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/* -*- 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
#ifndef mozilla_layers_ActiveElementManager_h
#define mozilla_layers_ActiveElementManager_h
#include "nsCOMPtr.h"
#include "nsISupportsImpl.h"
#include "mozilla/EnumSet.h"
namespace mozilla {
class CancelableRunnable;
namespace dom {
class Element;
class EventTarget;
} // namespace dom
namespace layers {
class DelayedClearElementActivation;
namespace apz {
enum class SingleTapState : uint8_t;
} // namespace apz
/**
* Manages setting and clearing the ':active' CSS pseudostate in the presence
* of touch input.
*/
class ActiveElementManager final {
~ActiveElementManager();
public:
NS_INLINE_DECL_REFCOUNTING(ActiveElementManager)
ActiveElementManager();
/**
* Specify the target of a touch. Typically this should be called right
* after HandleTouchStart(), but in cases where the APZ needs to wait for
* a content response the HandleTouchStart() may be delayed, in which case
* this function can be called first.
* |aTarget| may be nullptr.
*/
void SetTargetElement(dom::EventTarget* aTarget);
/**
* Handle a touch-start state notification from APZ. This notification
* may be delayed until after touch listeners have responded to the APZ.
* @param aCanBePanOrZoom whether the touch can be a pan or double-tap-to-zoom
*/
void HandleTouchStart(bool aCanBePanOrZoom);
/**
* Clear the active element.
*/
void ClearActivation();
/**
* Handle a touch-end or touch-cancel event.
* @param aWasClick whether the touch was a click
*/
bool HandleTouchEndEvent(apz::SingleTapState aState);
/**
* Handle a touch-end state notification from APZ. This notification may be
* delayed until after touch listeners have responded to the APZ.
*/
bool HandleTouchEnd(apz::SingleTapState aState);
/**
* Possibly clear active element sate in response to a single tap.
*/
void ProcessSingleTap();
/**
* Cleanup on window destroy.
*/
void Destroy();
private:
/**
* The target of the first touch point in the current touch block.
*/
RefPtr<dom::Element> mTarget;
/**
* Whether the current touch block can be a pan or double-tap-to-zoom. Set in
* HandleTouchStart().
*/
bool mCanBePanOrZoom;
/**
* Whether mCanBePanOrZoom has been set for the current touch block.
* We need to keep track of this to allow HandleTouchStart() and
* SetTargetElement() to be called in either order.
*/
bool mCanBePanOrZoomSet;
bool mSingleTapBeforeActivation;
enum class TouchEndState : uint8_t {
GotTouchEndNotification,
GotTouchEndEvent,
};
using TouchEndStates = EnumSet<TouchEndState>;
/**
* A flag tracks whether `APZStateChange::eEndTouch` notification has arrived
* and whether `eTouchEnd` event has arrived.
*/
TouchEndStates mTouchEndState;
/**
* A tri-state variable to represent the single tap state when both of
* `APZStateChange::eEndTouch` notification and `eTouchEnd` event arrived.
*/
apz::SingleTapState mSingleTapState;
/**
* A task for calling SetActive() after a timeout.
*/
RefPtr<CancelableRunnable> mSetActiveTask;
// Store the pending single tap event element activation clearing
// task.
RefPtr<DelayedClearElementActivation> mDelayedClearElementActivation;
// Helpers
void TriggerElementActivation();
void SetActive(dom::Element* aTarget);
void ResetActive();
void ResetTouchBlockState();
void SetActiveTask(const nsCOMPtr<dom::Element>& aTarget);
void CancelTask();
// Returns true if the function changed the active element state.
bool MaybeChangeActiveState(apz::SingleTapState aState);
};
} // namespace layers
} // namespace mozilla
#endif /* mozilla_layers_ActiveElementManager_h */