bool hitTestFlow(const RenderBlockFlow& flow, const Layout& layout, const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction hitTestAction)
{
if (hitTestAction != HitTestForeground)
return false;
if (!layout.runCount())
return false;
RenderStyle& style = flow.style();
if (style.visibility() != VISIBLE || style.pointerEvents() == PE_NONE)
return false;
RenderObject& renderer = *flow.firstChild();
LayoutRect rangeRect = locationInContainer.boundingBox();
rangeRect.moveBy(-accumulatedOffset);
auto resolver = lineResolver(flow, layout);
for (FloatRect lineRect : resolver.rangeForRect(rangeRect)) {
lineRect.moveBy(accumulatedOffset);
if (!locationInContainer.intersects(lineRect))
continue;
renderer.updateHitTestResult(result, locationInContainer.point() - toLayoutSize(accumulatedOffset));
if (!result.addNodeToRectBasedTestResult(renderer.node(), request, locationInContainer, lineRect))
return true;
}
return false;
}
LayoutRect RenderMultiColumnSet::columnRectAt(unsigned index) const
{
LayoutUnit colLogicalWidth = computedColumnWidth();
LayoutUnit colLogicalHeight = computedColumnHeight();
LayoutUnit colLogicalTop = borderAndPaddingBefore();
LayoutUnit colLogicalLeft = borderAndPaddingLogicalLeft();
LayoutUnit colGap = columnGap();
RenderBlockFlow* parentFlow = toRenderBlockFlow(parent());
bool progressionReversed = parentFlow->multiColumnFlowThread()->progressionIsReversed();
bool progressionInline = parentFlow->multiColumnFlowThread()->progressionIsInline();
if (progressionInline) {
if (style().isLeftToRightDirection() ^ progressionReversed)
colLogicalLeft += index * (colLogicalWidth + colGap);
else
colLogicalLeft += contentLogicalWidth() - colLogicalWidth - index * (colLogicalWidth + colGap);
} else {
if (!progressionReversed)
colLogicalTop += index * (colLogicalHeight + colGap);
else
colLogicalTop += contentLogicalHeight() - colLogicalHeight - index * (colLogicalHeight + colGap);
}
if (isHorizontalWritingMode())
return LayoutRect(colLogicalLeft, colLogicalTop, colLogicalWidth, colLogicalHeight);
return LayoutRect(colLogicalTop, colLogicalLeft, colLogicalHeight, colLogicalWidth);
}
static inline InlineFlowBox* flowBoxForRenderer(RenderObject* renderer)
{
if (!renderer)
return 0;
if (renderer->isRenderBlock()) {
// If we're given a block element, it has to be a RenderSVGText.
ASSERT(renderer->isSVGText());
RenderBlockFlow* renderBlockFlow = toRenderBlockFlow(renderer);
// RenderSVGText only ever contains a single line box.
InlineFlowBox* flowBox = renderBlockFlow->firstLineBox();
ASSERT(flowBox == renderBlockFlow->lastLineBox());
return flowBox;
}
if (renderer->isRenderInline()) {
// We're given a RenderSVGInline or objects that derive from it (RenderSVGTSpan / RenderSVGTextPath)
RenderInline* renderInline = toRenderInline(renderer);
// RenderSVGInline only ever contains a single line box.
InlineFlowBox* flowBox = renderInline->firstLineBox();
ASSERT(flowBox == renderInline->lastLineBox());
return flowBox;
}
ASSERT_NOT_REACHED();
return 0;
}
void LayoutState::establishLineGrid(RenderBlockFlow* block)
{
// First check to see if this grid has been established already.
if (m_lineGrid) {
if (m_lineGrid->style().lineGrid() == block->style().lineGrid())
return;
RenderBlockFlow* currentGrid = m_lineGrid;
for (LayoutState* currentState = m_next.get(); currentState; currentState = currentState->m_next.get()) {
if (currentState->m_lineGrid == currentGrid)
continue;
currentGrid = currentState->m_lineGrid;
if (!currentGrid)
break;
if (currentGrid->style().lineGrid() == block->style().lineGrid()) {
m_lineGrid = currentGrid;
m_lineGridOffset = currentState->m_lineGridOffset;
return;
}
}
}
// We didn't find an already-established grid with this identifier. Our render object establishes the grid.
