+
+    public void close_file() throws GLib.Error {
+        if (null != input) {
+            input.close();
+            input = null;
+        }
+    }
+
+    public void nonsection_skip(uint64 skip_amount) throws GLib.Error {
+        skip_uint64(input, skip_amount);
+    }
+
+    public void skip(uint64 skip_amount) throws GLib.Error {
+        advance_section_offset(skip_amount);
+        skip_uint64(input, skip_amount);
+    }
+
+    public AVIChunk get_first_child_chunk() {
+        return new AVIChunk.with_input_stream(input, this);
+    }
+
+    private void advance_section_offset(uint64 amount) {
+        if ((section_offset + amount) > section_size)
+            amount = section_size - section_offset;
+
+        section_offset += amount;
+        if (null != parent) {
+            parent.advance_section_offset(amount);
+        }
+    }
+
+    public uchar read_byte() throws GLib.Error {
+        advance_section_offset(1);
+        return input.read_byte();
+    }
+
+    public uint16 read_uint16() throws GLib.Error {
+       advance_section_offset(2);
+       return input.read_uint16();
+    }
+
+    public void read_chunk() throws GLib.Error {
+        // don't use checked reads here because they advance the section offset, which we're trying
+        // to determine here
+        GLib.StringBuilder sb = new GLib.StringBuilder();
+        sb.append_c((char) input.read_byte());
+        sb.append_c((char) input.read_byte());
+        sb.append_c((char) input.read_byte());
+        sb.append_c((char) input.read_byte());
+        section_name = sb.str;
+        section_size = input.read_uint32();
+        section_offset = 0;
+    }
+
+    public string read_name() throws GLib.Error {
+        GLib.StringBuilder sb = new GLib.StringBuilder();
+        sb.append_c((char) read_byte());
+        sb.append_c((char) read_byte());
+        sb.append_c((char) read_byte());
+        sb.append_c((char) read_byte());
+        return sb.str;
+    }
+
+    public void next_chunk() throws GLib.Error {
+        skip(section_size_remaining());
+        section_size = 0;
+        section_offset = 0;
+    }
+
+    public string get_current_chunk_name() {
+        return section_name;
+    }
+
+    public bool is_last_chunk() {
+        return section_size == 0;
+    }
+
+    public uint64 section_size_remaining() {
+        assert(section_size >= section_offset);
+        return section_size - section_offset;
+    }
+
+    // Reads section contents into a string.
+    public string section_to_string() throws GLib.Error {
+        GLib.StringBuilder sb = new GLib.StringBuilder();
+        while (section_offset < section_size) {
+            sb.append_c((char) read_byte());
+            if (sb.len > MAX_STRING_TO_SECTION_LENGTH) {
+                return sb.str;
+            }
+        }
+        return sb.str;
+    }
+
+}
diff --git a/src/video-support/AVIMetadataLoader.vala b/src/video-support/AVIMetadataLoader.vala
new file mode 100644
index 0000000..2b507e2
--- /dev/null
+++ b/src/video-support/AVIMetadataLoader.vala
@@ -0,0 +1,227 @@
+public class AVIMetadataLoader {
+
+    private File file = null;
+
+    // A numerical date string, i.e 2010:01:28 14:54:25
+    private const int NUMERICAL_DATE_LENGTH = 19;
+
+    // Marker for timestamp section in a Nikon nctg blob.
+    private const uint16 NIKON_NCTG_TIMESTAMP_MARKER = 0x13;
+
+    // Size limit to ensure we don't parse forever on a bad file.
+    private const int MAX_STRD_LENGTH = 100;
+
+    public AVIMetadataLoader(File file) {
+        this.file = file;
+    }
+
+    public MetadataDateTime? get_creation_date_time() {
+        return new MetadataDateTime(get_creation_date_time_for_avi());
+    }
+
+    public string? get_title() {
+        // Not supported.
+        return null;
+    }
+
+    // Checks if the given file is an AVI file.
+    public bool is_supported() {
+        AVIChunk chunk = new AVIChunk(file);
+        bool ret = false;
+        try {
+            chunk.open_file();
+            chunk.read_chunk();
+            // Look for the header and identifier.
+            if ("RIFF" == chunk.get_current_chunk_name() &&
+                "AVI " == chunk.read_name()) {
+                ret = true;
+            }
+        } catch (GLib.Error e) {
+            debug("Error while testing for AVI file: %s", e.message);
+        }
+
+        try {
+            chunk.close_file();
+        } catch (GLib.Error e) {
+            debug("Error while closing AVI file: %s", e.message);
+        }
+        return ret;
+    }
+
+    // Parses a Nikon nctg tag.  Based losely on avi_read_nikon() in FFmpeg.
+    private string read_nikon_nctg_tag(AVIChunk chunk) throws GLib.Error {
+        bool found_date = false;
+        while (chunk.section_size_remaining() > sizeof(uint16)*2) {
+            uint16 tag = chunk.read_uint16();
+            uint16 size = chunk.read_uint16();
+            if (NIKON_NCTG_TIMESTAMP_MARKER == tag) {
+                found_date = true;
+                break;
+            }
+            chunk.skip(size);
+        }
+
+        if (found_date) {
+            // Read numerical date string, example: 2010:01:28 14:54:25
+            GLib.StringBuilder sb = new GLib.StringBuilder();
+            for (int i = 0; i < NUMERICAL_DATE_LENGTH; i++) {
+                sb.append_c((char) chunk.read_byte());
+            }
+            return sb.str;
+        }
+        return "";
+    }
+
+    // Parses a Fujifilm strd tag. Based on information from:
+    // http://www.eden-foundation.org/products/code/film_date_stamp/index.html
+    private string read_fuji_strd_tag(AVIChunk chunk) throws GLib.Error {
+        chunk.skip(98); // Ignore 98-byte binary blob.
+        chunk.skip(8); // Ignore the string "FUJIFILM"
+        // Read until we find four colons, then two more chars.
+        int colons = 0;
+        int post_colons = 0;
+        GLib.StringBuilder sb = new GLib.StringBuilder();
+        // End of date is two chars past the fourth colon.
+        while (colons <= 4 && post_colons < 2) {
+            char c = (char) chunk.read_byte();
+            if (4 == colons) {
+                post_colons++;
+            }
+            if (':' == c) {
+                colons++;
+            }
+            if (c.isprint()) {
+                sb.append_c(c);
+            }
+            if (sb.len > MAX_STRD_LENGTH) {
+                return ""; // Give up searching.
+            }
+        }
+
+        if (sb.str.length < NUMERICAL_DATE_LENGTH) {
+            return "";
+        }
+        // Date is now at the end of the string.
+        return sb.str.substring(sb.str.length - NUMERICAL_DATE_LENGTH);
+    }
+
+    // Recursively read file until the section is found.
+    private string? read_section(AVIChunk chunk) throws GLib.Error {
+        while (true) {
+            chunk.read_chunk();
+            string name = chunk.get_current_chunk_name();
+            if ("IDIT" == name) {
+                return chunk.section_to_string();
+            } else if ("nctg" == name) {
+                return read_nikon_nctg_tag(chunk);
+            } else if ("strd" == name) {
+                return read_fuji_strd_tag(chunk);
+            }
+
+            if ("LIST" == name) {
+                chunk.read_name(); // Read past list name.
+                string result = read_section(chunk.get_first_child_chunk());
+                if (null != result) {
+                    return result;
+                }
+            }
+
+            if (chunk.is_last_chunk()) {
+                break;
+            }
+            chunk.next_chunk();
+        }
+        return null;
+    }
+
+    // Parses a date from a string.
+    // Largely based on GStreamer's avi/gstavidemux.c
+    // and the information here:
+    // http://www.eden-foundation.org/products/code/film_date_stamp/index.html
+    private DateTime? parse_date(string sdate) {
+        if (sdate.length == 0) {
+            return null;
+        }
+
+        int year, month, day, hour, min, sec;
+        char weekday[4];
+        char monthstr[4];
+        DateTime parsed_date;
+
+        if (sdate[0].isdigit()) {
+            // Format is: 2005:08:17 11:42:43
+            // Format is: 2010/11/30/ 19:42
+            // Format is: 2010/11/30 19:42
+            string tmp = sdate.dup();
+            tmp.canon("0123456789 ", ' '); // strip everything but numbers and spaces
+            sec = 0;
+            int result = tmp.scanf("%d %d %d %d %d %d", out year, out month, out day, out hour, out min, out sec);
+            if(result < 5) {
+                return null;
+            }
+
+            parsed_date = new DateTime.utc(year, month, day, hour, min, sec);
+        } else {
+            // Format is: Mon Mar  3 09:44:56 2008
+            if(7 != sdate.scanf("%3s %3s %d %d:%d:%d %d", weekday, monthstr, out day, out hour,
+                  out min, out sec, out year)) {
+                return null; // Error
+            }
+            parsed_date = new DateTime.local(year, month_from_string((string)monthstr), day, hour, min, sec);
+        }
+
+        return parsed_date;
+    }
+
+    private DateMonth month_from_string(string s) {
+        switch (s.down()) {
+        case "jan":
+            return DateMonth.JANUARY;
+        case "feb":
+            return DateMonth.FEBRUARY;
+        case "mar":
+            return DateMonth.MARCH;
+        case "apr":
+            return DateMonth.APRIL;
+        case "may":
+            return DateMonth.MAY;
+        case "jun":
+            return DateMonth.JUNE;
+        case "jul":
+            return DateMonth.JULY;
+        case "aug":
+            return DateMonth.AUGUST;
+        case "sep":
+            return DateMonth.SEPTEMBER;
+        case "oct":
+            return DateMonth.OCTOBER;
+        case "nov":
+            return DateMonth.NOVEMBER;
+        case "dec":
+            return DateMonth.DECEMBER;
+        }
+        return DateMonth.BAD_MONTH;
+    }
+
+    private DateTime? get_creation_date_time_for_avi() {
+        AVIChunk chunk = new AVIChunk(file);
+        DateTime? timestamp = null;
+        try {
+            chunk.open_file();
+            chunk.nonsection_skip(12); // Advance past 12 byte header.
