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.
}
void RenderMultiColumnSet::prepareForLayout()
{
RenderBlockFlow* multicolBlock = multiColumnBlockFlow();
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->borderBefore() + multicolBlock->paddingBefore());
// 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(), -1);
if (m_maxColumnHeight == -1)
m_maxColumnHeight = RenderFlowThread::maxLogicalHeight();
}
if (!multicolStyle->logicalMaxHeight().isUndefined()) {
LayoutUnit logicalMaxHeight = multicolBlock->computeContentLogicalHeight(multicolStyle->logicalMaxHeight(), -1);
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;
}