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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef AccessibleCaretEventHub_h
#define AccessibleCaretEventHub_h
#include "mozilla/EventForwards.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/WeakPtr.h"
#include "nsCOMPtr.h"
#include "nsIFrame.h"
#include "nsIReflowObserver.h"
#include "nsIScrollObserver.h"
#include "nsISelectionListener.h"
#include "nsPoint.h"
#include "mozilla/RefPtr.h"
#include "nsWeakReference.h"
class nsDocShell;
class nsIPresShell;
class nsITimer;
namespace mozilla {
class AccessibleCaretManager;
class WidgetKeyboardEvent;
class WidgetMouseEvent;
class WidgetTouchEvent;
// -----------------------------------------------------------------------------
// Each PresShell holds a shared pointer to an AccessibleCaretEventHub; each
// AccessibleCaretEventHub holds a unique pointer to an AccessibleCaretManager.
// Thus, there's one AccessibleCaretManager per PresShell.
//
// AccessibleCaretEventHub implements a state pattern. It receives events from
// PresShell and callbacks by observers and listeners, and then relays them to
// the current concrete state which calls necessary event-handling methods in
// AccessibleCaretManager.
//
// We separate AccessibleCaretEventHub from AccessibleCaretManager to make the
// state transitions in AccessibleCaretEventHub testable. We put (nearly) all
// the operations involving PresShell, Selection, and AccessibleCaret
// manipulation in AccessibleCaretManager so that we can mock methods in
// AccessibleCaretManager in gtest. We test the correctness of the state
// transitions by giving events, callbacks, and the return values by mocked
// methods of AccessibleCaretEventHub. See TestAccessibleCaretEventHub.cpp.
//
// Besides dealing with real events, AccessibleCaretEventHub could also
// synthesize fake long-tap events and inject those events to itself on the
// platform lacks eMouseLongTap. Turn on this preference
// "layout.accessiblecaret.use_long_tap_injector" for the fake long-tap events.
//
// State transition diagram:
// http://hg.mozilla.org/mozilla-central/raw-file/default/layout/base/doc/AccessibleCaretEventHubStates.png
// Source code of the diagram:
// http://hg.mozilla.org/mozilla-central/file/default/layout/base/doc/AccessibleCaretEventHubStates.dot
//
// Please see the wiki page for more information.
// https://wiki.mozilla.org/AccessibleCaret
//
class AccessibleCaretEventHub : public nsIReflowObserver,
public nsIScrollObserver,
public nsISelectionListener,
public nsSupportsWeakReference
{
public:
explicit AccessibleCaretEventHub(nsIPresShell* aPresShell);
void Init();
void Terminate();
nsEventStatus HandleEvent(WidgetEvent* aEvent);
// Call this function to notify the blur event happened.
void NotifyBlur(bool aIsLeavingDocument);
NS_DECL_ISUPPORTS
NS_DECL_NSIREFLOWOBSERVER
NS_DECL_NSISELECTIONLISTENER
// Override nsIScrollObserver methods.
virtual void ScrollPositionChanged() override;
virtual void AsyncPanZoomStarted() override;
virtual void AsyncPanZoomStopped() override;
// Base state
class State;
State* GetState() const;
protected:
virtual ~AccessibleCaretEventHub();
#define MOZ_DECL_STATE_CLASS_GETTER(aClassName) \
class aClassName; \
static State* aClassName();
#define MOZ_IMPL_STATE_CLASS_GETTER(aClassName) \
AccessibleCaretEventHub::State* AccessibleCaretEventHub::aClassName() \
{ \
static class aClassName singleton; \
return &singleton; \
}
// Concrete state getters
MOZ_DECL_STATE_CLASS_GETTER(NoActionState)
MOZ_DECL_STATE_CLASS_GETTER(PressCaretState)
MOZ_DECL_STATE_CLASS_GETTER(DragCaretState)
MOZ_DECL_STATE_CLASS_GETTER(PressNoCaretState)
MOZ_DECL_STATE_CLASS_GETTER(ScrollState)
MOZ_DECL_STATE_CLASS_GETTER(PostScrollState)
MOZ_DECL_STATE_CLASS_GETTER(LongTapState)
void SetState(State* aState);
nsEventStatus HandleMouseEvent(WidgetMouseEvent* aEvent);
nsEventStatus HandleTouchEvent(WidgetTouchEvent* aEvent);
nsEventStatus HandleKeyboardEvent(WidgetKeyboardEvent* aEvent);
virtual nsPoint GetTouchEventPosition(WidgetTouchEvent* aEvent,
int32_t aIdentifier) const;
virtual nsPoint GetMouseEventPosition(WidgetMouseEvent* aEvent) const;
bool MoveDistanceIsLarge(const nsPoint& aPoint) const;
void LaunchLongTapInjector();
void CancelLongTapInjector();
static void FireLongTap(nsITimer* aTimer, void* aAccessibleCaretEventHub);
void LaunchScrollEndInjector();
void CancelScrollEndInjector();
static void FireScrollEnd(nsITimer* aTimer, void* aAccessibleCaretEventHub);
// Member variables
State* mState = NoActionState();
// Will be set to nullptr in Terminate().