m_lineGrid = block;
m_lineGridOffset = m_layoutOffset;
}
TextFragmentIterator::TextFragmentIterator(const RenderBlockFlow& flow)
: m_flowContents(flow)
, m_currentSegment(m_flowContents.begin())
, m_lineBreakIterator(m_currentSegment->text, flow.style().locale())
, m_style(flow.style())
{
}
inline static float availableWidthAtOffset(const RenderBlockFlow& block, const LayoutUnit& offset, IndentTextOrNot shouldIndentText,
float& newLineLeft, float& newLineRight, const LayoutUnit& lineHeight = 0)
{
newLineLeft = block.logicalLeftOffsetForLine(offset, shouldIndentText, lineHeight);
newLineRight = block.logicalRightOffsetForLine(offset, shouldIndentText, lineHeight);
return std::max(0.0f, newLineRight - newLineLeft);
}
LayoutUnit RenderMultiColumnSet::columnGap() const
{
RenderBlockFlow* parentBlock = multiColumnBlockFlow();
if (parentBlock->style()->hasNormalColumnGap())
return parentBlock->style()->fontDescription().computedPixelSize(); // "1em" is recommended as the normal gap setting. Matches <p> margins.
return parentBlock->style()->columnGap();
}
static RenderBlockFlow* createAnonymousRubyInlineBlock(RenderObject* ruby)
{
RefPtr<RenderStyle> newStyle = RenderStyle::createAnonymousStyleWithDisplay(ruby->style(), INLINE_BLOCK);
RenderBlockFlow* newBlock = RenderBlockFlow::createAnonymous(&ruby->document());
newBlock->setStyle(newStyle.release());
return newBlock;
}
ShapeOutsideDeltas ShapeOutsideInfo::computeDeltasForContainingBlockLine(const RenderBlockFlow& containingBlock, const FloatingObject& floatingObject, LayoutUnit lineTop, LayoutUnit lineHeight)
{
ASSERT(lineHeight >= 0);
LayoutUnit borderBoxTop = containingBlock.logicalTopForFloat(floatingObject) + containingBlock.marginBeforeForChild(m_renderer);
LayoutUnit borderBoxLineTop = lineTop - borderBoxTop;
if (isShapeDirty() || !m_shapeOutsideDeltas.isForLine(borderBoxLineTop, lineHeight)) {
LayoutUnit referenceBoxLineTop = borderBoxLineTop - logicalTopOffset();
LayoutUnit floatMarginBoxWidth = std::max<LayoutUnit>(LayoutUnit(), containingBlock.logicalWidthForFloat(floatingObject));
if (computedShape().lineOverlapsShapeMarginBounds(referenceBoxLineTop, lineHeight)) {
LineSegment segment = computedShape().getExcludedInterval((borderBoxLineTop - logicalTopOffset()), std::min(lineHeight, shapeLogicalBottom() - borderBoxLineTop));
if (segment.isValid) {
LayoutUnit logicalLeftMargin = containingBlock.style().isLeftToRightDirection() ? containingBlock.marginStartForChild(m_renderer) : containingBlock.marginEndForChild(m_renderer);
LayoutUnit rawLeftMarginBoxDelta = segment.logicalLeft + logicalLeftOffset() + logicalLeftMargin;
LayoutUnit leftMarginBoxDelta = clampTo<LayoutUnit>(rawLeftMarginBoxDelta, LayoutUnit(), floatMarginBoxWidth);
LayoutUnit logicalRightMargin = containingBlock.style().isLeftToRightDirection() ? containingBlock.marginEndForChild(m_renderer) : containingBlock.marginStartForChild(m_renderer);
LayoutUnit rawRightMarginBoxDelta = segment.logicalRight + logicalLeftOffset() - containingBlock.logicalWidthForChild(m_renderer) - logicalRightMargin;
LayoutUnit rightMarginBoxDelta = clampTo<LayoutUnit>(rawRightMarginBoxDelta, -floatMarginBoxWidth, LayoutUnit());
m_shapeOutsideDeltas = ShapeOutsideDeltas(leftMarginBoxDelta, rightMarginBoxDelta, true, borderBoxLineTop, lineHeight);
return m_shapeOutsideDeltas;
}
}
// Lines that do not overlap the shape should act as if the float
// wasn't there for layout purposes. So we set the deltas to remove the
// entire width of the float
m_shapeOutsideDeltas = ShapeOutsideDeltas(floatMarginBoxWidth, -floatMarginBoxWidth, false, borderBoxLineTop, lineHeight);
}
return m_shapeOutsideDeltas;
}
void RenderMultiColumnFlowThread::evacuateAndDestroy()
{
RenderBlockFlow* multicolContainer = multiColumnBlockFlow();
m_beingEvacuated = true;
// Delete the line box tree.
deleteLines();
LayoutStateDisabler layoutStateDisabler(&view());
// First promote all children of the flow thread. Before we move them to the flow thread's
// container, we need to unregister the flow thread, so that they aren't just re-added again to
// the flow thread that we're trying to empty.
multicolContainer->setMultiColumnFlowThread(nullptr);
moveAllChildrenTo(multicolContainer, true);
// Move spanners back to their original DOM position in the tree, and destroy the placeholders.
