/* * Copyright (C) 2012 Apple 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. * 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 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 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef ScrollingStateTree_h #define ScrollingStateTree_h #if ENABLE(THREADED_SCROLLING) || USE(COORDINATED_GRAPHICS) #include "ScrollingStateScrollingNode.h" #include <wtf/OwnPtr.h> #include <wtf/PassOwnPtr.h> #include <wtf/RefPtr.h> namespace WebCore { // The ScrollingStateTree is a tree that managed ScrollingStateNodes. The nodes keep track of the current // state of scrolling related properties. Whenever any properties change, the scrolling coordinator // will be informed and will schedule a timer that will clone the new state tree and send it over to // the scrolling thread, avoiding locking. class ScrollingStateTree { friend class ScrollingStateNode; public: static PassOwnPtr<ScrollingStateTree> create(); ~ScrollingStateTree(); ScrollingStateScrollingNode* rootStateNode() const { return m_rootStateNode.get(); } ScrollingStateNode* stateNodeForID(ScrollingNodeID); ScrollingNodeID attachNode(ScrollingNodeType, ScrollingNodeID, ScrollingNodeID parentID); void detachNode(ScrollingNodeID); void clear(); const Vector<ScrollingNodeID>& removedNodes() const { return m_nodesRemovedSinceLastCommit; } // Copies the current tree state and clears the changed properties mask in the original. PassOwnPtr<ScrollingStateTree> commit(); void setHasChangedProperties(bool changedProperties) { m_hasChangedProperties = changedProperties; } bool hasChangedProperties() const { return m_hasChangedProperties; } bool hasNewRootStateNode() const { return m_hasNewRootStateNode; } private: ScrollingStateTree(); void setRootStateNode(PassOwnPtr<ScrollingStateScrollingNode> rootStateNode) { m_rootStateNode = rootStateNode; } void removeNode(ScrollingStateNode*); void didRemoveNode(ScrollingNodeID); PassOwnPtr<ScrollingStateTree> clone(); HashMap<ScrollingNodeID, ScrollingStateNode*> m_stateNodeMap; OwnPtr<ScrollingStateScrollingNode> m_rootStateNode; Vector<ScrollingNodeID> m_nodesRemovedSinceLastCommit; bool m_hasChangedProperties; bool m_hasNewRootStateNode; }; } // namespace WebCore #endif // ENABLE(THREADED_SCROLLING) || USE(COORDINATED_GRAPHICS) #endif // ScrollingStateTree_h