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Diffstat (limited to 'layout/base/AccessibleCaretEventHub.h')
| -rw-r--r-- | layout/base/AccessibleCaretEventHub.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/layout/base/AccessibleCaretEventHub.h b/layout/base/AccessibleCaretEventHub.h new file mode 100644 index 000000000..6681f8669 --- /dev/null +++ b/layout/base/AccessibleCaretEventHub.h @@ -0,0 +1,226 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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 |