summaryrefslogtreecommitdiff
path: root/src/faces/FaceShape.vala
blob: 1ff01fd303ff88d7c5dc9ec64cc4caab2540bcc2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
/* 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 FaceShape : Object {
    public const string SHAPE_TYPE = null;
    
    protected const int FACE_WINDOW_MARGIN = 5;
    protected const int LABEL_MARGIN = 12;
    protected const int LABEL_PADDING = 9;
    
    public signal void add_me_requested(FaceShape face_shape);
    public signal void delete_me_requested();
    
    protected FacesTool.EditingFaceToolWindow face_window;
    protected Gdk.CursorType current_cursor_type = Gdk.CursorType.BOTTOM_RIGHT_CORNER;
    protected EditingTools.PhotoCanvas canvas;
    protected string serialized = null;
    
    private bool editable = true;
    private bool visible = true;
    private bool known = true;
    
    private weak FacesTool.FaceWidget face_widget = null;
    
    protected FaceShape(EditingTools.PhotoCanvas canvas) {
        this.canvas = canvas;
        this.canvas.new_surface.connect(prepare_ctx);
        
        prepare_ctx(this.canvas.get_default_ctx(), this.canvas.get_surface_dim());
        
        face_window = new FacesTool.EditingFaceToolWindow(this.canvas.get_container());
        face_window.key_pressed.connect(key_press_event);
        
        face_window.show_all();
        face_window.hide();
        
        this.canvas.get_drawing_window().set_cursor(new Gdk.Cursor(current_cursor_type));
    }
    
    ~FaceShape() {
        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));
    }
    
    public static FaceShape from_serialized(EditingTools.PhotoCanvas canvas, string serialized)
    throws FaceShapeError {
        FaceShape face_shape;
        
        string[] args = serialized.split(";");
        switch (args[0]) {
            case "Rectangle":
                face_shape = FaceRectangle.from_serialized(canvas, args);
                
                break;
            default:
                assert_not_reached();
        }
        
        face_shape.serialized = serialized;
        
        return face_shape;
    }
    
    public void set_name(string face_name) {
        face_window.entry.set_text(face_name);
    }
    
    public string? get_name() {
        string face_name = face_window.entry.get_text();
        
        return face_name == "" ? null : face_name;
    }
    
    public void set_known(bool known) {
        this.known = known;
    }
    
    public bool get_known() {
        return known;
    }
    
    public void set_widget(FacesTool.FaceWidget face_widget) {
        this.face_widget = face_widget;
    }
    
    public FacesTool.FaceWidget get_widget() {
        assert(face_widget != null);
        
        return face_widget;
    }
    
    public void hide() {
        visible = false;
        erase();
        
        if (editable)
            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));
    }
    
    public void show() {
        visible = true;
        paint();
        
        if (editable) {
            update_face_window_position();
            face_window.show();
            face_window.present();
            
            if (!known)
                face_window.entry.select_region(0, -1);
        }
    }
    
    public bool is_visible() {
        return visible;
    }
    
    public bool is_editable() {
        return editable;
    }
    
    public void set_editable(bool editable) {
        if (visible && editable != is_editable()) {
            hide();
            this.editable = editable;
            show();
            
            return;
        }
        
        this.editable = editable;
    }
    
    public bool key_press_event(Gdk.EventKey event) {
        switch (Gdk.keyval_name(event.keyval)) {
            case "Escape":
                delete_me_requested();
            break;
            case "Return":
            case "KP_Enter":
                add_me_requested(this);
            break;
            default:
                return false;
        }
        
        return true;
    }
    
    public abstract string serialize();
    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);
    public abstract void on_motion(int x, int y, Gdk.ModifierType mask);
    public abstract void on_left_released(int x, int y);
    public abstract bool on_left_click(int x, int y);
    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);
    
    protected abstract void paint();
    protected abstract void erase();
}

public class FaceRectangle : FaceShape {
    public new const string SHAPE_TYPE = "Rectangle";
    
    private const int FACE_MIN_SIZE = 8;
    public const int NULL_SIZE = 0;
    
    private Box box;
    private Box? label_box;
    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);
        
        Gdk.Rectangle scaled_pixbuf_pos = canvas.get_scaled_pixbuf_position();
        x -= scaled_pixbuf_pos.x;
        y -= scaled_pixbuf_pos.y;
        
