LayoutUnit RenderMultiColumnSet::heightAdjustedForSetOffset(LayoutUnit height) const { RenderMultiColumnBlock* multicolBlock = toRenderMultiColumnBlock(parent()); 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() { RenderMultiColumnBlock* multicolBlock = toRenderMultiColumnBlock(parent()); 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->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->columnHeightAvailable())); } clearForcedBreaks(); // Nuke previously stored minimum column height. Contents may have changed for all we know. m_minimumColumnHeight = 0; }