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/*
* 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.
*/
#include "config.h"
#include "ScrollingStateTree.h"
#if ENABLE(THREADED_SCROLLING) || USE(COORDINATED_GRAPHICS)
#include "ScrollingStateFixedNode.h"
#include "ScrollingStateScrollingNode.h"
#include "ScrollingStateStickyNode.h"
namespace WebCore {
PassOwnPtr<ScrollingStateTree> ScrollingStateTree::create()
{
return adoptPtr(new ScrollingStateTree);
}
ScrollingStateTree::ScrollingStateTree()
: m_hasChangedProperties(false)
, m_hasNewRootStateNode(false)
{
}
ScrollingStateTree::~ScrollingStateTree()
{
}
ScrollingNodeID ScrollingStateTree::attachNode(ScrollingNodeType nodeType, ScrollingNodeID newNodeID, ScrollingNodeID parentID)
{
ASSERT(newNodeID);
if (ScrollingStateNode* node = stateNodeForID(newNodeID)) {
ScrollingStateNode* parent = stateNodeForID(parentID);
if (!parent)
return newNodeID;
if (node->parent() == parent)
return newNodeID;
// The node is being re-parented. To do that, we'll remove it, and then re-create a new node.
removeNode(node);
}
ScrollingStateNode* newNode = 0;
if (!parentID) {
// If we're resetting the root node, we should clear the HashMap and destroy the current children.
clear();
setRootStateNode(ScrollingStateScrollingNode::create(this, newNodeID));
newNode = rootStateNode();
m_hasNewRootStateNode = true;
} else {
ScrollingStateNode* parent = stateNodeForID(parentID);
if (!parent)
return 0;
switch (nodeType) {
case FixedNode: {
OwnPtr<ScrollingStateFixedNode> fixedNode = ScrollingStateFixedNode::create(this, newNodeID);
newNode = fixedNode.get();
parent->appendChild(fixedNode.release());
break;
}
case StickyNode: {
OwnPtr<ScrollingStateStickyNode> stickyNode = ScrollingStateStickyNode::create(this, newNodeID);
newNode = stickyNode.get();
parent->appendChild(stickyNode.release());
break;
}
case ScrollingNode: {
// FIXME: We currently only support child nodes that are fixed.
ASSERT_NOT_REACHED();
OwnPtr<ScrollingStateScrollingNode> scrollingNode = ScrollingStateScrollingNode::create(this, newNodeID);
newNode = scrollingNode.get();
parent->appendChild(scrollingNode.release());
break;
}
}
}
m_stateNodeMap.set(newNodeID, newNode);
return newNodeID;
}
void ScrollingStateTree::detachNode(ScrollingNodeID nodeID)
{
if (!nodeID)
return;
// The node may not be found if clearStateTree() was recently called.
ScrollingStateNode* node = m_stateNodeMap.take(nodeID);
if (!node)
return;
removeNode(node);
}
void ScrollingStateTree::clear()
{
removeNode(rootStateNode());
m_stateNodeMap.clear();
}
PassOwnPtr<ScrollingStateTree> ScrollingStateTree::commit()
{
// This function clones and resets the current state tree, but leaves the tree structure intact.
OwnPtr<ScrollingStateTree> treeStateClone = ScrollingStateTree::create();
if (m_rootStateNode)
treeStateClone->setRootStateNode(static_pointer_cast<ScrollingStateScrollingNode>(m_rootStateNode->cloneAndReset()));
// Copy the IDs of the nodes that have been removed since the last commit into the clone.
treeStateClone->m_nodesRemovedSinceLastCommit.swap(m_nodesRemovedSinceLastCommit);
// Now the clone tree has changed properties, and the original tree does not.
treeStateClone->m_hasChangedProperties = true;
m_hasChangedProperties = false;
treeStateClone->m_hasNewRootStateNode = m_hasNewRootStateNode;
m_hasNewRootStateNode = false;
return treeStateClone.release();
}
void ScrollingStateTree::removeNode(ScrollingStateNode* node)
{
if (!node)
return;
if (node == m_rootStateNode) {
didRemoveNode(node->scrollingNodeID());
m_rootStateNode = nullptr;
return;
}
ASSERT(m_rootStateNode);
m_rootStateNode->removeChild(node);
// ScrollingStateTree::removeNode() will destroy children, so we have to make sure we remove those children
// from the HashMap.
size_t size = m_nodesRemovedSinceLastCommit.size();
for (size_t i = 0; i < size; ++i)
m_stateNodeMap.remove(m_nodesRemovedSinceLastCommit[i]);
}
void ScrollingStateTree::didRemoveNode(ScrollingNodeID nodeID)
{
m_nodesRemovedSinceLastCommit.append(nodeID);
m_hasChangedProperties = true;
}
ScrollingStateNode* ScrollingStateTree::stateNodeForID(ScrollingNodeID scrollLayerID)
{
if (!scrollLayerID)
return 0;
HashMap<ScrollingNodeID, ScrollingStateNode*>::const_iterator it = m_stateNodeMap.find(scrollLayerID);
if (it == m_stateNodeMap.end())
return 0;
ASSERT(it->value->scrollingNodeID() == scrollLayerID);
return it->value;
}
} // namespace WebCore
#endif // ENABLE(THREADED_SCROLLING) || USE(COORDINATED_GRAPHICS)
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