1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "ui/views/widget/root_view.h"
6
7#include <algorithm>
8
9#include "base/logging.h"
10#include "base/message_loop/message_loop.h"
11#include "ui/accessibility/ax_view_state.h"
12#include "ui/base/cursor/cursor.h"
13#include "ui/base/dragdrop/drag_drop_types.h"
14#include "ui/base/ui_base_switches_util.h"
15#include "ui/compositor/layer.h"
16#include "ui/events/event.h"
17#include "ui/events/keycodes/keyboard_codes.h"
18#include "ui/gfx/canvas.h"
19#include "ui/views/drag_controller.h"
20#include "ui/views/focus/view_storage.h"
21#include "ui/views/layout/fill_layout.h"
22#include "ui/views/view_targeter.h"
23#include "ui/views/widget/root_view_targeter.h"
24#include "ui/views/widget/widget.h"
25#include "ui/views/widget/widget_delegate.h"
26
27typedef ui::EventDispatchDetails DispatchDetails;
28
29namespace views {
30namespace internal {
31
32namespace {
33
34enum EventType {
35  EVENT_ENTER,
36  EVENT_EXIT
37};
38
39class MouseEnterExitEvent : public ui::MouseEvent {
40 public:
41  MouseEnterExitEvent(const ui::MouseEvent& event, ui::EventType type)
42      : ui::MouseEvent(event,
43                       static_cast<View*>(NULL),
44                       static_cast<View*>(NULL)) {
45    DCHECK(type == ui::ET_MOUSE_ENTERED ||
46           type == ui::ET_MOUSE_EXITED);
47    SetType(type);
48  }
49
50  virtual ~MouseEnterExitEvent() {}
51};
52
53}  // namespace
54
55// This event handler receives events in the pre-target phase and takes care of
56// the following:
57//   - Shows keyboard-triggered context menus.
58class PreEventDispatchHandler : public ui::EventHandler {
59 public:
60  explicit PreEventDispatchHandler(View* owner)
61      : owner_(owner) {
62  }
63  virtual ~PreEventDispatchHandler() {}
64
65 private:
66  // ui::EventHandler:
67  virtual void OnKeyEvent(ui::KeyEvent* event) OVERRIDE {
68    CHECK_EQ(ui::EP_PRETARGET, event->phase());
69    if (event->handled())
70      return;
71
72    View* v = NULL;
73    if (owner_->GetFocusManager())  // Can be NULL in unittests.
74      v = owner_->GetFocusManager()->GetFocusedView();
75
76    // Special case to handle keyboard-triggered context menus.
77    if (v && v->enabled() && ((event->key_code() == ui::VKEY_APPS) ||
78       (event->key_code() == ui::VKEY_F10 && event->IsShiftDown()))) {
79      // Clamp the menu location within the visible bounds of each ancestor view
80      // to avoid showing the menu over a completely different view or window.
81      gfx::Point location = v->GetKeyboardContextMenuLocation();
82      for (View* parent = v->parent(); parent; parent = parent->parent()) {
83        const gfx::Rect& parent_bounds = parent->GetBoundsInScreen();
84        location.SetToMax(parent_bounds.origin());
85        location.SetToMin(parent_bounds.bottom_right());
86      }
87      v->ShowContextMenu(location, ui::MENU_SOURCE_KEYBOARD);
88      event->StopPropagation();
89    }
90  }
91
92  View* owner_;
93
94  DISALLOW_COPY_AND_ASSIGN(PreEventDispatchHandler);
95};
96
97// This event handler receives events in the post-target phase and takes care of
98// the following:
99//   - Generates context menu, or initiates drag-and-drop, from gesture events.
