LayoutUnit MultiColumnFragmentainerGroup::calculateMaxColumnHeight() const
{
LayoutBlockFlow* multicolBlock = m_columnSet.multiColumnBlockFlow();
const ComputedStyle& multicolStyle = multicolBlock->styleRef();
LayoutMultiColumnFlowThread* flowThread = m_columnSet.multiColumnFlowThread();
LayoutUnit availableHeight = flowThread->columnHeightAvailable();
LayoutUnit maxColumnHeight = availableHeight ? availableHeight : LayoutUnit::max();
if (!multicolStyle.logicalMaxHeight().isMaxSizeNone()) {
LayoutUnit logicalMaxHeight = multicolBlock->computeContentLogicalHeight(MaxSize, multicolStyle.logicalMaxHeight(), -1);
if (logicalMaxHeight != -1 && maxColumnHeight > logicalMaxHeight)
maxColumnHeight = logicalMaxHeight;
}
LayoutUnit maxHeight = heightAdjustedForRowOffset(maxColumnHeight);
if (LayoutMultiColumnFlowThread* enclosingFlowThread = flowThread->enclosingFlowThread()) {
if (enclosingFlowThread->isPageLogicalHeightKnown()) {
// We're nested inside another fragmentation context whose fragmentainer heights are
// known. This constrains the max height.
LayoutUnit remainingOuterLogicalHeight = enclosingFlowThread->pageRemainingLogicalHeightForOffset(blockOffsetInEnclosingFlowThread(), LayoutBlock::AssociateWithLatterPage);
ASSERT(remainingOuterLogicalHeight > 0);
if (maxHeight > remainingOuterLogicalHeight)
maxHeight = remainingOuterLogicalHeight;
}
}
return maxHeight;
}
void MultiColumnFragmentainerGroup::resetColumnHeight()
{
// Nuke previously stored minimum column height. Contents may have changed for all we know.
m_minimumColumnHeight = 0;
m_maxColumnHeight = calculateMaxColumnHeight();
LayoutMultiColumnFlowThread* flowThread = m_columnSet.multiColumnFlowThread();
LayoutMultiColumnFlowThread* enclosingFlowThread = flowThread->enclosingFlowThread();
if (enclosingFlowThread && enclosingFlowThread->isPageLogicalHeightKnown()) {
// TODO(mstensho): Do this better. If height is auto here, we shouldn't set a
// height, or forced breaks and pagination struts might mess up column balancing.
LayoutUnit columnHeight = heightIsAuto() ? m_maxColumnHeight : heightAdjustedForRowOffset(flowThread->columnHeightAvailable());
setAndConstrainColumnHeight(columnHeight);
} else if (heightIsAuto()) {
m_columnHeight = LayoutUnit();
} else {
setAndConstrainColumnHeight(heightAdjustedForRowOffset(flowThread->columnHeightAvailable()));
}
}
LayoutUnit MultiColumnFragmentainerGroup::calculateMaxColumnHeight() const
{
LayoutBlockFlow* multicolBlock = m_columnSet.multiColumnBlockFlow();
const ComputedStyle& multicolStyle = multicolBlock->styleRef();
LayoutUnit availableHeight = m_columnSet.multiColumnFlowThread()->columnHeightAvailable();
LayoutUnit maxColumnHeight = availableHeight ? availableHeight : LayoutUnit::max();
if (!multicolStyle.logicalMaxHeight().isMaxSizeNone()) {
LayoutUnit logicalMaxHeight = multicolBlock->computeContentLogicalHeight(MaxSize, multicolStyle.logicalMaxHeight(), -1);
if (logicalMaxHeight != -1 && maxColumnHeight > logicalMaxHeight)
maxColumnHeight = logicalMaxHeight;
}
return heightAdjustedForRowOffset(maxColumnHeight);
}
LayoutUnit MultiColumnFragmentainerGroup::calculateMaxColumnHeight() const
{
LayoutMultiColumnFlowThread* flowThread = m_columnSet.multiColumnFlowThread();
LayoutUnit maxColumnHeight = flowThread->maxColumnLogicalHeight();
LayoutUnit maxHeight = heightAdjustedForRowOffset(maxColumnHeight);
if (FragmentationContext* enclosingFragmentationContext = flowThread->enclosingFragmentationContext()) {
if (enclosingFragmentationContext->isFragmentainerLogicalHeightKnown()) {
// We're nested inside another fragmentation context whose fragmentainer heights are
// known. This constrains the max height.
LayoutUnit remainingOuterLogicalHeight = enclosingFragmentationContext->remainingLogicalHeightAt(blockOffsetInEnclosingFragmentationContext());
ASSERT(remainingOuterLogicalHeight > 0);
if (maxHeight > remainingOuterLogicalHeight)
maxHeight = remainingOuterLogicalHeight;
}
}
return maxHeight;
}
void MultiColumnFragmentainerGroup::resetColumnHeight()
{
m_maxColumnHeight = calculateMaxColumnHeight();
LayoutMultiColumnFlowThread* flowThread = m_columnSet.multiColumnFlowThread();
if (m_columnSet.heightIsAuto()) {
FragmentationContext* enclosingFragmentationContext = flowThread->enclosingFragmentationContext();
if (enclosingFragmentationContext && enclosingFragmentationContext->isFragmentainerLogicalHeightKnown()) {
// Even if height is auto, we set an initial height, in order to tell how much content
// this MultiColumnFragmentainerGroup can hold, and when we need to append a new one.
m_columnHeight = m_maxColumnHeight;
} else {
m_columnHeight = LayoutUnit();
}
} else {
setAndConstrainColumnHeight(heightAdjustedForRowOffset(flowThread->columnHeightAvailable()));
}
}
void MultiColumnFragmentainerGroup::resetColumnHeight()
{
// Nuke previously stored minimum column height. Contents may have changed for all we know.
m_minimumColumnHeight = 0;
m_maxColumnHeight = calculateMaxColumnHeight();
LayoutUnit oldColumnHeight = m_columnHeight;
if (heightIsAuto())
m_columnHeight = LayoutUnit();
else
setAndConstrainColumnHeight(heightAdjustedForRowOffset(m_columnSet.multiColumnFlowThread()->columnHeightAvailable()));
if (m_columnHeight != oldColumnHeight)
m_columnSet.setChildNeedsLayout(MarkOnlyThis);
// Content runs are only needed in the initial layout pass, in order to find an initial column
// height, and should have been deleted afterwards. We're about to rebuild the content runs, so
// the list needs to be empty.
ASSERT(m_contentRuns.isEmpty());
}