+            string sdate = read_section(chunk);
+            if (null != sdate) {
+                timestamp = parse_date(sdate.strip());
+            }
+        } catch (GLib.Error e) {
+            debug("Error while reading AVI file: %s", e.message);
+        }
+
+        try {
+            chunk.close_file();
+        } catch (GLib.Error e) {
+            debug("Error while closing AVI file: %s", e.message);
+        }
+        return timestamp;
+    }
+}
diff --git a/src/video-support/QuickTimeAtom.vala b/src/video-support/QuickTimeAtom.vala
new file mode 100644
index 0000000..996046a
--- /dev/null
+++ b/src/video-support/QuickTimeAtom.vala
@@ -0,0 +1,118 @@
+private class QuickTimeAtom {
+    private GLib.File file = null;
+    private string section_name = "";
+    private uint64 section_size = 0;
+    private uint64 section_offset = 0;
+    private GLib.DataInputStream input = null;
+    private QuickTimeAtom? parent = null;
+
+    public QuickTimeAtom(GLib.File file) {
+        this.file = file;
+    }
+
+    private QuickTimeAtom.with_input_stream(GLib.DataInputStream input, QuickTimeAtom parent) {
+        this.input = input;
+        this.parent = parent;
+    }
+
+    public void open_file() throws GLib.Error {
+        close_file();
+        input = new GLib.DataInputStream(file.read());
+        input.set_byte_order(DataStreamByteOrder.BIG_ENDIAN);
+        section_size = 0;
+        section_offset = 0;
+        section_name = "";
+    }
+
+    public void close_file() throws GLib.Error {
+        if (null != input) {
+            input.close();
+            input = null;
+        }
+    }
+
+    private void advance_section_offset(uint64 amount) {
+        section_offset += amount;
+        if (null != parent) {
+            parent.advance_section_offset(amount);
+        }
+    }
+
+    public QuickTimeAtom get_first_child_atom() {
+        // Child will simply have the input stream
+        // but not the size/offset.  This works because
+        // child atoms follow immediately after a header,
+        // so no skipping is required to access the child
+        // from the current position.
+        return new QuickTimeAtom.with_input_stream(input, this);
+    }
+
+    public uchar read_byte() throws GLib.Error {
+        advance_section_offset(1);
+        return input.read_byte();
+    }
+
+    public uint32 read_uint32() throws GLib.Error {
+        advance_section_offset(4);
+        return input.read_uint32();
+    }
+
+    public uint64 read_uint64() throws GLib.Error {
+        advance_section_offset(8);
+        return input.read_uint64();
+    }
+
+    public void read_atom() throws GLib.Error {
+        // Read atom size.
+        section_size = read_uint32();
+
+        // Read atom name.
+        GLib.StringBuilder sb = new GLib.StringBuilder();
+        sb.append_c((char) read_byte());
+        sb.append_c((char) read_byte());
+        sb.append_c((char) read_byte());
+        sb.append_c((char) read_byte());
+        section_name = sb.str;
+
+        // Check string.
+        if (section_name.length != 4) {
+            throw new IOError.NOT_SUPPORTED("QuickTime atom name length is invalid for %s",
+                file.get_path());
+        }
+        for (int i = 0; i < section_name.length; i++) {
+            if (!section_name[i].isprint()) {
+                throw new IOError.NOT_SUPPORTED("Bad QuickTime atom in file %s", file.get_path());
+            }
+        }
+
+        if (1 == section_size) {
+            // This indicates the section size is a 64-bit
+            // value, specified below the atom name.
+            section_size = read_uint64();
+        }
+    }
+
+    private void skip(uint64 skip_amount) throws GLib.Error {
+        skip_uint64(input, skip_amount);
+    }
+
+    public uint64 section_size_remaining() {
+        assert(section_size >= section_offset);
+        return section_size - section_offset;
+    }
+
+    public void next_atom() throws GLib.Error {
+        skip(section_size_remaining());
+        section_size = 0;
+        section_offset = 0;
+    }
+
+    public string get_current_atom_name() {
+        return section_name;
+    }
+
+    public bool is_last_atom() {
+        return 0 == section_size;
+    }
+
+}
diff --git a/src/video-support/QuicktimeMetdataLoader.vala b/src/video-support/QuicktimeMetdataLoader.vala
new file mode 100644
index 0000000..0a831d2
--- /dev/null
+++ b/src/video-support/QuicktimeMetdataLoader.vala
@@ -0,0 +1,127 @@
+public class QuickTimeMetadataLoader {
+
+    // Quicktime calendar date/time format is number of seconds since January 1, 1904.
+    // This converts to UNIX time (66 years + 17 leap days).
+    public const int64 QUICKTIME_EPOCH_ADJUSTMENT = 2082844800;
+
+    private File file = null;
+
+    public QuickTimeMetadataLoader(File file) {
+        this.file = file;
+    }
+
+    public MetadataDateTime? get_creation_date_time() {
+        var dt = get_creation_date_time_for_quicktime();
+        if (dt == null) {
+            return null;
+        } else {
+            return new MetadataDateTime(dt);
+        }
+    }
+
+    public string? get_title() {
+        // Not supported.
+        return null;
+    }
+
+    // Checks if the given file is a QuickTime file.
+    public bool is_supported() {
+        QuickTimeAtom test = new QuickTimeAtom(file);
+
+        bool ret = false;
+        try {
+            test.open_file();
+            test.read_atom();
+
+            // Look for the header.
+            if ("ftyp" == test.get_current_atom_name()) {
+                ret = true;
+            } else {
+                // Some versions of QuickTime don't have
+                // an ftyp section, so we'll just look
+                // for the mandatory moov section.
+                while(true) {
+                    if ("moov" == test.get_current_atom_name()) {
+                        ret = true;
+                        break;
+                    }
+                    test.next_atom();
+                    test.read_atom();
+                    if (test.is_last_atom()) {
+                        break;
+                    }
+                }
+            }
+        } catch (GLib.Error e) {
+            debug("Error while testing for QuickTime file for %s: %s", file.get_path(), e.message);
+        }
+
+        try {
+            test.close_file();
+        } catch (GLib.Error e) {
+            debug("Error while closing Quicktime file: %s", e.message);
+        }
+        return ret;
+    }
+
+    private DateTime? get_creation_date_time_for_quicktime() {
+        QuickTimeAtom test = new QuickTimeAtom(file);
+        DateTime? timestamp = null;
+
+        try {
+            test.open_file();
+            bool done = false;
+            while(!done) {
+                // Look for "moov" section.
+                test.read_atom();
+                if (test.is_last_atom()) break;
+                if ("moov" == test.get_current_atom_name()) {
+                    QuickTimeAtom child = test.get_first_child_atom();
+                    while (!done) {
+                        // Look for "mvhd" section, or break if none is found.
+                        child.read_atom();
+                        if (child.is_last_atom() || 0 == child.section_size_remaining()) {
+                            done = true;
+                            break;
+                        }
+
+                        if ("mvhd" == child.get_current_atom_name()) {
+                            // Skip 4 bytes (version + flags)
+                            child.read_uint32();
+                            // Grab the timestamp.
+
+                            // Some Android phones package videos recorded with their internal cameras in a 3GP
+                            // container that looks suspiciously like a QuickTime container but really isn't -- for
+                            // the timestamps of these Android 3GP videos are relative to the UNIX epoch
+                            // (January 1, 1970) instead of the QuickTime epoch (January 1, 1904). So, if we detect a
+                            // QuickTime movie with a negative timestamp, we can be pretty sure it isn't a valid
+                            // QuickTime movie that was shot before 1904 but is instead a non-compliant 3GP video
+                            // file. If we detect such a video, we correct its time. See this Redmine ticket
+                            // (https://bugzilla.gnome.org/show_bug.cgi?id=717384) for more information.
+
+                            if ((child.read_uint32() - QUICKTIME_EPOCH_ADJUSTMENT) < 0) {
+                                timestamp = new DateTime.from_unix_utc(child.read_uint32());
+                            } else {
+                                timestamp = new DateTime.from_unix_utc(child.read_uint32() - QUICKTIME_EPOCH_ADJUSTMENT);
+                            }
+                            done = true;
+                            break;
+                        }
+                        child.next_atom();
+                    }
+                }
+                test.next_atom();
+            }
+        } catch (GLib.Error e) {
+            debug("Error while testing for QuickTime file: %s", e.message);
+        }
+
+        try {
+            test.close_file();
+        } catch (GLib.Error e) {
+            debug("Error while closing Quicktime file: %s", e.message);
+        }
+
+        return timestamp;
+    }
+}
diff --git a/src/VideoSupport.vala b/src/video-support/Video.vala
index ec827ea..0238d7f 100644
--- a/src/VideoSupport.vala
+++ b/src/video-support/Video.vala
@@ -4,352 +4,32 @@
  * See the COPYING file in this distribution.
  */
 
-public errordomain VideoError {
-    FILE,          // there's a problem reading the video container file (doesn't exist, no read
-                   // permission, etc.)
-
-    CONTENTS,      // we can read the container file but its contents are indecipherable (no codec,
-                   // malformed data, etc.)
