cc/TreeSynchronizer.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 TreeSynchronizer_h
   6 #define TreeSynchronizer_h
   7
   8 #include <wtf/HashMap.h>
   9 #include <wtf/Noncopyable.h>
  10 #include <wtf/OwnPtr.h>
  11 #include <wtf/PassOwnPtr.h>
  12
  13 namespace WebCore {
  14
  15 class CCLayerImpl;
  16 class CCLayerTreeHostImpl;
  17 class LayerChromium;
  18
  19 class TreeSynchronizer {
  20 WTF_MAKE_NONCOPYABLE(TreeSynchronizer);
  21 public:
  22     // Accepts a LayerChromium tree and returns a reference to a CCLayerImpl tree that duplicates the structure
  23     // of the LayerChromium tree, reusing the CCLayerImpls in the tree provided by oldCCLayerImplRoot if possible.
  24     static PassOwnPtr<CCLayerImpl> synchronizeTrees(LayerChromium* layerRoot, PassOwnPtr<CCLayerImpl> oldCCLayerImplRoot, CCLayerTreeHostImpl*);
  25
  26 private:
  27     TreeSynchronizer(); // Not instantiable.
  28
  29     typedef HashMap<int, OwnPtr<CCLayerImpl> > OwnPtrCCLayerImplMap;
  30     typedef HashMap<int, CCLayerImpl*> RawPtrCCLayerImplMap;
  31
  32     // Declared as static member functions so they can access functions on LayerChromium as a friend class.
  33     static PassOwnPtr<CCLayerImpl> reuseOrCreateCCLayerImpl(RawPtrCCLayerImplMap& newLayers, OwnPtrCCLayerImplMap& oldLayers, LayerChromium*);
  34     static void collectExistingCCLayerImplRecursive(OwnPtrCCLayerImplMap& oldLayers, PassOwnPtr<CCLayerImpl>);
  35     static PassOwnPtr<CCLayerImpl> synchronizeTreeRecursive(RawPtrCCLayerImplMap& newLayers, OwnPtrCCLayerImplMap& oldLayers, LayerChromium*, CCLayerTreeHostImpl*);
  36     static void updateScrollbarLayerPointersRecursive(const RawPtrCCLayerImplMap& newLayers, LayerChromium*);
  37 };
  38
  39 } // namespace WebCore
  40
  41 #endif // TreeSynchronizer_h