ui/aura/window_event_dispatcher.cc

   1 // Copyright 2014 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/aura/window_event_dispatcher.h"
   6
   7 #include "base/bind.h"
   8 #include "base/debug/trace_event.h"
   9 #include "base/logging.h"
  10 #include "base/message_loop/message_loop.h"
  11 #include "ui/aura/client/capture_client.h"
  12 #include "ui/aura/client/cursor_client.h"
  13 #include "ui/aura/client/event_client.h"
  14 #include "ui/aura/client/focus_client.h"
  15 #include "ui/aura/client/screen_position_client.h"
  16 #include "ui/aura/env.h"
  17 #include "ui/aura/window.h"
  18 #include "ui/aura/window_delegate.h"
  19 #include "ui/aura/window_targeter.h"
  20 #include "ui/aura/window_tracker.h"
  21 #include "ui/aura/window_tree_host.h"
  22 #include "ui/base/hit_test.h"
  23 #include "ui/compositor/dip_util.h"
  24 #include "ui/events/event.h"
  25 #include "ui/events/gestures/gesture_recognizer.h"
  26 #include "ui/events/gestures/gesture_types.h"
  27
  28 typedef ui::EventDispatchDetails DispatchDetails;
  29
  30 namespace aura {
  31
  32 namespace {
  33
  34 // Returns true if |target| has a non-client (frame) component at |location|,
  35 // in window coordinates.
  36 bool IsNonClientLocation(Window* target, const gfx::Point& location) {
  37   if (!target->delegate())
  38     return false;
  39   int hit_test_code = target->delegate()->GetNonClientComponent(location);
  40   return hit_test_code != HTCLIENT && hit_test_code != HTNOWHERE;
  41 }
  42
  43 Window* ConsumerToWindow(ui::GestureConsumer* consumer) {
  44   return consumer ? static_cast<Window*>(consumer) : NULL;
  45 }
  46
  47 void SetLastMouseLocation(const Window* root_window,
  48                           const gfx::Point& location_in_root) {
  49   client::ScreenPositionClient* client =
  50       client::GetScreenPositionClient(root_window);
  51   if (client) {
  52     gfx::Point location_in_screen = location_in_root;
  53     client->ConvertPointToScreen(root_window, &location_in_screen);
  54     Env::GetInstance()->set_last_mouse_location(location_in_screen);
  55   } else {
  56     Env::GetInstance()->set_last_mouse_location(location_in_root);
  57   }
  58 }
  59
  60 bool IsEventCandidateForHold(const ui::Event& event) {
  61   if (event.type() == ui::ET_TOUCH_MOVED)
  62     return true;
  63   if (event.type() == ui::ET_MOUSE_DRAGGED)
  64     return true;
  65   if (event.IsMouseEvent() && (event.flags() & ui::EF_IS_SYNTHESIZED))
  66     return true;
  67   return false;
  68 }
  69
  70 }  // namespace
  71
  72 ////////////////////////////////////////////////////////////////////////////////
  73 // WindowEventDispatcher, public:
  74
  75 WindowEventDispatcher::WindowEventDispatcher(WindowTreeHost* host)
  76     : host_(host),
  77       touch_ids_down_(0),
  78       mouse_pressed_handler_(NULL),
  79       mouse_moved_handler_(NULL),
  80       event_dispatch_target_(NULL),
  81       old_dispatch_target_(NULL),
  82       synthesize_mouse_move_(false),
  83       move_hold_count_(0),
  84       dispatching_held_event_(false),
  85       observer_manager_(this),
  86       repost_event_factory_(this),
  87       held_event_factory_(this) {
  88   ui::GestureRecognizer::Get()->AddGestureEventHelper(this);
  89   Env::GetInstance()->AddObserver(this);
  90 }
  91
  92 WindowEventDispatcher::~WindowEventDispatcher() {
  93   TRACE_EVENT0("shutdown", "WindowEventDispatcher::Destructor");
  94   Env::GetInstance()->RemoveObserver(this);
  95   ui::GestureRecognizer::Get()->RemoveGestureEventHelper(this);
  96 }
  97
  98 void WindowEventDispatcher::RepostEvent(const ui::LocatedEvent& event) {
  99   DCHECK(event.type() == ui::ET_MOUSE_PRESSED ||
 100          event.type() == ui::ET_GESTURE_TAP_DOWN);
 101   // We allow for only one outstanding repostable event. This is used
 102   // in exiting context menus.  A dropped repost request is allowed.
 103   if (event.type() == ui::ET_MOUSE_PRESSED) {
 104     held_repostable_event_.reset(
 105         new ui::MouseEvent(
 106             static_cast<const ui::MouseEvent&>(event),
 107             static_cast<aura::Window*>(event.target()),
 108             window()));
 109     base::MessageLoop::current()->PostNonNestableTask(
 110         FROM_HERE, base::Bind(
 111             base::IgnoreResult(&WindowEventDispatcher::DispatchHeldEvents),
 112             repost_event_factory_.GetWeakPtr()));
 113   } else {
 114     DCHECK(event.type() == ui::ET_GESTURE_TAP_DOWN);
 115     held_repostable_event_.reset();
 116     // TODO(rbyers): Reposing of gestures is tricky to get
 117     // right, so it's not yet supported.  crbug.com/170987.
