summaryrefslogtreecommitdiff
path: root/chromium/components/exo/pointer.cc
blob: cc5735f5eb9785930b3c7ee60a245ff0e4f41e44 (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
// Copyright 2015 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 "components/exo/pointer.h"

#include <utility>

#include "base/bind.h"
#include "base/feature_list.h"
#include "base/threading/sequenced_task_runner_handle.h"
#include "components/exo/input_trace.h"
#include "components/exo/pointer_constraint_delegate.h"
#include "components/exo/pointer_delegate.h"
#include "components/exo/pointer_gesture_pinch_delegate.h"
#include "components/exo/relative_pointer_delegate.h"
#include "components/exo/seat.h"
#include "components/exo/shell_surface_util.h"
#include "components/exo/surface.h"
#include "components/exo/wm_helper.h"
#include "components/viz/common/frame_sinks/copy_output_request.h"
#include "components/viz/common/frame_sinks/copy_output_result.h"
#include "ui/aura/client/capture_client.h"
#include "ui/aura/client/cursor_client.h"
#include "ui/aura/env.h"
#include "ui/aura/window.h"
#include "ui/base/cursor/cursor_size.h"
#include "ui/base/cursor/cursor_util.h"
#include "ui/base/cursor/mojom/cursor_type.mojom-shared.h"
#include "ui/display/manager/display_manager.h"
#include "ui/display/manager/managed_display_info.h"
#include "ui/display/screen.h"
#include "ui/events/event.h"
#include "ui/gfx/geometry/vector2d_conversions.h"
#include "ui/gfx/transform_util.h"
#include "ui/views/widget/widget.h"

#if defined(OS_CHROMEOS)
#include "ash/public/cpp/shell_window_ids.h"
#include "ash/wm/window_util.h"
#include "chromeos/constants/chromeos_features.h"
#endif

#if defined(USE_OZONE)
#include "ui/base/cursor/cursor_factory.h"
#endif

namespace exo {

// Controls Pointer capture in exo/wayland.
const base::Feature kPointerCapture{"ExoPointerCapture",
                                    base::FEATURE_ENABLED_BY_DEFAULT};

namespace {

// TODO(oshima): Some accessibility features, including large cursors, disable
// hardware cursors. Ash does not support compositing for custom cursors, so it
// replaces them with the default cursor. As a result, this scale has no effect
// for now. See crbug.com/708378.
const float kLargeCursorScale = 2.8f;

const double kLocatedEventEpsilonSquared = 1.0 / (2000.0 * 2000.0);

bool SameLocation(const gfx::PointF& location_in_target,
                  const gfx::PointF& location) {
  // In general, it is good practice to compare floats using an epsilon.
  // In particular, the mouse location_f() could differ between the
  // MOUSE_PRESSED and MOUSE_RELEASED events. At MOUSE_RELEASED, it will have a
  // targeter() already cached, while at MOUSE_PRESSED, it will have to
  // calculate it passing through all the hierarchy of windows, and that could
  // generate rounding error. std::numeric_limits<float>::epsilon() is not big
  // enough to catch this rounding error.
  gfx::Vector2dF offset = location_in_target - location;
  return offset.LengthSquared() < (2 * kLocatedEventEpsilonSquared);
}

display::ManagedDisplayInfo GetCaptureDisplayInfo() {
  display::ManagedDisplayInfo capture_info;
  for (const auto& display : display::Screen::GetScreen()->GetAllDisplays()) {
    const auto& info = WMHelper::GetInstance()->GetDisplayInfo(display.id());
    if (info.device_scale_factor() >= capture_info.device_scale_factor())
      capture_info = info;
  }
  return capture_info;
}

int GetContainerIdForMouseCursor() {
#if defined(OS_CHROMEOS)
  return ash::kShellWindowId_MouseCursorContainer;
#else
  NOTIMPLEMENTED();
  return -1;
#endif
}

}  // namespace

////////////////////////////////////////////////////////////////////////////////
// Pointer, public:

