ui/aura/window_event_dispatcher.cc

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
IsNonClientLocation
ConsumerToWindow
SetLastMouseLocation
IsEventCandidateForHold
held_event_factory_
RepostEvent
OnMouseEventsEnableStateChanged
DispatchCancelModeEvent
DispatchGestureEvent
DispatchMouseExitAtPoint
ProcessedTouchEvent
HoldPointerMoves
ReleasePointerMoves
GetLastMouseLocationInRoot
OnHostLostMouseGrab
OnCursorMovedToRootLocation
OnPostNotifiedWindowDestroying
window
window
TransformEventForDeviceScaleFactor
DispatchMouseExitToHidingWindow
DispatchMouseEnterOrExit
ProcessGestures
OnWindowHidden
GetGestureTarget
UpdateCapture
OnOtherRootGotCapture
SetNativeCapture
ReleaseNativeCapture
GetRootTarget
PrepareEventForDispatch
CanDispatchToTarget
PreDispatchEvent
PostDispatchEvent
CanDispatchToConsumer
DispatchPostponedGestureEvent
DispatchCancelTouchEvent
OnWindowDestroying
OnWindowDestroyed
OnWindowAddedToRootWindow
OnWindowRemovingFromRootWindow
OnWindowVisibilityChanging
OnWindowVisibilityChanged
OnWindowBoundsChanged
OnWindowTransforming
OnWindowTransformed
OnWindowInitialized
DispatchHeldEvents
PostSynthesizeMouseMove
SynthesizeMouseMoveAfterChangeToWindow
SynthesizeMouseMoveEvent
PreDispatchLocatedEvent
PreDispatchMouseEvent
PreDispatchTouchEvent
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/aura/window_event_dispatcher.h"

#include "base/bind.h"
#include "base/debug/trace_event.h"
#include "base/logging.h"
#include "base/message_loop/message_loop.h"
#include "ui/aura/client/capture_client.h"
#include "ui/aura/client/cursor_client.h"
#include "ui/aura/client/event_client.h"
#include "ui/aura/client/focus_client.h"
#include "ui/aura/client/screen_position_client.h"
#include "ui/aura/env.h"
#include "ui/aura/window.h"
#include "ui/aura/window_delegate.h"
#include "ui/aura/window_targeter.h"
#include "ui/aura/window_tracker.h"
#include "ui/aura/window_tree_host.h"
#include "ui/base/hit_test.h"
#include "ui/compositor/dip_util.h"
#include "ui/events/event.h"
#include "ui/events/gestures/gesture_recognizer.h"
#include "ui/events/gestures/gesture_types.h"

typedef ui::EventDispatchDetails DispatchDetails;

namespace aura {

namespace {

// Returns true if |target| has a non-client (frame) component at |location|,
// in window coordinates.
bool IsNonClientLocation(Window* target, const gfx::Point& location) {
  if (!target->delegate())
    return false;
  int hit_test_code = target->delegate()->GetNonClientComponent(location);
  return hit_test_code != HTCLIENT && hit_test_code != HTNOWHERE;
}

Window* ConsumerToWindow(ui::GestureConsumer* consumer) {
  return consumer ? static_cast<Window*>(consumer) : NULL;
}

void SetLastMouseLocation(const Window* root_window,
                          const gfx::Point& location_in_root) {
  client::ScreenPositionClient* client =
      client::GetScreenPositionClient(root_window);
  if (client) {
    gfx::Point location_in_screen = location_in_root;
    client->ConvertPointToScreen(root_window, &location_in_screen);
    Env::GetInstance()->set_last_mouse_location(location_in_screen);
  } else {
    Env::GetInstance()->set_last_mouse_location(location_in_root);
  }
}

bool IsEventCandidateForHold(const ui::Event& event) {
  if (event.type() == ui::ET_TOUCH_MOVED)
    return true;
  if (event.type() == ui::ET_MOUSE_DRAGGED)
    return true;
  if (event.IsMouseEvent() && (event.flags() & ui::EF_IS_SYNTHESIZED))
    return true;
  return false;
}

}  // namespace

////////////////////////////////////////////////////////////////////////////////
// WindowEventDispatcher, public:

WindowEventDispatcher::WindowEventDispatcher(WindowTreeHost* host)
    : host_(host),
      touch_ids_down_(0),
      mouse_pressed_handler_(NULL),
      mouse_moved_handler_(NULL),
      event_dispatch_target_(NULL),
      old_dispatch_target_(NULL),
      synthesize_mouse_move_(false),
      move_hold_count_(0),
      dispatching_held_event_(false),
      observer_manager_(this),
      repost_event_factory_(this),
      held_event_factory_(this) {
  ui::GestureRecognizer::Get()->AddGestureEventHelper(this);
  Env::GetInstance()->AddObserver(this);
}

WindowEventDispatcher::~WindowEventDispatcher() {
  TRACE_EVENT0("shutdown", "WindowEventDispatcher::Destructor");
  Env::GetInstance()->RemoveObserver(this);
  ui::GestureRecognizer::Get()->RemoveGestureEventHelper(this);
}

void WindowEventDispatcher::RepostEvent(const ui::LocatedEvent& event) {
  DCHECK(event.type() == ui::ET_MOUSE_PRESSED ||
         event.type() == ui::ET_GESTURE_TAP_DOWN);
  // We allow for only one outstanding repostable event. This is used
  // in exiting context menus.  A dropped repost request is allowed.
  if (event.type() == ui::ET_MOUSE_PRESSED) {
    held_repostable_event_.reset(
        new ui::MouseEvent(
            static_cast<const ui::MouseEvent&>(event),
            static_cast<aura::Window*>(event.target()),
            window()));
    base::MessageLoop::current()->PostNonNestableTask(
        FROM_HERE, base::Bind(
            base::IgnoreResult(&WindowEventDispatcher::DispatchHeldEvents),
            repost_event_factory_.GetWeakPtr()));
  } else {
    DCHECK(event.type() == ui::ET_GESTURE_TAP_DOWN);
    held_repostable_event_.reset();
    // TODO(rbyers): Reposing of gestures is tricky to get
    // right, so it's not yet supported.  crbug.com/170987.
  }
}

void WindowEventDispatcher::OnMouseEventsEnableStateChanged(bool enabled) {
  // Send entered / exited so that visual state can be updated to match
  // mouse events state.
  PostSynthesizeMouseMove();
  // TODO(mazda): Add code to disable mouse events when |enabled| == false.
}

void WindowEventDispatcher::DispatchCancelModeEvent() {
  ui::CancelModeEvent event;
  Window* focused_window = client::GetFocusClient(window())->GetFocusedWindow();
  if (focused_window && !window()->Contains(focused_window))
    focused_window = NULL;
  DispatchDetails details =
      DispatchEvent(focused_window ? focused_window : window(), &event);
  if (details.dispatcher_destroyed)
    return;
}

void WindowEventDispatcher::DispatchGestureEvent(ui::GestureEvent* event) {
  DispatchDetails details = DispatchHeldEvents();
  if (details.dispatcher_destroyed)
    return;

  Window* target = GetGestureTarget(event);
  if (target) {
    event->ConvertLocationToTarget(window(), target);
    DispatchDetails details = DispatchEvent(target, event);
    if (details.dispatcher_destroyed)
      return;
  }
}

void WindowEventDispatcher::DispatchMouseExitAtPoint(const gfx::Point& point) {
  ui::MouseEvent event(ui::ET_MOUSE_EXITED, point, point, ui::EF_NONE,
                       ui::EF_NONE);
  DispatchDetails details =
      DispatchMouseEnterOrExit(event, ui::ET_MOUSE_EXITED);
  if (details.dispatcher_destroyed)
    return;
}

void WindowEventDispatcher::ProcessedTouchEvent(ui::TouchEvent* event,
                                                Window* window,
                                                ui::EventResult result) {
  scoped_ptr<ui::GestureRecognizer::Gestures> gestures;
  gestures.reset(ui::GestureRecognizer::Get()->
      ProcessTouchEventForGesture(*event, result, window));
  DispatchDetails details = ProcessGestures(gestures.get());
  if (details.dispatcher_destroyed)
    return;
}

void WindowEventDispatcher::HoldPointerMoves() {
  if (!move_hold_count_)
    held_event_factory_.InvalidateWeakPtrs();
  ++move_hold_count_;
  TRACE_EVENT_ASYNC_BEGIN0("ui", "WindowEventDispatcher::HoldPointerMoves",
                           this);
}