SpannerMap::iterator it;
while ((it = m_spannerMap.begin()) != m_spannerMap.end()) {
RenderBox* spanner = it->key;
RenderMultiColumnSpannerPlaceholder* placeholder = it->value;
RenderBlockFlow* originalContainer = toRenderBlockFlow(placeholder->parent());
multicolContainer->removeChild(*spanner);
originalContainer->addChild(spanner, placeholder);
placeholder->destroy();
m_spannerMap.remove(it);
}
// Remove all sets.
while (RenderMultiColumnSet* columnSet = firstMultiColumnSet())
columnSet->destroy();
destroy();
}
LayoutUnit RenderMultiColumnSet::heightAdjustedForSetOffset(LayoutUnit height) const
{
RenderBlockFlow* multicolBlock = multiColumnBlockFlow();
LayoutUnit contentLogicalTop = logicalTop() - multicolBlock->borderBefore() - multicolBlock->paddingBefore();
height -= contentLogicalTop;
return max(height, LayoutUnit(1)); // Let's avoid zero height, as that would probably cause an infinite amount of columns to be created.
}
LayoutUnit RenderMultiColumnSet::columnGap() const
{
// FIXME: Eventually we will cache the column gap when the widths of columns start varying, but for now we just
// go to the parent block to get the gap.
RenderBlockFlow* parentBlock = toRenderBlockFlow(parent());
if (parentBlock->style().hasNormalColumnGap())
return parentBlock->style().fontDescription().computedPixelSize(); // "1em" is recommended as the normal gap setting. Matches <p> margins.
return parentBlock->style().columnGap();
}
void RenderMultiColumnSet::updateLogicalWidth()
{
RenderBlockFlow* parentBlock = toRenderBlockFlow(parent());
setComputedColumnWidthAndCount(parentBlock->multiColumnFlowThread()->columnWidth(), parentBlock->multiColumnFlowThread()->columnCount()); // FIXME: This will eventually vary if we are contained inside regions.
// FIXME: When we add regions support, we'll start it off at the width of the multi-column
// block in that particular region.
setLogicalWidth(parentBox()->contentLogicalWidth());
}
void collectFlowOverflow(RenderBlockFlow& flow, const Layout& layout)
{
auto resolver = lineResolver(flow, layout);
for (auto it = resolver.begin(), end = resolver.end(); it != end; ++it) {
auto rect = *it;
flow.addLayoutOverflow(rect);
flow.addVisualOverflow(rect);
}
}
FloatPoint InlineBox::locationIncludingFlipping()
{
if (!renderer()->style()->isFlippedBlocksWritingMode())
return FloatPoint(x(), y());
RenderBlockFlow* block = root()->block();
if (block->style()->isHorizontalWritingMode())
return FloatPoint(x(), block->height() - height() - y());
else
return FloatPoint(block->width() - width() - x(), y());
}
void collectFlowOverflow(RenderBlockFlow& flow, const Layout& layout)
{
float strokeOverflow = std::ceil(flow.style().textStrokeWidth());
for (FloatRect lineRect : lineResolver(flow, layout)) {
LayoutRect inflatedLineRect(lineRect);
inflatedLineRect.inflate(strokeOverflow);
flow.addLayoutOverflow(inflatedLineRect);
flow.addVisualOverflow(inflatedLineRect);
}
}
void RenderMultiColumnFlowThread::populate()
{
RenderBlockFlow* multicolContainer = multiColumnBlockFlow();
ASSERT(!nextSibling());
// Reparent children preceding the flow thread into the flow thread. It's multicol content
// now. At this point there's obviously nothing after the flow thread, but renderers (column
// sets and spanners) will be inserted there as we insert elements into the flow thread.
