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/*
* Copyright (C) 2011 Adobe Systems Incorporated. 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 THE COPYRIGHT HOLDER "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 THE COPYRIGHT HOLDER 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 "RenderFragmentContainer.h"
#include "GraphicsContext.h"
#include "HitTestResult.h"
#include "IntRect.h"
#include "LayoutRepainter.h"
#include "Range.h"
#include "RenderBoxFragmentInfo.h"
#include "RenderFragmentedFlow.h"
#include "RenderInline.h"
#include "RenderIterator.h"
#include "RenderLayer.h"
#include "RenderView.h"
#include "StyleResolver.h"
#include <wtf/IsoMallocInlines.h>
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(RenderFragmentContainer);
RenderFragmentContainer::RenderFragmentContainer(Element& element, RenderStyle&& style, RenderFragmentedFlow* fragmentedFlow)
: RenderBlockFlow(element, WTFMove(style))
, m_fragmentedFlow(fragmentedFlow)
, m_isValid(false)
{
}
RenderFragmentContainer::RenderFragmentContainer(Document& document, RenderStyle&& style, RenderFragmentedFlow* fragmentedFlow)
: RenderBlockFlow(document, WTFMove(style))
, m_fragmentedFlow(fragmentedFlow)
, m_isValid(false)
{
}
LayoutPoint RenderFragmentContainer::mapFragmentPointIntoFragmentedFlowCoordinates(const LayoutPoint& point)
{
// Assuming the point is relative to the fragment block, 3 cases will be considered:
// a) top margin, padding or border.
// b) bottom margin, padding or border.
// c) non-content fragment area.
LayoutUnit pointLogicalTop(isHorizontalWritingMode() ? point.y() : point.x());
LayoutUnit pointLogicalLeft(isHorizontalWritingMode() ? point.x() : point.y());
LayoutUnit fragmentedFlowLogicalTop(isHorizontalWritingMode() ? m_fragmentedFlowPortionRect.y() : m_fragmentedFlowPortionRect.x());
LayoutUnit fragmentedFlowLogicalLeft(isHorizontalWritingMode() ? m_fragmentedFlowPortionRect.x() : m_fragmentedFlowPortionRect.y());
LayoutUnit fragmentedFlowPortionTopBound(isHorizontalWritingMode() ? m_fragmentedFlowPortionRect.height() : m_fragmentedFlowPortionRect.width());
LayoutUnit fragmentedFlowPortionLeftBound(isHorizontalWritingMode() ? m_fragmentedFlowPortionRect.width() : m_fragmentedFlowPortionRect.height());
LayoutUnit fragmentedFlowPortionTopMax(isHorizontalWritingMode() ? m_fragmentedFlowPortionRect.maxY() : m_fragmentedFlowPortionRect.maxX());
LayoutUnit fragmentedFlowPortionLeftMax(isHorizontalWritingMode() ? m_fragmentedFlowPortionRect.maxX() : m_fragmentedFlowPortionRect.maxY());
LayoutUnit effectiveFixedPointDenominator;
effectiveFixedPointDenominator.setRawValue(1);
if (pointLogicalTop < 0) {
LayoutPoint pointInThread(0, fragmentedFlowLogicalTop);
return isHorizontalWritingMode() ? pointInThread : pointInThread.transposedPoint();
}
if (pointLogicalTop >= fragmentedFlowPortionTopBound) {
LayoutPoint pointInThread(fragmentedFlowPortionLeftBound, fragmentedFlowPortionTopMax - effectiveFixedPointDenominator);
return isHorizontalWritingMode() ? pointInThread : pointInThread.transposedPoint();
}
if (pointLogicalLeft < 0) {
LayoutPoint pointInThread(fragmentedFlowLogicalLeft, pointLogicalTop + fragmentedFlowLogicalTop);
return isHorizontalWritingMode() ? pointInThread : pointInThread.transposedPoint();
}
if (pointLogicalLeft >= fragmentedFlowPortionLeftBound) {
LayoutPoint pointInThread(fragmentedFlowPortionLeftMax - effectiveFixedPointDenominator, pointLogicalTop + fragmentedFlowLogicalTop);
return isHorizontalWritingMode() ? pointInThread : pointInThread.transposedPoint();
}
LayoutPoint pointInThread(pointLogicalLeft + fragmentedFlowLogicalLeft, pointLogicalTop + fragmentedFlowLogicalTop);
return isHorizontalWritingMode() ? pointInThread : pointInThread.transposedPoint();
}
VisiblePosition RenderFragmentContainer::positionForPoint(const LayoutPoint& point, const RenderFragmentContainer* fragment)
{
if (!isValid() || !m_fragmentedFlow->firstChild()) // checking for empty fragment blocks.
