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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 "ScrollingTreeFixedNode.h"
#if ENABLE(ASYNC_SCROLLING)
#include "ScrollingStateFixedNode.h"
#include "ScrollingThread.h"
#include "ScrollingTree.h"
#include "ScrollingTreeFrameScrollingNode.h"
#include "ScrollingTreeOverflowScrollProxyNode.h"
#include "ScrollingTreeOverflowScrollingNode.h"
#include "ScrollingTreePositionedNode.h"
#include "ScrollingTreeStickyNode.h"
#include <wtf/text/TextStream.h>
namespace WebCore {
ScrollingTreeFixedNode::ScrollingTreeFixedNode(ScrollingTree& scrollingTree, ScrollingNodeID nodeID)
: ScrollingTreeNode(scrollingTree, ScrollingNodeType::Fixed, nodeID)
{
scrollingTree.fixedOrStickyNodeAdded();
}
ScrollingTreeFixedNode::~ScrollingTreeFixedNode()
{
scrollingTree().fixedOrStickyNodeRemoved();
}
bool ScrollingTreeFixedNode::commitStateBeforeChildren(const ScrollingStateNode& stateNode)
{
if (!is<ScrollingStateFixedNode>(stateNode))
return false;
const auto& fixedStateNode = downcast<ScrollingStateFixedNode>(stateNode);
if (stateNode.hasChangedProperty(ScrollingStateNode::Property::ViewportConstraints))
m_constraints = fixedStateNode.viewportConstraints();
return true;
}
FloatPoint ScrollingTreeFixedNode::computeLayerPosition() const
{
FloatSize overflowScrollDelta;
ScrollingTreeStickyNode* lastStickyNode = nullptr;
for (RefPtr ancestor = parent(); ancestor; ancestor = ancestor->parent()) {
if (is<ScrollingTreeFrameScrollingNode>(*ancestor)) {
// Fixed nodes are positioned relative to the containing frame scrolling node.
// We bail out after finding one.
auto layoutViewport = downcast<ScrollingTreeFrameScrollingNode>(*ancestor).layoutViewport();
return m_constraints.layerPositionForViewportRect(layoutViewport) - overflowScrollDelta;
}
if (is<ScrollingTreeOverflowScrollingNode>(*ancestor)) {
// To keep the layer still during async scrolling we adjust by how much the position has changed since layout.
auto& overflowNode = downcast<ScrollingTreeOverflowScrollingNode>(*ancestor);
overflowScrollDelta -= overflowNode.scrollDeltaSinceLastCommit();
continue;
}
if (is<ScrollingTreeOverflowScrollProxyNode>(*ancestor)) {
// To keep the layer still during async scrolling we adjust by how much the position has changed since layout.
auto& overflowNode = downcast<ScrollingTreeOverflowScrollProxyNode>(*ancestor);
overflowScrollDelta -= overflowNode.scrollDeltaSinceLastCommit();
continue;
}
if (is<ScrollingTreePositionedNode>(*ancestor)) {
auto& positioningAncestor = downcast<ScrollingTreePositionedNode>(*ancestor);
// See if sticky node already handled this positioning node.
// FIXME: Include positioning node information to sticky/fixed node to avoid these tests.
if (lastStickyNode && lastStickyNode->layer() == positioningAncestor.layer())
continue;
if (positioningAncestor.layer() != layer())
overflowScrollDelta -= positioningAncestor.scrollDeltaSinceLastCommit();
continue;
}
if (is<ScrollingTreeStickyNode>(*ancestor)) {
auto& stickyNode = downcast<ScrollingTreeStickyNode>(*ancestor);
overflowScrollDelta += stickyNode.scrollDeltaSinceLastCommit();
lastStickyNode = &stickyNode;
continue;
}
if (is<ScrollingTreeFixedNode>(*ancestor)) {
// The ancestor fixed node has already applied the needed corrections to say put.
return m_constraints.layerPositionAtLastLayout() - overflowScrollDelta;
}
}
ASSERT_NOT_REACHED();
return FloatPoint();
}
void ScrollingTreeFixedNode::dumpProperties(TextStream& ts, OptionSet<ScrollingStateTreeAsTextBehavior> behavior) const
{
ts << "fixed node";
ScrollingTreeNode::dumpProperties(ts, behavior);
ts.dumpProperty("fixed constraints", m_constraints);
}
} // namespace WebCore
#endif // ENABLE(ASYNC_SCROLLING)
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