void WindowEventDispatcher::ReleasePointerMoves() {
  --move_hold_count_;
  DCHECK_GE(move_hold_count_, 0);
  if (!move_hold_count_ && held_move_event_) {
    // We don't want to call DispatchHeldEvents directly, because this might be
    // called from a deep stack while another event, in which case dispatching
    // another one may not be safe/expected.  Instead we post a task, that we
    // may cancel if HoldPointerMoves is called again before it executes.
    base::MessageLoop::current()->PostNonNestableTask(
        FROM_HERE, base::Bind(
          base::IgnoreResult(&WindowEventDispatcher::DispatchHeldEvents),
          held_event_factory_.GetWeakPtr()));
  }
  TRACE_EVENT_ASYNC_END0("ui", "WindowEventDispatcher::HoldPointerMoves", this);
}

gfx::Point WindowEventDispatcher::GetLastMouseLocationInRoot() const {
  gfx::Point location = Env::GetInstance()->last_mouse_location();
  client::ScreenPositionClient* client =
      client::GetScreenPositionClient(window());
  if (client)
    client->ConvertPointFromScreen(window(), &location);
  return location;
}

void WindowEventDispatcher::OnHostLostMouseGrab() {
  mouse_pressed_handler_ = NULL;
  mouse_moved_handler_ = NULL;
}

void WindowEventDispatcher::OnCursorMovedToRootLocation(
    const gfx::Point& root_location) {
  SetLastMouseLocation(window(), root_location);
  synthesize_mouse_move_ = false;
}

void WindowEventDispatcher::OnPostNotifiedWindowDestroying(Window* window) {
  OnWindowHidden(window, WINDOW_DESTROYED);
}

////////////////////////////////////////////////////////////////////////////////
// WindowEventDispatcher, private:

Window* WindowEventDispatcher::window() {
  return host_->window();
}

const Window* WindowEventDispatcher::window() const {
  return host_->window();
}

void WindowEventDispatcher::TransformEventForDeviceScaleFactor(
    ui::LocatedEvent* event) {
  event->UpdateForRootTransform(host_->GetInverseRootTransform());
}

void WindowEventDispatcher::DispatchMouseExitToHidingWindow(Window* window) {
  // The mouse capture is intentionally ignored. Think that a mouse enters
  // to a window, the window sets the capture, the mouse exits the window,
  // and then it releases the capture. In that case OnMouseExited won't
  // be called. So it is natural not to emit OnMouseExited even though
  // |window| is the capture window.
  gfx::Point last_mouse_location = GetLastMouseLocationInRoot();
  if (window->Contains(mouse_moved_handler_) &&
      window->ContainsPointInRoot(last_mouse_location))
    DispatchMouseExitAtPoint(last_mouse_location);
}

ui::EventDispatchDetails WindowEventDispatcher::DispatchMouseEnterOrExit(
    const ui::MouseEvent& event,
    ui::EventType type) {
  if (event.type() != ui::ET_MOUSE_CAPTURE_CHANGED &&
      !(event.flags() & ui::EF_IS_SYNTHESIZED)) {
    SetLastMouseLocation(window(), event.root_location());
  }

  if (!mouse_moved_handler_ || !mouse_moved_handler_->delegate() ||
      !window()->Contains(mouse_moved_handler_))
    return DispatchDetails();

  // |event| may be an event in the process of being dispatched to a target (in
  // which case its locations will be in the event's target's coordinate
  // system), or a synthetic event created in root-window (in which case, the
  // event's target will be NULL, and the event will be in the root-window's
  // coordinate system.
  aura::Window* target = static_cast<Window*>(event.target());
  if (!target)
    target = window();
  ui::MouseEvent translated_event(event,
                                  target,
                                  mouse_moved_handler_,
                                  type,
                                  event.flags() | ui::EF_IS_SYNTHESIZED);
  return DispatchEvent(mouse_moved_handler_, &translated_event);
}

ui::EventDispatchDetails WindowEventDispatcher::ProcessGestures(
    ui::GestureRecognizer::Gestures* gestures) {
  DispatchDetails details;
  if (!gestures || gestures->empty())
    return details;