return RenderBlock::positionForPoint(point, fragment);
return m_fragmentedFlow->positionForPoint(mapFragmentPointIntoFragmentedFlowCoordinates(point), this);
}
LayoutUnit RenderFragmentContainer::pageLogicalWidth() const
{
ASSERT(isValid());
return m_fragmentedFlow->isHorizontalWritingMode() ? contentWidth() : contentHeight();
}
LayoutUnit RenderFragmentContainer::pageLogicalHeight() const
{
ASSERT(isValid());
return m_fragmentedFlow->isHorizontalWritingMode() ? contentHeight() : contentWidth();
}
LayoutUnit RenderFragmentContainer::logicalHeightOfAllFragmentedFlowContent() const
{
return pageLogicalHeight();
}
LayoutRect RenderFragmentContainer::fragmentedFlowPortionOverflowRect()
{
return overflowRectForFragmentedFlowPortion(fragmentedFlowPortionRect(), isFirstFragment(), isLastFragment(), VisualOverflow);
}
LayoutPoint RenderFragmentContainer::fragmentedFlowPortionLocation() const
{
LayoutPoint portionLocation;
LayoutRect portionRect = fragmentedFlowPortionRect();
if (fragmentedFlow()->style().isFlippedBlocksWritingMode()) {
LayoutRect flippedFragmentedFlowPortionRect(portionRect);
fragmentedFlow()->flipForWritingMode(flippedFragmentedFlowPortionRect);
portionLocation = flippedFragmentedFlowPortionRect.location();
} else
portionLocation = portionRect.location();
return portionLocation;
}
LayoutRect RenderFragmentContainer::overflowRectForFragmentedFlowPortion(const LayoutRect& fragmentedFlowPortionRect, bool isFirstPortion, bool isLastPortion, OverflowType overflowType)
{
ASSERT(isValid());
if (shouldClipFragmentedFlowContent())
return fragmentedFlowPortionRect;
LayoutRect fragmentedFlowOverflow = overflowType == VisualOverflow ? visualOverflowRectForBox(*m_fragmentedFlow) : layoutOverflowRectForBox(m_fragmentedFlow);
LayoutRect clipRect;
if (m_fragmentedFlow->isHorizontalWritingMode()) {
LayoutUnit minY = isFirstPortion ? fragmentedFlowOverflow.y() : fragmentedFlowPortionRect.y();
LayoutUnit maxY = isLastPortion ? std::max(fragmentedFlowPortionRect.maxY(), fragmentedFlowOverflow.maxY()) : fragmentedFlowPortionRect.maxY();
bool clipX = style().overflowX() != OVISIBLE;
LayoutUnit minX = clipX ? fragmentedFlowPortionRect.x() : std::min(fragmentedFlowPortionRect.x(), fragmentedFlowOverflow.x());
LayoutUnit maxX = clipX ? fragmentedFlowPortionRect.maxX() : std::max(fragmentedFlowPortionRect.maxX(), fragmentedFlowOverflow.maxX());
clipRect = LayoutRect(minX, minY, maxX - minX, maxY - minY);
} else {
LayoutUnit minX = isFirstPortion ? fragmentedFlowOverflow.x() : fragmentedFlowPortionRect.x();
LayoutUnit maxX = isLastPortion ? std::max(fragmentedFlowPortionRect.maxX(), fragmentedFlowOverflow.maxX()) : fragmentedFlowPortionRect.maxX();
bool clipY = style().overflowY() != OVISIBLE;
LayoutUnit minY = clipY ? fragmentedFlowPortionRect.y() : std::min(fragmentedFlowPortionRect.y(), fragmentedFlowOverflow.y());
