src/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
 144   Window* target = GetGestureTarget(event);
 145   if (target) {
 146     event->ConvertLocationToTarget(window(), target);
 147     DispatchDetails details = DispatchEvent(target, event);
 148     if (details.dispatcher_destroyed)
 149       return;
 150   }
 151 }
 152
 153 DispatchDetails WindowEventDispatcher::DispatchMouseExitAtPoint(
 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(event, ui::ET_MOUSE_EXITED);
 158 }
 159
 160 void WindowEventDispatcher::ProcessedTouchEvent(ui::TouchEvent* event,
 161                                                 Window* window,
 162                                                 ui::EventResult result) {
 163   // TODO(tdresser): Move this to PreDispatchTouchEvent, to enable eager
 164   // gesture detection. See crbug.com/410280.
 165   if (!ui::GestureRecognizer::Get()
 166            ->ProcessTouchEventPreDispatch(*event, window)) {
 167     return;
 168   }
 169
 170   // Once we've fully migrated to the eager gesture detector, we won't need to
 171   // pass an event here.
 172   scoped_ptr<ui::GestureRecognizer::Gestures> gestures(
 173       ui::GestureRecognizer::Get()->ProcessTouchEventOnAsyncAck(
 174           *event, result, window));
 175   DispatchDetails details = ProcessGestures(gestures.get());
 176   if (details.dispatcher_destroyed)
 177     return;
 178 }
 179
 180 void WindowEventDispatcher::HoldPointerMoves() {
 181   if (!move_hold_count_)
 182     held_event_factory_.InvalidateWeakPtrs();
 183   ++move_hold_count_;
 184   TRACE_EVENT_ASYNC_BEGIN0("ui", "WindowEventDispatcher::HoldPointerMoves",
 185                            this);
 186 }
 187
 188 void WindowEventDispatcher::ReleasePointerMoves() {
 189   --move_hold_count_;
 190   DCHECK_GE(move_hold_count_, 0);
 191   if (!move_hold_count_ && held_move_event_) {
 192     // We don't want to call DispatchHeldEvents directly, because this might be
 193     // called from a deep stack while another event, in which case dispatching
 194     // another one may not be safe/expected.  Instead we post a task, that we
 195     // may cancel if HoldPointerMoves is called again before it executes.
 196     base::MessageLoop::current()->PostNonNestableTask(
 197         FROM_HERE, base::Bind(
 198           base::IgnoreResult(&WindowEventDispatcher::DispatchHeldEvents),
 199           held_event_factory_.GetWeakPtr()));
 200   }
 201   TRACE_EVENT_ASYNC_END0("ui", "WindowEventDispatcher::HoldPointerMoves", this);
 202 }
 203
 204 gfx::Point WindowEventDispatcher::GetLastMouseLocationInRoot() const {
 205   gfx::Point location = Env::GetInstance()->last_mouse_location();
 206   client::ScreenPositionClient* client =
 207       client::GetScreenPositionClient(window());
 208   if (client)
 209     client->ConvertPointFromScreen(window(), &location);
 210   return location;
 211 }
 212
 213 void WindowEventDispatcher::OnHostLostMouseGrab() {
 214   mouse_pressed_handler_ = NULL;
 215   mouse_moved_handler_ = NULL;
 216 }
 217
 218 void WindowEventDispatcher::OnCursorMovedToRootLocation(
 219     const gfx::Point& root_location) {
 220   SetLastMouseLocation(window(), root_location);
 221   synthesize_mouse_move_ = false;
 222 }
 223
 224 void WindowEventDispatcher::OnPostNotifiedWindowDestroying(Window* window) {
 225   OnWindowHidden(window, WINDOW_DESTROYED);
 226 }
 227
 228 ////////////////////////////////////////////////////////////////////////////////
 229 // WindowEventDispatcher, private:
 230
 231 Window* WindowEventDispatcher::window() {
 232   return host_->window();
 233 }
 234
 235 const Window* WindowEventDispatcher::window() const {
 236   return host_->window();
 237 }
 238
 239 void WindowEventDispatcher::TransformEventForDeviceScaleFactor(
 240     ui::LocatedEvent* event) {
 241   event->UpdateForRootTransform(host_->GetInverseRootTransform());
 242 }
 243
 244 void WindowEventDispatcher::DispatchMouseExitToHidingWindow(Window* window) {
 245   // The mouse capture is intentionally ignored. Think that a mouse enters
 246   // to a window, the window sets the capture, the mouse exits the window,
 247   // and then it releases the capture. In that case OnMouseExited won't
 248   // be called. So it is natural not to emit OnMouseExited even though
 249   // |window| is the capture window.