  Window* target = GetGestureTarget(gestures->get().at(0));
  for (size_t i = 0; i < gestures->size(); ++i) {
    ui::GestureEvent* event = gestures->get().at(i);
    event->ConvertLocationToTarget(window(), target);
    details = DispatchEvent(target, event);
    if (details.dispatcher_destroyed || details.target_destroyed)
      break;
  }
  return details;
}

void WindowEventDispatcher::OnWindowHidden(Window* invisible,
                                           WindowHiddenReason reason) {
  // If the window the mouse was pressed in becomes invisible, it should no
  // longer receive mouse events.
  if (invisible->Contains(mouse_pressed_handler_))
    mouse_pressed_handler_ = NULL;
  if (invisible->Contains(mouse_moved_handler_))
    mouse_moved_handler_ = NULL;

  // If events are being dispatched from a nested message-loop, and the target
  // of the outer loop is hidden or moved to another dispatcher during
  // dispatching events in the inner loop, then reset the target for the outer
  // loop.
  if (invisible->Contains(old_dispatch_target_))
    old_dispatch_target_ = NULL;

  invisible->CleanupGestureState();

  // Do not clear the capture, and the |event_dispatch_target_| if the
  // window is moving across hosts, because the target itself is actually still
  // visible and clearing them stops further event processing, which can cause
  // unexpected behaviors. See crbug.com/157583
  if (reason != WINDOW_MOVING) {
    // We don't ask |invisible| here, because invisible may have been removed
    // from the window hierarchy already by the time this function is called
    // (OnWindowDestroyed).
    client::CaptureClient* capture_client =
        client::GetCaptureClient(host_->window());
    Window* capture_window =
        capture_client ? capture_client->GetCaptureWindow() : NULL;

    if (invisible->Contains(event_dispatch_target_))
      event_dispatch_target_ = NULL;

    // If the ancestor of the capture window is hidden, release the capture.
    // Note that this may delete the window so do not use capture_window
    // after this.
    if (invisible->Contains(capture_window) && invisible != window())
      capture_window->ReleaseCapture();
  }
}

Window* WindowEventDispatcher::GetGestureTarget(ui::GestureEvent* event) {
  Window* target = NULL;
  if (!event->IsEndingEvent()) {
    // The window that received the start event (e.g. scroll begin) needs to
    // receive the end event (e.g. scroll end).
    target = client::GetCaptureWindow(window());
  }
  if (!target) {
    target = ConsumerToWindow(
        ui::GestureRecognizer::Get()->GetTargetForGestureEvent(*event));
  }

  return target;
}

////////////////////////////////////////////////////////////////////////////////
// WindowEventDispatcher, aura::client::CaptureDelegate implementation:

void WindowEventDispatcher::UpdateCapture(Window* old_capture,
                                          Window* new_capture) {
  // |mouse_moved_handler_| may have been set to a Window in a different root
  // (see below). Clear it here to ensure we don't end up referencing a stale
  // Window.
  if (mouse_moved_handler_ && !window()->Contains(mouse_moved_handler_))
    mouse_moved_handler_ = NULL;

  if (old_capture && old_capture->GetRootWindow() == window() &&
      old_capture->delegate()) {
    // Send a capture changed event with bogus location data.
    ui::MouseEvent event(ui::ET_MOUSE_CAPTURE_CHANGED, gfx::Point(),
                         gfx::Point(), 0, 0);

    DispatchDetails details = DispatchEvent(old_capture, &event);
    if (details.dispatcher_destroyed)
      return;

    old_capture->delegate()->OnCaptureLost();
  }

  if (new_capture) {
    // Make all subsequent mouse events go to the capture window. We shouldn't
    // need to send an event here as OnCaptureLost() should take care of that.
    if (mouse_moved_handler_ || Env::GetInstance()->IsMouseButtonDown())
      mouse_moved_handler_ = new_capture;
  } else {
    // Make sure mouse_moved_handler gets updated.
    DispatchDetails details = SynthesizeMouseMoveEvent();
    if (details.dispatcher_destroyed)
      return;
  }
  mouse_pressed_handler_ = NULL;
}

void WindowEventDispatcher::OnOtherRootGotCapture() {
  mouse_moved_handler_ = NULL;
  mouse_pressed_handler_ = NULL;
}

void WindowEventDispatcher::SetNativeCapture() {
  host_->SetCapture();
}

void WindowEventDispatcher::ReleaseNativeCapture() {
  host_->ReleaseCapture();
}