LayoutUnit maxY = clipY ? fragmentedFlowPortionRect.maxY() : std::max(fragmentedFlowPortionRect.y(), fragmentedFlowOverflow.maxY());
clipRect = LayoutRect(minX, minY, maxX - minX, maxY - minY);
}
return clipRect;
}
LayoutUnit RenderFragmentContainer::pageLogicalTopForOffset(LayoutUnit /* offset */) const
{
return fragmentedFlow()->isHorizontalWritingMode() ? fragmentedFlowPortionRect().y() : fragmentedFlowPortionRect().x();
}
LayoutUnit RenderFragmentContainer::pageLogicalHeightForOffset(LayoutUnit /* offset */) const
{
return pageLogicalHeight();
}
bool RenderFragmentContainer::isFirstFragment() const
{
ASSERT(isValid());
return m_fragmentedFlow->firstFragment() == this;
}
bool RenderFragmentContainer::isLastFragment() const
{
ASSERT(isValid());
return m_fragmentedFlow->lastFragment() == this;
}
bool RenderFragmentContainer::shouldClipFragmentedFlowContent() const
{
return hasOverflowClip();
}
void RenderFragmentContainer::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
RenderBlockFlow::styleDidChange(diff, oldStyle);
if (!isValid())
return;
if (oldStyle && oldStyle->writingMode() != style().writingMode())
m_fragmentedFlow->fragmentChangedWritingMode(this);
}
void RenderFragmentContainer::computeOverflowFromFragmentedFlow()
{
ASSERT(isValid());
LayoutRect layoutRect = layoutOverflowRectForBox(m_fragmentedFlow);
layoutRect.setLocation(contentBoxRect().location() + (layoutRect.location() - m_fragmentedFlowPortionRect.location()));
// FIXME: Correctly adjust the layout overflow for writing modes.
addLayoutOverflow(layoutRect);
RenderFragmentedFlow* enclosingRenderFragmentedFlow = enclosingFragmentedFlow();
if (enclosingRenderFragmentedFlow)
enclosingRenderFragmentedFlow->addFragmentsLayoutOverflow(this, layoutRect);
updateLayerTransform();
updateScrollInfoAfterLayout();
}
void RenderFragmentContainer::repaintFragmentedFlowContent(const LayoutRect& repaintRect)
{
repaintFragmentedFlowContentRectangle(repaintRect, fragmentedFlowPortionRect(), contentBoxRect().location());
}
void RenderFragmentContainer::repaintFragmentedFlowContentRectangle(const LayoutRect& repaintRect, const LayoutRect& fragmentedFlowPortionRect, const LayoutPoint& fragmentLocation, const LayoutRect* fragmentedFlowPortionClipRect)
{
ASSERT(isValid());
// We only have to issue a repaint in this fragment if the fragment rect intersects the repaint rect.
LayoutRect clippedRect(repaintRect);
if (fragmentedFlowPortionClipRect) {
LayoutRect flippedFragmentedFlowPortionClipRect(*fragmentedFlowPortionClipRect);
fragmentedFlow()->flipForWritingMode(flippedFragmentedFlowPortionClipRect);
clippedRect.intersect(flippedFragmentedFlowPortionClipRect);
}
if (clippedRect.isEmpty())
return;
LayoutRect flippedFragmentedFlowPortionRect(fragmentedFlowPortionRect);
fragmentedFlow()->flipForWritingMode(flippedFragmentedFlowPortionRect); // Put the fragment rects into physical coordinates.
