sky/engine/platform/graphics/Canvas2DLayerManager.h

/*
Copyright (C) 2012 Google Inc. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1.  Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
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    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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*/

#ifndef SKY_ENGINE_PLATFORM_GRAPHICS_CANVAS2DLAYERMANAGER_H_
#define SKY_ENGINE_PLATFORM_GRAPHICS_CANVAS2DLAYERMANAGER_H_

#include "sky/engine/platform/Timer.h"
#include "sky/engine/platform/graphics/Canvas2DLayerBridge.h"

class Canvas2DLayerManagerTest;

namespace blink {

class PLATFORM_EXPORT Canvas2DLayerManager {
public:
    static Canvas2DLayerManager& get();

    void init(size_t maxBytesAllocated, size_t targetBytesAllocated);
    virtual ~Canvas2DLayerManager();

    void layerTransientResourceAllocationChanged(Canvas2DLayerBridge*, intptr_t deltaBytes = 0);
    void layerDidDraw(Canvas2DLayerBridge*);

    bool isInList(Canvas2DLayerBridge*) const;
private:
    Canvas2DLayerManager();

    // internal methods
    void freeMemoryIfNecessary();
    void addLayerToList(Canvas2DLayerBridge*);

    void limitPendingFramesTimerFired(Timer<Canvas2DLayerManager>*);

    size_t m_bytesAllocated;
    size_t m_maxBytesAllocated;
    size_t m_targetBytesAllocated;
    Timer<Canvas2DLayerManager> m_limitPendingFramesTimer;
    DoublyLinkedList<Canvas2DLayerBridge> m_layerList;

    friend class ::Canvas2DLayerManagerTest; // for unit testing
};

} // namespace blink

#endif  // SKY_ENGINE_PLATFORM_GRAPHICS_CANVAS2DLAYERMANAGER_H_