LayoutUnit LayoutMultiColumnSet::nextLogicalTopForUnbreakableContent(LayoutUnit flowThreadOffset, LayoutUnit contentLogicalHeight) const
{
ASSERT(pageLogicalTopForOffset(flowThreadOffset) == flowThreadOffset);
LayoutMultiColumnFlowThread* enclosingFlowThread = multiColumnFlowThread()->enclosingFlowThread();
if (!enclosingFlowThread) {
// If there's no enclosing fragmentation context, there'll ever be only one row, and all
// columns there will have the same height.
return flowThreadOffset;
}
// Assert the problematic situation. If we have no problem with the column height, why are we
// even here?
ASSERT(pageLogicalHeightForOffset(flowThreadOffset) < contentLogicalHeight);
// There's a likelihood for subsequent rows to be taller than the first one.
// TODO(mstensho): if we're doubly nested (e.g. multicol in multicol in multicol), we need to
// look beyond the first row here.
const MultiColumnFragmentainerGroup& firstRow = firstFragmentainerGroup();
LayoutUnit firstRowLogicalBottomInFlowThread = firstRow.logicalTopInFlowThread() + firstRow.logicalHeight() * usedColumnCount();
if (flowThreadOffset >= firstRowLogicalBottomInFlowThread)
return flowThreadOffset; // We're not in the first row. Give up.
LayoutUnit newLogicalHeight = enclosingFlowThread->pageLogicalHeightForOffset(firstRowLogicalBottomInFlowThread);
if (contentLogicalHeight > newLogicalHeight) {
// The next outer column or page doesn't have enough space either. Give up and stay where
// we are.
return flowThreadOffset;
}
return firstRowLogicalBottomInFlowThread;
}
bool RenderMultiColumnFlowThread::addForcedRegionBreak(const RenderBlock* block, LayoutUnit offset, RenderBox* /*breakChild*/, bool /*isBefore*/, LayoutUnit* offsetBreakAdjustment)
{
if (RenderMultiColumnSet* multicolSet = toRenderMultiColumnSet(regionAtBlockOffset(block, offset))) {
multicolSet->addForcedBreak(offset);
if (offsetBreakAdjustment)
*offsetBreakAdjustment = pageLogicalHeightForOffset(offset) ? pageRemainingLogicalHeightForOffset(offset, IncludePageBoundary) : LayoutUnit::fromPixel(0);
return true;
}
return false;
}
LayoutUnit LayoutMultiColumnFlowThread::fragmentainerLogicalHeightAt(LayoutUnit blockOffset)
{
return pageLogicalHeightForOffset(blockOffset);
}