LayoutStateDisabler layoutStateDisabler(&view());
multicolContainer->moveChildrenTo(this, multicolContainer->firstChild(), this, true);
}
void paintFlow(const RenderBlockFlow& flow, const Layout& layout, PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
if (paintInfo.phase != PaintPhaseForeground)
return;
RenderStyle& style = flow.style();
if (style.visibility() != VISIBLE)
return;
bool debugBordersEnabled = flow.frame().settings().simpleLineLayoutDebugBordersEnabled();
TextPainter textPainter(paintInfo.context());
textPainter.setFont(style.fontCascade());
textPainter.setTextPaintStyle(computeTextPaintStyle(flow.frame(), style, paintInfo));
Optional<TextDecorationPainter> textDecorationPainter;
if (style.textDecorationsInEffect() != TextDecorationNone) {
const RenderText* textRenderer = childrenOfType<RenderText>(flow).first();
if (textRenderer) {
textDecorationPainter = TextDecorationPainter(paintInfo.context(), style.textDecorationsInEffect(), *textRenderer, false);
textDecorationPainter->setFont(style.fontCascade());
textDecorationPainter->setBaseline(style.fontMetrics().ascent());
}
}
LayoutRect paintRect = paintInfo.rect;
paintRect.moveBy(-paintOffset);
auto resolver = runResolver(flow, layout);
float strokeOverflow = std::ceil(flow.style().textStrokeWidth());
float deviceScaleFactor = flow.document().deviceScaleFactor();
for (auto run : resolver.rangeForRect(paintRect)) {
if (run.start() == run.end())
continue;
FloatRect rect = run.rect();
FloatRect visualOverflowRect = rect;
visualOverflowRect.inflate(strokeOverflow);
if (paintRect.y() > visualOverflowRect.maxY() || paintRect.maxY() < visualOverflowRect.y())
continue;
TextRun textRun(run.text());
textRun.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
// x position indicates the line offset from the rootbox. It's always 0 in case of simple line layout.
textRun.setXPos(0);
FloatPoint textOrigin = FloatPoint(rect.x() + paintOffset.x(), roundToDevicePixel(run.baselinePosition() + paintOffset.y(), deviceScaleFactor));
textPainter.paintText(textRun, textRun.length(), rect, textOrigin);
if (textDecorationPainter) {
textDecorationPainter->setWidth(rect.width());
textDecorationPainter->paintTextDecoration(textRun, textOrigin, rect.location() + paintOffset);
}
if (debugBordersEnabled)
paintDebugBorders(paintInfo.context(), LayoutRect(run.rect()), paintOffset);
}
}
void collectFlowOverflow(RenderBlockFlow& flow, const Layout& layout)
{
auto resolver = lineResolver(flow, layout);
float strokeOverflow = ceilf(flow.style().textStrokeWidth());
for (auto it = resolver.begin(), end = resolver.end(); it != end; ++it) {
auto rect = LayoutRect(*it);
rect.inflate(strokeOverflow);
flow.addLayoutOverflow(rect);
flow.addVisualOverflow(rect);
}
}
static bool newFloatShrinksLine(const FloatingObject& newFloat, const RenderBlockFlow& block, bool isFirstLine)
{
LayoutUnit blockOffset = block.logicalHeight();
if (blockOffset >= block.logicalTopForFloat(newFloat) && blockOffset < block.logicalBottomForFloat(newFloat))
return true;
// initial-letter float always shrinks the first line.