        // If half_width is NULL_SIZE we are creating a new FaceShape,
        // otherwise we are only showing a previously created one.
        if (half_width == NULL_SIZE) {
            box = Box(x, y, x, y);
            
            in_manipulation = BoxLocation.BOTTOM_RIGHT;
            last_grab_x = x;
            last_grab_y = y;
        } else {
            Dimensions pixbuf_dimensions = Dimensions.for_pixbuf(canvas.get_scaled_pixbuf());
            int right = (x + half_width).clamp(x, pixbuf_dimensions.width);
            int bottom = (y + half_height).clamp(y, pixbuf_dimensions.height);
        
            box = Box(x - half_width, y - half_height, right, bottom);
        }
    }
    
    ~FaceRectangle() {
        if (!is_editable())
            erase_label();
    }
    
    public static new FaceRectangle from_serialized(EditingTools.PhotoCanvas canvas, string[] args)
        throws FaceShapeError {
        assert(args[0] == SHAPE_TYPE);
        
        Photo photo = canvas.get_photo();
        Dimensions raw_dim = photo.get_raw_dimensions();
        
        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]));
        int half_height = (int) (raw_dim.height * double.parse(args[4]));
        
        Box box = Box(x - half_width, y - half_height, x + half_width, y + half_height);
        
        Dimensions current_dim = Dimensions.for_pixbuf(canvas.get_scaled_pixbuf());
        Box raw_cropped;
        
        if (photo.get_raw_crop(out raw_cropped)) {
            box.left = box.left.clamp(raw_cropped.left, box.left) - raw_cropped.left;
            box.right = box.right.clamp(box.right, raw_cropped.right) - raw_cropped.left;
            box.top = box.top.clamp(raw_cropped.top, box.top) - raw_cropped.top;
            box.bottom = box.bottom.clamp(box.bottom, raw_cropped.bottom) - raw_cropped.top;
            
            box = photo.get_orientation().rotate_box(raw_cropped.get_dimensions(), box);
            
            Box cropped;
            photo.get_crop(out cropped);
            box = box.get_scaled_similar(cropped.get_dimensions(), current_dim);
        } else {
            box = photo.get_orientation().rotate_box(raw_dim, box);
            
            box = box.get_scaled_similar(photo.get_dimensions(), current_dim);
        }
        
        Gdk.Rectangle scaled_pixbuf_pos = canvas.get_scaled_pixbuf_position();
        box.left += scaled_pixbuf_pos.x;
        box.right += scaled_pixbuf_pos.x;
        box.top += scaled_pixbuf_pos.y;
        box.bottom += scaled_pixbuf_pos.y;
        
        half_width = box.get_width() / 2;
        half_height = box.get_height() / 2;
        
        if (half_width < FACE_MIN_SIZE || half_height < FACE_MIN_SIZE)
            throw new FaceShapeError.CANT_CREATE("FaceShape is out of cropped photo area");
        
        return new FaceRectangle(canvas, box.left + half_width, box.top + half_height,
            half_width, half_height);
    }
    
    public override void update_face_window_position() {
        AppWindow appWindow = AppWindow.get_instance();
        Gtk.Allocation face_window_alloc;
        Gdk.Rectangle scaled_pixbuf_pos = canvas.get_scaled_pixbuf_position();
        int x = 0;
        int y = 0;
        
        if (canvas.get_container() == appWindow) {
            appWindow.get_current_page().get_window().get_origin(out x, out y);
        } else assert(canvas.get_container() is FullscreenWindow);
        
        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;
        
        face_window.move(x, y);
    }
    
    protected override void paint() {
        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);
        
        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();
    }
    
    private void paint_label() {
        Cairo.Context ctx = canvas.get_default_ctx();
        Gdk.Rectangle scaled_pixbuf_pos = canvas.get_scaled_pixbuf_position();
        
        ctx.save();
        
        Cairo.TextExtents text_extents = Cairo.TextExtents();
        ctx.text_extents(get_name(), out text_extents);
        
        int width = (int) text_extents.width + LABEL_PADDING;
        int height = (int) text_extents.height;
        int x = box.left + (box.get_width() - width) / 2;
        int y = box.bottom + LABEL_MARGIN;
        
        label_box = Box(x, y, x + width, y + height + LABEL_PADDING);
        
        x += scaled_pixbuf_pos.x;
        y += scaled_pixbuf_pos.y;
        
        ctx.rectangle(x, y, width, height + LABEL_PADDING);
        ctx.set_source_rgba(0, 0, 0, 0.6);
        ctx.fill();
        
        ctx.set_source_rgb(1, 1, 1);
        ctx.move_to(x + LABEL_PADDING / 2, y + height + LABEL_PADDING / 2);
        ctx.show_text(get_name());
        
        ctx.restore();
    }
    
    private void erase_label() {
        if (label_box == null)
            return;
        