////////////////////////////////////////////////////////////////////////////////
// WindowEventDispatcher, ui::EventProcessor implementation:
ui::EventTarget* WindowEventDispatcher::GetRootTarget() {
  return window();
}

void WindowEventDispatcher::PrepareEventForDispatch(ui::Event* event) {
  if (dispatching_held_event_) {
    // The held events are already in |window()|'s coordinate system. So it is
    // not necessary to apply the transform to convert from the host's
    // coordinate system to |window()|'s coordinate system.
    return;
  }
  if (event->IsMouseEvent() ||
      event->IsScrollEvent() ||
      event->IsTouchEvent() ||
      event->IsGestureEvent()) {
    TransformEventForDeviceScaleFactor(static_cast<ui::LocatedEvent*>(event));
  }
}

////////////////////////////////////////////////////////////////////////////////
// WindowEventDispatcher, ui::EventDispatcherDelegate implementation:

bool WindowEventDispatcher::CanDispatchToTarget(ui::EventTarget* target) {
  return event_dispatch_target_ == target;
}

ui::EventDispatchDetails WindowEventDispatcher::PreDispatchEvent(
    ui::EventTarget* target,
    ui::Event* event) {
  Window* target_window = static_cast<Window*>(target);
  CHECK(window()->Contains(target_window));

  if (!dispatching_held_event_) {
    bool can_be_held = IsEventCandidateForHold(*event);
    if (!move_hold_count_ || !can_be_held) {
      if (can_be_held)
        held_move_event_.reset();
      DispatchDetails details = DispatchHeldEvents();
      if (details.dispatcher_destroyed || details.target_destroyed)
        return details;
    }
  }

  if (event->IsMouseEvent()) {
    PreDispatchMouseEvent(target_window, static_cast<ui::MouseEvent*>(event));
  } else if (event->IsScrollEvent()) {
    PreDispatchLocatedEvent(target_window,
                            static_cast<ui::ScrollEvent*>(event));
  } else if (event->IsTouchEvent()) {
    PreDispatchTouchEvent(target_window, static_cast<ui::TouchEvent*>(event));
  }
  old_dispatch_target_ = event_dispatch_target_;
  event_dispatch_target_ = static_cast<Window*>(target);
  return DispatchDetails();
}

ui::EventDispatchDetails WindowEventDispatcher::PostDispatchEvent(
    ui::EventTarget* target,
    const ui::Event& event) {
  DispatchDetails details;
  if (!target || target != event_dispatch_target_)
    details.target_destroyed = true;
  event_dispatch_target_ = old_dispatch_target_;
  old_dispatch_target_ = NULL;
#ifndef NDEBUG
  DCHECK(!event_dispatch_target_ || window()->Contains(event_dispatch_target_));
#endif

  if (event.IsTouchEvent() && !details.target_destroyed) {
    // Do not let 'held' touch events contribute to any gestures.
    if (!held_move_event_ || !held_move_event_->IsTouchEvent()) {
      ui::TouchEvent orig_event(static_cast<const ui::TouchEvent&>(event),
                                static_cast<Window*>(event.target()), window());
      // Get the list of GestureEvents from GestureRecognizer.
      scoped_ptr<ui::GestureRecognizer::Gestures> gestures;
      gestures.reset(ui::GestureRecognizer::Get()->
          ProcessTouchEventForGesture(orig_event, event.result(),
                                      static_cast<Window*>(target)));
      return ProcessGestures(gestures.get());
    }
  }

  return details;
}

////////////////////////////////////////////////////////////////////////////////
// WindowEventDispatcher, ui::GestureEventHelper implementation:

bool WindowEventDispatcher::CanDispatchToConsumer(
    ui::GestureConsumer* consumer) {
  Window* consumer_window = ConsumerToWindow(consumer);
  return (consumer_window && consumer_window->GetRootWindow() == window());
}

void WindowEventDispatcher::DispatchPostponedGestureEvent(
    ui::GestureEvent* event) {
  DispatchGestureEvent(event);
}

void WindowEventDispatcher::DispatchCancelTouchEvent(ui::TouchEvent* event) {
  DispatchDetails details = OnEventFromSource(event);
  if (details.dispatcher_destroyed)
    return;
}

////////////////////////////////////////////////////////////////////////////////
// WindowEventDispatcher, WindowObserver implementation:

void WindowEventDispatcher::OnWindowDestroying(Window* window) {
  if (!host_->window()->Contains(window))
    return;