 118   }
 119 }
 120
 121 void WindowEventDispatcher::OnMouseEventsEnableStateChanged(bool enabled) {
 122   // Send entered / exited so that visual state can be updated to match
 123   // mouse events state.
 124   PostSynthesizeMouseMove();
 125   // TODO(mazda): Add code to disable mouse events when |enabled| == false.
 126 }
 127
 128 void WindowEventDispatcher::DispatchCancelModeEvent() {
 129   ui::CancelModeEvent event;
 130   Window* focused_window = client::GetFocusClient(window())->GetFocusedWindow();
 131   if (focused_window && !window()->Contains(focused_window))
 132     focused_window = NULL;
 133   DispatchDetails details =
 134       DispatchEvent(focused_window ? focused_window : window(), &event);
 135   if (details.dispatcher_destroyed)
 136     return;
 137 }
 138
 139 void WindowEventDispatcher::DispatchGestureEvent(ui::GestureEvent* event) {
 140   DispatchDetails details = DispatchHeldEvents();
 141   if (details.dispatcher_destroyed)
 142     return;
 143   Window* target = GetGestureTarget(event);
 144   if (target) {
 145     event->ConvertLocationToTarget(window(), target);
 146     DispatchDetails details = DispatchEvent(target, event);
 147     if (details.dispatcher_destroyed)
 148       return;
 149   }
 150 }
 151
 152 DispatchDetails WindowEventDispatcher::DispatchMouseExitAtPoint(
 153     Window* window,
 154     const gfx::Point& point) {
 155   ui::MouseEvent event(ui::ET_MOUSE_EXITED, point, point, ui::EF_NONE,
 156                        ui::EF_NONE);
 157   return DispatchMouseEnterOrExit(window, event, ui::ET_MOUSE_EXITED);
 158 }
 159
 160 void WindowEventDispatcher::ProcessedTouchEvent(ui::TouchEvent* event,
 161                                                 Window* window,
 162                                                 ui::EventResult result) {
 163   // Once we've fully migrated to the eager gesture detector, we won't need to
 164   // pass an event here.
 165   scoped_ptr<ui::GestureRecognizer::Gestures> gestures(
 166       ui::GestureRecognizer::Get()->AckAsyncTouchEvent(
 167           *event, result, window));
 168   DispatchDetails details = ProcessGestures(gestures.get());
 169   if (details.dispatcher_destroyed)
 170     return;
 171 }
 172
 173 void WindowEventDispatcher::HoldPointerMoves() {
 174   if (!move_hold_count_)
 175     held_event_factory_.InvalidateWeakPtrs();
 176   ++move_hold_count_;
 177   TRACE_EVENT_ASYNC_BEGIN0("ui", "WindowEventDispatcher::HoldPointerMoves",
 178                            this);
 179 }
 180
 181 void WindowEventDispatcher::ReleasePointerMoves() {
 182   --move_hold_count_;
 183   DCHECK_GE(move_hold_count_, 0);
 184   if (!move_hold_count_ && held_move_event_) {
 185     // We don't want to call DispatchHeldEvents directly, because this might be
 186     // called from a deep stack while another event, in which case dispatching
 187     // another one may not be safe/expected.  Instead we post a task, that we
 188     // may cancel if HoldPointerMoves is called again before it executes.
 189     base::MessageLoop::current()->PostNonNestableTask(
 190         FROM_HERE, base::Bind(
 191           base::IgnoreResult(&WindowEventDispatcher::DispatchHeldEvents),
 192           held_event_factory_.GetWeakPtr()));
 193   }
 194   TRACE_EVENT_ASYNC_END0("ui", "WindowEventDispatcher::HoldPointerMoves", this);
 195 }
 196
 197 gfx::Point WindowEventDispatcher::GetLastMouseLocationInRoot() const {
 198   gfx::Point location = Env::GetInstance()->last_mouse_location();
 199   client::ScreenPositionClient* client =
 200       client::GetScreenPositionClient(window());
 201   if (client)
 202     client->ConvertPointFromScreen(window(), &location);
 203   return location;
 204 }
 205
 206 void WindowEventDispatcher::OnHostLostMouseGrab() {
 207   mouse_pressed_handler_ = NULL;
 208   mouse_moved_handler_ = NULL;
 209 }
 210
 211 void WindowEventDispatcher::OnCursorMovedToRootLocation(
 212     const gfx::Point& root_location) {
 213   SetLastMouseLocation(window(), root_location);
 214   synthesize_mouse_move_ = false;
 215 }
 216
 217 void WindowEventDispatcher::OnPostNotifiedWindowDestroying(Window* window) {
 218   OnWindowHidden(window, WINDOW_DESTROYED);
 219 }
 220
 221 ////////////////////////////////////////////////////////////////////////////////
 222 // WindowEventDispatcher, private:
 223
 224 Window* WindowEventDispatcher::window() {
 225   return host_->window();
 226 }
 227
 228 const Window* WindowEventDispatcher::window() const {
 229   return host_->window();
 230 }
 231
 232 void WindowEventDispatcher::TransformEventForDeviceScaleFactor(
 233     ui::LocatedEvent* event) {
 234   event->UpdateForRootTransform(host_->GetInverseRootTransform());
 235 }
 236
 237 void WindowEventDispatcher::DispatchMouseExitToHidingWindow(Window* window) {
 238   // The mouse capture is intentionally ignored. Think that a mouse enters
 239   // to a window, the window sets the capture, the mouse exits the window,
 240   // and then it releases the capture. In that case OnMouseExited won't
 241   // be called. So it is natural not to emit OnMouseExited even though
 242   // |window| is the capture window.
