1 files changed, 221 insertions, 0 deletions
diff --git a/src/core/SourceCollection.vala b/src/core/SourceCollection.vala
new file mode 100644
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+++ b/src/core/SourceCollection.vala
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+/* Copyright 2011-2014 Yorba Foundation
+ *
+ * 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 SourceCollection : DataCollection {
+    private class DestroyCounter : Object {
+        public Marker remove_marker;
+        public Gee.ArrayList<DataSource> notify_list = new Gee.ArrayList<DataSource>();
+        public Gee.ArrayList<MediaSource> not_removed = new Gee.ArrayList<MediaSource>();
+        
+        public DestroyCounter(Marker remove_marker) {
+            this.remove_marker = remove_marker;
+        }
+    }
+    
+    // When this signal is fired, the items are about to be unlinked from the collection.  The
+    // appropriate remove signals will follow.
+    public virtual signal void items_unlinking(Gee.Collection<DataSource> unlinking) {
+    }
+    
+    // When this signal is fired, the items are being relinked to the collection.  The appropriate
+    // add signals have already been fired.
+    public virtual signal void items_relinked(Gee.Collection<DataSource> relinked) {
+    }
+    
+    // When this signal is fired, the item is still part of the collection but its own destroy()
+    // has already been called.
+    public virtual signal void item_destroyed(DataSource source) {
+    }
+    
+    // When this signal is fired, the item is still part of the collection but its own destroy()
+    // has already been called.
+    public virtual signal void items_destroyed(Gee.Collection<DataSource> destroyed) {
+    }
+    
+    // When this signal is fired, the unlinked item has been unlinked from the collection previously
+    // and its destroy() has been called.
+    public virtual signal void unlinked_destroyed(DataSource source) {
+    }
+    
+    // When this signal is fired, the backlink to the ContainerSource has already been removed.
+    public virtual signal void backlink_removed(SourceBacklink backlink,
+        Gee.Collection<DataSource> sources) {
+    }
+    
+    private Gee.MultiMap<SourceBacklink, DataSource>? backlinks = null;
+    
+    public SourceCollection(string name) {
+        base (name);
+    }
+    
+    public abstract bool holds_type_of_source(DataSource source);
+    
+    protected virtual void notify_items_unlinking(Gee.Collection<DataSource> unlinking) {
+        items_unlinking(unlinking);
+    }
+    
+    protected virtual void notify_items_relinked(Gee.Collection<DataSource> relinked) {
+        items_relinked(relinked);
+    }
+    
+    protected virtual void notify_item_destroyed(DataSource source) {
+        item_destroyed(source);
+    }
+    
+    protected virtual void notify_items_destroyed(Gee.Collection<DataSource> destroyed) {
+        items_destroyed(destroyed);
+    }
+    
+    // This is only called by DataSource.
+    public virtual void notify_unlinked_destroyed(DataSource unlinked) {
+        unlinked_destroyed(unlinked);
+    }
+    
+    protected virtual void notify_backlink_removed(SourceBacklink backlink,
+        Gee.Collection<DataSource> sources) {
+        backlink_removed(backlink, sources);
+    }
+    
+    protected override bool valid_type(DataObject object) {
+        return object is DataSource;
+    }
+    
+    // Destroy all marked items and optionally have them delete their backing.  Returns the
+    // number of items which failed to delete their backing (if delete_backing is true) or zero.
+    public int destroy_marked(Marker marker, bool delete_backing, ProgressMonitor? monitor = null,
+        Gee.List<MediaSource>? not_removed = null) {
+        DestroyCounter counter = new DestroyCounter(start_marking());
+        
+        if (delete_backing)
+            act_on_marked(marker, destroy_and_delete_source, monitor, counter);
+        else
+            act_on_marked(marker, destroy_source, monitor, counter);
+        
+        // notify of destruction
+        foreach (DataSource source in counter.notify_list)
+            notify_item_destroyed(source);
+        notify_items_destroyed(counter.notify_list);
+        
+        // remove once all destroyed
+        remove_marked(counter.remove_marker);
+        
+        if (null != not_removed) {
+            not_removed.add_all(counter.not_removed);
+        }
+        
+        return counter.not_removed.size;
+    }
+    
+    private bool destroy_and_delete_source(DataObject object, Object? user) {
+        bool success = false;
+        try {
+            success = ((DataSource) object).internal_delete_backing();
+        } catch (Error err) {
+            success = false;
+        }
+        
+        if (!success && object is MediaSource) {
+            ((DestroyCounter) user).not_removed.add((MediaSource) object);
+        }
+        
+        return destroy_source(object, user) && success;
+    }
+    
+    private bool destroy_source(DataObject object, Object? user) {
+        DataSource source = (DataSource) object;
+        
+        source.internal_mark_for_destroy();
+        source.destroy();
+        
+        ((DestroyCounter) user).remove_marker.mark(source);
+        ((DestroyCounter) user).notify_list.add(source);
+        
+        return true;
+    }
+    
+    // This is only called by DataSource.
+    public void internal_backlink_set(DataSource source, SourceBacklink backlink) {
+        if (backlinks == null) {
+            backlinks = new Gee.HashMultiMap<SourceBacklink, DataSource>(SourceBacklink.hash_func,
+                SourceBacklink.equal_func);
+        }
+        
+        backlinks.set(backlink, source);
+    }
+    
+    // This is only called by DataSource.
+    public void internal_backlink_removed(DataSource source, SourceBacklink backlink) {
+        assert(backlinks != null);
+        
+        bool removed = backlinks.remove(backlink, source);
+        assert(removed);
+    }
+    
+    public virtual bool has_backlink(SourceBacklink backlink) {
+        return backlinks != null ? backlinks.contains(backlink) : false;
+    }
+    
+    public Gee.Collection<DataSource>? unlink_marked(Marker marker, ProgressMonitor? monitor = null) {
+        Gee.ArrayList<DataSource> list = new Gee.ArrayList<DataSource>();
+        act_on_marked(marker, prepare_for_unlink, monitor, list);
+        
+        if (list.size == 0)
+            return null;
+        
+        notify_items_unlinking(list);
+        
+        remove_marked(mark_many(list));
+        
+        return list;
+    }
+    
+    private bool prepare_for_unlink(DataObject object, Object? user) {
+        DataSource source = (DataSource) object;
+        
+        source.notify_unlinking(this);
+        ((Gee.List<DataSource>) user).add(source);
+        
+        return true;
+    }
+    
+    public void relink(DataSource source) {
+        source.notify_relinking(this);
+        
+        add(source);
+        notify_items_relinked((Gee.Collection<DataSource>) get_singleton(source));
+        
+        source.notify_relinked();
+    }
+    
+    public void relink_many(Gee.Collection<DataSource> relink) {
+        if (relink.size == 0)
+            return;
+        
+        foreach (DataSource source in relink)
+            source.notify_relinking(this);
+        
+        add_many(relink);
+        notify_items_relinked(relink);
+        
+        foreach (DataSource source in relink)
+            source.notify_relinked();
+    }
+    
+    public virtual void remove_backlink(SourceBacklink backlink) {
+        if (backlinks == null)
+            return;
+        
+        // create copy because the DataSources will be removing the backlinks
+        Gee.ArrayList<DataSource> sources = new Gee.ArrayList<DataSource>();
+        sources.add_all(backlinks.get(backlink));
+        
+        foreach (DataSource source in sources)
+            source.remove_backlink(backlink);
+        
+        notify_backlink_removed(backlink, sources);
+    }
+}
+