 250   gfx::Point last_mouse_location = GetLastMouseLocationInRoot();
 251   if (window->Contains(mouse_moved_handler_) &&
 252       window->ContainsPointInRoot(last_mouse_location)) {
 253     DispatchDetails details = DispatchMouseExitAtPoint(last_mouse_location);
 254     if (details.dispatcher_destroyed)
 255       return;
 256   }
 257 }
 258
 259 ui::EventDispatchDetails WindowEventDispatcher::DispatchMouseEnterOrExit(
 260     const ui::MouseEvent& event,
 261     ui::EventType type) {
 262   if (event.type() != ui::ET_MOUSE_CAPTURE_CHANGED &&
 263       !(event.flags() & ui::EF_IS_SYNTHESIZED)) {
 264     SetLastMouseLocation(window(), event.root_location());
 265   }
 266
 267   if (!mouse_moved_handler_ || !mouse_moved_handler_->delegate() ||
 268       !window()->Contains(mouse_moved_handler_))
 269     return DispatchDetails();
 270
 271   // |event| may be an event in the process of being dispatched to a target (in
 272   // which case its locations will be in the event's target's coordinate
 273   // system), or a synthetic event created in root-window (in which case, the
 274   // event's target will be NULL, and the event will be in the root-window's
 275   // coordinate system.
 276   aura::Window* target = static_cast<Window*>(event.target());
 277   if (!target)
 278     target = window();
 279   ui::MouseEvent translated_event(event,
 280                                   target,
 281                                   mouse_moved_handler_,
 282                                   type,
 283                                   event.flags() | ui::EF_IS_SYNTHESIZED);
 284   return DispatchEvent(mouse_moved_handler_, &translated_event);
 285 }
 286
 287 ui::EventDispatchDetails WindowEventDispatcher::ProcessGestures(
 288     ui::GestureRecognizer::Gestures* gestures) {
 289   DispatchDetails details;
 290   if (!gestures || gestures->empty())
 291     return details;
 292
 293   Window* target = GetGestureTarget(gestures->get().at(0));
 294   if (!target)
 295     return details;
 296
 297   for (size_t i = 0; i < gestures->size(); ++i) {
 298     ui::GestureEvent* event = gestures->get().at(i);
 299     event->ConvertLocationToTarget(window(), target);
 300     details = DispatchEvent(target, event);
 301     if (details.dispatcher_destroyed || details.target_destroyed)
 302       break;
 303   }
 304   return details;
 305 }
 306
 307 void WindowEventDispatcher::OnWindowHidden(Window* invisible,
 308                                            WindowHiddenReason reason) {
 309   // If the window the mouse was pressed in becomes invisible, it should no
 310   // longer receive mouse events.
 311   if (invisible->Contains(mouse_pressed_handler_))
 312     mouse_pressed_handler_ = NULL;
 313   if (invisible->Contains(mouse_moved_handler_))
 314     mouse_moved_handler_ = NULL;
 315
 316   // If events are being dispatched from a nested message-loop, and the target
 317   // of the outer loop is hidden or moved to another dispatcher during
 318   // dispatching events in the inner loop, then reset the target for the outer
 319   // loop.
 320   if (invisible->Contains(old_dispatch_target_))
 321     old_dispatch_target_ = NULL;
 322
 323   invisible->CleanupGestureState();
 324
 325   // Do not clear the capture, and the |event_dispatch_target_| if the
 326   // window is moving across hosts, because the target itself is actually still
 327   // visible and clearing them stops further event processing, which can cause
 328   // unexpected behaviors. See crbug.com/157583
 329   if (reason != WINDOW_MOVING) {
 330     // We don't ask |invisible| here, because invisible may have been removed
 331     // from the window hierarchy already by the time this function is called
 332     // (OnWindowDestroyed).