Pointer::Pointer(PointerDelegate* delegate, Seat* seat)
    : SurfaceTreeHost("ExoPointer"),
      delegate_(delegate),
      seat_(seat),
      cursor_(ui::mojom::CursorType::kNull),
      capture_scale_(GetCaptureDisplayInfo().device_scale_factor()),
      capture_ratio_(GetCaptureDisplayInfo().GetDensityRatio()),
      cursor_capture_source_id_(base::UnguessableToken::Create()) {
  WMHelper* helper = WMHelper::GetInstance();
  helper->AddPreTargetHandler(this);
  // TODO(sky): CursorClient does not exist in mash
  // yet. https://crbug.com/631103.
  aura::client::CursorClient* cursor_client = helper->GetCursorClient();
  if (cursor_client)
    cursor_client->AddObserver(this);
  helper->AddFocusObserver(this);
}

Pointer::~Pointer() {
  delegate_->OnPointerDestroying(this);
  if (focus_surface_) {
    focus_surface_->RemoveSurfaceObserver(this);
  }
  if (pinch_delegate_)
    pinch_delegate_->OnPointerDestroying(this);
  if (relative_pointer_delegate_)
    relative_pointer_delegate_->OnPointerDestroying(this);
  if (pointer_constraint_delegate_) {
    pointer_constraint_delegate_->GetConstrainedSurface()
        ->RemoveSurfaceObserver(this);
    pointer_constraint_delegate_->OnConstraintBroken();
  }
  WMHelper* helper = WMHelper::GetInstance();
  helper->RemovePreTargetHandler(this);
  // TODO(sky): CursorClient does not exist in mash
  // yet. https://crbug.com/631103.
  aura::client::CursorClient* cursor_client = helper->GetCursorClient();
  if (cursor_client)
    cursor_client->RemoveObserver(this);
  if (root_surface())
    root_surface()->RemoveSurfaceObserver(this);
  helper->RemoveFocusObserver(this);
}

void Pointer::SetCursor(Surface* surface, const gfx::Point& hotspot) {
  // Early out if the pointer doesn't have a surface in focus.
  if (!focus_surface_)
    return;

  // This is used to avoid unnecessary cursor changes.
  bool cursor_changed = false;

  // If surface is different than the current pointer surface then remove the
  // current surface and add the new surface.
  if (surface != root_surface()) {
    if (surface && surface->HasSurfaceDelegate()) {
      DLOG(ERROR) << "Surface has already been assigned a role";
      return;
    }
    UpdatePointerSurface(surface);
    cursor_changed = true;
  } else if (!surface && cursor_ != ui::mojom::CursorType::kNone) {
    cursor_changed = true;
  }

  if (hotspot != hotspot_) {
    hotspot_ = hotspot;
    cursor_changed = true;
  }

  // Early out if cursor did not change.
  if (!cursor_changed)
    return;

  // If |SurfaceTreeHost::root_surface_| is set then asynchronously capture a
  // snapshot of cursor, otherwise cancel pending capture and immediately set
  // the cursor to "none".
  if (root_surface()) {
    cursor_ = ui::mojom::CursorType::kCustom;
    CaptureCursor(hotspot);
  } else {
    cursor_ = ui::mojom::CursorType::kNone;
    cursor_bitmap_.reset();
    cursor_capture_weak_ptr_factory_.InvalidateWeakPtrs();
    UpdateCursor();
  }
}

void Pointer::SetCursorType(ui::mojom::CursorType cursor_type) {
  // Early out if the pointer doesn't have a surface in focus.
  if (!focus_surface_)
    return;

  if (cursor_ == cursor_type)
    return;
  cursor_ = cursor_type;
  cursor_bitmap_.reset();
  UpdatePointerSurface(nullptr);
  cursor_capture_weak_ptr_factory_.InvalidateWeakPtrs();
  UpdateCursor();
}

void Pointer::SetGesturePinchDelegate(PointerGesturePinchDelegate* delegate) {
  // For the |pinch_delegate_| (and |relative_pointer_delegate_| below) it is
  // possible to bind multiple extensions to the same pointer interface (not
  // that this is a particularly reasonable thing to do). When that happens we
  // choose to only keep a single binding alive, so we simulate pointer
  // destruction for the previous binding.
  if (pinch_delegate_)
    pinch_delegate_->OnPointerDestroying(this);
  pinch_delegate_ = delegate;
}

