summaryrefslogtreecommitdiffstats
path: root/chromium/ash/wm/workspace/workspace_window_resizer.cc
blob: b8cd5049448f4ee18726872c62a32600b5d8958d (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
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ash/wm/workspace/workspace_window_resizer.h"

#include <algorithm>
#include <cmath>
#include <utility>
#include <vector>

#include "ash/ash_switches.h"
#include "ash/display/display_controller.h"
#include "ash/root_window_controller.h"
#include "ash/screen_ash.h"
#include "ash/shell.h"
#include "ash/shell_window_ids.h"
#include "ash/wm/coordinate_conversion.h"
#include "ash/wm/default_window_resizer.h"
#include "ash/wm/dock/docked_window_layout_manager.h"
#include "ash/wm/dock/docked_window_resizer.h"
#include "ash/wm/drag_window_resizer.h"
#include "ash/wm/panels/panel_window_resizer.h"
#include "ash/wm/window_state.h"
#include "ash/wm/window_util.h"
#include "ash/wm/workspace/phantom_window_controller.h"
#include "ash/wm/workspace/snap_sizer.h"
#include "base/command_line.h"
#include "base/memory/weak_ptr.h"
#include "ui/aura/client/aura_constants.h"
#include "ui/aura/client/screen_position_client.h"
#include "ui/aura/client/window_types.h"
#include "ui/aura/root_window.h"
#include "ui/aura/window.h"
#include "ui/aura/window_delegate.h"
#include "ui/base/hit_test.h"
#include "ui/compositor/layer.h"
#include "ui/gfx/screen.h"
#include "ui/gfx/transform.h"

namespace ash {

scoped_ptr<WindowResizer> CreateWindowResizer(
    aura::Window* window,
    const gfx::Point& point_in_parent,
    int window_component,
    aura::client::WindowMoveSource source) {
  DCHECK(window);
  wm::WindowState* window_state = wm::GetWindowState(window);
  // No need to return a resizer when the window cannot get resized or when a
  // resizer already exists for this window.
  if ((!window_state->CanResize() && window_component != HTCAPTION) ||
      window_state->window_resizer()) {
    return scoped_ptr<WindowResizer>();
  }

  // TODO(varkha): The chaining of window resizers causes some of the logic
  // to be repeated and the logic flow difficult to control. With some windows
  // classes using reparenting during drag operations it becomes challenging to
  // implement proper transition from one resizer to another during or at the
  // end of the drag. This also causes http://crbug.com/247085.
  // It seems the only thing the panel or dock resizer needs to do is notify the
  // layout manager when a docked window is being dragged. We should have a
  // better way of doing this, perhaps by having a way of observing drags or
  // having a generic drag window wrapper which informs a layout manager that a
  // drag has started or stopped.
  // It may be possible to refactor and eliminate chaining.
  WindowResizer* window_resizer = NULL;
  if (window->parent() &&
      (window->parent()->id() == internal::kShellWindowId_DefaultContainer ||
       window->parent()->id() == internal::kShellWindowId_DockedContainer ||
       window->parent()->id() == internal::kShellWindowId_PanelContainer)) {
    // Allow dragging maximized windows if it's not tracked by workspace. This
    // is set by tab dragging code.
    if (!window_state->IsNormalShowState() &&
        (window_component != HTCAPTION ||
         !window_state->is_dragged())) {
      return scoped_ptr<WindowResizer>();
    }
    window_resizer = internal::WorkspaceWindowResizer::Create(
        window,
        point_in_parent,
        window_component,
        source,
        std::vector<aura::Window*>());
  } else if (window_state->IsNormalShowState()) {
    window_resizer = DefaultWindowResizer::Create(
        window, point_in_parent, window_component, source);
  }
  if (window_resizer) {
    window_resizer = internal::DragWindowResizer::Create(
        window_resizer, window, point_in_parent, window_component, source);
  }
  if (window_resizer && window->type() == aura::client::WINDOW_TYPE_PANEL) {
    window_resizer = PanelWindowResizer::Create(
        window_resizer, window, point_in_parent, window_component, source);
  }
  if (switches::UseDockedWindows() &&
      window_resizer && window->parent() &&
      !window->transient_parent() &&
      (window->parent()->id() == internal::kShellWindowId_DefaultContainer ||
       window->parent()->id() == internal::kShellWindowId_DockedContainer ||
       window->parent()->id() == internal::kShellWindowId_PanelContainer)) {
    window_resizer = internal::DockedWindowResizer::Create(
        window_resizer, window, point_in_parent, window_component, source);
  }
  window_state->set_window_resizer_(window_resizer);
  return make_scoped_ptr<WindowResizer>(window_resizer);
}

namespace internal {

namespace {

// Snapping distance used instead of WorkspaceWindowResizer::kScreenEdgeInset
// when resizing a window using touchscreen.
const int kScreenEdgeInsetForTouchResize = 32;

// Returns true if the window should stick to the edge.
bool ShouldStickToEdge(int distance_from_edge, int sticky_size) {
  if (CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kAshEnableStickyEdges)) {
    // TODO(varkha): Consider keeping snapping behavior for touch drag.
    return distance_from_edge < 0 &&
           distance_from_edge > -sticky_size;
  }
  return distance_from_edge < sticky_size &&
         distance_from_edge > -sticky_size * 2;
}