 243   gfx::Point last_mouse_location = GetLastMouseLocationInRoot();
 244   if (window->Contains(mouse_moved_handler_) &&
 245       window->ContainsPointInRoot(last_mouse_location)) {
 246     DispatchDetails details =
 247         DispatchMouseExitAtPoint(window, last_mouse_location);
 248     if (details.dispatcher_destroyed)
 249       return;
 250   }
 251 }
 252
 253 ui::EventDispatchDetails WindowEventDispatcher::DispatchMouseEnterOrExit(
 254     Window* target,
 255     const ui::MouseEvent& event,
 256     ui::EventType type) {
 257   if (event.type() != ui::ET_MOUSE_CAPTURE_CHANGED &&
 258       !(event.flags() & ui::EF_IS_SYNTHESIZED)) {
 259     SetLastMouseLocation(window(), event.root_location());
 260   }
 261
 262   if (!mouse_moved_handler_ || !mouse_moved_handler_->delegate() ||
 263       !window()->Contains(mouse_moved_handler_))
 264     return DispatchDetails();
 265
 266   // |event| may be an event in the process of being dispatched to a target (in
 267   // which case its locations will be in the event's target's coordinate
 268   // system), or a synthetic event created in root-window (in which case, the
 269   // event's target will be NULL, and the event will be in the root-window's
 270   // coordinate system.
 271   if (!target)
 272     target = window();
 273   ui::MouseEvent translated_event(event,
 274                                   target,
 275                                   mouse_moved_handler_,
 276                                   type,
 277                                   event.flags() | ui::EF_IS_SYNTHESIZED);
 278   return DispatchEvent(mouse_moved_handler_, &translated_event);
 279 }
 280
 281 ui::EventDispatchDetails WindowEventDispatcher::ProcessGestures(
 282     ui::GestureRecognizer::Gestures* gestures) {
 283   DispatchDetails details;
 284   if (!gestures || gestures->empty())
 285     return details;
 286
 287   Window* target = GetGestureTarget(gestures->get().at(0));
 288   if (!target)
 289     return details;
 290
 291   for (size_t i = 0; i < gestures->size(); ++i) {
 292     ui::GestureEvent* event = gestures->get().at(i);
 293     event->ConvertLocationToTarget(window(), target);
 294     details = DispatchEvent(target, event);
 295     if (details.dispatcher_destroyed || details.target_destroyed)
 296       break;
 297   }
 298   return details;
 299 }
 300
 301 void WindowEventDispatcher::OnWindowHidden(Window* invisible,
 302                                            WindowHiddenReason reason) {
 303   // If the window the mouse was pressed in becomes invisible, it should no
 304   // longer receive mouse events.
 305   if (invisible->Contains(mouse_pressed_handler_))
 306     mouse_pressed_handler_ = NULL;
 307   if (invisible->Contains(mouse_moved_handler_))
 308     mouse_moved_handler_ = NULL;
 309
 310   // If events are being dispatched from a nested message-loop, and the target
 311   // of the outer loop is hidden or moved to another dispatcher during
 312   // dispatching events in the inner loop, then reset the target for the outer
 313   // loop.
 314   if (invisible->Contains(old_dispatch_target_))
 315     old_dispatch_target_ = NULL;
 316
 317   invisible->CleanupGestureState();
 318
 319   // Do not clear the capture, and the |event_dispatch_target_| if the
 320   // window is moving across hosts, because the target itself is actually still
 321   // visible and clearing them stops further event processing, which can cause
 322   // unexpected behaviors. See crbug.com/157583
 323   if (reason != WINDOW_MOVING) {
 324     // We don't ask |invisible| here, because invisible may have been removed
 325     // from the window hierarchy already by the time this function is called
 326     // (OnWindowDestroyed).
 327     client::CaptureClient* capture_client =
 328         client::GetCaptureClient(host_->window());
 329     Window* capture_window =
 330         capture_client ? capture_client->GetCaptureWindow() : NULL;
 331
 332     if (invisible->Contains(event_dispatch_target_))
 333       event_dispatch_target_ = NULL;
 334
 335     // If the ancestor of the capture window is hidden, release the capture.
