// 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.
#ifndef UI_AURA_WINDOW_EVENT_DISPATCHER_H_
#define UI_AURA_WINDOW_EVENT_DISPATCHER_H_
#include <vector>
#include "base/basictypes.h"
#include "base/gtest_prod_util.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/message_loop/message_loop.h"
#include "base/scoped_observer.h"
#include "ui/aura/aura_export.h"
#include "ui/aura/client/capture_delegate.h"
#include "ui/aura/env_observer.h"
#include "ui/aura/window_observer.h"
#include "ui/base/cursor/cursor.h"
#include "ui/events/event_constants.h"
#include "ui/events/event_processor.h"
#include "ui/events/event_targeter.h"
#include "ui/events/gestures/gesture_recognizer.h"
#include "ui/events/gestures/gesture_types.h"
#include "ui/gfx/native_widget_types.h"
#include "ui/gfx/point.h"
namespace gfx {
class Size;
class Transform;
}
namespace ui {
class GestureEvent;
class GestureRecognizer;
class KeyEvent;
class MouseEvent;
class ScrollEvent;
class TouchEvent;
}
namespace aura {
class TestScreen;
class WindowTargeter;
class WindowTreeHost;
// WindowEventDispatcher orchestrates event dispatch within a window tree
// owned by WindowTreeHost. WTH also owns the WED.
// TODO(beng): In progress, remove functionality not directly related to
// event dispatch.
class AURA_EXPORT WindowEventDispatcher : public ui::EventProcessor,
public ui::GestureEventHelper,
public client::CaptureDelegate,
public WindowObserver,
public EnvObserver {
public:
explicit WindowEventDispatcher(WindowTreeHost* host);
virtual ~WindowEventDispatcher();
Window* mouse_pressed_handler() { return mouse_pressed_handler_; }
Window* mouse_moved_handler() { return mouse_moved_handler_; }
// Repost event for re-processing. Used when exiting context menus.
// We only support the ET_MOUSE_PRESSED and ET_GESTURE_TAP_DOWN event
// types (although the latter is currently a no-op).
void RepostEvent(const ui::LocatedEvent& event);
// Invoked when the mouse events get enabled or disabled.
void OnMouseEventsEnableStateChanged(bool enabled);
void DispatchCancelModeEvent();
// Handles a gesture event. Returns true if handled. Unlike the other
// event-dispatching function (e.g. for touch/mouse/keyboard events), gesture
// events are dispatched from GestureRecognizer instead of WindowTreeHost.
void DispatchGestureEvent(ui::GestureEvent* event);
// Dispatches a ui::ET_MOUSE_EXITED event at |point|.
// TODO(beng): needed only for WTH::OnCursorVisibilityChanged().
void DispatchMouseExitAtPoint(const gfx::Point& point);
// Gesture Recognition -------------------------------------------------------
// When a touch event is dispatched to a Window, it may want to process the
// touch event asynchronously. In such cases, the window should consume the
// event during the event dispatch. Once the event is properly processed, the
// window should let the WindowEventDispatcher know about the result of the
// event processing, so that gesture events can be properly created and
// dispatched.
void ProcessedTouchEvent(ui::TouchEvent* event,
Window* window,
ui::EventResult result);
// These methods are used to defer the processing of mouse/touch events
// related to resize. A client (typically a RenderWidgetHostViewAura) can call
// HoldPointerMoves when an resize is initiated and then ReleasePointerMoves
// once the resize is completed.
//
// More than one hold can be invoked and each hold must be cancelled by a
// release before we resume normal operation.
void HoldPointerMoves();
void ReleasePointerMoves();
// Gets the last location seen in a mouse event in this root window's
// coordinates. This may return a point outside the root window's bounds.
gfx::Point GetLastMouseLocationInRoot() const;
void OnHostLostMouseGrab();
void OnCursorMovedToRootLocation(const gfx::Point& root_location);
// TODO(beng): This is only needed because this cleanup needs to happen after
// all other observers are notified of OnWindowDestroying() but
// before OnWindowDestroyed() is sent (i.e. while the window
// hierarchy is still intact). This didn't seem worth adding a
// generic notification for as only this class needs to implement
// it. I would however like to find a way to do this via an
// observer.
void OnPostNotifiedWindowDestroying(Window* window);
private:
FRIEND_TEST_ALL_PREFIXES(WindowEventDispatcherTest,
KeepTranslatedEventInRoot);
friend class Window;
friend class TestScreen;
// The parameter for OnWindowHidden() to specify why window is hidden.
enum WindowHiddenReason {
WINDOW_DESTROYED, // Window is destroyed.
WINDOW_HIDDEN, // Window is hidden.
WINDOW_MOVING, // Window is temporarily marked as hidden due to move
// across root windows.
};
Window* window();
const Window* window() const;
// Updates the event with the appropriate transform for the device scale
// factor. The WindowEventDispatcher dispatches events in the physical pixel
// coordinate. But the event processing from WindowEventDispatcher onwards
// happen in device-independent pixel coordinate. So it is necessary to update
// the event received from the host.
void TransformEventForDeviceScaleFactor(ui::LocatedEvent* event);
// Dispatches OnMouseExited to the |window| which is hiding if necessary.
void DispatchMouseExitToHidingWindow(Window* window);
// Dispatches the specified event type (intended for enter/exit) to the
// |mouse_moved_handler_|.
ui::EventDispatchDetails DispatchMouseEnterOrExit(
const ui::MouseEvent& event,
ui::EventType type) WARN_UNUSED_RESULT;
ui::EventDispatchDetails ProcessGestures(
ui::GestureRecognizer::Gestures* gestures) WARN_UNUSED_RESULT;
// Called when a window becomes invisible, either by being removed
// from root window hierarchy, via SetVisible(false) or being destroyed.