100class PostEventDispatchHandler : public ui::EventHandler {
101 public:
102  PostEventDispatchHandler()
103      : touch_dnd_enabled_(::switches::IsTouchDragDropEnabled()) {
104  }
105  virtual ~PostEventDispatchHandler() {}
106
107 private:
108  // Overridden from ui::EventHandler:
109  virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE {
110    DCHECK_EQ(ui::EP_POSTTARGET, event->phase());
111    if (event->handled())
112      return;
113
114    View* target = static_cast<View*>(event->target());
115    gfx::Point location = event->location();
116    if (touch_dnd_enabled_ &&
117        event->type() == ui::ET_GESTURE_LONG_PRESS &&
118        (!target->drag_controller() ||
119         target->drag_controller()->CanStartDragForView(
120             target, location, location))) {
121      if (target->DoDrag(*event, location,
122          ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH)) {
123        event->StopPropagation();
124        return;
125      }
126    }
127
128    if (target->context_menu_controller() &&
129        (event->type() == ui::ET_GESTURE_LONG_PRESS ||
130         event->type() == ui::ET_GESTURE_LONG_TAP ||
131         event->type() == ui::ET_GESTURE_TWO_FINGER_TAP)) {
132      gfx::Point screen_location(location);
133      View::ConvertPointToScreen(target, &screen_location);
134      target->ShowContextMenu(screen_location, ui::MENU_SOURCE_TOUCH);
135      event->StopPropagation();
136    }
137  }
138
139  bool touch_dnd_enabled_;
140
141  DISALLOW_COPY_AND_ASSIGN(PostEventDispatchHandler);
142};
143
144// static
145const char RootView::kViewClassName[] = "RootView";
146
147////////////////////////////////////////////////////////////////////////////////
148// RootView, public:
149
150// Creation and lifetime -------------------------------------------------------
151
152RootView::RootView(Widget* widget)
153    : widget_(widget),
154      mouse_pressed_handler_(NULL),
155      mouse_move_handler_(NULL),
156      last_click_handler_(NULL),
157      explicit_mouse_handler_(false),
158      last_mouse_event_flags_(0),
159      last_mouse_event_x_(-1),
160      last_mouse_event_y_(-1),
161      gesture_handler_(NULL),
162      gesture_handler_set_before_processing_(false),
163      pre_dispatch_handler_(new internal::PreEventDispatchHandler(this)),
164      post_dispatch_handler_(new internal::PostEventDispatchHandler),
165      focus_search_(this, false, false),
166      focus_traversable_parent_(NULL),
167      focus_traversable_parent_view_(NULL),
168      event_dispatch_target_(NULL),
169      old_dispatch_target_(NULL) {
170  AddPreTargetHandler(pre_dispatch_handler_.get());
171  AddPostTargetHandler(post_dispatch_handler_.get());
172  SetEventTargeter(scoped_ptr<ViewTargeter>(new RootViewTargeter(this, this)));
173}
174
175RootView::~RootView() {
176  // If we have children remove them explicitly so to make sure a remove
177  // notification is sent for each one of them.
178  if (has_children())
179    RemoveAllChildViews(true);
180}
181
182// Tree operations -------------------------------------------------------------
183
184void RootView::SetContentsView(View* contents_view) {
185  DCHECK(contents_view && GetWidget()->native_widget()) <<
186      "Can't be called until after the native widget is created!";
187  // The ContentsView must be set up _after_ the window is created so that its
188  // Widget pointer is valid.
189  SetLayoutManager(new FillLayout);
190  if (has_children())
191    RemoveAllChildViews(true);
192  AddChildView(contents_view);
193
194  // Force a layout now, since the attached hierarchy won't be ready for the
195  // containing window's bounds. Note that we call Layout directly rather than
196  // calling the widget's size changed handler, since the RootView's bounds may
197  // not have changed, which will cause the Layout not to be done otherwise.
198  Layout();
199}
200
201View* RootView::GetContentsView() {
202  return child_count() > 0 ? child_at(0) : NULL;
203}
204
205void RootView::NotifyNativeViewHierarchyChanged() {
206  PropagateNativeViewHierarchyChanged();
207}
208
209// Focus -----------------------------------------------------------------------
210
211void RootView::SetFocusTraversableParent(FocusTraversable* focus_traversable) {
212  DCHECK(focus_traversable != this);
213  focus_traversable_parent_ = focus_traversable;
214}
215
216void RootView::SetFocusTraversableParentView(View* view) {
217  focus_traversable_parent_view_ = view;
218}
219
220// System events ---------------------------------------------------------------
221
222void RootView::ThemeChanged() {
223  View::PropagateThemeChanged();
224}
225
226void RootView::LocaleChanged() {
227  View::PropagateLocaleChanged();
228}
229
230////////////////////////////////////////////////////////////////////////////////
231// RootView, FocusTraversable implementation:
232
233FocusSearch* RootView::GetFocusSearch() {
234  return &focus_search_;
235}
236
237FocusTraversable* RootView::GetFocusTraversableParent() {
238  return focus_traversable_parent_;
239}
240
241View* RootView::GetFocusTraversableParentView() {
242  return focus_traversable_parent_view_;
243}
244
245////////////////////////////////////////////////////////////////////////////////
246// RootView, ui::EventProcessor overrides:
247
248ui::EventTarget* RootView::GetRootTarget() {
249  return this;
250}
251
252ui::EventDispatchDetails RootView::OnEventFromSource(ui::Event* event) {
253  if (event->IsKeyEvent())
254    return EventProcessor::OnEventFromSource(event);
255
256  if (event->IsScrollEvent())
257    return EventProcessor::OnEventFromSource(event);
258
259  if (event->IsGestureEvent()) {
260    // TODO(tdanderson): Once DispatchGestureEvent() has been removed, move
261    //                   all of this logic into an override of a new
262    //                   virtual method
263    //                   EventProcessor::OnEventProcessingStarted() (which
264    //                   returns false if no processing should take place).