// Put the fragment rect into the fragment's physical coordinate space.
clippedRect.setLocation(fragmentLocation + (clippedRect.location() - flippedFragmentedFlowPortionRect.location()));
// Now switch to the fragment's writing mode coordinate space and let it repaint itself.
flipForWritingMode(clippedRect);
// Issue the repaint.
repaintRectangle(clippedRect);
}
void RenderFragmentContainer::installFragmentedFlow()
{
ASSERT_NOT_REACHED();
}
void RenderFragmentContainer::attachFragment()
{
if (renderTreeBeingDestroyed())
return;
// A fragment starts off invalid.
setIsValid(false);
// Initialize the flow thread reference and create the flow thread object if needed.
// The flow thread lifetime is influenced by the number of fragments attached to it,
// and we are attaching the fragment to the flow thread.
installFragmentedFlow();
if (!m_fragmentedFlow)
return;
// Only after adding the fragment to the thread, the fragment is marked to be valid.
m_fragmentedFlow->addFragmentToThread(this);
}
void RenderFragmentContainer::detachFragment()
{
if (m_fragmentedFlow)
m_fragmentedFlow->removeFragmentFromThread(this);
m_fragmentedFlow = nullptr;
}
RenderBoxFragmentInfo* RenderFragmentContainer::renderBoxFragmentInfo(const RenderBox* box) const
{
ASSERT(isValid());
return m_renderBoxFragmentInfo.get(box);
}
RenderBoxFragmentInfo* RenderFragmentContainer::setRenderBoxFragmentInfo(const RenderBox* box, LayoutUnit logicalLeftInset, LayoutUnit logicalRightInset,
bool containingBlockChainIsInset)
{
ASSERT(isValid());
std::unique_ptr<RenderBoxFragmentInfo>& boxInfo = m_renderBoxFragmentInfo.add(box, std::make_unique<RenderBoxFragmentInfo>(logicalLeftInset, logicalRightInset, containingBlockChainIsInset)).iterator->value;
return boxInfo.get();
}
std::unique_ptr<RenderBoxFragmentInfo> RenderFragmentContainer::takeRenderBoxFragmentInfo(const RenderBox* box)
{
return m_renderBoxFragmentInfo.take(box);
}
void RenderFragmentContainer::removeRenderBoxFragmentInfo(const RenderBox& box)
{
m_renderBoxFragmentInfo.remove(&box);
}
void RenderFragmentContainer::deleteAllRenderBoxFragmentInfo()
{
m_renderBoxFragmentInfo.clear();
}
LayoutUnit RenderFragmentContainer::logicalTopOfFragmentedFlowContentRect(const LayoutRect& rect) const
{
ASSERT(isValid());
return fragmentedFlow()->isHorizontalWritingMode() ? rect.y() : rect.x();
}
LayoutUnit RenderFragmentContainer::logicalBottomOfFragmentedFlowContentRect(const LayoutRect& rect) const
{
ASSERT(isValid());
return fragmentedFlow()->isHorizontalWritingMode() ? rect.maxY() : rect.maxX();
}
void RenderFragmentContainer::insertedIntoTree()
{
attachFragment();
if (isValid())
RenderBlockFlow::insertedIntoTree();
}
void RenderFragmentContainer::willBeRemovedFromTree()
{
RenderBlockFlow::willBeRemovedFromTree();
detachFragment();
}
void RenderFragmentContainer::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
{
if (!isValid()) {
RenderBlockFlow::computeIntrinsicLogicalWidths(minLogicalWidth, maxLogicalWidth);
return;
}
minLogicalWidth = m_fragmentedFlow->minPreferredLogicalWidth();
maxLogicalWidth = m_fragmentedFlow->maxPreferredLogicalWidth();
}
void RenderFragmentContainer::computePreferredLogicalWidths()
{
ASSERT(preferredLogicalWidthsDirty());
if (!isValid()) {
RenderBlockFlow::computePreferredLogicalWidths();
return;
}
// FIXME: Currently, the code handles only the <length> case for min-width/max-width.