  DispatchMouseExitToHidingWindow(window);
  SynthesizeMouseMoveAfterChangeToWindow(window);
}

void WindowEventDispatcher::OnWindowDestroyed(Window* window) {
  // We observe all windows regardless of what root Window (if any) they're
  // attached to.
  observer_manager_.Remove(window);
}

void WindowEventDispatcher::OnWindowAddedToRootWindow(Window* attached) {
  if (!observer_manager_.IsObserving(attached))
    observer_manager_.Add(attached);

  if (!host_->window()->Contains(attached))
    return;

  SynthesizeMouseMoveAfterChangeToWindow(attached);
}

void WindowEventDispatcher::OnWindowRemovingFromRootWindow(Window* detached,
                                                           Window* new_root) {
  if (!host_->window()->Contains(detached))
    return;

  DCHECK(client::GetCaptureWindow(window()) != window());

  DispatchMouseExitToHidingWindow(detached);
  SynthesizeMouseMoveAfterChangeToWindow(detached);

  // Hiding the window releases capture which can implicitly destroy the window
  // so the window may no longer be valid after this call.
  OnWindowHidden(detached, new_root ? WINDOW_MOVING : WINDOW_HIDDEN);
}

void WindowEventDispatcher::OnWindowVisibilityChanging(Window* window,
                                                       bool visible) {
  if (!host_->window()->Contains(window))
    return;

  DispatchMouseExitToHidingWindow(window);
}

void WindowEventDispatcher::OnWindowVisibilityChanged(Window* window,
                                                      bool visible) {
  if (!host_->window()->Contains(window))
    return;

  if (window->ContainsPointInRoot(GetLastMouseLocationInRoot()))
    PostSynthesizeMouseMove();

  // Hiding the window releases capture which can implicitly destroy the window
  // so the window may no longer be valid after this call.
  if (!visible)
    OnWindowHidden(window, WINDOW_HIDDEN);
}

void WindowEventDispatcher::OnWindowBoundsChanged(Window* window,
                                                  const gfx::Rect& old_bounds,
                                                  const gfx::Rect& new_bounds) {
  if (!host_->window()->Contains(window))
    return;

  if (window == host_->window()) {
    TRACE_EVENT1("ui", "WindowEventDispatcher::OnWindowBoundsChanged(root)",
                 "size", new_bounds.size().ToString());

    DispatchDetails details = DispatchHeldEvents();
    if (details.dispatcher_destroyed)
      return;

    // Constrain the mouse position within the new root Window size.
    gfx::Point point;
    if (host_->QueryMouseLocation(&point)) {
      SetLastMouseLocation(
          host_->window(),
          ui::ConvertPointToDIP(host_->window()->layer(), point));
    }
    synthesize_mouse_move_ = false;
  }

  if (window->IsVisible()) {
    gfx::Rect old_bounds_in_root = old_bounds, new_bounds_in_root = new_bounds;
    Window::ConvertRectToTarget(window->parent(), host_->window(),
                                &old_bounds_in_root);
    Window::ConvertRectToTarget(window->parent(), host_->window(),
                                &new_bounds_in_root);
    gfx::Point last_mouse_location = GetLastMouseLocationInRoot();
    if (old_bounds_in_root.Contains(last_mouse_location) !=
        new_bounds_in_root.Contains(last_mouse_location)) {
      PostSynthesizeMouseMove();
    }
  }
}

void WindowEventDispatcher::OnWindowTransforming(Window* window) {
  if (!host_->window()->Contains(window))
    return;

  SynthesizeMouseMoveAfterChangeToWindow(window);
}

void WindowEventDispatcher::OnWindowTransformed(Window* window) {
  if (!host_->window()->Contains(window))
    return;

  SynthesizeMouseMoveAfterChangeToWindow(window);
}

///////////////////////////////////////////////////////////////////////////////
// WindowEventDispatcher, EnvObserver implementation:

void WindowEventDispatcher::OnWindowInitialized(Window* window) {
  observer_manager_.Add(window);
}

////////////////////////////////////////////////////////////////////////////////
// WindowEventDispatcher, private:

ui::EventDispatchDetails WindowEventDispatcher::DispatchHeldEvents() {
  if (!held_repostable_event_ && !held_move_event_)
    return DispatchDetails();

  CHECK(!dispatching_held_event_);
  dispatching_held_event_ = true;