        Gdk.Rectangle scaled_pixbuf_pos = canvas.get_scaled_pixbuf_position();
        int x = scaled_pixbuf_pos.x + label_box.left;
        int y = scaled_pixbuf_pos.y + label_box.top;
        
        Cairo.Context ctx = canvas.get_default_ctx();
        ctx.save();
        
        ctx.set_operator(Cairo.Operator.OVER);
        ctx.rectangle(x, y, label_box.get_width(), label_box.get_height());
        
        ctx.set_source_rgb(0.0, 0.0, 0.0);
        ctx.fill_preserve();
        
        ctx.set_source_surface(canvas.get_scaled_surface(),
            scaled_pixbuf_pos.x, scaled_pixbuf_pos.y);
        ctx.fill();
        
        canvas.invalidate_area(label_box);
        label_box = null;
        
        ctx.restore();
    }
    
    public override string serialize() {
        if (serialized != null)
            return serialized;
        
        double x;
        double y;
        double half_width;
        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(),
            y.to_string(), half_width.to_string(), half_height.to_string());
        
        return serialized;
    }
    
    public void get_geometry(out double x, out double y,
        out double half_width, out double half_height) {
        Photo photo = canvas.get_photo();
        Dimensions raw_dim = photo.get_raw_dimensions();
        
        Box temp_box = box;
        
        Dimensions current_dim = Dimensions.for_pixbuf(canvas.get_scaled_pixbuf());
        Box cropped;
        
        if (photo.get_crop(out cropped)) {
            temp_box = temp_box.get_scaled_similar(current_dim, cropped.get_dimensions());
            
            Box raw_cropped;
            photo.get_raw_crop(out raw_cropped);
            
            temp_box =
                photo.get_orientation().derotate_box(raw_cropped.get_dimensions(), temp_box);
            
            temp_box.left += raw_cropped.left;
            temp_box.right += raw_cropped.left;
            temp_box.top += raw_cropped.top;
            temp_box.bottom += raw_cropped.top;
        } else {
            temp_box = temp_box.get_scaled_similar(current_dim, photo.get_dimensions());
            
            temp_box = photo.get_orientation().derotate_box(raw_dim, temp_box);
        }
        
        x = (temp_box.left + (temp_box.get_width() / 2)) / (double) raw_dim.width;
        y = (temp_box.top + (temp_box.get_height() / 2)) / (double) raw_dim.height;
        
        double width_left_end = temp_box.left / (double) raw_dim.width;
        double width_right_end = temp_box.right / (double) raw_dim.width;
        double height_top_end = temp_box.top / (double) raw_dim.height;
        double height_bottom_end = temp_box.bottom / (double) raw_dim.height;
        
        half_width = (width_right_end - width_left_end) / 2;
        half_height = (height_bottom_end - height_top_end) / 2;
    }
    
    public override bool equals(FaceShape face_shape) {
        return serialize() == face_shape.serialize();
    }
    
    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_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);
    }
    
    private bool on_canvas_manipulation(int x, int y) {
        Gdk.Rectangle scaled_pos = canvas.get_scaled_pixbuf_position();
        
        // box is maintained in coordinates non-relative to photo's position on canvas ...
        // but bound tool to photo itself
        x -= scaled_pos.x;
        if (x < 0)
            x = 0;
        else if (x >= scaled_pos.width)
            x = scaled_pos.width - 1;
        
        y -= scaled_pos.y;
        if (y < 0)
            y = 0;
        else if (y >= scaled_pos.height)
            y = scaled_pos.height - 1;
        
        // need to make manipulations outside of box structure, because its methods do sanity
        // checking
        int left = box.left;
        int top = box.top;
        int right = box.right;
        int bottom = box.bottom;

