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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 "ScrollingConstraints.h"
#include <wtf/TZoneMallocInlines.h>
#include <wtf/text/TextStream.h>
namespace WebCore {
WTF_MAKE_TZONE_ALLOCATED_IMPL(AbsolutePositionConstraints);
WTF_MAKE_TZONE_ALLOCATED_IMPL(ViewportConstraints);
AbsolutePositionConstraints::AbsolutePositionConstraints(const FloatSize& alignmentOffset, const FloatPoint& layerPositionAtLastLayout)
: m_alignmentOffset(alignmentOffset)
, m_layerPositionAtLastLayout(layerPositionAtLastLayout)
{
}
FloatPoint ViewportConstraints::viewportRelativeLayerPosition(const FloatRect& viewportRect) const
{
FloatSize offset;
if (hasAnchorEdge(AnchorEdgeLeft) || !hasAnchorEdge(AnchorEdgeRight))
offset.setWidth(viewportRect.x() - m_viewportRectAtLastLayout.x());
else
offset.setWidth(viewportRect.maxX() - m_viewportRectAtLastLayout.maxX());
if (hasAnchorEdge(AnchorEdgeTop) || !hasAnchorEdge(AnchorEdgeBottom))
offset.setHeight(viewportRect.y() - m_viewportRectAtLastLayout.y());
else
offset.setHeight(viewportRect.maxY() - m_viewportRectAtLastLayout.maxY());
return m_layerPositionAtLastLayout + offset;
}
FloatSize StickyPositionViewportConstraints::computeStickyOffset(const FloatRect& constrainingRect) const
{
FloatRect boxRect = m_stickyBoxRect;
if (hasAnchorEdge(AnchorEdgeRight)) {
float rightLimit = constrainingRect.maxX() - m_rightOffset;
float rightDelta = std::min<float>(0, rightLimit - m_stickyBoxRect.maxX());
float availableSpace = std::min<float>(0, m_containingBlockRect.x() - m_stickyBoxRect.x());
if (rightDelta < availableSpace)
rightDelta = availableSpace;
boxRect.move(rightDelta, 0);
}
if (hasAnchorEdge(AnchorEdgeLeft)) {
float leftLimit = constrainingRect.x() + m_leftOffset;
float leftDelta = std::max<float>(0, leftLimit - m_stickyBoxRect.x());
float availableSpace = std::max<float>(0, m_containingBlockRect.maxX() - m_stickyBoxRect.maxX());
if (leftDelta > availableSpace)
leftDelta = availableSpace;
boxRect.move(leftDelta, 0);
}
if (hasAnchorEdge(AnchorEdgeBottom)) {
float bottomLimit = constrainingRect.maxY() - m_bottomOffset;
float bottomDelta = std::min<float>(0, bottomLimit - m_stickyBoxRect.maxY());
float availableSpace = std::min<float>(0, m_containingBlockRect.y() - m_stickyBoxRect.y());
if (bottomDelta < availableSpace)
bottomDelta = availableSpace;
boxRect.move(0, bottomDelta);
}
if (hasAnchorEdge(AnchorEdgeTop)) {
float topLimit = constrainingRect.y() + m_topOffset;
float topDelta = std::max<float>(0, topLimit - m_stickyBoxRect.y());
float availableSpace = std::max<float>(0, m_containingBlockRect.maxY() - m_stickyBoxRect.maxY());
if (topDelta > availableSpace)
topDelta = availableSpace;
boxRect.move(0, topDelta);
}
return boxRect.location() - m_stickyBoxRect.location();
}
FloatPoint StickyPositionViewportConstraints::anchorLayerPositionForConstrainingRect(const FloatRect& constrainingRect) const
{
FloatSize offset = computeStickyOffset(constrainingRect);
return anchorLayerPositionAtLastLayout() + offset - m_stickyOffsetAtLastLayout;
}
FloatPoint StickyPositionViewportConstraints::anchorLayerPositionAtLastLayout() const
{
return m_layerPositionAtLastLayout + m_anchorLayerOffsetAtLastLayout;
}
FloatRect StickyPositionViewportConstraints::computeStickyExtent() const
{
float minShiftX = 0;
float maxShiftX = 0;
float minShiftY = 0;
float maxShiftY = 0;
if (hasAnchorEdge(AnchorEdgeRight))
minShiftX = std::min<float>(0, m_containingBlockRect.x() - m_stickyBoxRect.x());
if (hasAnchorEdge(AnchorEdgeLeft))
maxShiftX = std::max<float>(0, m_containingBlockRect.maxX() - m_stickyBoxRect.maxX());
if (hasAnchorEdge(AnchorEdgeBottom))
minShiftY = std::min<float>(0, m_containingBlockRect.y() - m_stickyBoxRect.y());
if (hasAnchorEdge(AnchorEdgeTop))
maxShiftY = std::max<float>(0, m_containingBlockRect.maxY() - m_stickyBoxRect.maxY());
float minX = m_stickyBoxRect.x() + minShiftX;
float minY = m_stickyBoxRect.y() + minShiftY;
float maxX = m_stickyBoxRect.maxX() + maxShiftX;
float maxY = m_stickyBoxRect.maxY() + maxShiftY;
return FloatRect(minX, minY, maxX - minX, maxY - minY);
}
TextStream& operator<<(TextStream& ts, ScrollPositioningBehavior behavior)
{
switch (behavior) {
case ScrollPositioningBehavior::None: ts << "none"_s; break;
case ScrollPositioningBehavior::Stationary: ts << "stationary"_s; break;
case ScrollPositioningBehavior::Moves: ts << "moves"_s; break;
}
return ts;
}
TextStream& operator<<(TextStream& ts, const AbsolutePositionConstraints& constraints)
{
ts.dumpProperty("layer-position-at-last-layout"_s, constraints.layerPositionAtLastLayout());
return ts;
}
TextStream& operator<<(TextStream& ts, const FixedPositionViewportConstraints& constraints)
{
ts.dumpProperty("viewport-rect-at-last-layout"_s, constraints.viewportRectAtLastLayout());
ts.dumpProperty("layer-position-at-last-layout"_s, constraints.layerPositionAtLastLayout());
return ts;
}
TextStream& operator<<(TextStream& ts, const StickyPositionViewportConstraints& constraints)
{
ts.dumpProperty("sticky-position-at-last-layout"_s, constraints.stickyOffsetAtLastLayout());
ts.dumpProperty("viewport-rect-at-last-layout"_s, constraints.viewportRectAtLastLayout());
ts.dumpProperty("layer-position-at-last-layout"_s, constraints.layerPositionAtLastLayout());
ts.dumpProperty("anchor-layer-offset-at-last-layout"_s, constraints.anchorLayerOffsetAtLastLayout());
ts.dumpProperty("sticky-box-rect"_s, constraints.stickyBoxRect());
ts.dumpProperty("containing-block-rect"_s, constraints.containingBlockRect());
ts.dumpProperty("constraining-rect-at-last-layout"_s, constraints.constrainingRectAtLastLayout());
return ts;
}
} // namespace WebCore
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