1/* 2 * Copyright (C) 2012 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include "config.h" 27#include "ScrollingTreeStickyNode.h" 28 29#if ENABLE(ASYNC_SCROLLING) 30 31#include "ScrollingStateStickyNode.h" 32#include "ScrollingTree.h" 33#include "ScrollingTreeOverflowScrollingNode.h" 34#include <QuartzCore/CALayer.h> 35 36namespace WebCore { 37 38PassRefPtr<ScrollingTreeStickyNode> ScrollingTreeStickyNode::create(ScrollingTree& scrollingTree, ScrollingNodeID nodeID) 39{ 40 return adoptRef(new ScrollingTreeStickyNode(scrollingTree, nodeID)); 41} 42 43ScrollingTreeStickyNode::ScrollingTreeStickyNode(ScrollingTree& scrollingTree, ScrollingNodeID nodeID) 44 : ScrollingTreeNode(scrollingTree, StickyNode, nodeID) 45{ 46 scrollingTree.fixedOrStickyNodeAdded(); 47} 48 49ScrollingTreeStickyNode::~ScrollingTreeStickyNode() 50{ 51 scrollingTree().fixedOrStickyNodeRemoved(); 52} 53 54void ScrollingTreeStickyNode::updateBeforeChildren(const ScrollingStateNode& stateNode) 55{ 56 const ScrollingStateStickyNode& stickyStateNode = toScrollingStateStickyNode(stateNode); 57 58 if (stickyStateNode.hasChangedProperty(ScrollingStateNode::ScrollLayer)) 59 m_layer = stickyStateNode.layer(); 60 61 if (stateNode.hasChangedProperty(ScrollingStateStickyNode::ViewportConstraints)) 62 m_constraints = stickyStateNode.viewportConstraints(); 63} 64 65static inline CGPoint operator*(CGPoint& a, const CGSize& b) 66{ 67 return CGPointMake(a.x * b.width, a.y * b.height); 68} 69 70void ScrollingTreeStickyNode::updateLayersAfterAncestorChange(const ScrollingTreeNode& changedNode, const FloatRect& fixedPositionRect, const FloatSize& cumulativeDelta) 71{ 72 bool adjustStickyLayer = false; 73 FloatRect constrainingRect; 74 75 if (parent()->isOverflowScrollingNode()) { 76 constrainingRect = FloatRect(toScrollingTreeOverflowScrollingNode(parent())->scrollPosition(), m_constraints.constrainingRectAtLastLayout().size()); 77 adjustStickyLayer = true; 78 } else if (parent()->isFrameScrollingNode()) { 79 constrainingRect = fixedPositionRect; 80 adjustStickyLayer = true; 81 } 82 83 FloatSize deltaForDescendants = cumulativeDelta; 84 85 if (adjustStickyLayer) { 86 FloatPoint layerPosition = m_constraints.layerPositionForConstrainingRect(constrainingRect); 87 88 CGRect layerBounds = [m_layer bounds]; 89 CGPoint anchorPoint = [m_layer anchorPoint]; 90 CGPoint newPosition = layerPosition - m_constraints.alignmentOffset() + anchorPoint * layerBounds.size; 91 [m_layer setPosition:newPosition]; 92 93 deltaForDescendants = layerPosition - m_constraints.layerPositionAtLastLayout() + cumulativeDelta; 94 } 95 96 if (!m_children) 97 return; 98 99 for (auto& child : *m_children) 100 child->updateLayersAfterAncestorChange(changedNode, fixedPositionRect, deltaForDescendants); 101} 102 103} // namespace WebCore 104 105#endif // ENABLE(ASYNC_SCROLLING) 106