        // get extra geometric information needed to enforce constraints
        int photo_right_edge = canvas.get_scaled_pixbuf().width - 1;
        int photo_bottom_edge = canvas.get_scaled_pixbuf().height - 1;
        
        switch (in_manipulation) {
            case BoxLocation.LEFT_SIDE:
                left = x;
            break;

            case BoxLocation.TOP_SIDE:
                top = y;
            break;

            case BoxLocation.RIGHT_SIDE:
                right = x;
            break;

            case BoxLocation.BOTTOM_SIDE:
                bottom = y;
            break;

            case BoxLocation.TOP_LEFT:
                top = y;
                left = x;
            break;

            case BoxLocation.BOTTOM_LEFT:
                bottom = y;
                left = x;
            break;

            case BoxLocation.TOP_RIGHT:
                top = y;
                right = x;
            break;

            case BoxLocation.BOTTOM_RIGHT:
                bottom = y;
                right = x;
            break;

            case BoxLocation.INSIDE:
                assert(last_grab_x >= 0);
                assert(last_grab_y >= 0);
                
                int delta_x = (x - last_grab_x);
                int delta_y = (y - last_grab_y);
                
                last_grab_x = x;
                last_grab_y = y;

                int width = right - left + 1;
                int height = bottom - top + 1;
                
                left += delta_x;
                top += delta_y;
                right += delta_x;
                bottom += delta_y;
                
                // bound box inside of photo
                if (left < 0)
                    left = 0;
                
                if (top < 0)
                    top = 0;
                
                if (right >= scaled_pos.width)
                    right = scaled_pos.width - 1;
                
                if (bottom >= scaled_pos.height)
                    bottom = scaled_pos.height - 1;
                
                int adj_width = right - left + 1;
                int adj_height = bottom - top + 1;
                
                // don't let adjustments affect the size of the box
                if (adj_width != width) {
                    if (delta_x < 0)
                        right = left + width - 1;
                    else left = right - width + 1;
                }
                
                if (adj_height != height) {
                    if (delta_y < 0)
                        bottom = top + height - 1;
                    else top = bottom - height + 1;
                }
            break;
            
            default:
                // do nothing, not even a repaint
                return false;
        }

        // Check if the mouse has gone out of bounds, and if it has, make sure that the
        // face shape edges stay within the photo bounds.
        int width = right - left + 1;
        int height = bottom - top + 1;
        
        if (left < 0)
            left = 0;
        if (top < 0)
            top = 0;
        if (right > photo_right_edge)
            right = photo_right_edge;
        if (bottom > photo_bottom_edge)
            bottom = photo_bottom_edge;

        width = right - left + 1;
        height = bottom - top + 1;

        switch (in_manipulation) {
            case BoxLocation.LEFT_SIDE:
            case BoxLocation.TOP_LEFT:
            case BoxLocation.BOTTOM_LEFT:
                if (width < FACE_MIN_SIZE)
                    left = right - FACE_MIN_SIZE;
            break;
            
            case BoxLocation.RIGHT_SIDE:
            case BoxLocation.TOP_RIGHT:
            case BoxLocation.BOTTOM_RIGHT:
                if (width < FACE_MIN_SIZE)
                    right = left + FACE_MIN_SIZE;
            break;

            default:
            break;
        }

        switch (in_manipulation) {
            case BoxLocation.TOP_SIDE:
            case BoxLocation.TOP_LEFT:
            case BoxLocation.TOP_RIGHT:
                if (height < FACE_MIN_SIZE)
                    top = bottom - FACE_MIN_SIZE;
            break;

            case BoxLocation.BOTTOM_SIDE:
            case BoxLocation.BOTTOM_LEFT:
            case BoxLocation.BOTTOM_RIGHT:
                if (height < FACE_MIN_SIZE)
                    bottom = top + FACE_MIN_SIZE;
            break;
            
            default:
            break;
        }
       
        Box new_box = Box(left, top, right, bottom);
        
        if (!box.equals(new_box)) {
            erase();
            
            if (in_manipulation != BoxLocation.INSIDE)
                check_resized_box(new_box);
            
            box = new_box;
            paint();
        }
        
        if (is_editable())
            update_face_window_position();
        
        serialized = null;
        
        return false;
    }
    
    private void check_resized_box(Box new_box) {
        Box horizontal;
        bool horizontal_enlarged;
        Box vertical;
        bool vertical_enlarged;
        BoxComplements complements = box.resized_complements(new_box, out horizontal,
            out horizontal_enlarged, out vertical, out vertical_enlarged);
        
        // this should never happen ... this means that the operation wasn't a resize
        assert(complements != BoxComplements.NONE);
    }
    
    private void update_cursor(int x, int y) {
        // box is not maintained relative to photo's position on canvas
        Gdk.Rectangle scaled_pos = canvas.get_scaled_pixbuf_position();
        Box offset_scaled_box = box.get_offset(scaled_pos.x, scaled_pos.y);
        