void Pointer::RegisterRelativePointerDelegate(
    RelativePointerDelegate* delegate) {
  if (relative_pointer_delegate_)
    relative_pointer_delegate_->OnPointerDestroying(this);
  relative_pointer_delegate_ = delegate;
}

void Pointer::UnregisterRelativePointerDelegate(
    RelativePointerDelegate* delegate) {
  DCHECK(relative_pointer_delegate_ == delegate);
  relative_pointer_delegate_ = nullptr;
}

bool Pointer::ConstrainPointer(PointerConstraintDelegate* delegate) {
  // Pointer lock is a chromeos-only feature (i.e. the chromeos::features
  // namespace only exists in chromeos builds). So we do not compile pointer
  // lock support unless we are on chromeos.
#if defined(OS_CHROMEOS)
  Surface* constrained_surface = delegate->GetConstrainedSurface();
  // Pointer lock should be enabled for ARC by default. The kExoPointerLock
  // should only apply to Crostini windows.
  bool is_arc_window = ash::window_util::IsArcWindow(
      constrained_surface->window()->GetToplevelWindow());
  if (!is_arc_window &&
      !base::FeatureList::IsEnabled(chromeos::features::kExoPointerLock))
    return false;
  bool success = EnablePointerCapture(constrained_surface);
  if (success)
    pointer_constraint_delegate_ = delegate;
  return success;
#else
  NOTIMPLEMENTED();
  return false;
#endif
}

void Pointer::UnconstrainPointer() {
  if (pointer_constraint_delegate_) {
    DisablePointerCapture();
    pointer_constraint_delegate_ = nullptr;
  }
}

bool Pointer::EnablePointerCapture(Surface* capture_surface) {
  if (!base::FeatureList::IsEnabled(kPointerCapture))
    return false;

  if (capture_surface->window() !=
      WMHelper::GetInstance()->GetFocusedWindow()) {
    LOG(ERROR)
        << "Cannot enable pointer capture on a window that is not focused.";
    return false;
  }

  if (!capture_surface->HasSurfaceObserver(this))
    capture_surface->AddSurfaceObserver(this);

  capture_window_ = capture_surface->window();

  // Add a pre-target handler that can consume all mouse events before it gets
  // sent to other targets.
  aura::Env::GetInstance()->AddPreTargetHandler(
      this, ui::EventTarget::Priority::kSystem);

  location_when_pointer_capture_enabled_ = gfx::ToRoundedPoint(location_);

  if (ShouldMoveToCenter())
    MoveCursorToCenterOfActiveDisplay();

  return true;
}

void Pointer::DisablePointerCapture() {
  // Early out if pointer capture is not enabled.
  if (!capture_window_)
    return;

  // Remove the pre-target handler that consumes all mouse events.
  aura::Env::GetInstance()->RemovePreTargetHandler(this);

  aura::Window* root = capture_window_->GetRootWindow();
  gfx::Point p = location_when_pointer_capture_enabled_
                     ? *location_when_pointer_capture_enabled_
                     : root->bounds().CenterPoint();
  root->MoveCursorTo(p);

  capture_window_ = nullptr;
  location_when_pointer_capture_enabled_.reset();
  UpdateCursor();
}

////////////////////////////////////////////////////////////////////////////////
// SurfaceDelegate overrides:

void Pointer::OnSurfaceCommit() {
  SurfaceTreeHost::OnSurfaceCommit();

  // Capture new cursor to reflect result of commit.
  if (focus_surface_)
    CaptureCursor(hotspot_);
}

////////////////////////////////////////////////////////////////////////////////
// SurfaceObserver overrides:

void Pointer::OnSurfaceDestroying(Surface* surface) {
  if (surface && pointer_constraint_delegate_ &&
      surface == pointer_constraint_delegate_->GetConstrainedSurface()) {
    surface->RemoveSurfaceObserver(this);
    pointer_constraint_delegate_->OnConstraintBroken();
    UnconstrainPointer();
  }
  if (surface && surface->window() == capture_window_)
    DisablePointerCapture();
  if (surface == focus_surface_) {
    SetFocus(nullptr, gfx::PointF(), 0);
    return;
  }
  if (surface == root_surface()) {
    UpdatePointerSurface(nullptr);
    return;
  }
  NOTREACHED();
}