-}
-
-public class VideoImportParams {
-    // IN:
-    public File file;
-    public ImportID import_id = ImportID();
-    public string? md5;
-    public time_t exposure_time_override;
-    
-    // IN/OUT:
-    public Thumbnails? thumbnails;
-    
-    // OUT:
-    public VideoRow row = new VideoRow();
-    
-    public VideoImportParams(File file, ImportID import_id, string? md5,
-        Thumbnails? thumbnails = null, time_t exposure_time_override = 0) {
-        this.file = file;
-        this.import_id = import_id;
-        this.md5 = md5;
-        this.thumbnails = thumbnails;
-        this.exposure_time_override = exposure_time_override;
-    }
-}
-
-public class VideoReader {
-    private const double UNKNOWN_CLIP_DURATION = -1.0;
-    private const uint THUMBNAILER_TIMEOUT = 10000; // In milliseconds.
-
-    // File extensions for video containers that pack only metadata as per the AVCHD spec
-    private const string[] METADATA_ONLY_FILE_EXTENSIONS = { "bdm", "bdmv", "cpi", "mpl" };
-    
-    private double clip_duration = UNKNOWN_CLIP_DURATION;
-    private Gdk.Pixbuf preview_frame = null;
-    private File file = null;
-    private GLib.Pid thumbnailer_pid = 0;
-    public DateTime? timestamp { get; private set; default = null; }
-
-    public VideoReader(File file) {
-        this.file = file;
-     }
-    
-    public static bool is_supported_video_file(File file) {
-        var mime_type = ContentType.guess(file.get_basename(), new uchar[0], null);
-        // special case: deep-check content-type of files ending with .ogg
-        if (mime_type == "audio/ogg" && file.has_uri_scheme("file")) {
-            try {
-                var info = file.query_info(FileAttribute.STANDARD_CONTENT_TYPE,
-                                           FileQueryInfoFlags.NONE);
-                var content_type = info.get_content_type();
-                if (content_type != null && content_type.has_prefix ("video/")) {
-                    return true;
-                }
-            } catch (Error error) {
-                debug("Failed to query content type: %s", error.message);
-            }
-        }
-
-        return is_supported_video_filename(file.get_basename());
-    }
-
-    public static bool is_supported_video_filename(string filename) {
-        string mime_type;
-        mime_type = ContentType.guess(filename, new uchar[0], null);
-        // Guessed mp4 from filename has application/ as prefix, so check for mp4 in the end
-        if (mime_type.has_prefix ("video/") || mime_type.has_suffix("mp4")) {
-            string? extension = null;
-            string? name = null;
-            disassemble_filename(filename, out name, out extension);
-
-            if (extension == null)
-                return true;
-
-            foreach (string s in METADATA_ONLY_FILE_EXTENSIONS) {
-                if (utf8_ci_compare(s, extension) == 0)
-                    return false;
-            }
-
-            return true;
-        } else {
-            debug("Skipping %s, unsupported mime type %s", filename, mime_type);
-            return false;
-        }
-    }
-    
-    public static ImportResult prepare_for_import(VideoImportParams params) {
-#if MEASURE_IMPORT
-        Timer total_time = new Timer();
-#endif
-        File file = params.file;
-        
-        FileInfo info = null;
-        try {
-            info = file.query_info(DirectoryMonitor.SUPPLIED_ATTRIBUTES,
-                FileQueryInfoFlags.NOFOLLOW_SYMLINKS, null);
-        } catch (Error err) {
-            return ImportResult.FILE_ERROR;
-        }
-        
-        if (info.get_file_type() != FileType.REGULAR)
-            return ImportResult.NOT_A_FILE;
-        
-        if (!is_supported_video_file(file)) {
-            message("Not importing %s: file is marked as a video file but doesn't have a" +
-                "supported extension", file.get_path());
-            
-            return ImportResult.UNSUPPORTED_FORMAT;
-        }
-        
-        TimeVal timestamp = info.get_modification_time();
-        
-        // make sure params has a valid md5
-        assert(params.md5 != null);
-
-        time_t exposure_time = params.exposure_time_override;
-        string title = "";
-        string comment = "";
-        
-        VideoReader reader = new VideoReader(file);
-        bool is_interpretable = true;
-        double clip_duration = 0.0;
-        Gdk.Pixbuf preview_frame = reader.read_preview_frame();
-        try {
-            clip_duration = reader.read_clip_duration();
-        } catch (VideoError err) {
-            if (err is VideoError.FILE) {
-                return ImportResult.FILE_ERROR;
-            } else if (err is VideoError.CONTENTS) {
-                is_interpretable = false;
-                clip_duration = 0.0;
-            } else {
-                error("can't prepare video for import: an unknown kind of video error occurred");
-            }
-        }
-        
-        try {
-            VideoMetadata metadata = reader.read_metadata();
-            MetadataDateTime? creation_date_time = metadata.get_creation_date_time();
-            
-            if (creation_date_time != null && creation_date_time.get_timestamp() != 0)
-                exposure_time = creation_date_time.get_timestamp();
-            
-            string? video_title = metadata.get_title();
-            string? video_comment = metadata.get_comment();
-            if (video_title != null)
-                title = video_title;
-            if (video_comment != null)
-                comment = video_comment;
-        } catch (Error err) {
-            warning("Unable to read video metadata: %s", err.message);
-        }
-        
-        if (exposure_time == 0) {
-            // Use time reported by Gstreamer, if available.
-            exposure_time = (time_t) (reader.timestamp != null ? 
-                reader.timestamp.to_unix() : 0);
-        }
-        
-        params.row.video_id = VideoID();
-        params.row.filepath = file.get_path();
-        params.row.filesize = info.get_size();
-        params.row.timestamp = timestamp.tv_sec;
-        params.row.width = preview_frame.width;
-        params.row.height = preview_frame.height;
-        params.row.clip_duration = clip_duration;
-        params.row.is_interpretable = is_interpretable;
-        params.row.exposure_time = exposure_time;
-        params.row.import_id = params.import_id;
-        params.row.event_id = EventID();
-        params.row.md5 = params.md5;
-        params.row.time_created = 0;
-        params.row.title = title;
-        params.row.comment = comment;
-        params.row.backlinks = "";
-        params.row.time_reimported = 0;
-        params.row.flags = 0;
-
-        if (params.thumbnails != null) {
-            params.thumbnails = new Thumbnails();
-            ThumbnailCache.generate_for_video_frame(params.thumbnails, preview_frame);
-        }
-        
-#if MEASURE_IMPORT
-        debug("IMPORT: total time to import video = %lf", total_time.elapsed());
-#endif
-        return ImportResult.SUCCESS;
-    }
-    
-    private void read_internal() throws VideoError {
-        if (!does_file_exist())
-            throw new VideoError.FILE("video file '%s' does not exist or is inaccessible".printf(
-                file.get_path()));
-        
-        try {
-            Gst.PbUtils.Discoverer d = new Gst.PbUtils.Discoverer((Gst.ClockTime) (Gst.SECOND * 5));
-            Gst.PbUtils.DiscovererInfo info = d.discover_uri(file.get_uri());
-            
-            clip_duration = ((double) info.get_duration()) / 1000000000.0;
-            
-            // Get creation time.
-            // TODO: Note that TAG_DATE can be changed to TAG_DATE_TIME in the future
-            // (and the corresponding output struct) in order to implement #2836.
-            Date? video_date = null;
-            if (info.get_tags() != null && info.get_tags().get_date(Gst.Tags.DATE, out video_date)) {
-                // possible for get_date() to return true and a null Date
-                if (video_date != null) {
-                    timestamp = new DateTime.local(video_date.get_year(), video_date.get_month(),
-                        video_date.get_day(), 0, 0, 0);
-                }
-            }
-        } catch (Error e) {
-            debug("Video read error: %s", e.message);
-            throw new VideoError.CONTENTS("GStreamer couldn't extract clip information: %s"
-                .printf(e.message));
-        }
-    }
-    
-    // Used by thumbnailer() to kill the external process if need be.
-    private bool on_thumbnailer_timer() {
-        debug("Thumbnailer timer called");
-        if (thumbnailer_pid != 0) {
-            debug("Killing thumbnailer process: %d", thumbnailer_pid);
-#if VALA_0_40
-            Posix.kill(thumbnailer_pid, Posix.Signal.KILL);
-#else
-            Posix.kill(thumbnailer_pid, Posix.SIGKILL);
-#endif
-        }
-        return false; // Don't call again.
-    }
-    
-    // Performs video thumbnailing.
-    // Note: not thread-safe if called from the same instance of the class.
-    private Gdk.Pixbuf? thumbnailer(string video_file) {
-        // Use Shotwell's thumbnailer, redirect output to stdout.
-        debug("Launching thumbnailer process: %s", AppDirs.get_thumbnailer_bin().get_path());
-        string[] argv = {AppDirs.get_thumbnailer_bin().get_path(), video_file};
-        int child_stdout;
-        try {
-            GLib.Process.spawn_async_with_pipes(null, argv, null, GLib.SpawnFlags.SEARCH_PATH | 
-                GLib.SpawnFlags.DO_NOT_REAP_CHILD, null, out thumbnailer_pid, null, out child_stdout,
-                null);
-            debug("Spawned thumbnailer, child pid: %d", (int) thumbnailer_pid);
-        } catch (Error e) {
-            debug("Error spawning process: %s", e.message);
-            if (thumbnailer_pid != 0)
-                GLib.Process.close_pid(thumbnailer_pid);
-            return null;
-        }
-        
-        // Start timer.
-        Timeout.add(THUMBNAILER_TIMEOUT, on_thumbnailer_timer);
-        
-        // Read pixbuf from stream.