// |reason| specifies what triggered the hiding. Note that becoming invisible
// will cause a window to lose capture and some windows may destroy themselves
// on capture (like DragDropTracker).
void OnWindowHidden(Window* invisible, WindowHiddenReason reason);
// Returns a target window for the given gesture event.
Window* GetGestureTarget(ui::GestureEvent* event);
// Overridden from aura::client::CaptureDelegate:
virtual void UpdateCapture(Window* old_capture, Window* new_capture) OVERRIDE;
virtual void OnOtherRootGotCapture() OVERRIDE;
virtual void SetNativeCapture() OVERRIDE;
virtual void ReleaseNativeCapture() OVERRIDE;
// Overridden from ui::EventProcessor:
virtual ui::EventTarget* GetRootTarget() OVERRIDE;
virtual void PrepareEventForDispatch(ui::Event* event) OVERRIDE;
// Overridden from ui::EventDispatcherDelegate.
virtual bool CanDispatchToTarget(ui::EventTarget* target) OVERRIDE;
virtual ui::EventDispatchDetails PreDispatchEvent(ui::EventTarget* target,
ui::Event* event) OVERRIDE;
virtual ui::EventDispatchDetails PostDispatchEvent(
ui::EventTarget* target, const ui::Event& event) OVERRIDE;
// Overridden from ui::GestureEventHelper.
virtual bool CanDispatchToConsumer(ui::GestureConsumer* consumer) OVERRIDE;
virtual void DispatchPostponedGestureEvent(ui::GestureEvent* event) OVERRIDE;
virtual void DispatchCancelTouchEvent(ui::TouchEvent* event) OVERRIDE;
// Overridden from WindowObserver:
virtual void OnWindowDestroying(Window* window) OVERRIDE;
virtual void OnWindowDestroyed(Window* window) OVERRIDE;
virtual void OnWindowAddedToRootWindow(Window* window) OVERRIDE;
virtual void OnWindowRemovingFromRootWindow(Window* window,
Window* new_root) OVERRIDE;
virtual void OnWindowVisibilityChanging(Window* window,
bool visible) OVERRIDE;
virtual void OnWindowVisibilityChanged(Window* window, bool visible) OVERRIDE;
virtual void OnWindowBoundsChanged(Window* window,
const gfx::Rect& old_bounds,
const gfx::Rect& new_bounds) OVERRIDE;
virtual void OnWindowTransforming(Window* window) OVERRIDE;
virtual void OnWindowTransformed(Window* window) OVERRIDE;
// Overridden from EnvObserver:
virtual void OnWindowInitialized(Window* window) OVERRIDE;
// We hold and aggregate mouse drags and touch moves as a way of throttling
// resizes when HoldMouseMoves() is called. The following methods are used to
// dispatch held and newly incoming mouse and touch events, typically when an
// event other than one of these needs dispatching or a matching
// ReleaseMouseMoves()/ReleaseTouchMoves() is called. NOTE: because these
// methods dispatch events from WindowTreeHost the coordinates are in terms of
// the root.
ui::EventDispatchDetails DispatchHeldEvents() WARN_UNUSED_RESULT;
// Posts a task to send synthesized mouse move event if there is no a pending
// task.
void PostSynthesizeMouseMove();
// Creates and dispatches synthesized mouse move event using the
// current mouse location.
ui::EventDispatchDetails SynthesizeMouseMoveEvent() WARN_UNUSED_RESULT;
// Calls SynthesizeMouseMove() if |window| is currently visible and contains
// the mouse cursor.
void SynthesizeMouseMoveAfterChangeToWindow(Window* window);
void PreDispatchLocatedEvent(Window* target, ui::LocatedEvent* event);
void PreDispatchMouseEvent(Window* target, ui::MouseEvent* event);
void PreDispatchTouchEvent(Window* target, ui::TouchEvent* event);
WindowTreeHost* host_;
// Touch ids that are currently down.
uint32 touch_ids_down_;
Window* mouse_pressed_handler_;
Window* mouse_moved_handler_;
Window* event_dispatch_target_;
Window* old_dispatch_target_;
bool synthesize_mouse_move_;
// How many move holds are outstanding. We try to defer dispatching
// touch/mouse moves while the count is > 0.
int move_hold_count_;
// The location of |held_move_event_| is in |window_|'s coordinate.
scoped_ptr<ui::LocatedEvent> held_move_event_;
// Allowing for reposting of events. Used when exiting context menus.
scoped_ptr<ui::LocatedEvent> held_repostable_event_;
// Set when dispatching a held event.
bool dispatching_held_event_;
ScopedObserver<aura::Window, aura::WindowObserver> observer_manager_;
// Used to schedule reposting an event.
base::WeakPtrFactory<WindowEventDispatcher> repost_event_factory_;
// Used to schedule DispatchHeldEvents() when |move_hold_count_| goes to 0.
base::WeakPtrFactory<WindowEventDispatcher> held_event_factory_;
DISALLOW_COPY_AND_ASSIGN(WindowEventDispatcher);
};
} // namespace aura
#endif // UI_AURA_WINDOW_EVENT_DISPATCHER_H_