// It should also support other values, like percentage, calc or viewport relative.
m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = 0;
const RenderStyle& styleToUse = style();
if (styleToUse.logicalWidth().isFixed() && styleToUse.logicalWidth().value() > 0)
m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = adjustContentBoxLogicalWidthForBoxSizing(styleToUse.logicalWidth().value());
else
computeIntrinsicLogicalWidths(m_minPreferredLogicalWidth, m_maxPreferredLogicalWidth);
if (styleToUse.logicalMinWidth().isFixed() && styleToUse.logicalMinWidth().value() > 0) {
m_maxPreferredLogicalWidth = std::max(m_maxPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(styleToUse.logicalMinWidth().value()));
m_minPreferredLogicalWidth = std::max(m_minPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(styleToUse.logicalMinWidth().value()));
}
if (styleToUse.logicalMaxWidth().isFixed()) {
m_maxPreferredLogicalWidth = std::min(m_maxPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(styleToUse.logicalMaxWidth().value()));
m_minPreferredLogicalWidth = std::min(m_minPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(styleToUse.logicalMaxWidth().value()));
}
LayoutUnit borderAndPadding = borderAndPaddingLogicalWidth();
m_minPreferredLogicalWidth += borderAndPadding;
m_maxPreferredLogicalWidth += borderAndPadding;
setPreferredLogicalWidthsDirty(false);
}
void RenderFragmentContainer::adjustFragmentBoundsFromFragmentedFlowPortionRect(LayoutRect& fragmentBounds) const
{
LayoutRect flippedFragmentedFlowPortionRect = fragmentedFlowPortionRect();
fragmentedFlow()->flipForWritingMode(flippedFragmentedFlowPortionRect);
fragmentBounds.moveBy(flippedFragmentedFlowPortionRect.location());
}
void RenderFragmentContainer::ensureOverflowForBox(const RenderBox* box, RefPtr<RenderOverflow>& overflow, bool forceCreation)
{
ASSERT(m_fragmentedFlow->renderFragmentContainerList().contains(this));
ASSERT(isValid());
RenderBoxFragmentInfo* boxInfo = renderBoxFragmentInfo(box);
if (!boxInfo && !forceCreation)
return;
if (boxInfo && boxInfo->overflow()) {
overflow = boxInfo->overflow();
return;
}
LayoutRect borderBox = box->borderBoxRectInFragment(this);
LayoutRect clientBox;
ASSERT(m_fragmentedFlow->objectShouldFragmentInFlowFragment(box, this));
if (!borderBox.isEmpty()) {
borderBox = rectFlowPortionForBox(box, borderBox);
clientBox = box->clientBoxRectInFragment(this);
clientBox = rectFlowPortionForBox(box, clientBox);
m_fragmentedFlow->flipForWritingModeLocalCoordinates(borderBox);
m_fragmentedFlow->flipForWritingModeLocalCoordinates(clientBox);
}
if (boxInfo) {
boxInfo->createOverflow(clientBox, borderBox);
overflow = boxInfo->overflow();
} else
overflow = adoptRef(new RenderOverflow(clientBox, borderBox));
}
LayoutRect RenderFragmentContainer::rectFlowPortionForBox(const RenderBox* box, const LayoutRect& rect) const
{
LayoutRect mappedRect = m_fragmentedFlow->mapFromLocalToFragmentedFlow(box, rect);
RenderFragmentContainer* startFragment = nullptr;
RenderFragmentContainer* endFragment = nullptr;
if (m_fragmentedFlow->getFragmentRangeForBox(box, startFragment, endFragment)) {
if (fragmentedFlow()->isHorizontalWritingMode()) {
if (this != startFragment)
mappedRect.shiftYEdgeTo(std::max<LayoutUnit>(logicalTopForFragmentedFlowContent(), mappedRect.y()));
if (this != endFragment)
