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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. ``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
* 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 IN..0TERRUPTION) 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 "RenderMultiColumnFlow.h"
#include "HitTestResult.h"
#include "RenderIterator.h"
#include "RenderLayoutState.h"
#include "RenderMultiColumnSet.h"
#include "RenderMultiColumnSpannerPlaceholder.h"
#include "RenderTreeBuilder.h"
#include "RenderView.h"
#include "TransformState.h"
#include <wtf/IsoMallocInlines.h>
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(RenderMultiColumnFlow);
RenderMultiColumnFlow::RenderMultiColumnFlow(Document& document, RenderStyle&& style)
: RenderFragmentedFlow(document, WTFMove(style))
, m_spannerMap(std::make_unique<SpannerMap>())
, m_lastSetWorkedOn(nullptr)
, m_columnCount(1)
, m_columnWidth(0)
, m_columnHeightAvailable(0)
, m_inLayout(false)
, m_inBalancingPass(false)
, m_needsHeightsRecalculation(false)
, m_progressionIsInline(false)
, m_progressionIsReversed(false)
{
setFragmentedFlowState(InsideInFragmentedFlow);
}
RenderMultiColumnFlow::~RenderMultiColumnFlow() = default;
const char* RenderMultiColumnFlow::renderName() const
{
return "RenderMultiColumnFlowThread";
}
RenderMultiColumnSet* RenderMultiColumnFlow::firstMultiColumnSet() const
{
for (RenderObject* sibling = nextSibling(); sibling; sibling = sibling->nextSibling()) {
if (is<RenderMultiColumnSet>(*sibling))
return downcast<RenderMultiColumnSet>(sibling);
}
return nullptr;
}
RenderMultiColumnSet* RenderMultiColumnFlow::lastMultiColumnSet() const
{
for (RenderObject* sibling = multiColumnBlockFlow()->lastChild(); sibling; sibling = sibling->previousSibling()) {
if (is<RenderMultiColumnSet>(*sibling))
return downcast<RenderMultiColumnSet>(sibling);
}
return nullptr;
}
RenderBox* RenderMultiColumnFlow::firstColumnSetOrSpanner() const
{
if (RenderObject* sibling = nextSibling()) {
ASSERT(is<RenderBox>(*sibling));
ASSERT(is<RenderMultiColumnSet>(*sibling) || findColumnSpannerPlaceholder(downcast<RenderBox>(sibling)));
return downcast<RenderBox>(sibling);
}
return nullptr;
}
RenderBox* RenderMultiColumnFlow::nextColumnSetOrSpannerSiblingOf(const RenderBox* child)
{
return child ? child->nextSiblingBox() : nullptr;
}
RenderBox* RenderMultiColumnFlow::previousColumnSetOrSpannerSiblingOf(const RenderBox* child)
{
if (!child)
return nullptr;
if (auto* sibling = child->previousSiblingBox()) {
if (!is<RenderFragmentedFlow>(*sibling))
return sibling;
}
return nullptr;
}
RenderMultiColumnSpannerPlaceholder* RenderMultiColumnFlow::findColumnSpannerPlaceholder(RenderBox* spanner) const
{
return m_spannerMap->get(spanner).get();
}
void RenderMultiColumnFlow::layout()
{
ASSERT(!m_inLayout);
m_inLayout = true;
m_lastSetWorkedOn = nullptr;
if (RenderBox* first = firstColumnSetOrSpanner()) {
if (is<RenderMultiColumnSet>(*first)) {
m_lastSetWorkedOn = downcast<RenderMultiColumnSet>(first);
m_lastSetWorkedOn->beginFlow(this);
}
}
RenderFragmentedFlow::layout();
if (RenderMultiColumnSet* lastSet = lastMultiColumnSet()) {
if (!nextColumnSetOrSpannerSiblingOf(lastSet))
lastSet->endFlow(this, logicalHeight());
lastSet->expandToEncompassFragmentedFlowContentsIfNeeded();
}
m_inLayout = false;
m_lastSetWorkedOn = nullptr;
}
void RenderMultiColumnFlow::addFragmentToThread(RenderFragmentContainer* RenderFragmentContainer)
{
auto* columnSet = downcast<RenderMultiColumnSet>(RenderFragmentContainer);
if (RenderMultiColumnSet* nextSet = columnSet->nextSiblingMultiColumnSet()) {
RenderFragmentContainerList::iterator it = m_fragmentList.find(nextSet);
ASSERT(it != m_fragmentList.end());
m_fragmentList.insertBefore(it, columnSet);
} else
m_fragmentList.add(columnSet);
RenderFragmentContainer->setIsValid(true);
}
void RenderMultiColumnFlow::willBeRemovedFromTree()
{
// Detach all column sets from the flow thread. Cannot destroy them at this point, since they
// are siblings of this object, and there may be pointers to this object's sibling somewhere
// further up on the call stack.