-        Gdk.Pixbuf? buf = null;
-        try {
-            GLib.UnixInputStream unix_input = new GLib.UnixInputStream(child_stdout, true);
-            buf = new Gdk.Pixbuf.from_stream(unix_input, null);
-        } catch (Error e) {
-            debug("Error creating pixbuf: %s", e.message);
-            buf = null;
-        }
-        
-        // Make sure process exited properly.
-        int child_status = 0;
-        int ret_waitpid = Posix.waitpid(thumbnailer_pid, out child_status, 0);
-        if (ret_waitpid < 0) {
-            debug("waitpid returned error code: %d", ret_waitpid);
-            buf = null;
-        } else if (0 != Process.exit_status(child_status)) {
-            debug("Thumbnailer exited with error code: %d",
-                    Process.exit_status(child_status));
-            buf = null;
-        }
-        
-        GLib.Process.close_pid(thumbnailer_pid);
-        thumbnailer_pid = 0;
-        return buf;
-    }
-    
-    private bool does_file_exist() {
-        return FileUtils.test(file.get_path(), FileTest.EXISTS | FileTest.IS_REGULAR);
-    }
-    
-    public Gdk.Pixbuf? read_preview_frame() {
-        if (preview_frame != null)
-            return preview_frame;
-        
-        if (!does_file_exist())
-            return null;
-        
-        // Get preview frame from thumbnailer.
-        preview_frame = thumbnailer(file.get_path());
-        if (null == preview_frame)
-            preview_frame = Resources.get_noninterpretable_badge_pixbuf();
-        
-        return preview_frame;
-    }
-    
-    public double read_clip_duration() throws VideoError {
-        if (clip_duration == UNKNOWN_CLIP_DURATION)
-            read_internal();
-
-        return clip_duration;
-    }
-    
-    public VideoMetadata read_metadata() throws Error {
-        VideoMetadata metadata = new VideoMetadata();
-        metadata.read_from_file(File.new_for_path(file.get_path()));
-        
-        return metadata;
-    }
-}
-
 public class Video : VideoSource, Flaggable, Monitorable, Dateable {
     public const string TYPENAME = "video";
-    
+
     public const uint64 FLAG_TRASH =    0x0000000000000001;
     public const uint64 FLAG_OFFLINE =  0x0000000000000002;
     public const uint64 FLAG_FLAGGED =  0x0000000000000004;
-    
+
     public class InterpretableResults {
         internal Video video;
         internal bool update_interpretable = false;
         internal bool is_interpretable = false;
         internal Gdk.Pixbuf? new_thumbnail = null;
-        
+
         public InterpretableResults(Video video) {
             this.video = video;
         }
-        
+
         public void foreground_finish() {
             if (update_interpretable)
                 video.set_is_interpretable(is_interpretable);
-            
+
             if (new_thumbnail != null) {
                 try {
                     ThumbnailCache.replace(video, ThumbnailCache.Size.BIG, new_thumbnail);
                     ThumbnailCache.replace(video, ThumbnailCache.Size.MEDIUM, new_thumbnail);
-                    
+
                     video.notify_thumbnail_altered();
                 } catch (Error err) {
                     message("Unable to update video thumbnails for %s: %s", video.to_string(),
@@ -358,19 +38,19 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
             }
         }
     }
-    
+
     private static bool normal_regen_complete;
     private static bool offline_regen_complete;
     public static VideoSourceCollection global;
 
     private VideoRow backing_row;
-    
+
     public Video(VideoRow row) {
         this.backing_row = row;
-        
+
         // normalize user text
         this.backing_row.title = prep_title(this.backing_row.title);
-        
+
         if (((row.flags & FLAG_TRASH) != 0) || ((row.flags & FLAG_OFFLINE) != 0))
             rehydrate_backlinks(global, row.backlinks);
     }
@@ -381,7 +61,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
         //       https://bugzilla.gnome.org/show_bug.cgi?id=655594
         normal_regen_complete = false;
         offline_regen_complete = false;
-    
+
         // initialize GStreamer, but don't pass it our actual command line arguments -- we don't
         // want our end users to be able to parameterize the GStreamer configuration
         unowned string[] args = null;
@@ -404,7 +84,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
         }
 
         global = new VideoSourceCollection();
-        
+
         Gee.ArrayList<VideoRow?> all = VideoTable.get_instance().get_all();
         Gee.ArrayList<Video> all_videos = new Gee.ArrayList<Video>();
         Gee.ArrayList<Video> trashed_videos = new Gee.ArrayList<Video>();
@@ -412,14 +92,14 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
         int count = all.size;
         for (int ctr = 0; ctr < count; ctr++) {
             Video video = new Video(all.get(ctr));
-            
+
             if (video.is_trashed())
                 trashed_videos.add(video);
             else if (video.is_offline())
                 offline_videos.add(video);
             else
                 all_videos.add(video);
-            
+
             if (monitor != null)
                 monitor(ctr, count);
         }
@@ -428,7 +108,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
         global.add_many_to_offline(offline_videos);
         global.add_many(all_videos);
     }
-    
+
     public static void notify_normal_thumbs_regenerated() {
         if (normal_regen_complete)
             return;
@@ -449,12 +129,12 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
 
     public static void terminate() {
     }
-    
+
     public static ExporterUI? export_many(Gee.Collection<Video> videos, Exporter.CompletionCallback done,
-        bool export_in_place = false) {       
+        bool export_in_place = false) {
         if (videos.size == 0)
             return null;
-        
+
         // in place export is relatively easy -- provide a fast, separate code path for it
         if (export_in_place) {
              ExporterUI temp_exporter = new ExporterUI(new Exporter.for_temp_file(videos,
@@ -470,11 +150,11 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
                 video = v;
                 break;
             }
-            
+
             File save_as = ExportUI.choose_file(video.get_basename());
             if (save_as == null)
                 return null;
-            
+
             try {
                 AppWindow.get_instance().set_busy_cursor();
                 video.export(save_as);
@@ -483,7 +163,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
                 AppWindow.get_instance().set_normal_cursor();
                 export_error_dialog(save_as, false);
             }
-            
+
             return null;
         }
 
@@ -491,7 +171,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
         File export_dir = ExportUI.choose_dir(_("Export Videos"));
         if (export_dir == null)
             return null;
-        
+
         ExporterUI exporter = new ExporterUI(new Exporter(videos, export_dir,
             Scaling.for_original(), ExportFormatParameters.unmodified()));
         exporter.export(done);
@@ -499,7 +179,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
         return exporter;
     }
 
-    protected override void commit_backlinks(SourceCollection? sources, string? backlinks) {        
+    protected override void commit_backlinks(SourceCollection? sources, string? backlinks) {
         try {
             VideoTable.get_instance().update_backlinks(get_video_id(), backlinks);
             lock (backing_row) {
@@ -529,10 +209,10 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
         return false;
 #endif
     }
-    
+
     public static ImportResult import_create(VideoImportParams params, out Video video) {
         video = null;
-        
+
         // add to the database
         try {
             if (VideoTable.get_instance().add(params.row).is_invalid())
@@ -540,13 +220,13 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
         } catch (DatabaseError err) {
             return ImportResult.DATABASE_ERROR;
         }
-        
+
         // create local object but don't add to global until thumbnails generated
         video = new Video(params.row);
 
         return ImportResult.SUCCESS;
     }
-    
+
     public static void import_failed(Video video) {
         try {
             VideoTable.get_instance().remove(video.get_video_id());
@@ -554,17 +234,17 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
             AppWindow.database_error(err);
         }
     }
-    
+
     public override BackingFileState[] get_backing_files_state() {
         BackingFileState[] backing = new BackingFileState[1];
         lock (backing_row) {
-            backing[0] = new BackingFileState(backing_row.filepath, backing_row.filesize, 
+            backing[0] = new BackingFileState(backing_row.filepath, backing_row.filesize,
                 backing_row.timestamp, backing_row.md5);
         }
-        
+
         return backing;
     }
-    
+
     public override Gdk.Pixbuf? get_thumbnail(int scale) throws Error {
         return ThumbnailCache.fetch(this, scale);
     }
@@ -577,21 +257,21 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
 
     public override Gdk.Pixbuf get_preview_pixbuf(Scaling scaling) throws Error {
         Gdk.Pixbuf pixbuf = get_thumbnail(ThumbnailCache.Size.BIG);
-        
+
         return scaling.perform_on_pixbuf(pixbuf, Gdk.InterpType.NEAREST, true);
     }
 
     public override Gdk.Pixbuf? create_thumbnail(int scale) throws Error {
         VideoReader reader = new VideoReader(get_file());
         Gdk.Pixbuf? frame = reader.read_preview_frame();
-        
+
         return (frame != null) ? frame : Resources.get_noninterpretable_badge_pixbuf().copy();
     }
-    
+
     public override string get_typename() {
         return TYPENAME;
     }
-    
+
     public override int64 get_instance_id() {
         return get_video_id().id;
     }
@@ -605,7 +285,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
     public override PhotoFileFormat get_preferred_thumbnail_format() {
         return PhotoFileFormat.get_system_default_format();
     }
-    
+
     public override string? get_title() {
         lock (backing_row) {
             return backing_row.title;
@@ -614,7 +294,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
 
     public override void set_title(string? title) {
         string? new_title = prep_title(title);
-        
+
         lock (backing_row) {
             if (backing_row.title == new_title)
                 return;
@@ -641,7 +321,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
 
     public override bool set_comment(string? comment) {
         string? new_comment = prep_title(comment);
-        
+
         lock (backing_row) {
             if (backing_row.comment == new_comment)
                 return true;
@@ -656,7 +336,7 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
             // successfully committed to the database, so update it in the in-memory row cache