 333     client::CaptureClient* capture_client =
 334         client::GetCaptureClient(host_->window());
 335     Window* capture_window =
 336         capture_client ? capture_client->GetCaptureWindow() : NULL;
 337
 338     if (invisible->Contains(event_dispatch_target_))
 339       event_dispatch_target_ = NULL;
 340
 341     // If the ancestor of the capture window is hidden, release the capture.
 342     // Note that this may delete the window so do not use capture_window
 343     // after this.
 344     if (invisible->Contains(capture_window) && invisible != window())
 345       capture_window->ReleaseCapture();
 346   }
 347 }
 348
 349 Window* WindowEventDispatcher::GetGestureTarget(ui::GestureEvent* event) {
 350   Window* target = NULL;
 351   if (!event->IsEndingEvent()) {
 352     // The window that received the start event (e.g. scroll begin) needs to
 353     // receive the end event (e.g. scroll end).
 354     target = client::GetCaptureWindow(window());
 355   }
 356   if (!target) {
 357     target = ConsumerToWindow(
 358         ui::GestureRecognizer::Get()->GetTargetForGestureEvent(*event));
 359   }
 360
 361   return target;
 362 }
 363
 364 ////////////////////////////////////////////////////////////////////////////////
 365 // WindowEventDispatcher, aura::client::CaptureDelegate implementation:
 366
 367 void WindowEventDispatcher::UpdateCapture(Window* old_capture,
 368                                           Window* new_capture) {
 369   // |mouse_moved_handler_| may have been set to a Window in a different root
 370   // (see below). Clear it here to ensure we don't end up referencing a stale
 371   // Window.
 372   if (mouse_moved_handler_ && !window()->Contains(mouse_moved_handler_))
 373     mouse_moved_handler_ = NULL;
 374
 375   if (old_capture && old_capture->GetRootWindow() == window() &&
 376       old_capture->delegate()) {
 377     // Send a capture changed event with bogus location data.
 378     ui::MouseEvent event(ui::ET_MOUSE_CAPTURE_CHANGED, gfx::Point(),
 379                          gfx::Point(), 0, 0);
 380
 381     DispatchDetails details = DispatchEvent(old_capture, &event);
 382     if (details.dispatcher_destroyed)
 383       return;
 384
 385     old_capture->delegate()->OnCaptureLost();
 386   }
 387
 388   if (new_capture) {
 389     // Make all subsequent mouse events go to the capture window. We shouldn't
 390     // need to send an event here as OnCaptureLost() should take care of that.
 391     if (mouse_moved_handler_ || Env::GetInstance()->IsMouseButtonDown())
 392       mouse_moved_handler_ = new_capture;
 393   } else {
 394     // Make sure mouse_moved_handler gets updated.
 395     DispatchDetails details = SynthesizeMouseMoveEvent();
 396     if (details.dispatcher_destroyed)
 397       return;
 398   }
 399   mouse_pressed_handler_ = NULL;
 400 }
 401
 402 void WindowEventDispatcher::OnOtherRootGotCapture() {
 403   // Windows provides the TrackMouseEvents API which allows us to rely on the
 404   // OS to send us the mouse exit events (WM_MOUSELEAVE). Additionally on
 405   // desktop Windows, every top level window could potentially have its own
 406   // root window, in which case this function will get called whenever those
 407   // windows grab mouse capture. Sending mouse exit messages in these cases
 408   // causes subtle bugs like (crbug.com/394672).
 409 #if !defined(OS_WIN)
 410   if (mouse_moved_handler_) {
 411     // Dispatch a mouse exit to reset any state associated with hover. This is
 412     // important when going from no window having capture to a window having
 413     // capture because we do not dispatch ET_MOUSE_CAPTURE_CHANGED in this case.
