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