// Returns the coordinate along the secondary axis to snap to.
int CoordinateAlongSecondaryAxis(SecondaryMagnetismEdge edge,
                                 int leading,
                                 int trailing,
                                 int none) {
  switch (edge) {
    case SECONDARY_MAGNETISM_EDGE_LEADING:
      return leading;
    case SECONDARY_MAGNETISM_EDGE_TRAILING:
      return trailing;
    case SECONDARY_MAGNETISM_EDGE_NONE:
      return none;
  }
  NOTREACHED();
  return none;
}

// Returns the origin for |src| when magnetically attaching to |attach_to| along
// the edges |edges|. |edges| is a bitmask of the MagnetismEdges.
gfx::Point OriginForMagneticAttach(const gfx::Rect& src,
                                   const gfx::Rect& attach_to,
                                   const MatchedEdge& edge) {
  int x = 0, y = 0;
  switch (edge.primary_edge) {
    case MAGNETISM_EDGE_TOP:
      y = attach_to.bottom();
      break;
    case MAGNETISM_EDGE_LEFT:
      x = attach_to.right();
      break;
    case MAGNETISM_EDGE_BOTTOM:
      y = attach_to.y() - src.height();
      break;
    case MAGNETISM_EDGE_RIGHT:
      x = attach_to.x() - src.width();
      break;
  }
  switch (edge.primary_edge) {
    case MAGNETISM_EDGE_TOP:
    case MAGNETISM_EDGE_BOTTOM:
      x = CoordinateAlongSecondaryAxis(
          edge.secondary_edge, attach_to.x(), attach_to.right() - src.width(),
          src.x());
      break;
    case MAGNETISM_EDGE_LEFT:
    case MAGNETISM_EDGE_RIGHT:
      y = CoordinateAlongSecondaryAxis(
          edge.secondary_edge, attach_to.y(), attach_to.bottom() - src.height(),
          src.y());
      break;
  }
  return gfx::Point(x, y);
}

// Returns the bounds for a magnetic attach when resizing. |src| is the bounds
// of window being resized, |attach_to| the bounds of the window to attach to
// and |edge| identifies the edge to attach to.
gfx::Rect BoundsForMagneticResizeAttach(const gfx::Rect& src,
                                        const gfx::Rect& attach_to,
                                        const MatchedEdge& edge) {
  int x = src.x();
  int y = src.y();
  int w = src.width();
  int h = src.height();
  gfx::Point attach_origin(OriginForMagneticAttach(src, attach_to, edge));
  switch (edge.primary_edge) {
    case MAGNETISM_EDGE_LEFT:
      x = attach_origin.x();
      w = src.right() - x;
      break;
    case MAGNETISM_EDGE_RIGHT:
      w += attach_origin.x() - src.x();
      break;
    case MAGNETISM_EDGE_TOP:
      y = attach_origin.y();
      h = src.bottom() - y;
      break;
    case MAGNETISM_EDGE_BOTTOM:
      h += attach_origin.y() - src.y();
      break;
  }
  switch (edge.primary_edge) {
    case MAGNETISM_EDGE_LEFT:
    case MAGNETISM_EDGE_RIGHT:
      if (edge.secondary_edge == SECONDARY_MAGNETISM_EDGE_LEADING) {
        y = attach_origin.y();
        h = src.bottom() - y;
      } else if (edge.secondary_edge == SECONDARY_MAGNETISM_EDGE_TRAILING) {
        h += attach_origin.y() - src.y();
      }
      break;
    case MAGNETISM_EDGE_TOP:
    case MAGNETISM_EDGE_BOTTOM:
      if (edge.secondary_edge == SECONDARY_MAGNETISM_EDGE_LEADING) {
        x = attach_origin.x();
        w = src.right() - x;
      } else if (edge.secondary_edge == SECONDARY_MAGNETISM_EDGE_TRAILING) {
        w += attach_origin.x() - src.x();
      }
      break;
  }
  return gfx::Rect(x, y, w, h);
}

// Converts a window component edge to the magnetic edge to snap to.
uint32 WindowComponentToMagneticEdge(int window_component) {
  switch (window_component) {
    case HTTOPLEFT:
      return MAGNETISM_EDGE_LEFT | MAGNETISM_EDGE_TOP;
    case HTTOPRIGHT:
      return MAGNETISM_EDGE_TOP | MAGNETISM_EDGE_RIGHT;
    case HTBOTTOMLEFT:
      return MAGNETISM_EDGE_LEFT | MAGNETISM_EDGE_BOTTOM;
    case HTBOTTOMRIGHT:
      return MAGNETISM_EDGE_RIGHT | MAGNETISM_EDGE_BOTTOM;
    case HTTOP:
      return MAGNETISM_EDGE_TOP;
    case HTBOTTOM:
      return MAGNETISM_EDGE_BOTTOM;
    case HTRIGHT:
      return MAGNETISM_EDGE_RIGHT;
    case HTLEFT:
      return MAGNETISM_EDGE_LEFT;
    default:
      break;
  }
  return 0;
}

