src/ui/views/widget/root_view.cc

   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
  27 typedef ui::EventDispatchDetails DispatchDetails;
  28
  29 namespace views {
  30 namespace internal {
  31
  32 namespace {
  33
  34 enum EventType {
  35   EVENT_ENTER,
  36   EVENT_EXIT
  37 };
  38
  39 class 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.
  58 class 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.
 100 class 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
 145 const char RootView::kViewClassName[] = "RootView";
 146
 147 ////////////////////////////////////////////////////////////////////////////////
 148 // RootView, public:
 149
 150 // Creation and lifetime -------------------------------------------------------
 151
 152 RootView::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
 175 RootView::~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
 184 void 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
 201 View* RootView::GetContentsView() {
 202   return child_count() > 0 ? child_at(0) : NULL;
 203 }
 204
 205 void RootView::NotifyNativeViewHierarchyChanged() {
 206   PropagateNativeViewHierarchyChanged();
 207 }
 208
 209 // Focus -----------------------------------------------------------------------
 210
 211 void RootView::SetFocusTraversableParent(FocusTraversable* focus_traversable) {
 212   DCHECK(focus_traversable != this);
 213   focus_traversable_parent_ = focus_traversable;
 214 }
 215
 216 void RootView::SetFocusTraversableParentView(View* view) {
 217   focus_traversable_parent_view_ = view;
 218 }
 219
 220 // System events ---------------------------------------------------------------
 221
 222 void RootView::ThemeChanged() {
 223   View::PropagateThemeChanged();
 224 }
 225
 226 void RootView::LocaleChanged() {
 227   View::PropagateLocaleChanged();
 228 }
 229
 230 ////////////////////////////////////////////////////////////////////////////////
 231 // RootView, FocusTraversable implementation:
 232
 233 FocusSearch* RootView::GetFocusSearch() {
 234   return &focus_search_;
 235 }
 236
 237 FocusTraversable* RootView::GetFocusTraversableParent() {
 238   return focus_traversable_parent_;
 239 }
 240
 241 View* RootView::GetFocusTraversableParentView() {
 242   return focus_traversable_parent_view_;
 243 }
 244
 245 ////////////////////////////////////////////////////////////////////////////////
 246 // RootView, ui::EventProcessor overrides:
 247
 248 ui::EventTarget* RootView::GetRootTarget() {
 249   return this;
 250 }
 251
 252 ui::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
 303 void 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
 317 const Widget* RootView::GetWidget() const {
 318   return widget_;
 319 }
 320
 321 Widget* RootView::GetWidget() {
 322   return const_cast<Widget*>(const_cast<const RootView*>(this)->GetWidget());
 323 }
 324
 325 bool RootView::IsDrawn() const {
 326   return visible();
 327 }
 328
 329 void RootView::Layout() {
 330   View::Layout();
 331   widget_->OnRootViewLayout();
 332 }
 333
 334 const char* RootView::GetClassName() const {
 335   return kViewClassName;
 336 }
 337
 338 void 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
 349 bool 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
 431 bool 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
 445 void 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
 462 void 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
 488 void 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
 551 void 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
 564 bool 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
 577 void 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
 585 void RootView::GetAccessibleState(ui::AXViewState* state) {
 586   state->name = widget_->widget_delegate()->GetAccessibleWindowTitle();
 587   state->role = widget_->widget_delegate()->GetAccessibleWindowRole();
 588 }
 589
 590 void RootView::UpdateParentLayer() {
 591   if (layer())
 592     ReparentLayer(gfx::Vector2d(GetMirroredX(), y()), widget_->GetLayer());
 593 }
 594
 595 ////////////////////////////////////////////////////////////////////////////////
 596 // RootView, protected:
 597
 598 void 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
 616 void 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
 630 void 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
 637 gfx::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
 645 View::DragInfo* RootView::GetDragInfo() {
 646   return &drag_info_;
 647 }
 648
 649 ////////////////////////////////////////////////////////////////////////////////
 650 // RootView, private:
 651
 652 // Input -----------------------------------------------------------------------
 653
 654 void 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
 662 void 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
 668 void 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
 689 bool RootView::CanDispatchToTarget(ui::EventTarget* target) {
 690   return event_dispatch_target_ == target;
 691 }
 692
 693 ui::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
 717 ui::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