LayoutPoint RenderFlowThread::adjustedPositionRelativeToOffsetParent(const RenderBoxModelObject& boxModelObject, const LayoutPoint& startPoint)
{
LayoutPoint referencePoint = startPoint;
// FIXME: This needs to be adapted for different writing modes inside the flow thread.
RenderMultiColumnSet* startColumnSet = columnSetAtBlockOffset(referencePoint.y());
if (startColumnSet) {
// Take into account the offset coordinates of the columnSet.
RenderObject* currObject = startColumnSet;
RenderObject* currOffsetParentRenderer;
Element* currOffsetParentElement;
while ((currOffsetParentElement = currObject->offsetParent()) && (currOffsetParentRenderer = currOffsetParentElement->renderer())) {
if (currObject->isBoxModelObject())
referencePoint.move(toRenderBoxModelObject(currObject)->offsetLeft(), toRenderBoxModelObject(currObject)->offsetTop());
// Since we're looking for the offset relative to the body, we must also
// take into consideration the borders of the columnSet's offsetParent.
if (currOffsetParentRenderer->isBox() && !currOffsetParentRenderer->isBody())
referencePoint.move(toRenderBox(currOffsetParentRenderer)->borderLeft(), toRenderBox(currOffsetParentRenderer)->borderTop());
currObject = currOffsetParentRenderer;
}
// We need to check if any of this box's containing blocks start in a different columnSet
// and if so, drop the object's top position (which was computed relative to its containing block
// and is no longer valid) and recompute it using the columnSet in which it flows as reference.
bool wasComputedRelativeToOtherRegion = false;
const RenderBlock* objContainingBlock = boxModelObject.containingBlock();
while (objContainingBlock) {
// Check if this object is in a different columnSet.
RenderMultiColumnSet* parentStartRegion = 0;
RenderMultiColumnSet* parentEndRegion = 0;
getRegionRangeForBox(objContainingBlock, parentStartRegion, parentEndRegion);
if (parentStartRegion && parentStartRegion != startColumnSet) {
wasComputedRelativeToOtherRegion = true;
break;
}
objContainingBlock = objContainingBlock->containingBlock();
}
if (wasComputedRelativeToOtherRegion) {
// Get the logical top coordinate of the current object.
LayoutUnit top = 0;
if (boxModelObject.isRenderBlock()) {
top = toRenderBlock(&boxModelObject)->offsetFromLogicalTopOfFirstPage();
} else {
if (boxModelObject.containingBlock())
top = boxModelObject.containingBlock()->offsetFromLogicalTopOfFirstPage();
if (boxModelObject.isBox())
top += toRenderBox(&boxModelObject)->topLeftLocation().y();
else if (boxModelObject.isRenderInline())
top -= toRenderInline(&boxModelObject)->borderTop();
}
// Get the logical top of the columnSet this object starts in
// and compute the object's top, relative to the columnSet's top.
LayoutUnit regionLogicalTop = startColumnSet->pageLogicalTopForOffset(top);
LayoutUnit topRelativeToRegion = top - regionLogicalTop;
referencePoint.setY(startColumnSet->offsetTop() + topRelativeToRegion);
// Since the top has been overriden, check if the
// relative positioning must be reconsidered.
if (boxModelObject.isRelPositioned())
referencePoint.move(0, boxModelObject.relativePositionOffset().height());
}
// Since we're looking for the offset relative to the body, we must also
// take into consideration the borders of the columnSet.
referencePoint.move(startColumnSet->borderLeft(), startColumnSet->borderTop());
}
return referencePoint;
}