             backing_row.comment = new_comment;
         }
-        
+
         notify_altered(new Alteration("metadata", "comment"));
 
         return true;
@@ -711,10 +391,10 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
     public override void mark_offline() {
         add_flags(FLAG_OFFLINE);
     }
-    
+
     public override void mark_online() {
         remove_flags(FLAG_OFFLINE);
-        
+
         if ((!get_is_interpretable()))
             check_is_interpretable().foreground_finish();
     }
@@ -722,48 +402,48 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
     public override void trash() {
         add_flags(FLAG_TRASH);
     }
-    
+
     public override void untrash() {
         remove_flags(FLAG_TRASH);
     }
-    
+
     public bool is_flagged() {
         return is_flag_set(FLAG_FLAGGED);
     }
-    
+
     public void mark_flagged() {
         add_flags(FLAG_FLAGGED, new Alteration("metadata", "flagged"));
     }
-    
+
     public void mark_unflagged() {
         remove_flags(FLAG_FLAGGED, new Alteration("metadata", "flagged"));
     }
-    
+
     public override EventID get_event_id() {
         lock (backing_row) {
             return backing_row.event_id;
         }
     }
-    
+
     public override string to_string() {
         lock (backing_row) {
             return "[%s] %s".printf(backing_row.video_id.id.to_string(), backing_row.filepath);
         }
     }
-    
+
     public VideoID get_video_id() {
         lock (backing_row) {
             return backing_row.video_id;
         }
     }
-    
-    public override time_t get_exposure_time() {
+
+    public override DateTime? get_exposure_time() {
         lock (backing_row) {
             return backing_row.exposure_time;
         }
     }
-    
-    public void set_exposure_time(time_t time) {
+
+    public void set_exposure_time(DateTime time) {
         lock (backing_row) {
             try {
                 VideoTable.get_instance().set_exposure_time(backing_row.video_id, time);
@@ -772,10 +452,10 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
             }
             backing_row.exposure_time = time;
         }
-        
+
         notify_altered(new Alteration("metadata", "exposure-time"));
-    }    
-    
+    }
+
     public Dimensions get_frame_dimensions() {
         lock (backing_row) {
             return Dimensions(backing_row.width, backing_row.height);
@@ -785,99 +465,99 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
     public override Dimensions get_dimensions(Photo.Exception disallowed_steps = Photo.Exception.NONE) {
         return get_frame_dimensions();
     }
-    
+
     public override uint64 get_filesize() {
         return get_master_filesize();
     }
-    
+
     public override uint64 get_master_filesize() {
         lock (backing_row) {
             return backing_row.filesize;
         }
     }
-    
-    public override time_t get_timestamp() {
+
+    public override DateTime? get_timestamp() {
         lock (backing_row) {
             return backing_row.timestamp;
         }
     }
-    
+
     public void set_master_timestamp(FileInfo info) {
-        TimeVal time_val = info.get_modification_time();
-        
+        var time_val = info.get_modification_date_time();
+
         try {
             lock (backing_row) {
-                if (backing_row.timestamp == time_val.tv_sec)
+                if (backing_row.timestamp.equal(time_val))
                     return;
-                
-                VideoTable.get_instance().set_timestamp(backing_row.video_id, time_val.tv_sec);
-                backing_row.timestamp = time_val.tv_sec;
+
+                VideoTable.get_instance().set_timestamp(backing_row.video_id, time_val);
+                backing_row.timestamp = time_val;
             }
-        } catch (DatabaseError err) {
+        } catch (Error err) {
             AppWindow.database_error(err);
-            
+
             return;
         }
-        
+
         notify_altered(new Alteration("metadata", "master-timestamp"));
     }
-    
+
     public string get_filename() {
         lock (backing_row) {
             return backing_row.filepath;
         }
     }
-    
+
     public override File get_file() {
         return File.new_for_path(get_filename());
     }
-    
+
     public override File get_master_file() {
         return get_file();
     }
-    
+
     public void export(File dest_file) throws Error {
         File source_file = File.new_for_path(get_filename());
         source_file.copy(dest_file, FileCopyFlags.OVERWRITE | FileCopyFlags.TARGET_DEFAULT_PERMS,
             null, null);
     }
-    
+
     public double get_clip_duration() {
         lock (backing_row) {
             return backing_row.clip_duration;
         }
     }
-    
+
     public bool get_is_interpretable() {
         lock (backing_row) {
             return backing_row.is_interpretable;
         }
     }
-    
+
     private void set_is_interpretable(bool is_interpretable) {
         lock (backing_row) {
             if (backing_row.is_interpretable == is_interpretable)
                 return;
-            
+
             backing_row.is_interpretable = is_interpretable;
         }
-        
+
         try {
             VideoTable.get_instance().update_is_interpretable(get_video_id(), is_interpretable);
         } catch (DatabaseError e) {
             AppWindow.database_error(e);
         }
     }
-    
+
     // Intended to be called from a background thread but can be called from foreground as well.
     // Caller should call InterpretableResults.foreground_process() only from foreground thread,
     // however
     public InterpretableResults check_is_interpretable() {
         InterpretableResults results = new InterpretableResults(this);
-        
+
         double clip_duration = -1.0;
         Gdk.Pixbuf? preview_frame = null;
-        
+
         VideoReader backing_file_reader = new VideoReader(get_file());
         try {
             clip_duration = backing_file_reader.read_clip_duration();
@@ -887,111 +567,111 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
             // non-interpretable (e.g. its codec is not present on the users system).
             results.update_interpretable = get_is_interpretable();
             results.is_interpretable = false;
-            
+
             return results;
         }
-        
+
         // if already marked interpretable, this is only confirming what we already knew
         if (get_is_interpretable()) {
             results.update_interpretable = false;
             results.is_interpretable = true;
-            
+
             return results;
         }
-        
+
         debug("video %s has become interpretable", get_file().get_basename());
-        
+
         // save this here, this can be done in background thread
         lock (backing_row) {
             backing_row.clip_duration = clip_duration;
         }
-        
+
         results.update_interpretable = true;
         results.is_interpretable = true;
         results.new_thumbnail = preview_frame;
-        
+
         return results;
     }
-    
+
     public override void destroy() {
         VideoID video_id = get_video_id();
 
         ThumbnailCache.remove(this);
-        
+
         try {
             VideoTable.get_instance().remove(video_id);
         } catch (DatabaseError err) {
             error("failed to remove video %s from video table", to_string());
         }
-        
+
         base.destroy();
     }
 
     protected override bool internal_delete_backing() throws Error {
         bool ret = delete_original_file();
-        
+
         // Return false if parent method failed.
         return base.internal_delete_backing() && ret;
     }
-    
+
     private void notify_flags_altered(Alteration? additional_alteration) {
         Alteration alteration = new Alteration("metadata", "flags");
         if (additional_alteration != null)
             alteration = alteration.compress(additional_alteration);
-        
+
         notify_altered(alteration);
     }
-    
+
     public uint64 add_flags(uint64 flags_to_add, Alteration? additional_alteration = null) {
         uint64 new_flags;
         lock (backing_row) {
             new_flags = internal_add_flags(backing_row.flags, flags_to_add);
             if (backing_row.flags == new_flags)
                 return backing_row.flags;
-            
+
             try {
                 VideoTable.get_instance().set_flags(get_video_id(), new_flags);
             } catch (DatabaseError e) {
                 AppWindow.database_error(e);
                 return backing_row.flags;
             }
-            
+
             backing_row.flags = new_flags;
         }
-        
+
         notify_flags_altered(additional_alteration);
-        
+
         return new_flags;
     }
-    
+
     public uint64 remove_flags(uint64 flags_to_remove, Alteration? additional_alteration = null) {
         uint64 new_flags;
         lock (backing_row) {
             new_flags = internal_remove_flags(backing_row.flags, flags_to_remove);
             if (backing_row.flags == new_flags)
                 return backing_row.flags;
-            
+
             try {
                 VideoTable.get_instance().set_flags(get_video_id(), new_flags);
             } catch (DatabaseError e) {
                 AppWindow.database_error(e);
                 return backing_row.flags;
             }
-            
+
             backing_row.flags = new_flags;
         }
-        
+
         notify_flags_altered(additional_alteration);
-        
+
         return new_flags;
     }
-    
+
     public bool is_flag_set(uint64 flag) {
         lock (backing_row) {
             return internal_is_flag_set(backing_row.flags, flag);
         }
     }
-    
+
     public void set_master_file(File file) {
         string new_filepath = file.get_path();
         string? old_filepath = null;
@@ -999,195 +679,25 @@ public class Video : VideoSource, Flaggable, Monitorable, Dateable {
             lock (backing_row) {
                 if (backing_row.filepath == new_filepath)
                     return;
-                
+
                 old_filepath = backing_row.filepath;
-                
+
                 VideoTable.get_instance().set_filepath(backing_row.video_id, new_filepath);
                 backing_row.filepath = new_filepath;
             }
-        } catch (DatabaseError err) {
+        } catch (Error err) {
             AppWindow.database_error(err);
-            
+
             return;
         }
-        
+
         assert(old_filepath != null);
         notify_master_replaced(File.new_for_path(old_filepath), file);
-        
+
         notify_altered(new Alteration.from_list("backing:master,metadata:name"));
     }
-    
+
     public VideoMetadata read_metadata() throws Error {
         return (new VideoReader(get_file())).read_metadata();
     }
 }
-
-public class VideoSourceCollection : MediaSourceCollection {
-    public enum State {
-        UNKNOWN,
-        ONLINE,
-        OFFLINE,