mappedRect.setHeight(std::max<LayoutUnit>(0, std::min<LayoutUnit>(logicalBottomForFragmentedFlowContent() - mappedRect.y(), mappedRect.height())));
} else {
if (this != startFragment)
mappedRect.shiftXEdgeTo(std::max<LayoutUnit>(logicalTopForFragmentedFlowContent(), mappedRect.x()));
if (this != endFragment)
mappedRect.setWidth(std::max<LayoutUnit>(0, std::min<LayoutUnit>(logicalBottomForFragmentedFlowContent() - mappedRect.x(), mappedRect.width())));
}
}
return m_fragmentedFlow->mapFromFragmentedFlowToLocal(box, mappedRect);
}
void RenderFragmentContainer::addLayoutOverflowForBox(const RenderBox* box, const LayoutRect& rect)
{
if (rect.isEmpty())
return;
RefPtr<RenderOverflow> fragmentOverflow;
ensureOverflowForBox(box, fragmentOverflow, false);
if (!fragmentOverflow)
return;
fragmentOverflow->addLayoutOverflow(rect);
}
void RenderFragmentContainer::addVisualOverflowForBox(const RenderBox* box, const LayoutRect& rect)
{
if (rect.isEmpty())
return;
RefPtr<RenderOverflow> fragmentOverflow;
ensureOverflowForBox(box, fragmentOverflow, false);
if (!fragmentOverflow)
return;
LayoutRect flippedRect = rect;
fragmentedFlow()->flipForWritingModeLocalCoordinates(flippedRect);
fragmentOverflow->addVisualOverflow(flippedRect);
}
LayoutRect RenderFragmentContainer::layoutOverflowRectForBox(const RenderBox* box)
{
RefPtr<RenderOverflow> overflow;
ensureOverflowForBox(box, overflow, true);
ASSERT(overflow);
return overflow->layoutOverflowRect();
}
LayoutRect RenderFragmentContainer::visualOverflowRectForBox(const RenderBoxModelObject& box)
{
if (is<RenderInline>(box)) {
const RenderInline& inlineBox = downcast<RenderInline>(box);
return inlineBox.linesVisualOverflowBoundingBoxInFragment(this);
}
if (is<RenderBox>(box)) {
RefPtr<RenderOverflow> overflow;
ensureOverflowForBox(&downcast<RenderBox>(box), overflow, true);
ASSERT(overflow);
return overflow->visualOverflowRect();
}
ASSERT_NOT_REACHED();
return LayoutRect();
}
// FIXME: This doesn't work for writing modes.
LayoutRect RenderFragmentContainer::layoutOverflowRectForBoxForPropagation(const RenderBox* box)
{
// Only propagate interior layout overflow if we don't clip it.
LayoutRect rect = box->borderBoxRectInFragment(this);
rect = rectFlowPortionForBox(box, rect);
if (!box->hasOverflowClip())
rect.unite(layoutOverflowRectForBox(box));
bool hasTransform = box->hasTransform();
if (box->isInFlowPositioned() || hasTransform) {
if (hasTransform)
rect = box->layer()->currentTransform().mapRect(rect);
if (box->isInFlowPositioned())
rect.move(box->offsetForInFlowPosition());
}
return rect;
}
LayoutRect RenderFragmentContainer::visualOverflowRectForBoxForPropagation(const RenderBoxModelObject& box)
{
LayoutRect rect = visualOverflowRectForBox(box);
fragmentedFlow()->flipForWritingModeLocalCoordinates(rect);
return rect;
}
CurrentRenderFragmentContainerMaintainer::CurrentRenderFragmentContainerMaintainer(RenderFragmentContainer& fragment)
: m_fragment(fragment)
{
RenderFragmentedFlow* fragmentedFlow = fragment.fragmentedFlow();
// A flow thread can have only one current fragment.
ASSERT(!fragmentedFlow->currentFragment());
fragmentedFlow->setCurrentFragmentMaintainer(this);
}
CurrentRenderFragmentContainerMaintainer::~CurrentRenderFragmentContainerMaintainer()
{
RenderFragmentedFlow* fragmentedFlow = m_fragment.fragmentedFlow();
fragmentedFlow->setCurrentFragmentMaintainer(nullptr);
}
} // namespace WebCore