}  // namespace

// static
const int WorkspaceWindowResizer::kMinOnscreenSize = 20;

// static
const int WorkspaceWindowResizer::kMinOnscreenHeight = 32;

// static
const int WorkspaceWindowResizer::kScreenEdgeInset = 8;

// static
const int WorkspaceWindowResizer::kStickyDistancePixels = 64;

// static
WorkspaceWindowResizer* WorkspaceWindowResizer::instance_ = NULL;

// Represents the width or height of a window with constraints on its minimum
// and maximum size. 0 represents a lack of a constraint.
class WindowSize {
 public:
  WindowSize(int size, int min, int max)
      : size_(size),
        min_(min),
        max_(max) {
    // Grow the min/max bounds to include the starting size.
    if (is_underflowing())
      min_ = size_;
    if (is_overflowing())
      max_ = size_;
  }

  bool is_at_capacity(bool shrinking) {
    return size_ == (shrinking ? min_ : max_);
  }

  int size() const {
    return size_;
  }

  bool has_min() const {
    return min_ != 0;
  }

  bool has_max() const {
    return max_ != 0;
  }

  bool is_valid() const {
    return !is_overflowing() && !is_underflowing();
  }

  bool is_overflowing() const {
    return has_max() && size_ > max_;
  }

  bool is_underflowing() const {
    return has_min() && size_ < min_;
  }

  // Add |amount| to this WindowSize not exceeding min or max size constraints.
  // Returns by how much |size_| + |amount| exceeds the min/max constraints.
  int Add(int amount) {
    DCHECK(is_valid());
    int new_value = size_ + amount;

    if (has_min() && new_value < min_) {
      size_ = min_;
      return new_value - min_;
    }

    if (has_max() && new_value > max_) {
      size_ = max_;
      return new_value - max_;
    }

    size_ = new_value;
    return 0;
  }

 private:
  int size_;
  int min_;
  int max_;
};

WorkspaceWindowResizer::~WorkspaceWindowResizer() {
  if (did_lock_cursor_) {
    Shell* shell = Shell::GetInstance();
    shell->cursor_manager()->UnlockCursor();
  }
  if (instance_ == this)
    instance_ = NULL;
}

// static
WorkspaceWindowResizer* WorkspaceWindowResizer::Create(
    aura::Window* window,
    const gfx::Point& location_in_parent,
    int window_component,
    aura::client::WindowMoveSource source,
    const std::vector<aura::Window*>& attached_windows) {
  Details details(window, location_in_parent, window_component, source);
  return details.is_resizable ?
      new WorkspaceWindowResizer(details, attached_windows) : NULL;
}

void WorkspaceWindowResizer::Drag(const gfx::Point& location_in_parent,
                                  int event_flags) {
  last_mouse_location_ = location_in_parent;

  int sticky_size;
  if (event_flags & ui::EF_CONTROL_DOWN) {
    sticky_size = 0;
  } else if (CommandLine::ForCurrentProcess()->HasSwitch(
      switches::kAshEnableStickyEdges)) {
    sticky_size = kStickyDistancePixels;
  } else if ((details_.bounds_change & kBoundsChange_Resizes) &&
      details_.source == aura::client::WINDOW_MOVE_SOURCE_TOUCH) {
    sticky_size = kScreenEdgeInsetForTouchResize;
  } else {
    sticky_size = kScreenEdgeInset;
  }
  // |bounds| is in |window()->parent()|'s coordinates.
  gfx::Rect bounds = CalculateBoundsForDrag(details_, location_in_parent);
  if (window_state()->IsNormalShowState())
    AdjustBoundsForMainWindow(sticky_size, &bounds);

  if (bounds != window()->bounds()) {
    if (!did_move_or_resize_) {
      if (!details_.restore_bounds.IsEmpty())
        window_state()->ClearRestoreBounds();
      RestackWindows();
    }
    did_move_or_resize_ = true;
  }

  gfx::Point location_in_screen = location_in_parent;
  wm::ConvertPointToScreen(window()->parent(), &location_in_screen);

  aura::Window* root = NULL;
  gfx::Display display =
      ScreenAsh::FindDisplayContainingPoint(location_in_screen);
  // Track the last screen that the pointer was on to keep the snap phantom
  // window there.
  if (display.is_valid()) {
    root = Shell::GetInstance()->display_controller()->
        GetRootWindowForDisplayId(display.id());
  }
  if (!attached_windows_.empty())
    LayoutAttachedWindows(&bounds);
  if (bounds != window()->bounds()) {
    // SetBounds needs to be called to update the layout which affects where the
    // phantom window is drawn. Keep track if the window was destroyed during
    // the drag and quit early if so.
    base::WeakPtr<WorkspaceWindowResizer> resizer(
        weak_ptr_factory_.GetWeakPtr());
    window()->SetBounds(bounds);
    if (!resizer)
      return;
  }
  const bool in_original_root = !root || root == window()->GetRootWindow();
  // Hide a phantom window for snapping if the cursor is in another root window.
  if (in_original_root) {
    UpdateSnapPhantomWindow(location_in_parent, bounds);
  } else {
    snap_type_ = SNAP_NONE;
    snap_phantom_window_controller_.reset();
    snap_sizer_.reset();
    SetDraggedWindowDocked(false);
  }
}