-        TRASH
-    }
-    
-    public override TransactionController transaction_controller {
-        get {
-            if (_transaction_controller == null)
-                _transaction_controller = new MediaSourceTransactionController(this);
-            
-            return _transaction_controller;
-        }
-    }
-    
-    private TransactionController _transaction_controller = null;
-    private Gee.MultiMap<uint64?, Video> filesize_to_video =
-        new Gee.TreeMultiMap<uint64?, Video>(uint64_compare);
-    
-    public VideoSourceCollection() {
-        base("VideoSourceCollection", get_video_key);
-
-        get_trashcan().contents_altered.connect(on_trashcan_contents_altered);
-        get_offline_bin().contents_altered.connect(on_offline_contents_altered);
-    }
-    
-    protected override MediaSourceHoldingTank create_trashcan() {
-        return new MediaSourceHoldingTank(this, is_video_trashed, get_video_key);
-    }
-    
-    protected override MediaSourceHoldingTank create_offline_bin() {
-        return new MediaSourceHoldingTank(this, is_video_offline, get_video_key);
-    }
-    
-    public override MediaMonitor create_media_monitor(Workers workers, Cancellable cancellable) {
-        return new VideoMonitor(cancellable);
-    }
-    
-    public override bool holds_type_of_source(DataSource source) {
-        return source is Video;
-    }
-    
-    public override string get_typename() {
-        return Video.TYPENAME;
-    }
-    
-    public override bool is_file_recognized(File file) {
-        return VideoReader.is_supported_video_file(file);
-    }
-    
-    private void on_trashcan_contents_altered(Gee.Collection<DataSource>? added,
-        Gee.Collection<DataSource>? removed) {
-        trashcan_contents_altered((Gee.Collection<Video>?) added,
-            (Gee.Collection<Video>?) removed);
-    }
-
-    private void on_offline_contents_altered(Gee.Collection<DataSource>? added,
-        Gee.Collection<DataSource>? removed) {
-        offline_contents_altered((Gee.Collection<Video>?) added,
-            (Gee.Collection<Video>?) removed);
-    }
-
-    protected override MediaSource? fetch_by_numeric_id(int64 numeric_id) {
-        return fetch(VideoID(numeric_id));
-    }
-
-    public static int64 get_video_key(DataSource source) {
-        Video video = (Video) source;
-        VideoID video_id = video.get_video_id();
-        
-        return video_id.id;
-    }
-    
-    public static bool is_video_trashed(DataSource source) {
-        return ((Video) source).is_trashed();
-    }
-    
-    public static bool is_video_offline(DataSource source) {
-        return ((Video) source).is_offline();
-    }
-    
-    public Video fetch(VideoID video_id) {
-        return (Video) fetch_by_key(video_id.id);
-    }
-    
-    public override Gee.Collection<string> get_event_source_ids(EventID event_id){
-        return VideoTable.get_instance().get_event_source_ids(event_id);
-    }
-    
-    public Video? get_state_by_file(File file, out State state) {
-        Video? video = (Video?) fetch_by_master_file(file);
-        if (video != null) {
-            state = State.ONLINE;
-            
-            return video;
-        }
-        
-        video = (Video?) get_trashcan().fetch_by_master_file(file);
-        if (video != null) {
-            state = State.TRASH;
-            
-            return video;
-        }
-        
-        video = (Video?) get_offline_bin().fetch_by_master_file(file);
-        if (video != null) {
-            state = State.OFFLINE;
-            
-            return video;
-        }
-        
-        state = State.UNKNOWN;
-        
-        return null;
-    }
-    
-    private void compare_backing(Video video, FileInfo info, Gee.Collection<Video> matching_master) {
-        if (video.get_filesize() != info.get_size())
-            return;
-        
-        if (video.get_timestamp() == info.get_modification_time().tv_sec)
-            matching_master.add(video);
-    }
-    
-    public void fetch_by_matching_backing(FileInfo info, Gee.Collection<Video> matching_master) {
-        foreach (DataObject object in get_all())
-            compare_backing((Video) object, info, matching_master);
-        
-        foreach (MediaSource media in get_offline_bin_contents())
-            compare_backing((Video) media, info, matching_master);
-    }
-    
-    protected override void notify_contents_altered(Gee.Iterable<DataObject>? added,
-        Gee.Iterable<DataObject>? removed) {
-        if (added != null) {
-            foreach (DataObject object in added) {
-                Video video = (Video) object;
-                
-                filesize_to_video.set(video.get_master_filesize(), video);
-            }
-        }
-        
-        if (removed != null) {
-            foreach (DataObject object in removed) {
-                Video video = (Video) object;
-                
-                filesize_to_video.remove(video.get_master_filesize(), video);
-            }
-        }
-        
-        base.notify_contents_altered(added, removed);
-    }
-    
-    public VideoID get_basename_filesize_duplicate(string basename, uint64 filesize) {
-        foreach (Video video in filesize_to_video.get(filesize)) {
-            if (utf8_ci_compare(video.get_master_file().get_basename(), basename) == 0)
-                return video.get_video_id();
-        }
-        
-        return VideoID(); // the default constructor of the VideoID struct creates an invalid
-                          // video id, which is just what we want in this case
-    }
-    
-    public bool has_basename_filesize_duplicate(string basename, uint64 filesize) {
-        return get_basename_filesize_duplicate(basename, filesize).is_valid();
-    }
-}
diff --git a/src/video-support/VideoImportParams.vala b/src/video-support/VideoImportParams.vala
new file mode 100644
index 0000000..6804c53
--- /dev/null
+++ b/src/video-support/VideoImportParams.vala
@@ -0,0 +1,28 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+public class VideoImportParams {
+    // IN:
+    public File file;
+    public ImportID import_id = ImportID();
+    public string? md5;
+    public DateTime? exposure_time_override;
+
+    // IN/OUT:
+    public Thumbnails? thumbnails;
+
+    // OUT:
+    public VideoRow row = new VideoRow();
+
+    public VideoImportParams(File file, ImportID import_id, string? md5,
+        Thumbnails? thumbnails = null, DateTime? exposure_time_override = null) {
+        this.file = file;
+        this.import_id = import_id;
+        this.md5 = md5;
+        this.thumbnails = thumbnails;
+        this.exposure_time_override = exposure_time_override;
+    }
+}
diff --git a/src/video-support/VideoMetadata.vala b/src/video-support/VideoMetadata.vala
new file mode 100644
index 0000000..02580f8
--- /dev/null
+++ b/src/video-support/VideoMetadata.vala
@@ -0,0 +1,51 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later).  See the COPYING file in this distribution.
+ */
+
+public class VideoMetadata : MediaMetadata {
+
+    private MetadataDateTime timestamp = null;
+    private string title = null;
+    private string comment = null;
+
+    public VideoMetadata() {
+    }
+
+    ~VideoMetadata() {
+    }
+
+    public override void read_from_file(File file) throws Error {
+        QuickTimeMetadataLoader quicktime = new QuickTimeMetadataLoader(file);
+        if (quicktime.is_supported()) {
+            timestamp = quicktime.get_creation_date_time();
+            title = quicktime.get_title();
+	        // TODO: is there an quicktime.get_comment ??
+            comment = null;
+            return;
+        }
+        AVIMetadataLoader avi = new AVIMetadataLoader(file);
+        if (avi.is_supported()) {
+            timestamp = avi.get_creation_date_time();
+            title = avi.get_title();
+            comment = null;
+            return;
+        }
+
+        throw new IOError.NOT_SUPPORTED("File %s is not a supported video format", file.get_path());
+    }
+
+    public override MetadataDateTime? get_creation_date_time() {
+        return timestamp;
+    }
+
+    public override string? get_title() {
+        return title;
+    }
+
+    public override string? get_comment() {
+        return comment;
+    }
+
+}
diff --git a/src/video-support/VideoMetadataReaderProcess.vala b/src/video-support/VideoMetadataReaderProcess.vala
new file mode 100644
index 0000000..26d61a6
--- /dev/null
+++ b/src/video-support/VideoMetadataReaderProcess.vala
@@ -0,0 +1,66 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+using Gst;
+using Gst.PbUtils;
+
+int main(string[] args) {
+    Intl.setlocale(GLib.LocaleCategory.NUMERIC, "C");
+
+    var option_context = new OptionContext("- shotwell video metadata reader helper binary");
+    option_context.set_help_enabled(true);
+    option_context.add_group(Gst.init_get_option_group());
+
+    double clip_duration;
+    GLib.DateTime timestamp = null;
+
+    try {
+        option_context.parse(ref args);
+
+        if (args.length < 2)
+            throw new IOError.INVALID_ARGUMENT("Missing URI");
+
+        var f = File.new_for_commandline_arg (args[1]);
+
+        Gst.PbUtils.Discoverer d = new Gst.PbUtils.Discoverer((Gst.ClockTime) (Gst.SECOND * 5));
+        Gst.PbUtils.DiscovererInfo info = d.discover_uri(f.get_uri());
+
+        clip_duration = ((double) info.get_duration()) / 1000000000.0;
+
+        // Get creation time.
+        // TODO: Note that TAG_DATE can be changed to TAG_DATE_TIME in the future
+        // (and the corresponding output struct) in order to implement #2836.
+        Gst.DateTime? video_date = null;
+
+        Gst.TagList? tags = null;
+
+        var stream_info = info.get_stream_info();
+        if (stream_info is Gst.PbUtils.DiscovererContainerInfo) {
+            tags = ((Gst.PbUtils.DiscovererContainerInfo)stream_info).get_tags();
+        }
+        else if (stream_info is Gst.PbUtils.DiscovererStreamInfo) {
+            tags = ((Gst.PbUtils.DiscovererStreamInfo)stream_info).get_tags();
+        }
+
+        if (tags != null && tags.get_date_time(Gst.Tags.DATE_TIME, out video_date)) {
+            // possible for get_date() to return true and a null Date
+            if (video_date != null) {
+                timestamp = video_date.to_g_date_time().to_local();
+            }
+        }
+
+        print("%.3f\n", clip_duration);
+        if (timestamp != null) {
+            print("%s\n", timestamp.format_iso8601());
+        } else {
+            print("none\n");
+        }
+    } catch (Error error) {
+        critical("Failed to parse options: %s", error.message);
+
+        return 1;
+    }
+
+    return 0;
+}
diff --git a/src/video-support/VideoReader.vala b/src/video-support/VideoReader.vala
new file mode 100644
index 0000000..11f11e1
--- /dev/null
+++ b/src/video-support/VideoReader.vala
@@ -0,0 +1,317 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+public errordomain VideoError {
+    FILE,          // there's a problem reading the video container file (doesn't exist, no read
+                   // permission, etc.)