265    //                   Also move the implementation of
266    //                   PrepareEventForDispatch() into this new method.
267    //                   Then RootView::OnEventFromSource() can be removed.
268    ui::GestureEvent* gesture_event = event->AsGestureEvent();
269
270    // Do not dispatch ui::ET_GESTURE_BEGIN events.
271    if (gesture_event->type() == ui::ET_GESTURE_BEGIN)
272      return DispatchDetails();
273
274    // Ignore ui::ET_GESTURE_END events which do not correspond to the
275    // removal of the final touch point.
276    if (gesture_event->type() == ui::ET_GESTURE_END &&
277        gesture_event->details().touch_points() > 1) {
278      return DispatchDetails();
279    }
280
281    // Ignore subsequent gesture scroll events if no handler was set for a
282    // ui::ET_GESTURE_SCROLL_BEGIN event.
283    if (!gesture_handler_ &&
284        (gesture_event->type() == ui::ET_GESTURE_SCROLL_UPDATE ||
285         gesture_event->type() == ui::ET_GESTURE_SCROLL_END ||
286         gesture_event->type() == ui::ET_SCROLL_FLING_START)) {
287      return DispatchDetails();
288    }
289
290    gesture_handler_set_before_processing_ = !!gesture_handler_;
291    return EventProcessor::OnEventFromSource(event);
292  }
293
294  if (event->IsTouchEvent())
295    NOTREACHED() << "Touch events should not be sent to RootView.";
296
297  if (event->IsMouseEvent())
298    NOTREACHED() << "Should not be called with a MouseEvent.";
299
300  return DispatchDetails();
301}
302
303void RootView::OnEventProcessingFinished(ui::Event* event) {
304  // If |event| was not handled and |gesture_handler_| was not set by the
305  // dispatch of a previous gesture event, then no default gesture handler
306  // should be set prior to the next gesture event being received.
307  if (event->IsGestureEvent() &&
308      !event->handled() &&
309      !gesture_handler_set_before_processing_) {
310    gesture_handler_ = NULL;
311  }
312}
313
314////////////////////////////////////////////////////////////////////////////////
315// RootView, View overrides:
316
317const Widget* RootView::GetWidget() const {
318  return widget_;
319}
320
321Widget* RootView::GetWidget() {
322  return const_cast<Widget*>(const_cast<const RootView*>(this)->GetWidget());
323}
324
325bool RootView::IsDrawn() const {
326  return visible();
327}
328
329void RootView::Layout() {
330  View::Layout();
331  widget_->OnRootViewLayout();
332}
333
334const char* RootView::GetClassName() const {
335  return kViewClassName;
336}
337
338void RootView::SchedulePaintInRect(const gfx::Rect& rect) {
339  if (layer()) {
340    layer()->SchedulePaint(rect);
341  } else {
342    gfx::Rect xrect = ConvertRectToParent(rect);
343    gfx::Rect invalid_rect = gfx::IntersectRects(GetLocalBounds(), xrect);
344    if (!invalid_rect.IsEmpty())
345      widget_->SchedulePaintInRect(invalid_rect);
346  }
347}
348
349bool RootView::OnMousePressed(const ui::MouseEvent& event) {
350  UpdateCursor(event);
351  SetMouseLocationAndFlags(event);
352
353  // If mouse_pressed_handler_ is non null, we are currently processing
354  // a pressed -> drag -> released session. In that case we send the
355  // event to mouse_pressed_handler_
356  if (mouse_pressed_handler_) {
357    ui::MouseEvent mouse_pressed_event(event, static_cast<View*>(this),
358                                       mouse_pressed_handler_);
359    drag_info_.Reset();
360    ui::EventDispatchDetails dispatch_details =
361        DispatchEvent(mouse_pressed_handler_, &mouse_pressed_event);
362    if (dispatch_details.dispatcher_destroyed)
363      return true;
364    return true;
365  }
366  DCHECK(!explicit_mouse_handler_);
367
368  bool hit_disabled_view = false;
369  // Walk up the tree until we find a view that wants the mouse event.