void WorkspaceWindowResizer::CompleteDrag(int event_flags) {
  window_state()->set_bounds_changed_by_user(true);
  snap_phantom_window_controller_.reset();
  if (!did_move_or_resize_ || details_.window_component != HTCAPTION)
    return;

  bool snapped = false;
  // When the window is not in the normal show state, we do not snap the window.
  // This happens when the user minimizes or maximizes the window by keyboard
  // shortcut while dragging it. If the window is the result of dragging a tab
  // out of a maximized window, it's already in the normal show state when this
  // is called, so it does not matter.
  if (window_state()->IsNormalShowState() &&
      (window()->type() != aura::client::WINDOW_TYPE_PANEL ||
       !window_state()->panel_attached() ||
       dock_layout_->is_dragged_window_docked()) &&
      (snap_type_ == SNAP_LEFT || snap_type_ == SNAP_RIGHT)) {
    if (!window_state()->HasRestoreBounds()) {
      gfx::Rect initial_bounds = ScreenAsh::ConvertRectToScreen(
          window()->parent(), details_.initial_bounds_in_parent);
      window_state()->SetRestoreBoundsInScreen(
          details_.restore_bounds.IsEmpty() ?
          initial_bounds :
          details_.restore_bounds);
    }
    DCHECK(snap_sizer_);
    if (window_state()->CanResize() &&
        !dock_layout_->is_dragged_window_docked()) {
      snap_sizer_->SnapWindowToTargetBounds();
      snapped = true;
    }
  }
  if (window_state()->IsSnapped() && !snapped)
    window_state()->Restore();
}

void WorkspaceWindowResizer::RevertDrag() {
  window_state()->set_bounds_changed_by_user(initial_bounds_changed_by_user_);
  snap_phantom_window_controller_.reset();

  if (!did_move_or_resize_)
    return;

  window()->SetBounds(details_.initial_bounds_in_parent);
  if (!details_.restore_bounds.IsEmpty()) {
    window_state()->SetRestoreBoundsInScreen(details_.restore_bounds);
  }

  if (details_.window_component == HTRIGHT) {
    int last_x = details_.initial_bounds_in_parent.right();
    for (size_t i = 0; i < attached_windows_.size(); ++i) {
      gfx::Rect bounds(attached_windows_[i]->bounds());
      bounds.set_x(last_x);
      bounds.set_width(initial_size_[i]);
      attached_windows_[i]->SetBounds(bounds);
      last_x = attached_windows_[i]->bounds().right();
    }
  } else {
    int last_y = details_.initial_bounds_in_parent.bottom();
    for (size_t i = 0; i < attached_windows_.size(); ++i) {
      gfx::Rect bounds(attached_windows_[i]->bounds());
      bounds.set_y(last_y);
      bounds.set_height(initial_size_[i]);
      attached_windows_[i]->SetBounds(bounds);
      last_y = attached_windows_[i]->bounds().bottom();
    }
  }
}

aura::Window* WorkspaceWindowResizer::GetTarget() {
  return details_.window;
}

const gfx::Point& WorkspaceWindowResizer::GetInitialLocation() const {
  return details_.initial_location_in_parent;
}

WorkspaceWindowResizer::WorkspaceWindowResizer(
    const Details& details,
    const std::vector<aura::Window*>& attached_windows)
    : details_(details),
      attached_windows_(attached_windows),
      did_lock_cursor_(false),
      did_move_or_resize_(false),
      initial_bounds_changed_by_user_(
          details.window_state->bounds_changed_by_user()),
      total_min_(0),
      total_initial_size_(0),
      snap_type_(SNAP_NONE),
      num_mouse_moves_since_bounds_change_(0),
      magnetism_window_(NULL),
      weak_ptr_factory_(this) {
  DCHECK(details_.is_resizable);

  // A mousemove should still show the cursor even if the window is
  // being moved or resized with touch, so do not lock the cursor.
  if (details.source != aura::client::WINDOW_MOVE_SOURCE_TOUCH) {
    Shell* shell = Shell::GetInstance();
    shell->cursor_manager()->LockCursor();
    did_lock_cursor_ = true;
  }

  aura::Window* dock_container = Shell::GetContainer(
      window()->GetRootWindow(), kShellWindowId_DockedContainer);
  dock_layout_ = static_cast<DockedWindowLayoutManager*>(
      dock_container->layout_manager());

  // Only support attaching to the right/bottom.
  DCHECK(attached_windows_.empty() ||
         (details.window_component == HTRIGHT ||
          details.window_component == HTBOTTOM));

  // TODO: figure out how to deal with window going off the edge.

