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