370  for (mouse_pressed_handler_ = GetEventHandlerForPoint(event.location());
371       mouse_pressed_handler_ && (mouse_pressed_handler_ != this);
372       mouse_pressed_handler_ = mouse_pressed_handler_->parent()) {
373    DVLOG(1) << "OnMousePressed testing "
374        << mouse_pressed_handler_->GetClassName();
375    if (!mouse_pressed_handler_->enabled()) {
376      // Disabled views should eat events instead of propagating them upwards.
377      hit_disabled_view = true;
378      break;
379    }
380
381    // See if this view wants to handle the mouse press.
382    ui::MouseEvent mouse_pressed_event(event, static_cast<View*>(this),
383                                       mouse_pressed_handler_);
384
385    // Remove the double-click flag if the handler is different than the
386    // one which got the first click part of the double-click.
387    if (mouse_pressed_handler_ != last_click_handler_)
388      mouse_pressed_event.set_flags(event.flags() & ~ui::EF_IS_DOUBLE_CLICK);
389
390    drag_info_.Reset();
391    ui::EventDispatchDetails dispatch_details =
392        DispatchEvent(mouse_pressed_handler_, &mouse_pressed_event);
393    if (dispatch_details.dispatcher_destroyed)
394      return mouse_pressed_event.handled();
395
396    // The view could have removed itself from the tree when handling
397    // OnMousePressed().  In this case, the removal notification will have
398    // reset mouse_pressed_handler_ to NULL out from under us.  Detect this
399    // case and stop.  (See comments in view.h.)
400    //
401    // NOTE: Don't return true here, because we don't want the frame to
402    // forward future events to us when there's no handler.
403    if (!mouse_pressed_handler_)
404      break;
405
406    // If the view handled the event, leave mouse_pressed_handler_ set and
407    // return true, which will cause subsequent drag/release events to get
408    // forwarded to that view.
409    if (mouse_pressed_event.handled()) {
410      last_click_handler_ = mouse_pressed_handler_;
411      DVLOG(1) << "OnMousePressed handled by "
412          << mouse_pressed_handler_->GetClassName();
413      return true;
414    }
415  }
416
417  // Reset mouse_pressed_handler_ to indicate that no processing is occurring.
418  mouse_pressed_handler_ = NULL;
419
420  // In the event that a double-click is not handled after traversing the
421  // entire hierarchy (even as a single-click when sent to a different view),
422  // it must be marked as handled to avoid anything happening from default
423  // processing if it the first click-part was handled by us.
424  if (last_click_handler_ && (event.flags() & ui::EF_IS_DOUBLE_CLICK))
425    hit_disabled_view = true;
426
427  last_click_handler_ = NULL;
428  return hit_disabled_view;
429}
430
431bool RootView::OnMouseDragged(const ui::MouseEvent& event) {
432  if (mouse_pressed_handler_) {
433    SetMouseLocationAndFlags(event);
434
435    ui::MouseEvent mouse_event(event, static_cast<View*>(this),
436                               mouse_pressed_handler_);
437    ui::EventDispatchDetails dispatch_details =
438        DispatchEvent(mouse_pressed_handler_, &mouse_event);
439    if (dispatch_details.dispatcher_destroyed)
440      return false;
441  }
442  return false;
443}
444
445void RootView::OnMouseReleased(const ui::MouseEvent& event) {
446  UpdateCursor(event);
447
448  if (mouse_pressed_handler_) {
449    ui::MouseEvent mouse_released(event, static_cast<View*>(this),
450                                  mouse_pressed_handler_);
451    // We allow the view to delete us from the event dispatch callback. As such,
452    // configure state such that we're done first, then call View.