  DispatchDetails dispatch_details;
  if (held_repostable_event_) {
    if (held_repostable_event_->type() == ui::ET_MOUSE_PRESSED) {
      scoped_ptr<ui::MouseEvent> mouse_event(
          static_cast<ui::MouseEvent*>(held_repostable_event_.release()));
      dispatch_details = OnEventFromSource(mouse_event.get());
    } else {
      // TODO(rbyers): GESTURE_TAP_DOWN not yet supported: crbug.com/170987.
      NOTREACHED();
    }
    if (dispatch_details.dispatcher_destroyed)
      return dispatch_details;
  }

  if (held_move_event_) {
    // If a mouse move has been synthesized, the target location is suspect,
    // so drop the held mouse event.
    if (held_move_event_->IsTouchEvent() ||
        (held_move_event_->IsMouseEvent() && !synthesize_mouse_move_)) {
      dispatch_details = OnEventFromSource(held_move_event_.get());
    }
    if (!dispatch_details.dispatcher_destroyed)
      held_move_event_.reset();
  }

  if (!dispatch_details.dispatcher_destroyed)
    dispatching_held_event_ = false;
  return dispatch_details;
}

void WindowEventDispatcher::PostSynthesizeMouseMove() {
  if (synthesize_mouse_move_)
    return;
  synthesize_mouse_move_ = true;
  base::MessageLoop::current()->PostNonNestableTask(
      FROM_HERE,
      base::Bind(base::IgnoreResult(
          &WindowEventDispatcher::SynthesizeMouseMoveEvent),
          held_event_factory_.GetWeakPtr()));
}

void WindowEventDispatcher::SynthesizeMouseMoveAfterChangeToWindow(
    Window* window) {
  if (window->IsVisible() &&
      window->ContainsPointInRoot(GetLastMouseLocationInRoot())) {
    PostSynthesizeMouseMove();
  }
}

ui::EventDispatchDetails WindowEventDispatcher::SynthesizeMouseMoveEvent() {
  DispatchDetails details;
  if (!synthesize_mouse_move_)
    return details;
  synthesize_mouse_move_ = false;
  gfx::Point root_mouse_location = GetLastMouseLocationInRoot();
  if (!window()->bounds().Contains(root_mouse_location))
    return details;
  gfx::Point host_mouse_location = root_mouse_location;
  host_->ConvertPointToHost(&host_mouse_location);
  ui::MouseEvent event(ui::ET_MOUSE_MOVED,
                       host_mouse_location,
                       host_mouse_location,
                       ui::EF_IS_SYNTHESIZED,
                       0);
  return OnEventFromSource(&event);
}

void WindowEventDispatcher::PreDispatchLocatedEvent(Window* target,
                                                    ui::LocatedEvent* event) {
  int flags = event->flags();
  if (IsNonClientLocation(target, event->location()))
    flags |= ui::EF_IS_NON_CLIENT;
  event->set_flags(flags);

  if (!dispatching_held_event_ &&
      (event->IsMouseEvent() || event->IsScrollEvent()) &&
      !(event->flags() & ui::EF_IS_SYNTHESIZED)) {
    if (event->type() != ui::ET_MOUSE_CAPTURE_CHANGED)
      SetLastMouseLocation(window(), event->root_location());
    synthesize_mouse_move_ = false;
  }
}

void WindowEventDispatcher::PreDispatchMouseEvent(Window* target,
                                                  ui::MouseEvent* event) {
  client::CursorClient* cursor_client = client::GetCursorClient(window());
  // We allow synthesized mouse exit events through even if mouse events are
  // disabled. This ensures that hover state, etc on controls like buttons is
  // cleared.
  if (cursor_client &&
      !cursor_client->IsMouseEventsEnabled() &&
      (event->flags() & ui::EF_IS_SYNTHESIZED) &&
      (event->type() != ui::ET_MOUSE_EXITED)) {
    event->SetHandled();
    return;
  }

  if (IsEventCandidateForHold(*event) && !dispatching_held_event_) {
    if (move_hold_count_) {
      if (!(event->flags() & ui::EF_IS_SYNTHESIZED) &&
          event->type() != ui::ET_MOUSE_CAPTURE_CHANGED) {
        SetLastMouseLocation(window(), event->root_location());
      }
      held_move_event_.reset(new ui::MouseEvent(*event, target, window()));
      event->SetHandled();
      return;
    } else {
      // We may have a held event for a period between the time move_hold_count_
      // fell to 0 and the DispatchHeldEvents executes. Since we're going to
      // dispatch the new event directly below, we can reset the old one.
      held_move_event_.reset();
    }
  }