for (RenderMultiColumnSet* columnSet = firstMultiColumnSet(); columnSet; columnSet = columnSet->nextSiblingMultiColumnSet())
columnSet->detachFragment();
RenderFragmentedFlow::willBeRemovedFromTree();
}
void RenderMultiColumnFlow::fragmentedFlowDescendantBoxLaidOut(RenderBox* descendant)
{
if (!is<RenderMultiColumnSpannerPlaceholder>(*descendant))
return;
auto& placeholder = downcast<RenderMultiColumnSpannerPlaceholder>(*descendant);
RenderBlock* container = placeholder.containingBlock();
for (RenderBox* prev = previousColumnSetOrSpannerSiblingOf(placeholder.spanner()); prev; prev = previousColumnSetOrSpannerSiblingOf(prev)) {
if (is<RenderMultiColumnSet>(*prev)) {
downcast<RenderMultiColumnSet>(*prev).endFlow(container, placeholder.logicalTop());
break;
}
}
for (RenderBox* next = nextColumnSetOrSpannerSiblingOf(placeholder.spanner()); next; next = nextColumnSetOrSpannerSiblingOf(next)) {
if (is<RenderMultiColumnSet>(*next)) {
m_lastSetWorkedOn = downcast<RenderMultiColumnSet>(next);
m_lastSetWorkedOn->beginFlow(container);
break;
}
}
}
RenderBox::LogicalExtentComputedValues RenderMultiColumnFlow::computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop) const
{
// We simply remain at our intrinsic height.
return { logicalHeight, logicalTop, ComputedMarginValues() };
}
LayoutUnit RenderMultiColumnFlow::initialLogicalWidth() const
{
return columnWidth();
}
void RenderMultiColumnFlow::setPageBreak(const RenderBlock* block, LayoutUnit offset, LayoutUnit spaceShortage)
{
if (auto* multicolSet = downcast<RenderMultiColumnSet>(fragmentAtBlockOffset(block, offset)))
multicolSet->recordSpaceShortage(spaceShortage);
}
void RenderMultiColumnFlow::updateMinimumPageHeight(const RenderBlock* block, LayoutUnit offset, LayoutUnit minHeight)
{
if (auto* multicolSet = downcast<RenderMultiColumnSet>(fragmentAtBlockOffset(block, offset)))
multicolSet->updateMinimumColumnHeight(minHeight);
}
RenderFragmentContainer* RenderMultiColumnFlow::fragmentAtBlockOffset(const RenderBox* box, LayoutUnit offset, bool extendLastFragment) const
{
if (!m_inLayout)
return RenderFragmentedFlow::fragmentAtBlockOffset(box, offset, extendLastFragment);
// Layout in progress. We are calculating the set heights as we speak, so the fragment range
// information is not up-to-date.
RenderMultiColumnSet* columnSet = m_lastSetWorkedOn ? m_lastSetWorkedOn : firstMultiColumnSet();
if (!columnSet) {
// If there's no set, bail. This multicol is empty or only consists of spanners. There
// are no fragments.
return nullptr;
}
// The last set worked on is a good guess. But if we're not within the bounds, search for the
// right one.
if (offset < columnSet->logicalTopInFragmentedFlow()) {
do {
if (RenderMultiColumnSet* prev = columnSet->previousSiblingMultiColumnSet())
columnSet = prev;
else
break;
} while (offset < columnSet->logicalTopInFragmentedFlow());
} else {
while (offset >= columnSet->logicalBottomInFragmentedFlow()) {
RenderMultiColumnSet* next = columnSet->nextSiblingMultiColumnSet();
if (!next || !next->hasBeenFlowed())
break;
columnSet = next;
}
}
return columnSet;
}
void RenderMultiColumnFlow::setFragmentRangeForBox(const RenderBox& box, RenderFragmentContainer* startFragment, RenderFragmentContainer* endFragment)
{
// Some column sets may have zero height, which means that two or more sets may start at the
// exact same flow thread position, which means that some parts of the code may believe that a
// given box lives in sets that it doesn't really live in. Make some adjustments here and
// include such sets if they are adjacent to the start and/or end fragments.