453    View* mouse_pressed_handler = mouse_pressed_handler_;
454    SetMouseHandler(NULL);
455    ui::EventDispatchDetails dispatch_details =
456        DispatchEvent(mouse_pressed_handler, &mouse_released);
457    if (dispatch_details.dispatcher_destroyed)
458      return;
459  }
460}
461
462void RootView::OnMouseCaptureLost() {
463  // TODO: this likely needs to reset touch handler too.
464
465  if (mouse_pressed_handler_ || gesture_handler_) {
466    // Synthesize a release event for UpdateCursor.
467    if (mouse_pressed_handler_) {
468      gfx::Point last_point(last_mouse_event_x_, last_mouse_event_y_);
469      ui::MouseEvent release_event(ui::ET_MOUSE_RELEASED,
470                                   last_point, last_point,
471                                   last_mouse_event_flags_,
472                                   0);
473      UpdateCursor(release_event);
474    }
475    // We allow the view to delete us from OnMouseCaptureLost. As such,
476    // configure state such that we're done first, then call View.
477    View* mouse_pressed_handler = mouse_pressed_handler_;
478    View* gesture_handler = gesture_handler_;
479    SetMouseHandler(NULL);
480    if (mouse_pressed_handler)
481      mouse_pressed_handler->OnMouseCaptureLost();
482    else
483      gesture_handler->OnMouseCaptureLost();
484    // WARNING: we may have been deleted.
485  }
486}
487
488void RootView::OnMouseMoved(const ui::MouseEvent& event) {
489  View* v = GetEventHandlerForPoint(event.location());
490  // Find the first enabled view, or the existing move handler, whichever comes
491  // first.  The check for the existing handler is because if a view becomes
492  // disabled while handling moves, it's wrong to suddenly send ET_MOUSE_EXITED
493  // and ET_MOUSE_ENTERED events, because the mouse hasn't actually exited yet.
494  while (v && !v->enabled() && (v != mouse_move_handler_))
495    v = v->parent();
496  if (v && v != this) {
497    if (v != mouse_move_handler_) {
498      if (mouse_move_handler_ != NULL &&
499          (!mouse_move_handler_->notify_enter_exit_on_child() ||
500           !mouse_move_handler_->Contains(v))) {
501        MouseEnterExitEvent exit(event, ui::ET_MOUSE_EXITED);
502        exit.ConvertLocationToTarget(static_cast<View*>(this),
503                                     mouse_move_handler_);
504        ui::EventDispatchDetails dispatch_details =
505            DispatchEvent(mouse_move_handler_, &exit);
506        if (dispatch_details.dispatcher_destroyed)
507          return;
508        NotifyEnterExitOfDescendant(event, ui::ET_MOUSE_EXITED,
509            mouse_move_handler_, v);
510      }
511      View* old_handler = mouse_move_handler_;
512      mouse_move_handler_ = v;
513      if (!mouse_move_handler_->notify_enter_exit_on_child() ||
514          !mouse_move_handler_->Contains(old_handler)) {
515        MouseEnterExitEvent entered(event, ui::ET_MOUSE_ENTERED);
516        entered.ConvertLocationToTarget(static_cast<View*>(this),
517                                        mouse_move_handler_);
518        ui::EventDispatchDetails dispatch_details =
519            DispatchEvent(mouse_move_handler_, &entered);
520        if (dispatch_details.dispatcher_destroyed)
521          return;
522        NotifyEnterExitOfDescendant(event, ui::ET_MOUSE_ENTERED,
523            mouse_move_handler_, old_handler);
524      }
525    }
526    ui::MouseEvent moved_event(event, static_cast<View*>(this),
527                               mouse_move_handler_);
528    mouse_move_handler_->OnMouseMoved(moved_event);
529    // TODO(tdanderson): It may be possible to avoid setting the cursor twice
530    //                   (once here and once from CompoundEventFilter) on a
531    //                   mousemove. See crbug.com/351469.