+
+    CONTENTS,      // we can read the container file but its contents are indecipherable (no codec,
+                   // malformed data, etc.)
+}
+
+public class VideoReader {
+    private const double UNKNOWN_CLIP_DURATION = -1.0;
+    private const uint THUMBNAILER_TIMEOUT = 10000; // In milliseconds.
+
+    // File extensions for video containers that pack only metadata as per the AVCHD spec
+    private const string[] METADATA_ONLY_FILE_EXTENSIONS = { "bdm", "bdmv", "cpi", "mpl" };
+
+    private double clip_duration = UNKNOWN_CLIP_DURATION;
+    private Gdk.Pixbuf preview_frame = null;
+    private File file = null;
+    private Subprocess thumbnailer_process = null;
+    public DateTime? timestamp { get; private set; default = null; }
+
+    public VideoReader(File file) {
+        this.file = file;
+     }
+
+    public static bool is_supported_video_file(File file) {
+        var mime_type = ContentType.guess(file.get_basename(), new uchar[0], null);
+        // special case: deep-check content-type of files ending with .ogg
+        if (mime_type == "audio/ogg" && file.has_uri_scheme("file")) {
+            try {
+                var info = file.query_info(FileAttribute.STANDARD_CONTENT_TYPE,
+                                           FileQueryInfoFlags.NONE);
+                var content_type = info.get_content_type();
+                if (content_type != null && content_type.has_prefix ("video/")) {
+                    return true;
+                }
+            } catch (Error error) {
+                debug("Failed to query content type: %s", error.message);
+            }
+        }
+
+        return is_supported_video_filename(file.get_basename());
+    }
+
+    public static bool is_supported_video_filename(string filename) {
+        string mime_type;
+        mime_type = ContentType.guess(filename, new uchar[0], null);
+        // Guessed mp4/mxf from filename has application/ as prefix, so check for mp4/mxf in the end
+        if (mime_type.has_prefix ("video/") ||
+            mime_type.has_suffix("mp4") ||
+            mime_type.has_suffix("mxf")) {
+            string? extension = null;
+            string? name = null;
+            disassemble_filename(filename, out name, out extension);
+
+            if (extension == null)
+                return true;
+
+            foreach (string s in METADATA_ONLY_FILE_EXTENSIONS) {
+                if (utf8_ci_compare(s, extension) == 0)
+                    return false;
+            }
+
+            return true;
+        } else {
+            debug("Skipping %s, unsupported mime type %s", filename, mime_type);
+            return false;
+        }
+    }
+
+    public static ImportResult prepare_for_import(VideoImportParams params) {
+#if MEASURE_IMPORT
+        Timer total_time = new Timer();
+#endif
+        File file = params.file;
+
+        FileInfo info = null;
+        try {
+            info = file.query_info(DirectoryMonitor.SUPPLIED_ATTRIBUTES,
+                FileQueryInfoFlags.NOFOLLOW_SYMLINKS, null);
+        } catch (Error err) {
+            return ImportResult.FILE_ERROR;
+        }
+
+        if (info.get_file_type() != FileType.REGULAR)
+            return ImportResult.NOT_A_FILE;
+
+        if (!is_supported_video_file(file)) {
+            message("Not importing %s: file is marked as a video file but doesn't have a" +
+                "supported extension", file.get_path());
+
+            return ImportResult.UNSUPPORTED_FORMAT;
+        }
+
+        var timestamp = info.get_modification_date_time();
+
+        // make sure params has a valid md5
+        assert(params.md5 != null);
+
+        DateTime exposure_time = params.exposure_time_override;
+        string title = "";
+        string comment = "";
+
+        VideoReader reader = new VideoReader(file);
+        bool is_interpretable = true;
+        double clip_duration = 0.0;
+        Gdk.Pixbuf preview_frame = reader.read_preview_frame();
+        try {
+            clip_duration = reader.read_clip_duration();
+        } catch (VideoError err) {
+            if (err is VideoError.FILE) {
+                return ImportResult.FILE_ERROR;
+            } else if (err is VideoError.CONTENTS) {
+                is_interpretable = false;
+                clip_duration = 0.0;
+            } else {
+                error("can't prepare video for import: an unknown kind of video error occurred");
+            }
+        }
+
+        try {
+            VideoMetadata metadata = reader.read_metadata();
+            MetadataDateTime? creation_date_time = metadata.get_creation_date_time();
+
+            if (creation_date_time != null && creation_date_time.get_timestamp() != null)
+                exposure_time = creation_date_time.get_timestamp();
+
+            string? video_title = metadata.get_title();
+            string? video_comment = metadata.get_comment();
+            if (video_title != null)
+                title = video_title;
+            if (video_comment != null)
+                comment = video_comment;
+        } catch (Error err) {
+            warning("Unable to read video metadata: %s", err.message);
+        }
+
+        if (exposure_time == null) {
+            // Use time reported by Gstreamer, if available.
+            exposure_time = reader.timestamp;
+        }
+
+        params.row.video_id = VideoID();
+        params.row.filepath = file.get_path();
+        params.row.filesize = info.get_size();
+        params.row.timestamp = timestamp;
+        params.row.width = preview_frame.width;
+        params.row.height = preview_frame.height;
+        params.row.clip_duration = clip_duration;
+        params.row.is_interpretable = is_interpretable;
+        params.row.exposure_time = exposure_time;
+        params.row.import_id = params.import_id;
+        params.row.event_id = EventID();
+        params.row.md5 = params.md5;
+        params.row.time_created = 0;
+        params.row.title = title;
+        params.row.comment = comment;
+        params.row.backlinks = "";
+        params.row.time_reimported = 0;
+        params.row.flags = 0;
+
+        if (params.thumbnails != null) {
+            params.thumbnails = new Thumbnails();
+            ThumbnailCache.generate_for_video_frame(params.thumbnails, preview_frame);
+        }
+
+#if MEASURE_IMPORT
+        debug("IMPORT: total time to import video = %lf", total_time.elapsed());
+#endif
+        return ImportResult.SUCCESS;
+    }
+
+    private void read_internal() throws VideoError {
+        if (!does_file_exist())
+            throw new VideoError.FILE("video file '%s' does not exist or is inaccessible".printf(
+                file.get_path()));
+
+        uint id = 0;
+        try {
+            var cancellable = new Cancellable();
+
+            id = Timeout.add_seconds(10, () => {
+                cancellable.cancel();
+                id = 0;
+
+                return false;
+            });
+
+            Bytes stdout_buf = null;
+            Bytes stderr_buf = null;
+
+            var process = new GLib.Subprocess(GLib.SubprocessFlags.STDOUT_PIPE, AppDirs.get_metadata_helper().get_path(), file.get_uri());
+            var result = process.communicate(null, cancellable, out stdout_buf, out stderr_buf);
+            if (result && process.get_if_exited() && process.get_exit_status () == 0 && stdout_buf != null && stdout_buf.get_size() > 0) {
+                string[] lines = ((string) stdout_buf.get_data()).split("\n");
+
+                var old = Intl.setlocale(GLib.LocaleCategory.NUMERIC, "C");
+                clip_duration = double.parse(lines[0]);
+                Intl.setlocale(GLib.LocaleCategory.NUMERIC, old);
+                if (lines[1] != "none")
+                    timestamp = new DateTime.from_iso8601(lines[1], null);
+            } else {
+                string message = "";
+                if (stderr_buf != null && stderr_buf.get_size() > 0) {
+                    message = (string) stderr_buf.get_data();
+                }
+                warning ("External Metadata helper failed");
+            }
+        } catch (Error e) {
+            debug("Video read error: %s", e.message);
+            throw new VideoError.CONTENTS("GStreamer couldn't extract clip information: %s"
+                .printf(e.message));
+        }
+
+        if (id != 0) {
+            Source.remove(id);
+        }
+    }
+
+    // Used by thumbnailer() to kill the external process if need be.
+    private bool on_thumbnailer_timer() {
+        debug("Thumbnailer timer called");
+        if (thumbnailer_process != null) {
+            thumbnailer_process.force_exit();
+        }
+        return false; // Don't call again.
+    }
+
+    // Performs video thumbnailing.
+    // Note: not thread-safe if called from the same instance of the class.
+    private Gdk.Pixbuf? thumbnailer(string video_file) {
+        // Use Shotwell's thumbnailer, redirect output to stdout.
+        debug("Launching thumbnailer process: %s", AppDirs.get_thumbnailer_bin().get_path());
+        FileIOStream stream;
+        File output_file;
+        try {
+            output_file = File.new_tmp(null, out stream);
+        } catch (Error e) {
+            debug("Failed to create temporary file: %s", e.message);
+            return null;
+        }
+
+        try {
+            thumbnailer_process = new Subprocess(SubprocessFlags.NONE,
+                AppDirs.get_thumbnailer_bin().get_path(), video_file, output_file.get_path());
+        } catch (Error e) {
+            debug("Error spawning process: %s", e.message);
+            return null;
+        }
+
+        // Start timer.