for (RenderMultiColumnSet* columnSet = downcast<RenderMultiColumnSet>(*startFragment).previousSiblingMultiColumnSet(); columnSet; columnSet = columnSet->previousSiblingMultiColumnSet()) {
if (columnSet->logicalHeightInFragmentedFlow())
break;
startFragment = columnSet;
}
for (RenderMultiColumnSet* columnSet = downcast<RenderMultiColumnSet>(*startFragment).nextSiblingMultiColumnSet(); columnSet; columnSet = columnSet->nextSiblingMultiColumnSet()) {
if (columnSet->logicalHeightInFragmentedFlow())
break;
endFragment = columnSet;
}
RenderFragmentedFlow::setFragmentRangeForBox(box, startFragment, endFragment);
}
bool RenderMultiColumnFlow::addForcedFragmentBreak(const RenderBlock* block, LayoutUnit offset, RenderBox* /*breakChild*/, bool /*isBefore*/, LayoutUnit* offsetBreakAdjustment)
{
if (auto* multicolSet = downcast<RenderMultiColumnSet>(fragmentAtBlockOffset(block, offset))) {
multicolSet->addForcedBreak(offset);
if (offsetBreakAdjustment)
*offsetBreakAdjustment = pageLogicalHeightForOffset(offset) ? pageRemainingLogicalHeightForOffset(offset, IncludePageBoundary) : 0_lu;
return true;
}
return false;
}
LayoutSize RenderMultiColumnFlow::offsetFromContainer(RenderElement& enclosingContainer, const LayoutPoint& physicalPoint, bool* offsetDependsOnPoint) const
{
ASSERT(&enclosingContainer == container());
if (offsetDependsOnPoint)
*offsetDependsOnPoint = true;
LayoutPoint translatedPhysicalPoint(physicalPoint);
if (RenderFragmentContainer* fragment = physicalTranslationFromFlowToFragment(translatedPhysicalPoint))
translatedPhysicalPoint.moveBy(fragment->topLeftLocation());
LayoutSize offset(translatedPhysicalPoint.x(), translatedPhysicalPoint.y());
if (is<RenderBox>(enclosingContainer))
offset -= toLayoutSize(downcast<RenderBox>(enclosingContainer).scrollPosition());
return offset;
}
void RenderMultiColumnFlow::mapAbsoluteToLocalPoint(MapCoordinatesFlags mode, TransformState& transformState) const
{
// First get the transform state's point into the block flow thread's physical coordinate space.
parent()->mapAbsoluteToLocalPoint(mode, transformState);
LayoutPoint transformPoint(transformState.mappedPoint());
// Now walk through each fragment.
const RenderMultiColumnSet* candidateColumnSet = nullptr;
LayoutPoint candidatePoint;
LayoutSize candidateContainerOffset;
for (const auto& columnSet : childrenOfType<RenderMultiColumnSet>(*parent())) {
candidateContainerOffset = columnSet.offsetFromContainer(*parent(), LayoutPoint());
candidatePoint = transformPoint - candidateContainerOffset;
candidateColumnSet = &columnSet;
// We really have no clue what to do with overflow. We'll just use the closest fragment to the point in that case.
LayoutUnit pointOffset = isHorizontalWritingMode() ? candidatePoint.y() : candidatePoint.x();
LayoutUnit fragmentOffset = isHorizontalWritingMode() ? columnSet.topLeftLocation().y() : columnSet.topLeftLocation().x();
if (pointOffset < fragmentOffset + columnSet.logicalHeight())
break;
}
// Once we have a good guess as to which fragment we hit tested through (and yes, this was just a heuristic, but it's
// the best we could do), then we can map from the fragment into the flow thread.
LayoutSize translationOffset = physicalTranslationFromFragmentToFlow(candidateColumnSet, candidatePoint) + candidateContainerOffset;
bool preserve3D = mode & UseTransforms && (parent()->style().preserves3D() || style().preserves3D());
if (mode & UseTransforms && shouldUseTransformFromContainer(parent())) {
TransformationMatrix t;
getTransformFromContainer(parent(), translationOffset, t);
transformState.applyTransform(t, preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
} else
transformState.move(translationOffset.width(), translationOffset.height(), preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
}
LayoutSize RenderMultiColumnFlow::physicalTranslationFromFragmentToFlow(const RenderMultiColumnSet* columnSet, const LayoutPoint& physicalPoint) const
{
LayoutPoint logicalPoint = columnSet->flipForWritingMode(physicalPoint);
LayoutPoint translatedPoint = columnSet->translateFragmentPointToFragmentedFlow(logicalPoint);
LayoutPoint physicalTranslatedPoint = columnSet->flipForWritingMode(translatedPoint);
return physicalPoint - physicalTranslatedPoint;
}
RenderFragmentContainer* RenderMultiColumnFlow::mapFromFlowToFragment(TransformState& transformState) const
{
if (!hasValidFragmentInfo())
return nullptr;
// Get back into our local flow thread space.