532    if (!(moved_event.flags() & ui::EF_IS_NON_CLIENT))
533      widget_->SetCursor(mouse_move_handler_->GetCursor(moved_event));
534  } else if (mouse_move_handler_ != NULL) {
535    MouseEnterExitEvent exited(event, ui::ET_MOUSE_EXITED);
536    ui::EventDispatchDetails dispatch_details =
537        DispatchEvent(mouse_move_handler_, &exited);
538    if (dispatch_details.dispatcher_destroyed)
539      return;
540    NotifyEnterExitOfDescendant(event, ui::ET_MOUSE_EXITED,
541        mouse_move_handler_, v);
542    // On Aura the non-client area extends slightly outside the root view for
543    // some windows.  Let the non-client cursor handling code set the cursor
544    // as we do above.
545    if (!(event.flags() & ui::EF_IS_NON_CLIENT))
546      widget_->SetCursor(gfx::kNullCursor);
547    mouse_move_handler_ = NULL;
548  }
549}
550
551void RootView::OnMouseExited(const ui::MouseEvent& event) {
552  if (mouse_move_handler_ != NULL) {
553    MouseEnterExitEvent exited(event, ui::ET_MOUSE_EXITED);
554    ui::EventDispatchDetails dispatch_details =
555        DispatchEvent(mouse_move_handler_, &exited);
556    if (dispatch_details.dispatcher_destroyed)
557      return;
558    NotifyEnterExitOfDescendant(event, ui::ET_MOUSE_EXITED,
559        mouse_move_handler_, NULL);
560    mouse_move_handler_ = NULL;
561  }
562}
563
564bool RootView::OnMouseWheel(const ui::MouseWheelEvent& event) {
565  for (View* v = GetEventHandlerForPoint(event.location());
566       v && v != this && !event.handled(); v = v->parent()) {
567    ui::EventDispatchDetails dispatch_details =
568        DispatchEvent(v, const_cast<ui::MouseWheelEvent*>(&event));
569    if (dispatch_details.dispatcher_destroyed ||
570        dispatch_details.target_destroyed) {
571      return event.handled();
572    }
573  }
574  return event.handled();
575}
576
577void RootView::SetMouseHandler(View* new_mh) {
578  // If we're clearing the mouse handler, clear explicit_mouse_handler_ as well.
579  explicit_mouse_handler_ = (new_mh != NULL);
580  mouse_pressed_handler_ = new_mh;
581  gesture_handler_ = new_mh;
582  drag_info_.Reset();
583}
584
585void RootView::GetAccessibleState(ui::AXViewState* state) {
586  state->name = widget_->widget_delegate()->GetAccessibleWindowTitle();
587  state->role = widget_->widget_delegate()->GetAccessibleWindowRole();
588}
589
590void RootView::UpdateParentLayer() {
591  if (layer())
592    ReparentLayer(gfx::Vector2d(GetMirroredX(), y()), widget_->GetLayer());
593}
594
595////////////////////////////////////////////////////////////////////////////////
596// RootView, protected:
597
598void RootView::ViewHierarchyChanged(
599    const ViewHierarchyChangedDetails& details) {
600  widget_->ViewHierarchyChanged(details);
601
602  if (!details.is_add) {
603    if (!explicit_mouse_handler_ && mouse_pressed_handler_ == details.child)
604      mouse_pressed_handler_ = NULL;
605    if (mouse_move_handler_ == details.child)
606      mouse_move_handler_ = NULL;
607    if (gesture_handler_ == details.child)
608      gesture_handler_ = NULL;
609    if (event_dispatch_target_ == details.child)
610      event_dispatch_target_ = NULL;
611    if (old_dispatch_target_ == details.child)
612      old_dispatch_target_ = NULL;
613  }
614}
615
616void RootView::VisibilityChanged(View* /*starting_from*/, bool is_visible) {
617  if (!is_visible) {
618    // When the root view is being hidden (e.g. when widget is minimized)
619    // handlers are reset, so that after it is reshown, events are not captured
620    // by old handlers.