  // Calculate sizes so that we can maintain the ratios if we need to resize.
  int total_available = 0;
  for (size_t i = 0; i < attached_windows_.size(); ++i) {
    gfx::Size min(attached_windows_[i]->delegate()->GetMinimumSize());
    int initial_size = PrimaryAxisSize(attached_windows_[i]->bounds().size());
    initial_size_.push_back(initial_size);
    // If current size is smaller than the min, use the current size as the min.
    // This way we don't snap on resize.
    int min_size = std::min(initial_size,
                            std::max(PrimaryAxisSize(min), kMinOnscreenSize));
    total_min_ += min_size;
    total_initial_size_ += initial_size;
    total_available += std::max(min_size, initial_size) - min_size;
  }
  instance_ = this;
}

gfx::Rect WorkspaceWindowResizer::GetFinalBounds(
    const gfx::Rect& bounds) const {
  if (snap_phantom_window_controller_.get() &&
      snap_phantom_window_controller_->IsShowing()) {
    return snap_phantom_window_controller_->bounds_in_screen();
  }
  return bounds;
}

void WorkspaceWindowResizer::LayoutAttachedWindows(
    gfx::Rect* bounds) {
  gfx::Rect work_area(ScreenAsh::GetDisplayWorkAreaBoundsInParent(window()));
  int initial_size = PrimaryAxisSize(details_.initial_bounds_in_parent.size());
  int current_size = PrimaryAxisSize(bounds->size());
  int start = PrimaryAxisCoordinate(bounds->right(), bounds->bottom());
  int end = PrimaryAxisCoordinate(work_area.right(), work_area.bottom());

  int delta = current_size - initial_size;
  int available_size = end - start;
  std::vector<int> sizes;
  int leftovers = CalculateAttachedSizes(delta, available_size, &sizes);

  // leftovers > 0 means that the attached windows can't grow to compensate for
  // the shrinkage of the main window. This line causes the attached windows to
  // be moved so they are still flush against the main window, rather than the
  // main window being prevented from shrinking.
  leftovers = std::min(0, leftovers);
  // Reallocate any leftover pixels back into the main window. This is
  // necessary when, for example, the main window shrinks, but none of the
  // attached windows can grow without exceeding their max size constraints.
  // Adding the pixels back to the main window effectively prevents the main
  // window from resizing too far.
  if (details_.window_component == HTRIGHT)
    bounds->set_width(bounds->width() + leftovers);
  else
    bounds->set_height(bounds->height() + leftovers);

  DCHECK_EQ(attached_windows_.size(), sizes.size());
  int last = PrimaryAxisCoordinate(bounds->right(), bounds->bottom());
  for (size_t i = 0; i < attached_windows_.size(); ++i) {
    gfx::Rect attached_bounds(attached_windows_[i]->bounds());
    if (details_.window_component == HTRIGHT) {
      attached_bounds.set_x(last);
      attached_bounds.set_width(sizes[i]);
    } else {
      attached_bounds.set_y(last);
      attached_bounds.set_height(sizes[i]);
    }
    attached_windows_[i]->SetBounds(attached_bounds);
    last += sizes[i];
  }
}

int WorkspaceWindowResizer::CalculateAttachedSizes(
    int delta,
    int available_size,
    std::vector<int>* sizes) const {
  std::vector<WindowSize> window_sizes;
  CreateBucketsForAttached(&window_sizes);

  // How much we need to grow the attached by (collectively).
  int grow_attached_by = 0;
  if (delta > 0) {
    // If the attached windows don't fit when at their initial size, we will
    // have to shrink them by how much they overflow.
    if (total_initial_size_ >= available_size)
      grow_attached_by = available_size - total_initial_size_;
  } else {
    // If we're shrinking, we grow the attached so the total size remains
    // constant.
    grow_attached_by = -delta;
  }

  int leftover_pixels = 0;
  while (grow_attached_by != 0) {
    int leftovers = GrowFairly(grow_attached_by, window_sizes);
    if (leftovers == grow_attached_by) {
      leftover_pixels = leftovers;
      break;
    }
    grow_attached_by = leftovers;
  }

  for (size_t i = 0; i < window_sizes.size(); ++i)
    sizes->push_back(window_sizes[i].size());

  return leftover_pixels;
}

int WorkspaceWindowResizer::GrowFairly(
    int pixels,
    std::vector<WindowSize>& sizes) const {
  bool shrinking = pixels < 0;
  std::vector<WindowSize*> nonfull_windows;
  for (size_t i = 0; i < sizes.size(); ++i) {
    if (!sizes[i].is_at_capacity(shrinking))
      nonfull_windows.push_back(&sizes[i]);
  }
  std::vector<float> ratios;
  CalculateGrowthRatios(nonfull_windows, &ratios);

  int remaining_pixels = pixels;
  bool add_leftover_pixels_to_last = true;
  for (size_t i = 0; i < nonfull_windows.size(); ++i) {
    int grow_by = pixels * ratios[i];
    // Put any leftover pixels into the last window.
    if (i == nonfull_windows.size() - 1 && add_leftover_pixels_to_last)
      grow_by = remaining_pixels;
    int remainder = nonfull_windows[i]->Add(grow_by);
    int consumed = grow_by - remainder;
    remaining_pixels -= consumed;
    if (nonfull_windows[i]->is_at_capacity(shrinking) && remainder > 0) {
      // Because this window overflowed, some of the pixels in
      // |remaining_pixels| aren't there due to rounding errors. Rather than
      // unfairly giving all those pixels to the last window, we refrain from
      // allocating them so that this function can be called again to distribute
      // the pixels fairly.
      add_leftover_pixels_to_last = false;
    }
  }
  return remaining_pixels;
}