////////////////////////////////////////////////////////////////////////////////
// ui::EventHandler overrides:

void Pointer::OnMouseEvent(ui::MouseEvent* event) {
  seat_->SetLastLocation(event->root_location());

  Surface* target = GetEffectiveTargetForEvent(event);
  gfx::PointF location_in_target = event->location_f();
  if (target) {
    aura::Window::ConvertPointToTarget(
        static_cast<aura::Window*>(event->target()), target->window(),
        &location_in_target);
  }

  // Update focus if target is different than the current pointer focus.
  if (target != focus_surface_)
    SetFocus(target, location_in_target, event->button_flags());

  gfx::PointF location_in_root = GetLocationInRoot(target, location_in_target);

  if (!focus_surface_)
    return;

  TRACE_EXO_INPUT_EVENT(event);

  if (event->IsMouseEvent() && event->type() != ui::ET_MOUSE_CAPTURE_CHANGED) {
    // Generate motion event if location changed. We need to check location
    // here as mouse movement can generate both "moved" and "entered" events
    // but OnPointerMotion should only be called if location changed since
    // OnPointerEnter was called.
    // For synthesized events, they typically lack floating point precision
    // so to avoid generating mouse event jitter we consider the location of
    // these events to be the same as |location| if floored values match.
    bool same_location = !event->IsSynthesized()
                             ? SameLocation(location_in_root, location_)
                             : gfx::ToFlooredPoint(location_in_root) ==
                                   gfx::ToFlooredPoint(location_);
    if (!same_location) {
      bool needs_frame =
          HandleRelativePointerMotion(event->time_stamp(), location_in_root);
      if (capture_window_) {
        if (ShouldMoveToCenter())
          MoveCursorToCenterOfActiveDisplay();
      } else if (event->type() != ui::ET_MOUSE_EXITED) {
        delegate_->OnPointerMotion(event->time_stamp(), location_in_target);
        needs_frame = true;
      }
      if (needs_frame)
        delegate_->OnPointerFrame();
      location_ = location_in_root;
    }
  }
  switch (event->type()) {
    case ui::ET_MOUSE_RELEASED:
      seat_->AbortPendingDragOperation();
      FALLTHROUGH;
    case ui::ET_MOUSE_PRESSED: {
      delegate_->OnPointerButton(event->time_stamp(),
                                 event->changed_button_flags(),
                                 event->type() == ui::ET_MOUSE_PRESSED);
      delegate_->OnPointerFrame();
      break;
    }
    case ui::ET_SCROLL: {
      ui::ScrollEvent* scroll_event = static_cast<ui::ScrollEvent*>(event);

      // Scrolling with 3+ fingers should not be handled since it will be used
      // to trigger overview mode.
      if (scroll_event->finger_count() >= 3)
        break;
      delegate_->OnPointerScroll(
          event->time_stamp(),
          gfx::Vector2dF(scroll_event->x_offset(), scroll_event->y_offset()),
          false);
      delegate_->OnPointerFrame();
      break;
    }
    case ui::ET_MOUSEWHEEL: {
      delegate_->OnPointerScroll(
          event->time_stamp(),
          static_cast<ui::MouseWheelEvent*>(event)->offset(), true);
      delegate_->OnPointerFrame();
      break;
    }
    case ui::ET_SCROLL_FLING_START: {
      // Fling start in chrome signals the lifting of fingers after scrolling.
      // In wayland terms this signals the end of a scroll sequence.
      delegate_->OnPointerScrollStop(event->time_stamp());
      delegate_->OnPointerFrame();
      break;
    }
    case ui::ET_SCROLL_FLING_CANCEL: {
      // Fling cancel is generated very generously at every touch of the
      // touchpad. Since it's not directly supported by the delegate, we do not
      // want limit this event to only right after a fling start has been
      // generated to prevent erronous behavior.
      if (last_event_type_ == ui::ET_SCROLL_FLING_START) {
        // We emulate fling cancel by starting a new scroll sequence that
        // scrolls by 0 pixels, effectively stopping any kinetic scroll motion.
        delegate_->OnPointerScroll(event->time_stamp(), gfx::Vector2dF(),
                                   false);
        delegate_->OnPointerFrame();
        delegate_->OnPointerScrollStop(event->time_stamp());
        delegate_->OnPointerFrame();
      }
      break;
    }
    case ui::ET_MOUSE_MOVED:
    case ui::ET_MOUSE_DRAGGED:
    case ui::ET_MOUSE_ENTERED:
    case ui::ET_MOUSE_EXITED:
    case ui::ET_MOUSE_CAPTURE_CHANGED:
      break;
    default:
      NOTREACHED();
      break;
  }

  last_event_type_ = event->type();