621    explicit_mouse_handler_ = false;
622    mouse_pressed_handler_ = NULL;
623    mouse_move_handler_ = NULL;
624    gesture_handler_ = NULL;
625    event_dispatch_target_ = NULL;
626    old_dispatch_target_ = NULL;
627  }
628}
629
630void RootView::OnPaint(gfx::Canvas* canvas) {
631  if (!layer() || !layer()->fills_bounds_opaquely())
632    canvas->DrawColor(SK_ColorBLACK, SkXfermode::kClear_Mode);
633
634  View::OnPaint(canvas);
635}
636
637gfx::Vector2d RootView::CalculateOffsetToAncestorWithLayer(
638    ui::Layer** layer_parent) {
639  gfx::Vector2d offset(View::CalculateOffsetToAncestorWithLayer(layer_parent));
640  if (!layer() && layer_parent)
641    *layer_parent = widget_->GetLayer();
642  return offset;
643}
644
645View::DragInfo* RootView::GetDragInfo() {
646  return &drag_info_;
647}
648
649////////////////////////////////////////////////////////////////////////////////
650// RootView, private:
651
652// Input -----------------------------------------------------------------------
653
654void RootView::UpdateCursor(const ui::MouseEvent& event) {
655  if (!(event.flags() & ui::EF_IS_NON_CLIENT)) {
656    View* v = GetEventHandlerForPoint(event.location());
657    ui::MouseEvent me(event, static_cast<View*>(this), v);
658    widget_->SetCursor(v->GetCursor(me));
659  }
660}
661
662void RootView::SetMouseLocationAndFlags(const ui::MouseEvent& event) {
663  last_mouse_event_flags_ = event.flags();
664  last_mouse_event_x_ = event.x();
665  last_mouse_event_y_ = event.y();
666}
667
668void RootView::NotifyEnterExitOfDescendant(const ui::MouseEvent& event,
669                                           ui::EventType type,
670                                           View* view,
671                                           View* sibling) {
672  for (View* p = view->parent(); p; p = p->parent()) {
673    if (!p->notify_enter_exit_on_child())
674      continue;
675    if (sibling && p->Contains(sibling))
676      break;
677    // It is necessary to recreate the notify-event for each dispatch, since one
678    // of the callbacks can mark the event as handled, and that would cause
679    // incorrect event dispatch.
680    MouseEnterExitEvent notify_event(event, type);
681    ui::EventDispatchDetails dispatch_details = DispatchEvent(p, &notify_event);
682    if (dispatch_details.dispatcher_destroyed ||
683        dispatch_details.target_destroyed) {
684      return;
685    }
686  }
687}
688
689bool RootView::CanDispatchToTarget(ui::EventTarget* target) {
690  return event_dispatch_target_ == target;
691}
692
693ui::EventDispatchDetails RootView::PreDispatchEvent(ui::EventTarget* target,
694                                                    ui::Event* event) {
695  View* view = static_cast<View*>(target);
696  if (event->IsGestureEvent()) {
697    // Update |gesture_handler_| to indicate which View is currently handling
698    // gesture events.
699    // TODO(tdanderson): Look into moving this to PostDispatchEvent() and
700    //                   using |event_dispatch_target_| instead of
701    //                   |gesture_handler_| to detect if the view has been
702    //                   removed from the tree.
703    gesture_handler_ = view;
704
705    // Disabled views are permitted to be targets of gesture events, but
706    // gesture events should never actually be dispatched to them. Prevent
707    // dispatch by marking the event as handled.
708    if (!view->enabled())
709      event->SetHandled();
710  }
711
712  old_dispatch_target_ = event_dispatch_target_;
713  event_dispatch_target_ = view;
714  return DispatchDetails();
715}
716
717ui::EventDispatchDetails RootView::PostDispatchEvent(ui::EventTarget* target,
718                                                     const ui::Event& event) {
719  // The GESTURE_END event corresponding to the removal of the final touch
720  // point marks the end of a gesture sequence, so reset |gesture_handler_|
721  // to NULL.
722  if (event.type() == ui::ET_GESTURE_END) {
723    // In case a drag was in progress, reset all the handlers. Otherwise, just
724    // reset the gesture handler.
725    if (gesture_handler_ && gesture_handler_ == mouse_pressed_handler_)
726      SetMouseHandler(NULL);
727    else
728      gesture_handler_ = NULL;
729  }
730
731  DispatchDetails details;
732  if (target != event_dispatch_target_)
733    details.target_destroyed = true;
734
735  event_dispatch_target_ = old_dispatch_target_;
736  old_dispatch_target_ = NULL;
737
738#ifndef NDEBUG
739  DCHECK(!event_dispatch_target_ || Contains(event_dispatch_target_));
740#endif
741
742  return details;
743}
744
745}  // namespace internal
746}  // namespace views
747