 414     DispatchDetails details = DispatchMouseExitAtPoint(
 415         GetLastMouseLocationInRoot());
 416     if (details.dispatcher_destroyed)
 417       return;
 418   }
 419 #endif
 420
 421   mouse_moved_handler_ = NULL;
 422   mouse_pressed_handler_ = NULL;
 423 }
 424
 425 void WindowEventDispatcher::SetNativeCapture() {
 426   host_->SetCapture();
 427 }
 428
 429 void WindowEventDispatcher::ReleaseNativeCapture() {
 430   host_->ReleaseCapture();
 431 }
 432
 433 ////////////////////////////////////////////////////////////////////////////////
 434 // WindowEventDispatcher, ui::EventProcessor implementation:
 435 ui::EventTarget* WindowEventDispatcher::GetRootTarget() {
 436   return window();
 437 }
 438
 439 void WindowEventDispatcher::PrepareEventForDispatch(ui::Event* event) {
 440   if (dispatching_held_event_) {
 441     // The held events are already in |window()|'s coordinate system. So it is
 442     // not necessary to apply the transform to convert from the host's
 443     // coordinate system to |window()|'s coordinate system.
 444     return;
 445   }
 446   if (event->IsMouseEvent() ||
 447       event->IsScrollEvent() ||
 448       event->IsTouchEvent() ||
 449       event->IsGestureEvent()) {
 450     TransformEventForDeviceScaleFactor(static_cast<ui::LocatedEvent*>(event));
 451   }
 452 }
 453
 454 ////////////////////////////////////////////////////////////////////////////////
 455 // WindowEventDispatcher, ui::EventDispatcherDelegate implementation:
 456
 457 bool WindowEventDispatcher::CanDispatchToTarget(ui::EventTarget* target) {
 458   return event_dispatch_target_ == target;
 459 }
 460
 461 ui::EventDispatchDetails WindowEventDispatcher::PreDispatchEvent(
 462     ui::EventTarget* target,
 463     ui::Event* event) {
 464   Window* target_window = static_cast<Window*>(target);
 465   CHECK(window()->Contains(target_window));
 466
 467   if (!dispatching_held_event_) {
 468     bool can_be_held = IsEventCandidateForHold(*event);
 469     if (!move_hold_count_ || !can_be_held) {
 470       if (can_be_held)
 471         held_move_event_.reset();
 472       DispatchDetails details = DispatchHeldEvents();
 473       if (details.dispatcher_destroyed || details.target_destroyed)
 474         return details;
 475     }
 476   }
 477
 478   if (event->IsMouseEvent()) {
 479     PreDispatchMouseEvent(target_window, static_cast<ui::MouseEvent*>(event));
 480   } else if (event->IsScrollEvent()) {
 481     PreDispatchLocatedEvent(target_window,
 482                             static_cast<ui::ScrollEvent*>(event));
 483   } else if (event->IsTouchEvent()) {
 484     PreDispatchTouchEvent(target_window, static_cast<ui::TouchEvent*>(event));
 485   }
 486   old_dispatch_target_ = event_dispatch_target_;
 487   event_dispatch_target_ = static_cast<Window*>(target);
 488   return DispatchDetails();
 489 }
 490
 491 ui::EventDispatchDetails WindowEventDispatcher::PostDispatchEvent(
 492     ui::EventTarget* target,
 493     const ui::Event& event) {
 494   DispatchDetails details;
 495   if (!target || target != event_dispatch_target_)
 496     details.target_destroyed = true;
 497   event_dispatch_target_ = old_dispatch_target_;
 498   old_dispatch_target_ = NULL;
 499 #ifndef NDEBUG
 500   DCHECK(!event_dispatch_target_ || window()->Contains(event_dispatch_target_));
 501 #endif
 502
 503   if (event.IsTouchEvent() && !details.target_destroyed) {
 504     // Do not let 'held' touch events contribute to any gestures unless it is
 505     // being dispatched.
 506     if (dispatching_held_event_ || !held_move_event_ ||
 507         !held_move_event_->IsTouchEvent()) {
 508
 509       // Once we've fully migrated to the eager gesture detector, we won't
 510       // need to pass an event here.
 511       ui::TouchEvent orig_event(static_cast<const ui::TouchEvent&>(event),
 512                                 static_cast<Window*>(event.target()),
 513                                 window());
 514
 515       if (event.result() & ui::ER_CONSUMED)
 516         orig_event.StopPropagation();
 517
 518       // TODO(tdresser): Move this to PreDispatchTouchEvent, to enable eager
 519       // gesture detection. See crbug.com/410280.