        Gdk.CursorType cursor_type = Gdk.CursorType.LEFT_PTR;
        switch (offset_scaled_box.approx_location(x, y)) {
            case BoxLocation.LEFT_SIDE:
                cursor_type = Gdk.CursorType.LEFT_SIDE;
            break;

            case BoxLocation.TOP_SIDE:
                cursor_type = Gdk.CursorType.TOP_SIDE;
            break;

            case BoxLocation.RIGHT_SIDE:
                cursor_type = Gdk.CursorType.RIGHT_SIDE;
            break;

            case BoxLocation.BOTTOM_SIDE:
                cursor_type = Gdk.CursorType.BOTTOM_SIDE;
            break;

            case BoxLocation.TOP_LEFT:
                cursor_type = Gdk.CursorType.TOP_LEFT_CORNER;
            break;

            case BoxLocation.BOTTOM_LEFT:
                cursor_type = Gdk.CursorType.BOTTOM_LEFT_CORNER;
            break;

            case BoxLocation.TOP_RIGHT:
                cursor_type = Gdk.CursorType.TOP_RIGHT_CORNER;
            break;

            case BoxLocation.BOTTOM_RIGHT:
                cursor_type = Gdk.CursorType.BOTTOM_RIGHT_CORNER;
            break;

            case BoxLocation.INSIDE:
                cursor_type = Gdk.CursorType.FLEUR;
            break;
            
            default:
                // use Gdk.CursorType.LEFT_PTR
            break;
        }
        
        if (cursor_type != current_cursor_type) {
            Gdk.Cursor cursor = new Gdk.Cursor(cursor_type);
            canvas.get_drawing_window().set_cursor(cursor);
            current_cursor_type = cursor_type;
        }
    }
    
    public override void on_motion(int x, int y, Gdk.ModifierType mask) {
        // only deal with manipulating the box when click-and-dragging one of the edges
        // or the interior
        if (in_manipulation != BoxLocation.OUTSIDE)
            on_canvas_manipulation(x, y);
        
        update_cursor(x, y);
    }
    
    public override bool on_left_click(int x, int y) {
        Gdk.Rectangle scaled_pixbuf_pos = canvas.get_scaled_pixbuf_position();
        
        // box is not maintained relative to photo's position on canvas
        Box offset_scaled_box = box.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_box.approx_location(x, y);
        last_grab_x = x -= scaled_pixbuf_pos.x;
        last_grab_y = y -= scaled_pixbuf_pos.y;
        
        return box.approx_location(x, y) != BoxLocation.OUTSIDE;
    }
    
    public override void on_left_released(int x, int y) {
        if (box.get_width() < FACE_MIN_SIZE) {
            delete_me_requested();
            
            return;
        }
        
        if (is_editable()) {
            face_window.show();
            face_window.present();
        }
        
        // nothing to do if released outside of the face box
        if (in_manipulation == BoxLocation.OUTSIDE)
            return;
        
        // end manipulation
        in_manipulation = BoxLocation.OUTSIDE;
        last_grab_x = -1;
        last_grab_y = -1;
        
        update_cursor(x, y);
    }
    
    public override void on_resized_pixbuf(Dimensions old_dim, Gdk.Pixbuf scaled) {
        Dimensions new_dim = Dimensions.for_pixbuf(scaled);
        Dimensions uncropped_dim = canvas.get_photo().get_original_dimensions();
        
        Box new_box = box.get_scaled_similar(old_dim, uncropped_dim);
        
        // rescale back to new size
        box = new_box.get_scaled_similar(uncropped_dim, new_dim);
        update_face_window_position();
    }
    
    public override bool cursor_is_over(int x, int y) {
        // box is not maintained relative to photo's position on canvas
        Gdk.Rectangle scaled_pos = canvas.get_scaled_pixbuf_position();
        Box offset_scaled_box = box.get_offset(scaled_pos.x, scaled_pos.y);
        
        return offset_scaled_box.approx_location(x, y) != BoxLocation.OUTSIDE;
    }
    
    public override double get_distance(int x, int y) {
        double center_x = box.left + box.get_width() / 2.0;
        double center_y = box.top + box.get_height() / 2.0;
        
        return Math.sqrt((center_x - x) * (center_x - x) + (center_y - y) * (center_y - y));
    }
}