LayoutRect boxRect = transformState.mappedQuad().enclosingBoundingBox();
flipForWritingMode(boxRect);
// FIXME: We need to refactor RenderObject::absoluteQuads to be able to split the quads across fragments,
// for now we just take the center of the mapped enclosing box and map it to a column.
LayoutPoint centerPoint = boxRect.center();
LayoutUnit centerLogicalOffset = isHorizontalWritingMode() ? centerPoint.y() : centerPoint.x();
RenderFragmentContainer* RenderFragmentContainer = fragmentAtBlockOffset(this, centerLogicalOffset, true);
if (!RenderFragmentContainer)
return nullptr;
transformState.move(physicalTranslationOffsetFromFlowToFragment(RenderFragmentContainer, centerLogicalOffset));
return RenderFragmentContainer;
}
LayoutSize RenderMultiColumnFlow::physicalTranslationOffsetFromFlowToFragment(const RenderFragmentContainer* RenderFragmentContainer, const LayoutUnit logicalOffset) const
{
// Now that we know which multicolumn set we hit, we need to get the appropriate translation offset for the column.
const auto* columnSet = downcast<RenderMultiColumnSet>(RenderFragmentContainer);
LayoutPoint translationOffset = columnSet->columnTranslationForOffset(logicalOffset);
// Now we know how we want the rect to be translated into the fragment. At this point we're converting
// back to physical coordinates.
if (style().isFlippedBlocksWritingMode()) {
LayoutRect portionRect(columnSet->fragmentedFlowPortionRect());
LayoutRect columnRect = columnSet->columnRectAt(0);
LayoutUnit physicalDeltaFromPortionBottom = logicalHeight() - columnSet->logicalBottomInFragmentedFlow();
if (isHorizontalWritingMode())
columnRect.setHeight(portionRect.height());
else
columnRect.setWidth(portionRect.width());
columnSet->flipForWritingMode(columnRect);
if (isHorizontalWritingMode())
translationOffset.move(0_lu, columnRect.y() - portionRect.y() - physicalDeltaFromPortionBottom);
else
translationOffset.move(columnRect.x() - portionRect.x() - physicalDeltaFromPortionBottom, 0_lu);
}
return LayoutSize(translationOffset.x(), translationOffset.y());
}
RenderFragmentContainer* RenderMultiColumnFlow::physicalTranslationFromFlowToFragment(LayoutPoint& physicalPoint) const
{
if (!hasValidFragmentInfo())
return nullptr;
// Put the physical point into the flow thread's coordinate space.
LayoutPoint logicalPoint = flipForWritingMode(physicalPoint);
// Now get the fragment that we are in.
LayoutUnit logicalOffset = isHorizontalWritingMode() ? logicalPoint.y() : logicalPoint.x();
RenderFragmentContainer* RenderFragmentContainer = fragmentAtBlockOffset(this, logicalOffset, true);
if (!RenderFragmentContainer)
return nullptr;
// Translate to the coordinate space of the fragment.
LayoutSize translationOffset = physicalTranslationOffsetFromFlowToFragment(RenderFragmentContainer, logicalOffset);
// Now shift the physical point into the fragment's coordinate space.
physicalPoint += translationOffset;
return RenderFragmentContainer;
}
bool RenderMultiColumnFlow::isPageLogicalHeightKnown() const
{
if (RenderMultiColumnSet* columnSet = lastMultiColumnSet())
return columnSet->columnHeightComputed();
return false;
}
bool RenderMultiColumnFlow::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction hitTestAction)
{
// You cannot be inside an in-flow RenderFragmentedFlow without a corresponding DOM node. It's better to
// just let the ancestor figure out where we are instead.
if (hitTestAction == HitTestBlockBackground)
return false;
bool inside = RenderFragmentedFlow::nodeAtPoint(request, result, locationInContainer, accumulatedOffset, hitTestAction);
if (inside && !result.innerNode())
return false;
return inside;
}
bool RenderMultiColumnFlow::shouldCheckColumnBreaks() const
{
if (!parent()->isRenderView())
return true;
return view().frameView().pagination().behavesLikeColumns;
}
}