 520       if (!ui::GestureRecognizer::Get()
 521                ->ProcessTouchEventPreDispatch(orig_event,
 522                                               static_cast<Window*>(target))) {
 523         return details;
 524       }
 525
 526       scoped_ptr<ui::GestureRecognizer::Gestures> gestures;
 527
 528       gestures.reset(
 529           ui::GestureRecognizer::Get()->ProcessTouchEventPostDispatch(
 530               orig_event, event.result(), static_cast<Window*>(target)));
 531
 532       return ProcessGestures(gestures.get());
 533     }
 534   }
 535
 536   return details;
 537 }
 538
 539 ////////////////////////////////////////////////////////////////////////////////
 540 // WindowEventDispatcher, ui::GestureEventHelper implementation:
 541
 542 bool WindowEventDispatcher::CanDispatchToConsumer(
 543     ui::GestureConsumer* consumer) {
 544   Window* consumer_window = ConsumerToWindow(consumer);
 545   return (consumer_window && consumer_window->GetRootWindow() == window());
 546 }
 547
 548 void WindowEventDispatcher::DispatchCancelTouchEvent(ui::TouchEvent* event) {
 549   DispatchDetails details = OnEventFromSource(event);
 550   if (details.dispatcher_destroyed)
 551     return;
 552 }
 553
 554 ////////////////////////////////////////////////////////////////////////////////
 555 // WindowEventDispatcher, WindowObserver implementation:
 556
 557 void WindowEventDispatcher::OnWindowDestroying(Window* window) {
 558   if (!host_->window()->Contains(window))
 559     return;
 560
 561   DispatchMouseExitToHidingWindow(window);
 562   SynthesizeMouseMoveAfterChangeToWindow(window);
 563 }
 564
 565 void WindowEventDispatcher::OnWindowDestroyed(Window* window) {
 566   // We observe all windows regardless of what root Window (if any) they're
 567   // attached to.
 568   observer_manager_.Remove(window);
 569 }
 570
 571 void WindowEventDispatcher::OnWindowAddedToRootWindow(Window* attached) {
 572   if (!observer_manager_.IsObserving(attached))
 573     observer_manager_.Add(attached);
 574
 575   if (!host_->window()->Contains(attached))
 576     return;
 577
 578   SynthesizeMouseMoveAfterChangeToWindow(attached);
 579 }
 580
 581 void WindowEventDispatcher::OnWindowRemovingFromRootWindow(Window* detached,
 582                                                            Window* new_root) {
 583   if (!host_->window()->Contains(detached))
 584     return;
 585
 586   DCHECK(client::GetCaptureWindow(window()) != window());
 587
 588   DispatchMouseExitToHidingWindow(detached);
 589   SynthesizeMouseMoveAfterChangeToWindow(detached);
 590
 591   // Hiding the window releases capture which can implicitly destroy the window
 592   // so the window may no longer be valid after this call.
 593   OnWindowHidden(detached, new_root ? WINDOW_MOVING : WINDOW_HIDDEN);
 594 }
 595
 596 void WindowEventDispatcher::OnWindowVisibilityChanging(Window* window,
 597                                                        bool visible) {
 598   if (!host_->window()->Contains(window))
 599     return;
 600
 601   DispatchMouseExitToHidingWindow(window);
 602 }
 603
 604 void WindowEventDispatcher::OnWindowVisibilityChanged(Window* window,
 605                                                       bool visible) {
 606   if (!host_->window()->Contains(window))
 607     return;
 608
 609   if (window->ContainsPointInRoot(GetLastMouseLocationInRoot()))
 610     PostSynthesizeMouseMove();
 611
 612   // Hiding the window releases capture which can implicitly destroy the window
 613   // so the window may no longer be valid after this call.