 336     // Note that this may delete the window so do not use capture_window
 337     // after this.
 338     if (invisible->Contains(capture_window) && invisible != window())
 339       capture_window->ReleaseCapture();
 340   }
 341 }
 342
 343 Window* WindowEventDispatcher::GetGestureTarget(ui::GestureEvent* event) {
 344   Window* target = NULL;
 345   if (!event->IsEndingEvent()) {
 346     // The window that received the start event (e.g. scroll begin) needs to
 347     // receive the end event (e.g. scroll end).
 348     target = client::GetCaptureWindow(window());
 349   }
 350   if (!target) {
 351     target = ConsumerToWindow(
 352         ui::GestureRecognizer::Get()->GetTargetForGestureEvent(*event));
 353   }
 354
 355   return target;
 356 }
 357
 358 ////////////////////////////////////////////////////////////////////////////////
 359 // WindowEventDispatcher, aura::client::CaptureDelegate implementation:
 360
 361 void WindowEventDispatcher::UpdateCapture(Window* old_capture,
 362                                           Window* new_capture) {
 363   // |mouse_moved_handler_| may have been set to a Window in a different root
 364   // (see below). Clear it here to ensure we don't end up referencing a stale
 365   // Window.
 366   if (mouse_moved_handler_ && !window()->Contains(mouse_moved_handler_))
 367     mouse_moved_handler_ = NULL;
 368
 369   if (old_capture && old_capture->GetRootWindow() == window() &&
 370       old_capture->delegate()) {
 371     // Send a capture changed event with bogus location data.
 372     ui::MouseEvent event(ui::ET_MOUSE_CAPTURE_CHANGED, gfx::Point(),
 373                          gfx::Point(), 0, 0);
 374
 375     DispatchDetails details = DispatchEvent(old_capture, &event);
 376     if (details.dispatcher_destroyed)
 377       return;
 378
 379     if (!details.target_destroyed)
 380       old_capture->delegate()->OnCaptureLost();
 381   }
 382
 383   if (new_capture) {
 384     // Make all subsequent mouse events go to the capture window. We shouldn't
 385     // need to send an event here as OnCaptureLost() should take care of that.
 386     if (mouse_moved_handler_ || Env::GetInstance()->IsMouseButtonDown())
 387       mouse_moved_handler_ = new_capture;
 388   } else {
 389     // Make sure mouse_moved_handler gets updated.
 390     DispatchDetails details = SynthesizeMouseMoveEvent();
 391     if (details.dispatcher_destroyed)
 392       return;
 393   }
 394   mouse_pressed_handler_ = NULL;
 395 }
 396
 397 void WindowEventDispatcher::OnOtherRootGotCapture() {
 398   // Windows provides the TrackMouseEvents API which allows us to rely on the
 399   // OS to send us the mouse exit events (WM_MOUSELEAVE). Additionally on
 400   // desktop Windows, every top level window could potentially have its own
 401   // root window, in which case this function will get called whenever those
 402   // windows grab mouse capture. Sending mouse exit messages in these cases
 403   // causes subtle bugs like (crbug.com/394672).
 404 #if !defined(OS_WIN)
 405   if (mouse_moved_handler_) {
 406     // Dispatch a mouse exit to reset any state associated with hover. This is
 407     // important when going from no window having capture to a window having
 408     // capture because we do not dispatch ET_MOUSE_CAPTURE_CHANGED in this case.
 409     DispatchDetails details =
 410         DispatchMouseExitAtPoint(nullptr, GetLastMouseLocationInRoot());
 411     if (details.dispatcher_destroyed)
 412       return;
 413   }
 414 #endif
 415
 416   mouse_moved_handler_ = NULL;
 417   mouse_pressed_handler_ = NULL;
 418 }
 419
 420 void WindowEventDispatcher::SetNativeCapture() {
 421   host_->SetCapture();
 422 }
 423
 424 void WindowEventDispatcher::ReleaseNativeCapture() {
 425   host_->ReleaseCapture();
 426 }
 427
 428 ////////////////////////////////////////////////////////////////////////////////
 429 // WindowEventDispatcher, ui::EventProcessor implementation:
 430 ui::EventTarget* WindowEventDispatcher::GetRootTarget() {
 431   return window();
 432 }
 433
 434 void WindowEventDispatcher::OnEventProcessingStarted(ui::Event* event) {
 435   // The held events are already in |window()|'s coordinate system. So it is
 436   // not necessary to apply the transform to convert from the host's
 437   // coordinate system to |window()|'s coordinate system.
