TreeSynchronizer.h   [plain text]

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *
 * 1.  Redistributions of source code must retain the above copyright
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 * 2.  Redistributions in binary form must reproduce the above copyright
 *     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 AND ITS CONTRIBUTORS "AS IS" AND ANY
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 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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#ifndef TreeSynchronizer_h
#define TreeSynchronizer_h

#include <wtf/HashMap.h>
#include <wtf/Noncopyable.h>
#include <wtf/PassRefPtr.h>

namespace WebCore {

class CCLayerImpl;
class LayerChromium;

class TreeSynchronizer {
WTF_MAKE_NONCOPYABLE(TreeSynchronizer);
public:
    // Accepts a LayerChromium tree and returns a reference to a CCLayerImpl tree that duplicates the structure
    // of the LayerChromium tree, reusing the CCLayerImpls in the tree provided by oldCCLayerImplRoot if possible.
    static PassRefPtr<CCLayerImpl> synchronizeTrees(LayerChromium* layerRoot, PassRefPtr<CCLayerImpl> oldCCLayerImplRoot);

private:
    TreeSynchronizer(); // Not instantiable.

    typedef HashMap<int, RefPtr<CCLayerImpl> > CCLayerImplMap;

    // Declared as static member functions so they can access functions on LayerChromium as a friend class.
    static void addCCLayerImplsToMapRecursive(CCLayerImplMap&, CCLayerImpl*);
    static PassRefPtr<CCLayerImpl> synchronizeTreeRecursive(LayerChromium*, CCLayerImplMap&);
};

} // namespace WebCore

#endif // TreeSynchronizer_h