/* -*- 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