const auto& style = newFloat.renderer().style();
if (isFirstLine && style.styleType() == FIRST_LETTER && !style.initialLetter().isEmpty())
return true;
return false;
}
RunResolver::RunResolver(const RenderBlockFlow& flow, const Layout& layout)
: m_flowRenderer(flow)
, m_layout(layout)
, m_flowContents(flow)
, m_lineHeight(lineHeightFromFlow(flow))
, m_baseline(baselineFromFlow(flow))
, m_borderAndPaddingBefore(flow.borderAndPaddingBefore())
, m_ascent(flow.style().fontCascade().fontMetrics().ascent())
, m_descent(flow.style().fontCascade().fontMetrics().descent())
, m_visualOverflowOffset(visualOverflowForDecorations(flow.style(), nullptr).bottom)
, m_inQuirksMode(flow.document().inQuirksMode())
{
}
LayoutUnit RenderMultiColumnSet::calculateMaxColumnHeight() const
{
RenderBlockFlow* multicolBlock = multiColumnBlockFlow();
RenderStyle* multicolStyle = multicolBlock->style();
LayoutUnit availableHeight = multiColumnFlowThread()->columnHeightAvailable();
LayoutUnit maxColumnHeight = availableHeight ? availableHeight : RenderFlowThread::maxLogicalHeight();
if (!multicolStyle->logicalMaxHeight().isUndefined()) {
LayoutUnit logicalMaxHeight = multicolBlock->computeContentLogicalHeight(multicolStyle->logicalMaxHeight(), -1);
if (logicalMaxHeight != -1 && maxColumnHeight > logicalMaxHeight)
maxColumnHeight = logicalMaxHeight;
}
return heightAdjustedForSetOffset(maxColumnHeight);
}
LayoutUnit RenderMultiColumnSet::initialBlockOffsetForPainting() const
{
RenderBlockFlow* parentFlow = toRenderBlockFlow(parent());
bool progressionReversed = parentFlow->multiColumnFlowThread()->progressionIsReversed();
bool progressionIsInline = parentFlow->multiColumnFlowThread()->progressionIsInline();
LayoutUnit result = 0;
if (!progressionIsInline && progressionReversed) {
LayoutRect colRect = columnRectAt(0);
result = isHorizontalWritingMode() ? colRect.y() : colRect.x();
if (style().isFlippedBlocksWritingMode())
result = -result;
}
return result;
}
RootInlineBox::RootInlineBox(RenderBlockFlow& block)
: InlineFlowBox(block)
, m_lineBreakPos(0)
, m_lineBreakObj(nullptr)
{
setIsHorizontal(block.isHorizontalWritingMode());
}
FloatingObjects::FloatingObjects(const RenderBlockFlow& renderer)
: m_leftObjectsCount(0)
, m_rightObjectsCount(0)
, m_horizontalWritingMode(renderer.isHorizontalWritingMode())
, m_renderer(renderer)
{
}
static AvoidanceReasonFlags canUseForFontAndText(const RenderBlockFlow& flow, FallThrough fallthrough)
{
AvoidanceReasonFlags reasons = NoReason;
// We assume that all lines have metrics based purely on the primary font.
const auto& style = flow.style();
auto& primaryFont = style.fontCascade().primaryFont();
if (primaryFont.isLoading())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowIsMissingPrimaryFont, fallthrough);
if (primaryFont.isSVGFont())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasSVGFont, fallthrough);
for (const auto& textRenderer : childrenOfType<RenderText>(flow)) {
if (textRenderer.isCombineText())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowTextIsCombineText, fallthrough);
if (textRenderer.isCounter())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowTextIsRenderCounter, fallthrough);
if (textRenderer.isQuote())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowTextIsRenderQuote, fallthrough);
if (textRenderer.isTextFragment())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowTextIsTextFragment, fallthrough);
if (textRenderer.isSVGInlineText())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowTextIsSVGInlineText, fallthrough);
if (style.fontCascade().codePath(TextRun(textRenderer.text())) != FontCascade::Simple)
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowFontIsNotSimple, fallthrough);
auto textReasons = canUseForText(textRenderer, primaryFont, fallthrough);
if (textReasons != NoReason)
SET_REASON_AND_RETURN_IF_NEEDED(reasons, textReasons, fallthrough);
}
return reasons;
}
static void createTextRuns(Layout::RunVector& runs, RenderBlockFlow& flow, unsigned& lineCount)
{
LayoutUnit borderAndPaddingBefore = flow.borderAndPaddingBefore();
LayoutUnit lineHeight = lineHeightFromFlow(flow);
LineState line;
bool isEndOfContent = false;
TextFragmentIterator textFragmentIterator = TextFragmentIterator(flow);
do {
flow.setLogicalHeight(lineHeight * lineCount + borderAndPaddingBefore);
LineState previousLine = line;
unsigned previousRunCount = runs.size();
line = LineState();
updateLineConstrains(flow, line, !lineCount);
isEndOfContent = createLineRuns(line, previousLine, runs, textFragmentIterator);
closeLineEndingAndAdjustRuns(line, runs, previousRunCount, lineCount, textFragmentIterator);
} while (!isEndOfContent);
}
LayoutUnit RenderMultiColumnSet::heightAdjustedForSetOffset(LayoutUnit height) const
{
// Adjust for the top offset within the content box of the multicol container (containing
// block), unless this is the first set. We know that the top offset for the first set will be
// zero, but if the multicol container has non-zero top border or padding, the set's top offset
// (initially being 0 and relative to the border box) will be negative until it has been laid
// out. Had we used this bogus offset, we would calculate the wrong height, and risk performing
// a wasted layout iteration. Of course all other sets (if any) have this problem in the first
// layout pass too, but there's really nothing we can do there until the flow thread has been
// laid out anyway.
if (previousSiblingMultiColumnSet()) {
RenderBlockFlow* multicolBlock = multiColumnBlockFlow();
LayoutUnit contentLogicalTop = logicalTop() - multicolBlock->borderAndPaddingBefore();
height -= contentLogicalTop;
}
return max(height, LayoutUnit(1)); // Let's avoid zero height, as that would probably cause an infinite amount of columns to be created.
