/* -*- 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