  // Consume all mouse events when pointer capture is enabled.
  if (capture_window_) {
    event->SetHandled();
    event->StopPropagation();
  }
}

void Pointer::OnScrollEvent(ui::ScrollEvent* event) {
  OnMouseEvent(event);
}

void Pointer::OnGestureEvent(ui::GestureEvent* event) {
  // We don't want to handle gestures generated from touchscreen events,
  // we handle touch events in touch.cc
  if (event->details().device_type() != ui::GestureDeviceType::DEVICE_TOUCHPAD)
    return;

  if (!focus_surface_ || !pinch_delegate_)
    return;

  TRACE_EXO_INPUT_EVENT(event);

  switch (event->type()) {
    case ui::ET_GESTURE_PINCH_BEGIN:
      pinch_delegate_->OnPointerPinchBegin(event->unique_touch_event_id(),
                                           event->time_stamp(), focus_surface_);
      delegate_->OnPointerFrame();
      break;
    case ui::ET_GESTURE_PINCH_UPDATE:
      pinch_delegate_->OnPointerPinchUpdate(event->time_stamp(),
                                            event->details().scale());
      delegate_->OnPointerFrame();
      break;
    case ui::ET_GESTURE_PINCH_END:
      pinch_delegate_->OnPointerPinchEnd(event->unique_touch_event_id(),
                                         event->time_stamp());
      delegate_->OnPointerFrame();
      break;
    default:
      break;
  }

  // Consume all mouse events when pointer capture is enabled.
  if (capture_window_) {
    event->SetHandled();
    event->StopPropagation();
  }
}

////////////////////////////////////////////////////////////////////////////////
// aura::client::CursorClientObserver overrides:

void Pointer::OnCursorSizeChanged(ui::CursorSize cursor_size) {
  if (!focus_surface_)
    return;

  if (cursor_ != ui::mojom::CursorType::kNull)
    UpdateCursor();
}

void Pointer::OnCursorDisplayChanged(const display::Display& display) {
  UpdatePointerSurface(root_surface());
  auto info = GetCaptureDisplayInfo();
  capture_scale_ = info.device_scale_factor();
  capture_ratio_ = info.GetDensityRatio();

  auto* cursor_client = WMHelper::GetInstance()->GetCursorClient();
  // TODO(crbug.com/631103): CursorClient does not exist in mash yet.
  if (!cursor_client)
    return;
  if (cursor_ == ui::mojom::CursorType::kCustom &&
      cursor_ == cursor_client->GetCursor()) {
    // If the current cursor is still the one created by us,
    // it's our responsibility to update the cursor for the new display.
    // Don't check |focus_surface_| because it can be null while
    // dragging the window due to an event capture.
    UpdateCursor();
  }
}

////////////////////////////////////////////////////////////////////////////////
// aura::client::FocusChangeObserver overrides:

void Pointer::OnWindowFocused(aura::Window* gained_focus,
                              aura::Window* lost_focus) {
  if (capture_window_ && capture_window_ != gained_focus) {
    if (pointer_constraint_delegate_) {
      pointer_constraint_delegate_->OnConstraintBroken();
      UnconstrainPointer();
    } else {
      DisablePointerCapture();
    }
  }
}

////////////////////////////////////////////////////////////////////////////////
// Pointer, private:

Surface* Pointer::GetEffectiveTargetForEvent(
    const ui::LocatedEvent* event) const {
  if (capture_window_)
    return Surface::AsSurface(capture_window_);