+        Timeout.add(THUMBNAILER_TIMEOUT, on_thumbnailer_timer);
+
+        // Make sure process exited properly.
+        try {
+            thumbnailer_process.wait_check();
+
+            // Read pixbuf from stream.
+            Gdk.Pixbuf? buf = null;
+            try {
+                buf = new Gdk.Pixbuf.from_stream(stream.get_input_stream(), null);
+                return buf;
+            } catch (Error e) {
+                debug("Error creating pixbuf: %s", e.message);
+            }
+        } catch (Error err) {
+            debug("Thumbnailer process exited with error: %s", err.message);
+        }
+
+        try {
+            output_file.delete(null);
+        } catch (Error err) {
+            debug("Failed to remove temporary file: %s", err.message);
+        }
+        
+        return null;
+    }
+
+    private bool does_file_exist() {
+        return FileUtils.test(file.get_path(), FileTest.EXISTS | FileTest.IS_REGULAR);
+    }
+
+    public Gdk.Pixbuf? read_preview_frame() {
+        if (preview_frame != null)
+            return preview_frame;
+
+        if (!does_file_exist())
+            return null;
+
+        // Get preview frame from thumbnailer.
+        preview_frame = thumbnailer(file.get_path());
+        if (null == preview_frame)
+            preview_frame = Resources.get_noninterpretable_badge_pixbuf();
+
+        return preview_frame;
+    }
+
+    public double read_clip_duration() throws VideoError {
+        if (clip_duration == UNKNOWN_CLIP_DURATION)
+            read_internal();
+
+        return clip_duration;
+    }
+
+    public VideoMetadata read_metadata() throws Error {
+        VideoMetadata metadata = new VideoMetadata();
+        metadata.read_from_file(File.new_for_path(file.get_path()));
+
+        return metadata;
+    }
+}
diff --git a/src/video-support/VideoSourceCollection.vala b/src/video-support/VideoSourceCollection.vala
new file mode 100644
index 0000000..89daad3
--- /dev/null
+++ b/src/video-support/VideoSourceCollection.vala
@@ -0,0 +1,175 @@
+/* Copyright 2016 Software Freedom Conservancy Inc.
+ *
+ * This software is licensed under the GNU LGPL (version 2.1 or later).
+ * See the COPYING file in this distribution.
+ */
+
+public class VideoSourceCollection : MediaSourceCollection {
+    public enum State {
+        UNKNOWN,
+        ONLINE,
+        OFFLINE,
+        TRASH
+    }
+
+    public override TransactionController transaction_controller {
+        get {
+            if (_transaction_controller == null)
+                _transaction_controller = new MediaSourceTransactionController(this);
+
+            return _transaction_controller;
+        }
+    }
+
+    private TransactionController _transaction_controller = null;
+    private Gee.MultiMap<uint64?, Video> filesize_to_video =
+        new Gee.TreeMultiMap<uint64?, Video>(uint64_compare);
+
+    public VideoSourceCollection() {
+        base("VideoSourceCollection", get_video_key);
+
+        get_trashcan().contents_altered.connect(on_trashcan_contents_altered);
+        get_offline_bin().contents_altered.connect(on_offline_contents_altered);
+    }
+
+    protected override MediaSourceHoldingTank create_trashcan() {
+        return new MediaSourceHoldingTank(this, is_video_trashed, get_video_key);
+    }
+
+    protected override MediaSourceHoldingTank create_offline_bin() {
+        return new MediaSourceHoldingTank(this, is_video_offline, get_video_key);
+    }
+
+    public override MediaMonitor create_media_monitor(Workers workers, Cancellable cancellable) {
+        return new VideoMonitor(cancellable);
+    }
+
+    public override bool holds_type_of_source(DataSource source) {
+        return source is Video;
+    }
+
+    public override string get_typename() {
+        return Video.TYPENAME;
+    }
+
+    public override bool is_file_recognized(File file) {
+        return VideoReader.is_supported_video_file(file);
+    }
+
+    private void on_trashcan_contents_altered(Gee.Collection<DataSource>? added,
+        Gee.Collection<DataSource>? removed) {
+        trashcan_contents_altered((Gee.Collection<Video>?) added,
+            (Gee.Collection<Video>?) removed);
+    }
+
+    private void on_offline_contents_altered(Gee.Collection<DataSource>? added,
+        Gee.Collection<DataSource>? removed) {
+        offline_contents_altered((Gee.Collection<Video>?) added,
+            (Gee.Collection<Video>?) removed);
+    }
+
+    protected override MediaSource? fetch_by_numeric_id(int64 numeric_id) {
+        return fetch(VideoID(numeric_id));
+    }
+
+    public static int64 get_video_key(DataSource source) {
+        Video video = (Video) source;
+        VideoID video_id = video.get_video_id();
+
+        return video_id.id;
+    }
+
+    public static bool is_video_trashed(DataSource source) {
+        return ((Video) source).is_trashed();
+    }
+
+    public static bool is_video_offline(DataSource source) {
+        return ((Video) source).is_offline();
+    }
+
+    public Video fetch(VideoID video_id) {
+        return (Video) fetch_by_key(video_id.id);
+    }
+
+    public override Gee.Collection<string> get_event_source_ids(EventID event_id){
+        return VideoTable.get_instance().get_event_source_ids(event_id);
+    }
+
+    public Video? get_state_by_file(File file, out State state) {
+        Video? video = (Video?) fetch_by_master_file(file);
+        if (video != null) {
+            state = State.ONLINE;
+
+            return video;
+        }
+
+        video = (Video?) get_trashcan().fetch_by_master_file(file);
+        if (video != null) {
+            state = State.TRASH;
+
+            return video;
+        }
+
+        video = (Video?) get_offline_bin().fetch_by_master_file(file);
+        if (video != null) {
+            state = State.OFFLINE;
+
+            return video;
+        }
+
+        state = State.UNKNOWN;
+
+        return null;
+    }
+
+    private void compare_backing(Video video, FileInfo info, Gee.Collection<Video> matching_master) {
+        if (video.get_filesize() != info.get_size())
+            return;
+
+        if (video.get_timestamp().equal(info.get_modification_date_time()))
+            matching_master.add(video);
+    }
+
+    public void fetch_by_matching_backing(FileInfo info, Gee.Collection<Video> matching_master) {
+        foreach (DataObject object in get_all())
+            compare_backing((Video) object, info, matching_master);
+
+        foreach (MediaSource media in get_offline_bin_contents())
+            compare_backing((Video) media, info, matching_master);
+    }
+
+    protected override void notify_contents_altered(Gee.Iterable<DataObject>? added,
+        Gee.Iterable<DataObject>? removed) {
+        if (added != null) {
+            foreach (DataObject object in added) {
+                Video video = (Video) object;
+
+                filesize_to_video.set(video.get_master_filesize(), video);
+            }
+        }
+
+        if (removed != null) {
+            foreach (DataObject object in removed) {
+                Video video = (Video) object;
+
+                filesize_to_video.remove(video.get_master_filesize(), video);
+            }
+        }
+
+        base.notify_contents_altered(added, removed);
+    }
+
+    public VideoID get_basename_filesize_duplicate(string basename, uint64 filesize) {
+        foreach (Video video in filesize_to_video.get(filesize)) {
+            if (utf8_ci_compare(video.get_master_file().get_basename(), basename) == 0)
+                return video.get_video_id();
+        }
+
+        return VideoID(); // the default constructor of the VideoID struct creates an invalid
+                          // video id, which is just what we want in this case
+    }
+
+    public bool has_basename_filesize_duplicate(string basename, uint64 filesize) {
+        return get_basename_filesize_duplicate(basename, filesize).is_valid();
+    }
+}
diff --git a/src/video-support/meson.build b/src/video-support/meson.build
new file mode 100644
index 0000000..da3f9d7
--- /dev/null
+++ b/src/video-support/meson.build
@@ -0,0 +1,36 @@
+executable(
+    'shotwell-video-metadata-handler',
+    [
+        'VideoMetadataReaderProcess.vala'
+    ],
+    dependencies : [
+        gio,
+        gstreamer,
+        gstreamer_pbu
+    ],
+    c_args : '-DGST_PB_UTILS_IS_DISCOVERER_INFO=GST_IS_DISCOVERER_INFO'
+    # Work-around for wrong type-check macro generated by valac
+)
+
+libvideometadata_handling = static_library(
+    'video_metadata_handling',
+    [
+        'AVIChunk.vala',
+        'AVIMetadataLoader.vala',
+        'QuickTimeAtom.vala',
+        'QuicktimeMetdataLoader.vala',
+        'util.vala'
+    ],
+    vala_header : 'shotwell-internal-video-metadata-handling.h',
+    vala_vapi : 'shotwell-internal-video-metadata-handling.vapi',
+    include_directories : config_incdir,
+    dependencies : [
+        gio,
+        metadata
+    ]
+)
+
+metadata_handling = declare_dependency(
+    include_directories : include_directories('.'),
+    link_with : libvideometadata_handling
+)
diff --git a/src/video-support/util.vala b/src/video-support/util.vala
new file mode 100644
index 0000000..ad06680
--- /dev/null
+++ b/src/video-support/util.vala
@@ -0,0 +1,13 @@
+// Breaks a uint64 skip amount into several smaller skips.
+public void skip_uint64(InputStream input, uint64 skip_amount) throws GLib.Error {
+    while (skip_amount > 0) {
+        // skip() throws an error if the amount is too large, so check against ssize_t.MAX
+        if (skip_amount >= ssize_t.MAX) {
+            input.skip(ssize_t.MAX);
+            skip_amount -= ssize_t.MAX;
+        } else {
+            input.skip((size_t) skip_amount);
+            skip_amount = 0;
+        }
+    }
+}