 614   if (!visible)
 615     OnWindowHidden(window, WINDOW_HIDDEN);
 616 }
 617
 618 void WindowEventDispatcher::OnWindowBoundsChanged(Window* window,
 619                                                   const gfx::Rect& old_bounds,
 620                                                   const gfx::Rect& new_bounds) {
 621   if (!host_->window()->Contains(window))
 622     return;
 623
 624   if (window == host_->window()) {
 625     TRACE_EVENT1("ui", "WindowEventDispatcher::OnWindowBoundsChanged(root)",
 626                  "size", new_bounds.size().ToString());
 627
 628     DispatchDetails details = DispatchHeldEvents();
 629     if (details.dispatcher_destroyed)
 630       return;
 631
 632     synthesize_mouse_move_ = false;
 633   }
 634
 635   if (window->IsVisible() && !window->ignore_events()) {
 636     gfx::Rect old_bounds_in_root = old_bounds, new_bounds_in_root = new_bounds;
 637     Window::ConvertRectToTarget(window->parent(), host_->window(),
 638                                 &old_bounds_in_root);
 639     Window::ConvertRectToTarget(window->parent(), host_->window(),
 640                                 &new_bounds_in_root);
 641     gfx::Point last_mouse_location = GetLastMouseLocationInRoot();
 642     if (old_bounds_in_root.Contains(last_mouse_location) !=
 643         new_bounds_in_root.Contains(last_mouse_location)) {
 644       PostSynthesizeMouseMove();
 645     }
 646   }
 647 }
 648
 649 void WindowEventDispatcher::OnWindowTransforming(Window* window) {
 650   if (!host_->window()->Contains(window))
 651     return;
 652
 653   SynthesizeMouseMoveAfterChangeToWindow(window);
 654 }
 655
 656 void WindowEventDispatcher::OnWindowTransformed(Window* window) {
 657   if (!host_->window()->Contains(window))
 658     return;
 659
 660   SynthesizeMouseMoveAfterChangeToWindow(window);
 661 }
 662
 663 ///////////////////////////////////////////////////////////////////////////////
 664 // WindowEventDispatcher, EnvObserver implementation:
 665
 666 void WindowEventDispatcher::OnWindowInitialized(Window* window) {
 667   observer_manager_.Add(window);
 668 }
 669
 670 ////////////////////////////////////////////////////////////////////////////////
 671 // WindowEventDispatcher, private:
 672
 673 ui::EventDispatchDetails WindowEventDispatcher::DispatchHeldEvents() {
 674   if (!held_repostable_event_ && !held_move_event_)
 675     return DispatchDetails();
 676
 677   CHECK(!dispatching_held_event_);
 678   dispatching_held_event_ = true;
 679
 680   DispatchDetails dispatch_details;
 681   if (held_repostable_event_) {
 682     if (held_repostable_event_->type() == ui::ET_MOUSE_PRESSED) {
 683       scoped_ptr<ui::MouseEvent> mouse_event(
 684           static_cast<ui::MouseEvent*>(held_repostable_event_.release()));
 685       dispatch_details = OnEventFromSource(mouse_event.get());
 686     } else {
 687       // TODO(rbyers): GESTURE_TAP_DOWN not yet supported: crbug.com/170987.
 688       NOTREACHED();
 689     }
 690     if (dispatch_details.dispatcher_destroyed)
 691       return dispatch_details;
 692   }
 693
 694   if (held_move_event_) {
 695     // If a mouse move has been synthesized, the target location is suspect,
 696     // so drop the held mouse event.
 697     if (held_move_event_->IsTouchEvent() ||
 698         (held_move_event_->IsMouseEvent() && !synthesize_mouse_move_)) {
 699       dispatch_details = OnEventFromSource(held_move_event_.get());
 700     }
 701     if (!dispatch_details.dispatcher_destroyed)
 702       held_move_event_.reset();
 703   }
 704
 705   if (!dispatch_details.dispatcher_destroyed)
 706     dispatching_held_event_ = false;
 707   return dispatch_details;
 708 }
 709
 710 void WindowEventDispatcher::PostSynthesizeMouseMove() {
 711   if (synthesize_mouse_move_)
 712     return;
 713   synthesize_mouse_move_ = true;
 714   base::MessageLoop::current()->PostNonNestableTask(
 715       FROM_HERE,
 716       base::Bind(base::IgnoreResult(
 717           &WindowEventDispatcher::SynthesizeMouseMoveEvent),
 718           held_event_factory_.GetWeakPtr()));
 719 }
 720
 721 void WindowEventDispatcher::SynthesizeMouseMoveAfterChangeToWindow(
 722     Window* window) {
 723   if (window->IsVisible() &&
 724       window->ContainsPointInRoot(GetLastMouseLocationInRoot())) {
 725     PostSynthesizeMouseMove();
 726   }
 727 }
 728
 729 ui::EventDispatchDetails WindowEventDispatcher::SynthesizeMouseMoveEvent() {
 730   DispatchDetails details;
 731   if (!synthesize_mouse_move_)
 732     return details;
 733   synthesize_mouse_move_ = false;
 734
 735   // If one of the mouse buttons is currently down, then do not synthesize a
 736   // mouse-move event. In such cases, aura could synthesize a DRAGGED event
 737   // instead of a MOVED event, but in multi-display/multi-host scenarios, the
 738   // DRAGGED event can be synthesized in the incorrect host. So avoid
 739   // synthesizing any events at all.