 438   if (event->IsLocatedEvent() && !dispatching_held_event_)
 439     TransformEventForDeviceScaleFactor(static_cast<ui::LocatedEvent*>(event));
 440 }
 441
 442 ////////////////////////////////////////////////////////////////////////////////
 443 // WindowEventDispatcher, ui::EventDispatcherDelegate implementation:
 444
 445 bool WindowEventDispatcher::CanDispatchToTarget(ui::EventTarget* target) {
 446   return event_dispatch_target_ == target;
 447 }
 448
 449 ui::EventDispatchDetails WindowEventDispatcher::PreDispatchEvent(
 450     ui::EventTarget* target,
 451     ui::Event* event) {
 452   Window* target_window = static_cast<Window*>(target);
 453   CHECK(window()->Contains(target_window));
 454
 455   if (!dispatching_held_event_) {
 456     bool can_be_held = IsEventCandidateForHold(*event);
 457     if (!move_hold_count_ || !can_be_held) {
 458       if (can_be_held)
 459         held_move_event_.reset();
 460       DispatchDetails details = DispatchHeldEvents();
 461       if (details.dispatcher_destroyed || details.target_destroyed)
 462         return details;
 463     }
 464   }
 465
 466   if (event->IsMouseEvent()) {
 467     PreDispatchMouseEvent(target_window, static_cast<ui::MouseEvent*>(event));
 468   } else if (event->IsScrollEvent()) {
 469     PreDispatchLocatedEvent(target_window,
 470                             static_cast<ui::ScrollEvent*>(event));
 471   } else if (event->IsTouchEvent()) {
 472     PreDispatchTouchEvent(target_window, static_cast<ui::TouchEvent*>(event));
 473   }
 474   old_dispatch_target_ = event_dispatch_target_;
 475   event_dispatch_target_ = static_cast<Window*>(target);
 476   return DispatchDetails();
 477 }
 478
 479 ui::EventDispatchDetails WindowEventDispatcher::PostDispatchEvent(
 480     ui::EventTarget* target,
 481     const ui::Event& event) {
 482   DispatchDetails details;
 483   if (!target || target != event_dispatch_target_)
 484     details.target_destroyed = true;
 485   event_dispatch_target_ = old_dispatch_target_;
 486   old_dispatch_target_ = NULL;
 487 #ifndef NDEBUG
 488   DCHECK(!event_dispatch_target_ || window()->Contains(event_dispatch_target_));
 489 #endif
 490
 491   if (event.IsTouchEvent() && !details.target_destroyed) {
 492     // Do not let 'held' touch events contribute to any gestures unless it is
 493     // being dispatched.
 494     if (dispatching_held_event_ || !held_move_event_ ||
 495         !held_move_event_->IsTouchEvent()) {
 496       const ui::TouchEvent& touchevent =
 497           static_cast<const ui::TouchEvent&>(event);
 498
 499       if (!touchevent.synchronous_handling_disabled()) {
 500         scoped_ptr<ui::GestureRecognizer::Gestures> gestures;
 501
 502         // Once we've fully migrated to the eager gesture detector, we won't
 503         // need to pass an event here.
 504         gestures.reset(ui::GestureRecognizer::Get()->AckSyncTouchEvent(
 505             touchevent.unique_event_id(), event.result(),
 506             static_cast<Window*>(target)));
 507
 508         return ProcessGestures(gestures.get());
 509       }
 510     }
 511   }
 512
 513   return details;
 514 }
 515
 516 ////////////////////////////////////////////////////////////////////////////////
 517 // WindowEventDispatcher, ui::GestureEventHelper implementation:
 518
 519 bool WindowEventDispatcher::CanDispatchToConsumer(
 520     ui::GestureConsumer* consumer) {
 521   Window* consumer_window = ConsumerToWindow(consumer);
 522   return (consumer_window && consumer_window->GetRootWindow() == window());
 523 }
 524
 525 void WindowEventDispatcher::DispatchCancelTouchEvent(ui::TouchEvent* event) {
 526   // The touchcancel event's location is based on the last known location of
 527   // the pointer, in dips. OnEventFromSource expects events with co-ordinates
 528   // in raw pixels, so we convert back to raw pixels here.
 529   event->UpdateForRootTransform(host_->GetRootTransform());
 530   DispatchDetails details = OnEventFromSource(event);
 531   if (details.dispatcher_destroyed)
 532     return;
 533 }
 534
 535 ////////////////////////////////////////////////////////////////////////////////
 536 // WindowEventDispatcher, WindowObserver implementation:
 537
 538 void WindowEventDispatcher::OnWindowDestroying(Window* window) {
 539   if (!host_->window()->Contains(window))
 540     return;
 541
 542   SynthesizeMouseMoveAfterChangeToWindow(window);
 543 }
 544
 545 void WindowEventDispatcher::OnWindowDestroyed(Window* window) {
 546   // We observe all windows regardless of what root Window (if any) they're
 547   // attached to.
