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| -rw-r--r-- | layout/base/AccessibleCaretEventHub.h | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/layout/base/AccessibleCaretEventHub.h b/layout/base/AccessibleCaretEventHub.h new file mode 100644 index 0000000000..5b1ed581c7 --- /dev/null +++ b/layout/base/AccessibleCaretEventHub.h @@ -0,0 +1,241 @@ +/* -*- 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 mozilla_AccessibleCaretEventHub_h +#define mozilla_AccessibleCaretEventHub_h + +#include "LayoutConstants.h" +#include "mozilla/EventForwards.h" +#include "mozilla/MouseEvents.h" +#include "mozilla/UniquePtr.h" +#include "mozilla/WeakPtr.h" +#include "nsCOMPtr.h" +#include "nsDocShell.h" +#include "nsIReflowObserver.h" +#include "nsIScrollObserver.h" +#include "nsPoint.h" +#include "mozilla/RefPtr.h" +#include "nsWeakReference.h" + +class nsITimer; + +namespace mozilla { +class AccessibleCaretManager; +class PresShell; +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. +// +// Please see the in-tree document for state transition diagram and more +// information. +// HTML: https://firefox-source-docs.mozilla.org/layout/AccessibleCaret.html +// Source rst: layout/docs/AccessibleCaret.rst +// +class AccessibleCaretEventHub : public nsIReflowObserver, + public nsIScrollObserver, + public nsSupportsWeakReference { + public: + explicit AccessibleCaretEventHub(PresShell* aPresShell); + void Init(); + void Terminate(); + + MOZ_CAN_RUN_SCRIPT + nsEventStatus HandleEvent(WidgetEvent* aEvent); + + // Call this function to notify the blur event happened. + MOZ_CAN_RUN_SCRIPT + void NotifyBlur(bool aIsLeavingDocument); + + NS_DECL_ISUPPORTS + + // nsIReflowObserver + MOZ_CAN_RUN_SCRIPT_BOUNDARY + NS_IMETHOD Reflow(DOMHighResTimeStamp start, DOMHighResTimeStamp end) final; + MOZ_CAN_RUN_SCRIPT_BOUNDARY + NS_IMETHOD ReflowInterruptible(DOMHighResTimeStamp start, + DOMHighResTimeStamp end) final; + + // Override nsIScrollObserver methods. + MOZ_CAN_RUN_SCRIPT_BOUNDARY + virtual void ScrollPositionChanged() override; + MOZ_CAN_RUN_SCRIPT + virtual void AsyncPanZoomStarted() override; + MOZ_CAN_RUN_SCRIPT + virtual void AsyncPanZoomStopped() override; + + // Base state + class State; + State* GetState() const; + + MOZ_CAN_RUN_SCRIPT + void OnSelectionChange(dom::Document* aDocument, dom::Selection* aSelection, + int16_t aReason); + + bool ShouldDisableApz() const; + + protected: + virtual ~AccessibleCaretEventHub() = default; + +#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(LongTapState) + + void SetState(State* aState); + + MOZ_CAN_RUN_SCRIPT + nsEventStatus HandleMouseEvent(WidgetMouseEvent* aEvent); + MOZ_CAN_RUN_SCRIPT + nsEventStatus HandleTouchEvent(WidgetTouchEvent* aEvent); + MOZ_CAN_RUN_SCRIPT + 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(); + + MOZ_CAN_RUN_SCRIPT_BOUNDARY + static void FireLongTap(nsITimer* aTimer, void* aAccessibleCaretEventHub); + + void LaunchScrollEndInjector(); + void CancelScrollEndInjector(); + + MOZ_CAN_RUN_SCRIPT_BOUNDARY + static void FireScrollEnd(nsITimer* aTimer, void* aAccessibleCaretEventHub); + + // Member variables + State* mState = NoActionState(); + + // Will be set to nullptr in Terminate(). + PresShell* 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; + + // 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; + + 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 ""; } + + MOZ_CAN_RUN_SCRIPT + virtual nsEventStatus OnPress(AccessibleCaretEventHub* aContext, + const nsPoint& aPoint, int32_t aTouchId, + EventClassID aEventClass) { + return nsEventStatus_eIgnore; + } + + MOZ_CAN_RUN_SCRIPT + virtual nsEventStatus OnMove(AccessibleCaretEventHub* aContext, + const nsPoint& aPoint, + WidgetMouseEvent::Reason aReason) { + return nsEventStatus_eIgnore; + } + + MOZ_CAN_RUN_SCRIPT + virtual nsEventStatus OnRelease(AccessibleCaretEventHub* aContext) { + return nsEventStatus_eIgnore; + } + + MOZ_CAN_RUN_SCRIPT + virtual nsEventStatus OnLongTap(AccessibleCaretEventHub* aContext, + const nsPoint& aPoint) { + return nsEventStatus_eIgnore; + } + + MOZ_CAN_RUN_SCRIPT + virtual void OnScrollStart(AccessibleCaretEventHub* aContext) {} + MOZ_CAN_RUN_SCRIPT + virtual void OnScrollEnd(AccessibleCaretEventHub* aContext) {} + MOZ_CAN_RUN_SCRIPT + virtual void OnScrollPositionChanged(AccessibleCaretEventHub* aContext) {} + MOZ_CAN_RUN_SCRIPT + virtual void OnBlur(AccessibleCaretEventHub* aContext, + bool aIsLeavingDocument) {} + MOZ_CAN_RUN_SCRIPT + virtual void OnSelectionChanged(AccessibleCaretEventHub* aContext, + dom::Document* aDoc, dom::Selection* aSel, + int16_t aReason) {} + MOZ_CAN_RUN_SCRIPT + 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 // mozilla_AccessibleCaretEventHub_h |