  Surface* target = GetTargetSurfaceForLocatedEvent(event);

  if (!target)
    return nullptr;

  return delegate_->CanAcceptPointerEventsForSurface(target) ? target : nullptr;
}

void Pointer::SetFocus(Surface* surface,
                       const gfx::PointF& location,
                       int button_flags) {
  // First generate a leave event if we currently have a target in focus.
  if (focus_surface_) {
    delegate_->OnPointerLeave(focus_surface_);
    focus_surface_->RemoveSurfaceObserver(this);
    // Require SetCursor() to be called and cursor to be re-defined in
    // response to each OnPointerEnter() call.
    focus_surface_ = nullptr;
    cursor_capture_weak_ptr_factory_.InvalidateWeakPtrs();
  }
  // Second generate an enter event if focus moved to a new surface.
  if (surface) {
    delegate_->OnPointerEnter(surface, location, button_flags);
    location_ = GetLocationInRoot(surface, location);
    focus_surface_ = surface;
    if (!focus_surface_->HasSurfaceObserver(this))
      focus_surface_->AddSurfaceObserver(this);
  }
  delegate_->OnPointerFrame();
  UpdateCursor();
}

void Pointer::UpdatePointerSurface(Surface* surface) {
  if (root_surface()) {
    host_window()->SetTransform(gfx::Transform());
    if (host_window()->parent())
      host_window()->parent()->RemoveChild(host_window());
    root_surface()->RemoveSurfaceObserver(this);
    SetRootSurface(nullptr);
  }

  if (surface) {
    surface->AddSurfaceObserver(this);
    // Note: Surface window needs to be added to the tree so we can take a
    // snapshot. Where in the tree is not important but we might as well use
    // the cursor container.
    WMHelper::GetInstance()
        ->GetPrimaryDisplayContainer(GetContainerIdForMouseCursor())
        ->AddChild(host_window());
    SetRootSurface(surface);
  }
}

void Pointer::CaptureCursor(const gfx::Point& hotspot) {
  DCHECK(root_surface());
  DCHECK(focus_surface_);

  // Defer capture until surface commit.
  if (host_window()->bounds().IsEmpty())
    return;

  // Submit compositor frame to be captured.
  SubmitCompositorFrame();

  // Surface size is in DIPs, while layer size is in pseudo-DIP units that
  // depend on the DSF of the display mode. Scale the layer to capture the
  // surface at a constant pixel size, regardless of the primary display's
  // display mode DSF.
  display::Display display = display::Screen::GetScreen()->GetPrimaryDisplay();
  float scale = capture_scale_ / display.device_scale_factor();
  host_window()->SetTransform(gfx::GetScaleTransform(gfx::Point(), scale));

  std::unique_ptr<viz::CopyOutputRequest> request =
      std::make_unique<viz::CopyOutputRequest>(
          viz::CopyOutputRequest::ResultFormat::RGBA_BITMAP,
          base::BindOnce(&Pointer::OnCursorCaptured,
                         cursor_capture_weak_ptr_factory_.GetWeakPtr(),
                         hotspot));
  request->set_result_task_runner(base::SequencedTaskRunnerHandle::Get());

  request->set_source(cursor_capture_source_id_);
  host_window()->layer()->RequestCopyOfOutput(std::move(request));
}

void Pointer::OnCursorCaptured(const gfx::Point& hotspot,
                               std::unique_ptr<viz::CopyOutputResult> result) {
  if (!focus_surface_)
    return;

  // Only successful captures should update the cursor.
  if (result->IsEmpty())
    return;

  cursor_bitmap_ = result->AsSkBitmap();
  DCHECK(cursor_bitmap_.readyToDraw());
  cursor_hotspot_ = hotspot;
  UpdateCursor();
}

void Pointer::UpdateCursor() {
  WMHelper* helper = WMHelper::GetInstance();
  aura::client::CursorClient* cursor_client = helper->GetCursorClient();
  // TODO(crbug.com/631103): CursorClient does not exist in mash yet.
  if (!cursor_client)
    return;

  if (cursor_ == ui::mojom::CursorType::kCustom) {
    SkBitmap bitmap = cursor_bitmap_;
    gfx::Point hotspot =
        gfx::ScaleToFlooredPoint(cursor_hotspot_, capture_ratio_);