 548   observer_manager_.Remove(window);
 549 }
 550
 551 void WindowEventDispatcher::OnWindowAddedToRootWindow(Window* attached) {
 552   if (!observer_manager_.IsObserving(attached))
 553     observer_manager_.Add(attached);
 554
 555   if (!host_->window()->Contains(attached))
 556     return;
 557
 558   SynthesizeMouseMoveAfterChangeToWindow(attached);
 559 }
 560
 561 void WindowEventDispatcher::OnWindowRemovingFromRootWindow(Window* detached,
 562                                                            Window* new_root) {
 563   if (!host_->window()->Contains(detached))
 564     return;
 565
 566   DCHECK(client::GetCaptureWindow(window()) != window());
 567
 568   DispatchMouseExitToHidingWindow(detached);
 569   SynthesizeMouseMoveAfterChangeToWindow(detached);
 570
 571   // Hiding the window releases capture which can implicitly destroy the window
 572   // so the window may no longer be valid after this call.
 573   OnWindowHidden(detached, new_root ? WINDOW_MOVING : WINDOW_HIDDEN);
 574 }
 575
 576 void WindowEventDispatcher::OnWindowVisibilityChanging(Window* window,
 577                                                        bool visible) {
 578   if (!host_->window()->Contains(window))
 579     return;
 580
 581   DispatchMouseExitToHidingWindow(window);
 582 }
 583
 584 void WindowEventDispatcher::OnWindowVisibilityChanged(Window* window,
 585                                                       bool visible) {
 586   if (!host_->window()->Contains(window))
 587     return;
 588
 589   if (window->ContainsPointInRoot(GetLastMouseLocationInRoot()))
 590     PostSynthesizeMouseMove();
 591
 592   // Hiding the window releases capture which can implicitly destroy the window
 593   // so the window may no longer be valid after this call.
 594   if (!visible)
 595     OnWindowHidden(window, WINDOW_HIDDEN);
 596 }
 597
 598 void WindowEventDispatcher::OnWindowBoundsChanged(Window* window,
 599                                                   const gfx::Rect& old_bounds,
 600                                                   const gfx::Rect& new_bounds) {
 601   if (!host_->window()->Contains(window))
 602     return;
 603
 604   if (window == host_->window()) {
 605     TRACE_EVENT1("ui", "WindowEventDispatcher::OnWindowBoundsChanged(root)",
 606                  "size", new_bounds.size().ToString());
 607
 608     DispatchDetails details = DispatchHeldEvents();
 609     if (details.dispatcher_destroyed)
 610       return;
 611
 612     synthesize_mouse_move_ = false;
 613   }
 614
 615   if (window->IsVisible() && !window->ignore_events()) {
 616     gfx::Rect old_bounds_in_root = old_bounds, new_bounds_in_root = new_bounds;
 617     Window::ConvertRectToTarget(window->parent(), host_->window(),
 618                                 &old_bounds_in_root);
 619     Window::ConvertRectToTarget(window->parent(), host_->window(),
 620                                 &new_bounds_in_root);
 621     gfx::Point last_mouse_location = GetLastMouseLocationInRoot();
 622     if (old_bounds_in_root.Contains(last_mouse_location) !=
 623         new_bounds_in_root.Contains(last_mouse_location)) {
 624       PostSynthesizeMouseMove();
 625     }
 626   }
 627 }
 628
 629 void WindowEventDispatcher::OnWindowTransforming(Window* window) {
 630   if (!host_->window()->Contains(window))
 631     return;
 632
 633   SynthesizeMouseMoveAfterChangeToWindow(window);
 634 }
 635
 636 void WindowEventDispatcher::OnWindowTransformed(Window* window) {
 637   if (!host_->window()->Contains(window))
 638     return;
 639
 640   SynthesizeMouseMoveAfterChangeToWindow(window);
 641 }
 642
 643 ///////////////////////////////////////////////////////////////////////////////
 644 // WindowEventDispatcher, EnvObserver implementation:
 645
 646 void WindowEventDispatcher::OnWindowInitialized(Window* window) {
 647   observer_manager_.Add(window);
 648 }
 649
 650 ////////////////////////////////////////////////////////////////////////////////
 651 // WindowEventDispatcher, private:
 652
 653 ui::EventDispatchDetails WindowEventDispatcher::DispatchHeldEvents() {
 654   if (!held_repostable_event_ && !held_move_event_)
 655     return DispatchDetails();
 656
 657   CHECK(!dispatching_held_event_);
 658   dispatching_held_event_ = true;
 659
 660   DispatchDetails dispatch_details;
 661   if (held_repostable_event_) {
 662     if (held_repostable_event_->type() == ui::ET_MOUSE_PRESSED) {
 663       scoped_ptr<ui::MouseEvent> mouse_event(
 664           static_cast<ui::MouseEvent*>(held_repostable_event_.release()));
 665       dispatch_details = OnEventFromSource(mouse_event.get());
 666     } else {
 667       // TODO(rbyers): GESTURE_TAP_DOWN not yet supported: crbug.com/170987.
 668       NOTREACHED();
 669     }
 670     if (dispatch_details.dispatcher_destroyed)
 671       return dispatch_details;
 672   }
 673
 674   if (held_move_event_) {
 675     // If a mouse move has been synthesized, the target location is suspect,
 676     // so drop the held mouse event.