void WorkspaceWindowResizer::CalculateGrowthRatios(
    const std::vector<WindowSize*>& sizes,
    std::vector<float>* out_ratios) const {
  DCHECK(out_ratios->empty());
  int total_value = 0;
  for (size_t i = 0; i < sizes.size(); ++i)
    total_value += sizes[i]->size();

  for (size_t i = 0; i < sizes.size(); ++i)
    out_ratios->push_back(
        (static_cast<float>(sizes[i]->size())) / total_value);
}

void WorkspaceWindowResizer::CreateBucketsForAttached(
    std::vector<WindowSize>* sizes) const {
  for (size_t i = 0; i < attached_windows_.size(); i++) {
    int initial_size = initial_size_[i];
    aura::WindowDelegate* delegate = attached_windows_[i]->delegate();
    int min = PrimaryAxisSize(delegate->GetMinimumSize());
    int max = PrimaryAxisSize(delegate->GetMaximumSize());

    sizes->push_back(WindowSize(initial_size, min, max));
  }
}

void WorkspaceWindowResizer::MagneticallySnapToOtherWindows(gfx::Rect* bounds) {
  if (UpdateMagnetismWindow(*bounds, kAllMagnetismEdges)) {
    gfx::Point point = OriginForMagneticAttach(
        ScreenAsh::ConvertRectToScreen(window()->parent(), *bounds),
        magnetism_window_->GetBoundsInScreen(),
        magnetism_edge_);
    aura::client::GetScreenPositionClient(window()->GetRootWindow())->
        ConvertPointFromScreen(window()->parent(), &point);
    bounds->set_origin(point);
  }
}

void WorkspaceWindowResizer::MagneticallySnapResizeToOtherWindows(
    gfx::Rect* bounds) {
  const uint32 edges = WindowComponentToMagneticEdge(details_.window_component);
  if (UpdateMagnetismWindow(*bounds, edges)) {
    *bounds = ScreenAsh::ConvertRectFromScreen(
        window()->parent(),
        BoundsForMagneticResizeAttach(
            ScreenAsh::ConvertRectToScreen(window()->parent(), *bounds),
            magnetism_window_->GetBoundsInScreen(),
            magnetism_edge_));
  }
}

bool WorkspaceWindowResizer::UpdateMagnetismWindow(const gfx::Rect& bounds,
                                                   uint32 edges) {
  // |bounds| are in coordinates of original window's parent.
  gfx::Rect bounds_in_screen =
      ScreenAsh::ConvertRectToScreen(window()->parent(), bounds);
  MagnetismMatcher matcher(bounds_in_screen, edges);

  // If we snapped to a window then check it first. That way we don't bounce
  // around when close to multiple edges.
  if (magnetism_window_) {
    if (window_tracker_.Contains(magnetism_window_) &&
        matcher.ShouldAttach(magnetism_window_->GetBoundsInScreen(),
                             &magnetism_edge_)) {
      return true;
    }
    window_tracker_.Remove(magnetism_window_);
    magnetism_window_ = NULL;
  }

  // Avoid magnetically snapping windows that are not resizable.
  // TODO(oshima): change this to window.type() == TYPE_NORMAL.
  if (!window_state()->CanResize())
    return false;

  aura::Window::Windows root_windows = Shell::GetAllRootWindows();
  for (aura::Window::Windows::iterator iter = root_windows.begin();
       iter != root_windows.end(); ++iter) {
    const aura::Window* root_window = *iter;
    // Test all children from the desktop in each root window.
    const aura::Window::Windows& children = Shell::GetContainer(
        root_window, kShellWindowId_DefaultContainer)->children();
    for (aura::Window::Windows::const_reverse_iterator i = children.rbegin();
         i != children.rend() && !matcher.AreEdgesObscured(); ++i) {
      wm::WindowState* other_state = wm::GetWindowState(*i);
      if (other_state->window() == window() ||
          !other_state->window()->IsVisible() ||
          !other_state->IsNormalShowState() ||
          !other_state->CanResize()) {
        continue;
      }
      if (matcher.ShouldAttach(
              other_state->window()->GetBoundsInScreen(), &magnetism_edge_)) {
        magnetism_window_ = other_state->window();
        window_tracker_.Add(magnetism_window_);
        return true;
      }
    }
  }
  return false;
}