nsIPresShell* MOZ_NON_OWNING_REF mPresShell = nullptr;
UniquePtr<AccessibleCaretManager> mManager;
WeakPtr<nsDocShell> mDocShell;
// Use this timer for injecting a long tap event when APZ is disabled. If APZ
// is enabled, it will send long tap event to us.
nsCOMPtr<nsITimer> mLongTapInjectorTimer;
// Use this timer for injecting a simulated scroll end.
nsCOMPtr<nsITimer> mScrollEndInjectorTimer;
// Last mouse button down event or touch start event point.
nsPoint mPressPoint{ NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE };
// For filter multitouch event
int32_t mActiveTouchId = kInvalidTouchId;
// Flag to indicate the class has been initialized.
bool mInitialized = false;
// Flag to avoid calling Reflow() callback recursively.
bool mIsInReflowCallback = false;
// Simulate long tap if the platform does not support eMouseLongTap events.
static bool sUseLongTapInjector;
static const int32_t kScrollEndTimerDelay = 300;
static const int32_t kMoveStartToleranceInPixel = 5;
static const int32_t kInvalidTouchId = -1;
static const int32_t kDefaultTouchId = 0; // For mouse event
};
// -----------------------------------------------------------------------------
// The base class for concrete states. A concrete state should inherit from this
// class, and override the methods to handle the events or callbacks. A concrete
// state is also responsible for transforming itself to the next concrete state.
//
class AccessibleCaretEventHub::State
{
public:
virtual const char* Name() const { return ""; }
virtual nsEventStatus OnPress(AccessibleCaretEventHub* aContext,
const nsPoint& aPoint, int32_t aTouchId,
EventClassID aEventClass)
{
return nsEventStatus_eIgnore;
}
virtual nsEventStatus OnMove(AccessibleCaretEventHub* aContext,
const nsPoint& aPoint)
{
return nsEventStatus_eIgnore;
}
virtual nsEventStatus OnRelease(AccessibleCaretEventHub* aContext)
{
return nsEventStatus_eIgnore;
}
virtual nsEventStatus OnLongTap(AccessibleCaretEventHub* aContext,
const nsPoint& aPoint)
{
return nsEventStatus_eIgnore;
}
virtual void OnScrollStart(AccessibleCaretEventHub* aContext) {}
virtual void OnScrollEnd(AccessibleCaretEventHub* aContext) {}
virtual void OnScrollPositionChanged(AccessibleCaretEventHub* aContext) {}
virtual void OnBlur(AccessibleCaretEventHub* aContext,
bool aIsLeavingDocument) {}
virtual void OnSelectionChanged(AccessibleCaretEventHub* aContext,
nsIDOMDocument* aDoc, nsISelection* aSel,
int16_t aReason) {}
virtual void OnReflow(AccessibleCaretEventHub* aContext) {}
virtual void Enter(AccessibleCaretEventHub* aContext) {}
virtual void Leave(AccessibleCaretEventHub* aContext) {}
explicit State() = default;
virtual ~State() = default;
State(const State&) = delete;
State& operator=(const State&) = delete;
};
} // namespace mozilla
#endif // AccessibleCaretEventHub_h
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