 677     if (held_move_event_->IsTouchEvent() ||
 678         (held_move_event_->IsMouseEvent() && !synthesize_mouse_move_)) {
 679       dispatch_details = OnEventFromSource(held_move_event_.get());
 680     }
 681     if (!dispatch_details.dispatcher_destroyed)
 682       held_move_event_.reset();
 683   }
 684
 685   if (!dispatch_details.dispatcher_destroyed)
 686     dispatching_held_event_ = false;
 687   return dispatch_details;
 688 }
 689
 690 void WindowEventDispatcher::PostSynthesizeMouseMove() {
 691   if (synthesize_mouse_move_)
 692     return;
 693   synthesize_mouse_move_ = true;
 694   base::MessageLoop::current()->PostNonNestableTask(
 695       FROM_HERE,
 696       base::Bind(base::IgnoreResult(
 697           &WindowEventDispatcher::SynthesizeMouseMoveEvent),
 698           held_event_factory_.GetWeakPtr()));
 699 }
 700
 701 void WindowEventDispatcher::SynthesizeMouseMoveAfterChangeToWindow(
 702     Window* window) {
 703   if (window->IsVisible() &&
 704       window->ContainsPointInRoot(GetLastMouseLocationInRoot())) {
 705     PostSynthesizeMouseMove();
 706   }
 707 }
 708
 709 ui::EventDispatchDetails WindowEventDispatcher::SynthesizeMouseMoveEvent() {
 710   DispatchDetails details;
 711   if (!synthesize_mouse_move_)
 712     return details;
 713   synthesize_mouse_move_ = false;
 714
 715   // If one of the mouse buttons is currently down, then do not synthesize a
 716   // mouse-move event. In such cases, aura could synthesize a DRAGGED event
 717   // instead of a MOVED event, but in multi-display/multi-host scenarios, the
 718   // DRAGGED event can be synthesized in the incorrect host. So avoid
 719   // synthesizing any events at all.
 720   if (Env::GetInstance()->mouse_button_flags())
 721     return details;
 722
 723   gfx::Point root_mouse_location = GetLastMouseLocationInRoot();
 724   if (!window()->bounds().Contains(root_mouse_location))
 725     return details;
 726   gfx::Point host_mouse_location = root_mouse_location;
 727   host_->ConvertPointToHost(&host_mouse_location);
 728   ui::MouseEvent event(ui::ET_MOUSE_MOVED,
 729                        host_mouse_location,
 730                        host_mouse_location,
 731                        ui::EF_IS_SYNTHESIZED,
 732                        0);
 733   return OnEventFromSource(&event);
 734 }
 735
 736 void WindowEventDispatcher::PreDispatchLocatedEvent(Window* target,
 737                                                     ui::LocatedEvent* event) {
 738   int flags = event->flags();
 739   if (IsNonClientLocation(target, event->location()))
 740     flags |= ui::EF_IS_NON_CLIENT;
 741   event->set_flags(flags);
 742
 743   if (!dispatching_held_event_ &&
 744       (event->IsMouseEvent() || event->IsScrollEvent()) &&
 745       !(event->flags() & ui::EF_IS_SYNTHESIZED)) {
 746     if (event->type() != ui::ET_MOUSE_CAPTURE_CHANGED)
 747       SetLastMouseLocation(window(), event->root_location());
 748     synthesize_mouse_move_ = false;
 749   }
 750 }
 751
 752 void WindowEventDispatcher::PreDispatchMouseEvent(Window* target,
 753                                                   ui::MouseEvent* event) {
 754   client::CursorClient* cursor_client = client::GetCursorClient(window());
 755   // We allow synthesized mouse exit events through even if mouse events are
 756   // disabled. This ensures that hover state, etc on controls like buttons is
 757   // cleared.
 758   if (cursor_client &&
 759       !cursor_client->IsMouseEventsEnabled() &&
 760       (event->flags() & ui::EF_IS_SYNTHESIZED) &&
 761       (event->type() != ui::ET_MOUSE_EXITED)) {
 762     event->SetHandled();
 763     return;
 764   }
 765
 766   if (IsEventCandidateForHold(*event) && !dispatching_held_event_) {
 767     if (move_hold_count_) {
 768       if (!(event->flags() & ui::EF_IS_SYNTHESIZED) &&
 769           event->type() != ui::ET_MOUSE_CAPTURE_CHANGED) {
 770         SetLastMouseLocation(window(), event->root_location());
 771       }
 772       held_move_event_.reset(new ui::MouseEvent(*event, target, window()));
 773       event->SetHandled();
 774       return;
 775     } else {
 776       // We may have a held event for a period between the time move_hold_count_
 777       // fell to 0 and the DispatchHeldEvents executes. Since we're going to
 778       // dispatch the new event directly below, we can reset the old one.