void WorkspaceWindowResizer::AdjustBoundsForMainWindow(
    int sticky_size,
    gfx::Rect* bounds) {
  gfx::Point last_mouse_location_in_screen = last_mouse_location_;
  wm::ConvertPointToScreen(window()->parent(), &last_mouse_location_in_screen);
  gfx::Display display = Shell::GetScreen()->GetDisplayNearestPoint(
      last_mouse_location_in_screen);
  gfx::Rect work_area =
      ScreenAsh::ConvertRectFromScreen(window()->parent(), display.work_area());
  if (details_.window_component == HTCAPTION) {
    // Adjust the bounds to the work area where the mouse cursor is located.
    // Always keep kMinOnscreenHeight or the window height (whichever is less)
    // on the bottom.
    int max_y = work_area.bottom() - std::min(kMinOnscreenHeight,
                                              bounds->height());
    if (bounds->y() > max_y) {
      bounds->set_y(max_y);
    } else if (bounds->y() <= work_area.y()) {
      // Don't allow dragging above the top of the display until the mouse
      // cursor reaches the work area above if any.
      bounds->set_y(work_area.y());
    }

    if (sticky_size > 0) {
      // Possibly stick to edge except when a mouse pointer is outside the
      // work area.
      if (!(display.work_area().Contains(last_mouse_location_in_screen) &&
            StickToWorkAreaOnMove(work_area, sticky_size, bounds))) {
        MagneticallySnapToOtherWindows(bounds);
      }
    }
  } else if (sticky_size > 0) {
    MagneticallySnapResizeToOtherWindows(bounds);
    if (!magnetism_window_ && sticky_size > 0)
      StickToWorkAreaOnResize(work_area, sticky_size, bounds);
  }

  if (attached_windows_.empty())
    return;

  if (details_.window_component == HTRIGHT) {
    bounds->set_width(std::min(bounds->width(),
                               work_area.right() - total_min_ - bounds->x()));
  } else {
    DCHECK_EQ(HTBOTTOM, details_.window_component);
    bounds->set_height(std::min(bounds->height(),
                                work_area.bottom() - total_min_ - bounds->y()));
  }
}

bool WorkspaceWindowResizer::StickToWorkAreaOnMove(
    const gfx::Rect& work_area,
    int sticky_size,
    gfx::Rect* bounds) const {
  const int left_edge = work_area.x();
  const int right_edge = work_area.right();
  const int top_edge = work_area.y();
  const int bottom_edge = work_area.bottom();
  bool updated = false;
  if (ShouldStickToEdge(bounds->x() - left_edge, sticky_size)) {
    bounds->set_x(left_edge);
    updated = true;
  } else if (ShouldStickToEdge(right_edge - bounds->right(), sticky_size)) {
    bounds->set_x(right_edge - bounds->width());
    updated = true;
  }
  if (ShouldStickToEdge(bounds->y() - top_edge, sticky_size)) {
    bounds->set_y(top_edge);
    updated = true;
  } else if (ShouldStickToEdge(bottom_edge - bounds->bottom(), sticky_size) &&
             bounds->height() < (bottom_edge - top_edge)) {
    // Only snap to the bottom if the window is smaller than the work area.
    // Doing otherwise can lead to window snapping in weird ways as it bounces
    // between snapping to top then bottom.
    bounds->set_y(bottom_edge - bounds->height());
    updated = true;
  }
  return updated;
}

void WorkspaceWindowResizer::StickToWorkAreaOnResize(
    const gfx::Rect& work_area,
    int sticky_size,
    gfx::Rect* bounds) const {
  const uint32 edges = WindowComponentToMagneticEdge(details_.window_component);
  const int left_edge = work_area.x();
  const int right_edge = work_area.right();
  const int top_edge = work_area.y();
  const int bottom_edge = work_area.bottom();
  if (edges & MAGNETISM_EDGE_TOP &&
      ShouldStickToEdge(bounds->y() - top_edge, sticky_size)) {
    bounds->set_height(bounds->bottom() - top_edge);
    bounds->set_y(top_edge);
  }
  if (edges & MAGNETISM_EDGE_LEFT &&
      ShouldStickToEdge(bounds->x() - left_edge, sticky_size)) {
    bounds->set_width(bounds->right() - left_edge);
    bounds->set_x(left_edge);
  }
  if (edges & MAGNETISM_EDGE_BOTTOM &&
      ShouldStickToEdge(bottom_edge - bounds->bottom(), sticky_size)) {
    bounds->set_height(bottom_edge - bounds->y());
  }
  if (edges & MAGNETISM_EDGE_RIGHT &&
      ShouldStickToEdge(right_edge - bounds->right(), sticky_size)) {
    bounds->set_width(right_edge - bounds->x());
  }
}

int WorkspaceWindowResizer::PrimaryAxisSize(const gfx::Size& size) const {
  return PrimaryAxisCoordinate(size.width(), size.height());
}

int WorkspaceWindowResizer::PrimaryAxisCoordinate(int x, int y) const {
  switch (details_.window_component) {
    case HTRIGHT:
      return x;
    case HTBOTTOM:
      return y;
    default:
      NOTREACHED();
  }
  return 0;
}

void WorkspaceWindowResizer::UpdateSnapPhantomWindow(const gfx::Point& location,
                                                     const gfx::Rect& bounds) {
  if (!did_move_or_resize_ || details_.window_component != HTCAPTION)
    return;