 740   if (Env::GetInstance()->mouse_button_flags())
 741     return details;
 742
 743   gfx::Point root_mouse_location = GetLastMouseLocationInRoot();
 744   if (!window()->bounds().Contains(root_mouse_location))
 745     return details;
 746   gfx::Point host_mouse_location = root_mouse_location;
 747   host_->ConvertPointToHost(&host_mouse_location);
 748   ui::MouseEvent event(ui::ET_MOUSE_MOVED,
 749                        host_mouse_location,
 750                        host_mouse_location,
 751                        ui::EF_IS_SYNTHESIZED,
 752                        0);
 753   return OnEventFromSource(&event);
 754 }
 755
 756 void WindowEventDispatcher::PreDispatchLocatedEvent(Window* target,
 757                                                     ui::LocatedEvent* event) {
 758   int flags = event->flags();
 759   if (IsNonClientLocation(target, event->location()))
 760     flags |= ui::EF_IS_NON_CLIENT;
 761   event->set_flags(flags);
 762
 763   if (!dispatching_held_event_ &&
 764       (event->IsMouseEvent() || event->IsScrollEvent()) &&
 765       !(event->flags() & ui::EF_IS_SYNTHESIZED)) {
 766     if (event->type() != ui::ET_MOUSE_CAPTURE_CHANGED)
 767       SetLastMouseLocation(window(), event->root_location());
 768     synthesize_mouse_move_ = false;
 769   }
 770 }
 771
 772 void WindowEventDispatcher::PreDispatchMouseEvent(Window* target,
 773                                                   ui::MouseEvent* event) {
 774   client::CursorClient* cursor_client = client::GetCursorClient(window());
 775   // We allow synthesized mouse exit events through even if mouse events are
 776   // disabled. This ensures that hover state, etc on controls like buttons is
 777   // cleared.
 778   if (cursor_client &&
 779       !cursor_client->IsMouseEventsEnabled() &&
 780       (event->flags() & ui::EF_IS_SYNTHESIZED) &&
 781       (event->type() != ui::ET_MOUSE_EXITED)) {
 782     event->SetHandled();
 783     return;
 784   }
 785
 786   if (IsEventCandidateForHold(*event) && !dispatching_held_event_) {
 787     if (move_hold_count_) {
 788       if (!(event->flags() & ui::EF_IS_SYNTHESIZED) &&
 789           event->type() != ui::ET_MOUSE_CAPTURE_CHANGED) {
 790         SetLastMouseLocation(window(), event->root_location());
 791       }
 792       held_move_event_.reset(new ui::MouseEvent(*event, target, window()));
 793       event->SetHandled();
 794       return;
 795     } else {
 796       // We may have a held event for a period between the time move_hold_count_
 797       // fell to 0 and the DispatchHeldEvents executes. Since we're going to
 798       // dispatch the new event directly below, we can reset the old one.
