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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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_layers_PotentialCheckerboardDurationTracker_h
#define mozilla_layers_PotentialCheckerboardDurationTracker_h
#include "mozilla/TimeStamp.h"
namespace mozilla {
namespace layers {
/**
* This class allows the owner to track the duration of time considered
* "potentially checkerboarding". This is the union of two possibly-intersecting
* sets of time periods. The first set is that in which checkerboarding was
* actually happening, since by definition it could potentially be happening.
* The second set is that in which the APZC is actively transforming content
* in the compositor, since it could potentially transform it so as to display
* checkerboarding to the user.
* The caller of this class calls the appropriate methods to indicate the start
* and stop of these two sets, and this class manages accumulating the union
* of the various durations.
*/
class PotentialCheckerboardDurationTracker {
public:
PotentialCheckerboardDurationTracker();
/**
* This should be called if checkerboarding is encountered. It can be called
* multiple times during a checkerboard event.
*/
void CheckerboardSeen();
/**
* This should be called when checkerboarding is done. It must have been
* preceded by one or more calls to CheckerboardSeen().
*/
void CheckerboardDone();
/**
* This should be called at composition time, to indicate if the APZC is in
* a transforming state or not.
*/
void InTransform(bool aInTransform);
private:
bool Tracking() const;
private:
bool mInCheckerboard;
bool mInTransform;
TimeStamp mCurrentPeriodStart;
};
} // namespace layers
} // namespace mozilla
#endif // mozilla_layers_PotentialCheckerboardDurationTracker_h