  SnapType last_type = snap_type_;
  snap_type_ = GetSnapType(location);
  if (snap_type_ == SNAP_NONE || snap_type_ != last_type) {
    snap_phantom_window_controller_.reset();
    snap_sizer_.reset();
    if (snap_type_ == SNAP_NONE) {
      SetDraggedWindowDocked(false);
      return;
    }
  }
  const bool can_dock = dock_layout_->CanDockWindow(window(), snap_type_);
  const bool can_snap = window_state()->CanSnap();
  if (!can_snap && !can_dock) {
    snap_type_ = SNAP_NONE;
    snap_phantom_window_controller_.reset();
    snap_sizer_.reset();
    SetDraggedWindowDocked(false);
    return;
  }
  SnapSizer::Edge edge = (snap_type_ == SNAP_LEFT) ?
      SnapSizer::LEFT_EDGE : SnapSizer::RIGHT_EDGE;
  if (!snap_sizer_) {
    snap_sizer_.reset(new SnapSizer(window_state(),
                                    location,
                                    edge,
                                    internal::SnapSizer::OTHER_INPUT));
  } else {
    snap_sizer_->Update(location);
  }

  // Update phantom window with snapped or docked guide bounds.
  // Windows that cannot be snapped or are less wide than kMaxDockWidth can get
  // docked without going through a snapping sequence.
  gfx::Rect phantom_bounds;
  if (can_snap &&
      (!can_dock ||
       window()->bounds().width() > DockedWindowLayoutManager::kMaxDockWidth))
    phantom_bounds = snap_sizer_->target_bounds();
  const bool should_dock = can_dock &&
      (phantom_bounds.IsEmpty() ||
       snap_sizer_->end_of_sequence() ||
       dock_layout_->is_dragged_window_docked());
  SetDraggedWindowDocked(should_dock);
  snap_type_ = GetSnapType(location);
  if (dock_layout_->is_dragged_window_docked()) {
    phantom_bounds = ScreenAsh::ConvertRectFromScreen(
        window()->parent(), dock_layout_->dragged_bounds());
  }

  if (phantom_bounds.IsEmpty()) {
    snap_phantom_window_controller_.reset();
    return;
  }

  if (!snap_phantom_window_controller_) {
    snap_phantom_window_controller_.reset(
        new PhantomWindowController(window()));
  }
  snap_phantom_window_controller_->Show(ScreenAsh::ConvertRectToScreen(
      window()->parent(), phantom_bounds));
}

void WorkspaceWindowResizer::RestackWindows() {
  if (attached_windows_.empty())
    return;
  // Build a map from index in children to window, returning if there is a
  // window with a different parent.
  typedef std::map<size_t, aura::Window*> IndexToWindowMap;
  IndexToWindowMap map;
  aura::Window* parent = window()->parent();
  const aura::Window::Windows& windows(parent->children());
  map[std::find(windows.begin(), windows.end(), window()) -
      windows.begin()] = window();
  for (std::vector<aura::Window*>::const_iterator i =
           attached_windows_.begin(); i != attached_windows_.end(); ++i) {
    if ((*i)->parent() != parent)
      return;
    size_t index =
        std::find(windows.begin(), windows.end(), *i) - windows.begin();
    map[index] = *i;
  }

  // Reorder the windows starting at the topmost.
  parent->StackChildAtTop(map.rbegin()->second);
  for (IndexToWindowMap::const_reverse_iterator i = map.rbegin();
       i != map.rend(); ) {
    aura::Window* window = i->second;
    ++i;
    if (i != map.rend())
      parent->StackChildBelow(i->second, window);
  }
}

SnapType WorkspaceWindowResizer::GetSnapType(
    const gfx::Point& location) const {
  // TODO: this likely only wants total display area, not the area of a single
  // display.
  gfx::Rect area(ScreenAsh::GetDisplayWorkAreaBoundsInParent(window()));
  if (details_.source == aura::client::WINDOW_MOVE_SOURCE_TOUCH) {
    // Increase tolerance for touch-snapping near the screen edges. This is only
    // necessary when the work area left or right edge is same as screen edge.
    gfx::Rect display_bounds(ScreenAsh::GetDisplayBoundsInParent(window()));
    int inset_left = 0;
    if (area.x() == display_bounds.x())
      inset_left = kScreenEdgeInsetForTouchResize;
    int inset_right = 0;
    if (area.right() == display_bounds.right())
      inset_right = kScreenEdgeInsetForTouchResize;
    area.Inset(inset_left, 0, inset_right, 0);
  }
  if (location.x() <= area.x())
    return SNAP_LEFT;
  if (location.x() >= area.right() - 1)
    return SNAP_RIGHT;
  return SNAP_NONE;
}

void WorkspaceWindowResizer::SetDraggedWindowDocked(bool should_dock) {
  if (should_dock &&
      dock_layout_->GetAlignmentOfWindow(window()) != DOCKED_ALIGNMENT_NONE) {
    if (!dock_layout_->is_dragged_window_docked()) {
      window_state()->set_bounds_changed_by_user(false);
      dock_layout_->DockDraggedWindow(window());
    }
  } else {
    if (dock_layout_->is_dragged_window_docked()) {
      dock_layout_->UndockDraggedWindow();
      window_state()->set_bounds_changed_by_user(true);
    }
  }
}

}  // namespace internal
}  // namespace ash