 799       held_move_event_.reset();
 800     }
 801   }
 802
 803   const int kMouseButtonFlagMask = ui::EF_LEFT_MOUSE_BUTTON |
 804                                    ui::EF_MIDDLE_MOUSE_BUTTON |
 805                                    ui::EF_RIGHT_MOUSE_BUTTON;
 806   switch (event->type()) {
 807     case ui::ET_MOUSE_EXITED:
 808       if (!target || target == window()) {
 809         DispatchDetails details =
 810             DispatchMouseEnterOrExit(*event, ui::ET_MOUSE_EXITED);
 811         if (details.dispatcher_destroyed) {
 812           event->SetHandled();
 813           return;
 814         }
 815         mouse_moved_handler_ = NULL;
 816       }
 817       break;
 818     case ui::ET_MOUSE_MOVED:
 819       // Send an exit to the current |mouse_moved_handler_| and an enter to
 820       // |target|. Take care that both us and |target| aren't destroyed during
 821       // dispatch.
 822       if (target != mouse_moved_handler_) {
 823         aura::Window* old_mouse_moved_handler = mouse_moved_handler_;
 824         WindowTracker live_window;
 825         live_window.Add(target);
 826         DispatchDetails details =
 827             DispatchMouseEnterOrExit(*event, ui::ET_MOUSE_EXITED);
 828         if (details.dispatcher_destroyed) {
 829           event->SetHandled();
 830           return;
 831         }
 832         // If the |mouse_moved_handler_| changes out from under us, assume a
 833         // nested message loop ran and we don't need to do anything.
 834         if (mouse_moved_handler_ != old_mouse_moved_handler) {
 835           event->SetHandled();
 836           return;
 837         }
 838         if (!live_window.Contains(target) || details.target_destroyed) {
 839           mouse_moved_handler_ = NULL;
 840           event->SetHandled();
 841           return;
 842         }
 843         live_window.Remove(target);
 844
 845         mouse_moved_handler_ = target;
 846         details = DispatchMouseEnterOrExit(*event, ui::ET_MOUSE_ENTERED);
 847         if (details.dispatcher_destroyed || details.target_destroyed) {
 848           event->SetHandled();
 849           return;
 850         }
 851       }
 852       break;
 853     case ui::ET_MOUSE_PRESSED:
 854       // Don't set the mouse pressed handler for non client mouse down events.
 855       // These are only sent by Windows and are not always followed with non
 856       // client mouse up events which causes subsequent mouse events to be
 857       // sent to the wrong target.
 858       if (!(event->flags() & ui::EF_IS_NON_CLIENT) && !mouse_pressed_handler_)
 859         mouse_pressed_handler_ = target;
 860       Env::GetInstance()->set_mouse_button_flags(
 861           event->flags() & kMouseButtonFlagMask);
 862       break;
 863     case ui::ET_MOUSE_RELEASED:
 864       mouse_pressed_handler_ = NULL;
 865       Env::GetInstance()->set_mouse_button_flags(event->flags() &
 866           kMouseButtonFlagMask & ~event->changed_button_flags());
 867       break;
 868     default:
 869       break;
 870   }
 871
 872   PreDispatchLocatedEvent(target, event);
 873 }
 874
 875 void WindowEventDispatcher::PreDispatchTouchEvent(Window* target,
 876                                                   ui::TouchEvent* event) {
 877   switch (event->type()) {
 878     case ui::ET_TOUCH_PRESSED:
 879       touch_ids_down_ |= (1 << event->touch_id());
 880       Env::GetInstance()->set_touch_down(touch_ids_down_ != 0);
 881       break;
 882
 883       // Handle ET_TOUCH_CANCELLED only if it has a native event.
 884     case ui::ET_TOUCH_CANCELLED:
 885       if (!event->HasNativeEvent())
 886         break;
 887       // fallthrough
 888     case ui::ET_TOUCH_RELEASED:
 889       touch_ids_down_ = (touch_ids_down_ | (1 << event->touch_id())) ^
 890             (1 << event->touch_id());
 891       Env::GetInstance()->set_touch_down(touch_ids_down_ != 0);
 892       break;
 893
 894     case ui::ET_TOUCH_MOVED:
 895       if (move_hold_count_ && !dispatching_held_event_) {
 896         held_move_event_.reset(new ui::TouchEvent(*event, target, window()));
 897         event->SetHandled();
 898         return;
 899       }
 900       break;
 901
 902     default:
 903       NOTREACHED();
 904       break;
 905   }
 906
 907   PreDispatchLocatedEvent(target, event);
 908 }
 909
 910 }  // namespace aura