  const int kMouseButtonFlagMask = ui::EF_LEFT_MOUSE_BUTTON |
                                   ui::EF_MIDDLE_MOUSE_BUTTON |
                                   ui::EF_RIGHT_MOUSE_BUTTON;
  switch (event->type()) {
    case ui::ET_MOUSE_EXITED:
      if (!target || target == window()) {
        DispatchDetails details =
            DispatchMouseEnterOrExit(*event, ui::ET_MOUSE_EXITED);
        if (details.dispatcher_destroyed) {
          event->SetHandled();
          return;
        }
        mouse_moved_handler_ = NULL;
      }
      break;
    case ui::ET_MOUSE_MOVED:
      // Send an exit to the current |mouse_moved_handler_| and an enter to
      // |target|. Take care that both us and |target| aren't destroyed during
      // dispatch.
      if (target != mouse_moved_handler_) {
        aura::Window* old_mouse_moved_handler = mouse_moved_handler_;
        WindowTracker live_window;
        live_window.Add(target);
        DispatchDetails details =
            DispatchMouseEnterOrExit(*event, ui::ET_MOUSE_EXITED);
        if (details.dispatcher_destroyed) {
          event->SetHandled();
          return;
        }
        // If the |mouse_moved_handler_| changes out from under us, assume a
        // nested message loop ran and we don't need to do anything.
        if (mouse_moved_handler_ != old_mouse_moved_handler) {
          event->SetHandled();
          return;
        }
        if (!live_window.Contains(target) || details.target_destroyed) {
          mouse_moved_handler_ = NULL;
          event->SetHandled();
          return;
        }
        live_window.Remove(target);

        mouse_moved_handler_ = target;
        details = DispatchMouseEnterOrExit(*event, ui::ET_MOUSE_ENTERED);
        if (details.dispatcher_destroyed || details.target_destroyed) {
          event->SetHandled();
          return;
        }
      }
      break;
    case ui::ET_MOUSE_PRESSED:
      // Don't set the mouse pressed handler for non client mouse down events.
      // These are only sent by Windows and are not always followed with non
      // client mouse up events which causes subsequent mouse events to be
      // sent to the wrong target.
      if (!(event->flags() & ui::EF_IS_NON_CLIENT) && !mouse_pressed_handler_)
        mouse_pressed_handler_ = target;
      Env::GetInstance()->set_mouse_button_flags(
          event->flags() & kMouseButtonFlagMask);
      break;
    case ui::ET_MOUSE_RELEASED:
      mouse_pressed_handler_ = NULL;
      Env::GetInstance()->set_mouse_button_flags(event->flags() &
          kMouseButtonFlagMask & ~event->changed_button_flags());
      break;
    default:
      break;
  }

  PreDispatchLocatedEvent(target, event);
}

void WindowEventDispatcher::PreDispatchTouchEvent(Window* target,
                                                  ui::TouchEvent* event) {
  switch (event->type()) {
    case ui::ET_TOUCH_PRESSED:
      touch_ids_down_ |= (1 << event->touch_id());
      Env::GetInstance()->set_touch_down(touch_ids_down_ != 0);
      break;

      // Handle ET_TOUCH_CANCELLED only if it has a native event.
    case ui::ET_TOUCH_CANCELLED:
      if (!event->HasNativeEvent())
        break;
      // fallthrough
    case ui::ET_TOUCH_RELEASED:
      touch_ids_down_ = (touch_ids_down_ | (1 << event->touch_id())) ^
            (1 << event->touch_id());
      Env::GetInstance()->set_touch_down(touch_ids_down_ != 0);
      break;

    case ui::ET_TOUCH_MOVED:
      if (move_hold_count_ && !dispatching_held_event_) {
        held_move_event_.reset(new ui::TouchEvent(*event, target, window()));
        event->SetHandled();
        return;
      }
      break;

    default:
      NOTREACHED();
      break;
  }
  PreDispatchLocatedEvent(target, event);
}

}  // namespace aura
/* [<][>][^][v][top][bottom][index][help] */
root/ui/aura/window_event_dispatcher.cc

DEFINITIONS