    // TODO(oshima|weidongg): Add cutsom cursor API to handle size/display
    // change without explicit management like this. https://crbug.com/721601.
    const display::Display& display = cursor_client->GetDisplay();
    float scale =
        helper->GetDisplayInfo(display.id()).GetDensityRatio() / capture_ratio_;

    if (cursor_client->GetCursorSize() == ui::CursorSize::kLarge)
      scale *= kLargeCursorScale;

    // Use panel_rotation() rather than "natural" rotation, as it actually
    // relates to the hardware you're about to draw the cursor bitmap on.
    ui::ScaleAndRotateCursorBitmapAndHotpoint(scale, display.panel_rotation(),
                                              &bitmap, &hotspot);

    ui::PlatformCursor platform_cursor;
#if defined(USE_OZONE)
    // TODO(reveman): Add interface for creating cursors from GpuMemoryBuffers
    // and use that here instead of the current bitmap API.
    // https://crbug.com/686600
    platform_cursor =
        ui::CursorFactory::GetInstance()->CreateImageCursor(bitmap, hotspot);
#elif defined(USE_X11)
    XcursorImage* image = ui::SkBitmapToXcursorImage(&bitmap, hotspot);
    platform_cursor = ui::CreateReffedCustomXCursor(image);
#endif
    cursor_.SetPlatformCursor(platform_cursor);
    cursor_.set_custom_bitmap(bitmap);
    cursor_.set_custom_hotspot(hotspot);
#if defined(USE_OZONE)
    ui::CursorFactory::GetInstance()->UnrefImageCursor(platform_cursor);
#elif defined(USE_X11)
    ui::UnrefCustomXCursor(platform_cursor);
#endif
  }

  // If there is a focused surface, update its widget as the views framework
  // expect that Widget knows the current cursor. Otherwise update the
  // cursor directly on CursorClient.
  if (focus_surface_) {
    aura::Window* window = focus_surface_->window();
    do {
      views::Widget* widget = views::Widget::GetWidgetForNativeView(window);
      if (widget) {
        widget->SetCursor(cursor_);
        return;
      }
      window = window->parent();
    } while (window);
  } else {
    cursor_client->SetCursor(cursor_);
  }
}

gfx::PointF Pointer::GetLocationInRoot(Surface* target,
                                       gfx::PointF location_in_target) {
  if (!target || !target->window())
    return location_in_target;
  aura::Window* w = target->window();
  gfx::PointF p(location_in_target.x(), location_in_target.y());
  aura::Window::ConvertPointToTarget(w, w->GetRootWindow(), &p);
  return gfx::PointF(p.x(), p.y());
}

bool Pointer::ShouldMoveToCenter() {
  if (!capture_window_)
    return false;

  gfx::Rect rect = capture_window_->GetRootWindow()->bounds();
  rect.Inset(rect.width() / 6, rect.height() / 6);
  return !rect.Contains(location_.x(), location_.y());
}

void Pointer::MoveCursorToCenterOfActiveDisplay() {
  if (!capture_window_)
    return;
  aura::Window* root = capture_window_->GetRootWindow();
  gfx::Point p = root->bounds().CenterPoint();
  location_synthetic_move_ = p;
  root->MoveCursorTo(p);
}

bool Pointer::HandleRelativePointerMotion(base::TimeTicks time_stamp,
                                          gfx::PointF location_in_root) {
  if (!relative_pointer_delegate_)
    return false;

  if (location_synthetic_move_) {
    gfx::Point synthetic = *location_synthetic_move_;
    // Since MoveCursorTo() takes integer coordinates, the resulting move could
    // have a conversion error of up to 2 due to fractional scale factors.
    if (std::abs(location_in_root.x() - synthetic.x()) <= 2 &&
        std::abs(location_in_root.y() - synthetic.y()) <= 2) {
      // This was a synthetic move event, so do not forward it and clear the
      // synthetic move.
      location_synthetic_move_.reset();
      return false;
    }
  }

  gfx::PointF delta(location_in_root.x() - location_.x(),
                    location_in_root.y() - location_.y());
  relative_pointer_delegate_->OnPointerRelativeMotion(time_stamp, delta);
  return true;
}

}  // namespace exo