 779       held_move_event_.reset();
 780     }
 781   }
 782
 783   const int kMouseButtonFlagMask = ui::EF_LEFT_MOUSE_BUTTON |
 784                                    ui::EF_MIDDLE_MOUSE_BUTTON |
 785                                    ui::EF_RIGHT_MOUSE_BUTTON;
 786   switch (event->type()) {
 787     case ui::ET_MOUSE_EXITED:
 788       if (!target || target == window()) {
 789         DispatchDetails details =
 790             DispatchMouseEnterOrExit(target, *event, ui::ET_MOUSE_EXITED);
 791         if (details.dispatcher_destroyed) {
 792           event->SetHandled();
 793           return;
 794         }
 795         mouse_moved_handler_ = NULL;
 796       }
 797       break;
 798     case ui::ET_MOUSE_MOVED:
 799       // Send an exit to the current |mouse_moved_handler_| and an enter to
 800       // |target|. Take care that both us and |target| aren't destroyed during
 801       // dispatch.
 802       if (target != mouse_moved_handler_) {
 803         aura::Window* old_mouse_moved_handler = mouse_moved_handler_;
 804         WindowTracker live_window;
 805         live_window.Add(target);
 806         DispatchDetails details =
 807             DispatchMouseEnterOrExit(target, *event, ui::ET_MOUSE_EXITED);
 808         if (details.dispatcher_destroyed) {
 809           event->SetHandled();
 810           return;
 811         }
 812         // If the |mouse_moved_handler_| changes out from under us, assume a
 813         // nested message loop ran and we don't need to do anything.
 814         if (mouse_moved_handler_ != old_mouse_moved_handler) {
 815           event->SetHandled();
 816           return;
 817         }
 818         if (!live_window.Contains(target) || details.target_destroyed) {
 819           mouse_moved_handler_ = NULL;
 820           event->SetHandled();
 821           return;
 822         }
 823         live_window.Remove(target);
 824
 825         mouse_moved_handler_ = target;
 826         details =
 827             DispatchMouseEnterOrExit(target, *event, ui::ET_MOUSE_ENTERED);
 828         if (details.dispatcher_destroyed || details.target_destroyed) {
 829           event->SetHandled();
 830           return;
 831         }
 832       }
 833       break;
 834     case ui::ET_MOUSE_PRESSED:
 835       // Don't set the mouse pressed handler for non client mouse down events.
 836       // These are only sent by Windows and are not always followed with non
 837       // client mouse up events which causes subsequent mouse events to be
 838       // sent to the wrong target.
 839       if (!(event->flags() & ui::EF_IS_NON_CLIENT) && !mouse_pressed_handler_)
 840         mouse_pressed_handler_ = target;
 841       Env::GetInstance()->set_mouse_button_flags(
 842           event->flags() & kMouseButtonFlagMask);
 843       break;
 844     case ui::ET_MOUSE_RELEASED:
 845       mouse_pressed_handler_ = NULL;
 846       Env::GetInstance()->set_mouse_button_flags(event->flags() &
 847           kMouseButtonFlagMask & ~event->changed_button_flags());
 848       break;
 849     default:
 850       break;
 851   }
 852
 853   PreDispatchLocatedEvent(target, event);
 854 }
 855
 856 void WindowEventDispatcher::PreDispatchTouchEvent(Window* target,
 857                                                   ui::TouchEvent* event) {
 858   switch (event->type()) {
 859     case ui::ET_TOUCH_PRESSED:
 860       touch_ids_down_ |= (1 << event->touch_id());
 861       Env::GetInstance()->set_touch_down(touch_ids_down_ != 0);
 862       break;
 863
 864       // Handle ET_TOUCH_CANCELLED only if it has a native event.
 865     case ui::ET_TOUCH_CANCELLED:
 866       if (!event->HasNativeEvent())
 867         break;
 868       // fallthrough
 869     case ui::ET_TOUCH_RELEASED:
 870       touch_ids_down_ = (touch_ids_down_ | (1 << event->touch_id())) ^
 871             (1 << event->touch_id());
 872       Env::GetInstance()->set_touch_down(touch_ids_down_ != 0);
 873       break;
 874
 875     case ui::ET_TOUCH_MOVED:
 876       if (move_hold_count_ && !dispatching_held_event_) {
 877         held_move_event_.reset(new ui::TouchEvent(*event, target, window()));
 878         event->SetHandled();
 879         return;
 880       }
 881       break;
 882
 883     default:
 884       NOTREACHED();
 885       break;
 886   }
 887
 888   ui::TouchEvent orig_event(*event, target, window());
 889   if (!ui::GestureRecognizer::Get()->ProcessTouchEventPreDispatch(&orig_event,
 890                                                                   target)) {
 891     // The event is invalid - ignore it.
 892     event->StopPropagation();
 893     event->DisableSynchronousHandling();
 894     return;
 895   }
 896
 897   // This flag is set depending on the gestures recognized in the call above,
 898   // and needs to propagate with the forwarded event.
 899   event->set_may_cause_scrolling(orig_event.may_cause_scrolling());
 900
 901   PreDispatchLocatedEvent(target, event);
 902 }
 903
 904 }  // namespace aura