}
void RenderMultiColumnSet::prepareForLayout()
{
RenderBlockFlow* multicolBlock = toRenderBlockFlow(parent());
const RenderStyle& multicolStyle = multicolBlock->style();
// Set box logical top.
ASSERT(!previousSiblingBox() || !previousSiblingBox()->isRenderMultiColumnSet()); // FIXME: multiple set not implemented; need to examine previous set to calculate the correct logical top.
setLogicalTop(multicolBlock->borderAndPaddingBefore());
// Set box width.
updateLogicalWidth();
if (multicolBlock->multiColumnFlowThread()->requiresBalancing()) {
// Set maximum column height. We will not stretch beyond this.
m_maxColumnHeight = RenderFlowThread::maxLogicalHeight();
if (!multicolStyle.logicalHeight().isAuto()) {
m_maxColumnHeight = multicolBlock->computeContentLogicalHeight(multicolStyle.logicalHeight());
if (m_maxColumnHeight == -1)
m_maxColumnHeight = RenderFlowThread::maxLogicalHeight();
}
if (!multicolStyle.logicalMaxHeight().isUndefined()) {
LayoutUnit logicalMaxHeight = multicolBlock->computeContentLogicalHeight(multicolStyle.logicalMaxHeight());
if (logicalMaxHeight != -1 && m_maxColumnHeight > logicalMaxHeight)
m_maxColumnHeight = logicalMaxHeight;
}
m_maxColumnHeight = heightAdjustedForSetOffset(m_maxColumnHeight);
m_computedColumnHeight = 0; // Restart balancing.
} else
setAndConstrainColumnHeight(heightAdjustedForSetOffset(multicolBlock->multiColumnFlowThread()->columnHeightAvailable()));
clearForcedBreaks();
// Nuke previously stored minimum column height. Contents may have changed for all we know.
m_minimumColumnHeight = 0;
}
void RenderMultiColumnSet::adjustRegionBoundsFromFlowThreadPortionRect(const LayoutPoint& layerOffset, LayoutRect& regionBounds)
{
LayoutUnit layerLogicalTop = isHorizontalWritingMode() ? layerOffset.y() : layerOffset.x();
unsigned startColumn = columnIndexAtOffset(layerLogicalTop);
LayoutUnit colGap = columnGap();
LayoutUnit colLogicalWidth = computedColumnWidth();
LayoutRect flowThreadPortion = flowThreadPortionRectAt(startColumn);
LayoutPoint translationOffset;
RenderBlockFlow* parentFlow = toRenderBlockFlow(parent());
bool progressionReversed = parentFlow->multiColumnFlowThread()->progressionIsReversed();
bool progressionIsInline = parentFlow->multiColumnFlowThread()->progressionIsInline();
LayoutUnit initialBlockOffset = initialBlockOffsetForPainting();
LayoutUnit inlineOffset = progressionIsInline ? startColumn * (colLogicalWidth + colGap) : LayoutUnit();
bool leftToRight = style().isLeftToRightDirection() ^ progressionReversed;
if (!leftToRight) {
inlineOffset = -inlineOffset;
if (progressionReversed)
inlineOffset += contentLogicalWidth() - colLogicalWidth;
}
translationOffset.setX(inlineOffset);
LayoutUnit blockOffset = initialBlockOffset + (isHorizontalWritingMode() ? -flowThreadPortion.y() : -flowThreadPortion.x());
if (!progressionIsInline) {
if (!progressionReversed)
blockOffset = startColumn * colGap;
else
blockOffset -= startColumn * (computedColumnHeight() + colGap);
}
if (isFlippedBlocksWritingMode(style().writingMode()))
blockOffset = -blockOffset;
translationOffset.setY(blockOffset);
if (!isHorizontalWritingMode())
translationOffset = translationOffset.transposedPoint();
// FIXME: The translation needs to include the multicolumn set's content offset within the
// multicolumn block as well. This won't be an issue until we start creating multiple multicolumn sets.
regionBounds.moveBy(roundedIntPoint(-translationOffset));
}
