cc/tree_synchronizer.h

   1 // Copyright 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CC_TREE_SYNCHRONIZER_H_
   6 #define CC_TREE_SYNCHRONIZER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "cc/cc_export.h"
  11 #include "cc/scoped_ptr_hash_map.h"
  12
  13 namespace cc {
  14
  15 class LayerImpl;
  16 class LayerTreeImpl;
  17 class Layer;
  18
  19 class CC_EXPORT TreeSynchronizer {
  20 public:
  21     // Accepts a Layer tree and returns a reference to a LayerImpl tree that duplicates the structure
  22     // of the Layer tree, reusing the LayerImpls in the tree provided by oldLayerImplRoot if possible.
  23     static scoped_ptr<LayerImpl> synchronizeTrees(Layer* layerRoot, scoped_ptr<LayerImpl> oldLayerImplRoot, LayerTreeImpl*);
  24
  25 private:
  26     TreeSynchronizer(); // Not instantiable.
  27
  28     typedef ScopedPtrHashMap<int, LayerImpl> ScopedPtrLayerImplMap;
  29     typedef base::hash_map<int, LayerImpl*> RawPtrLayerImplMap;
  30
  31     // Declared as static member functions so they can access functions on Layer as a friend class.
  32     static scoped_ptr<LayerImpl> reuseOrCreateLayerImpl(RawPtrLayerImplMap& newLayers, ScopedPtrLayerImplMap& oldLayers, Layer*, LayerTreeImpl*);
  33     static void collectExistingLayerImplRecursive(ScopedPtrLayerImplMap& oldLayers, scoped_ptr<LayerImpl>);
  34     static scoped_ptr<LayerImpl> synchronizeTreeRecursive(RawPtrLayerImplMap& newLayers, ScopedPtrLayerImplMap& oldLayers, Layer*, LayerTreeImpl*);
  35     static void updateScrollbarLayerPointersRecursive(const RawPtrLayerImplMap& newLayers, Layer*);
  36
  37     DISALLOW_COPY_AND_ASSIGN(TreeSynchronizer);
  38 };
  39
  40 } // namespace cc
  41
  42 #endif  // CC_TREE_SYNCHRONIZER_H_