// Collect the fixed positioned layers that have the named flows as containing block
// These layers are painted and hit-tested starting from RenderView not from regions.
void FlowThreadController::collectFixedPositionedLayers(Vector<RenderLayer*>& fixedPosLayers) const
{
for (auto iter = m_renderNamedFlowThreadList->begin(), end = m_renderNamedFlowThreadList->end(); iter != end; ++iter) {
RenderNamedFlowThread* flowRenderer = *iter;
// If the named flow does not have any regions attached, a fixed element should not be
// displayed even if the fixed element is positioned/sized by the viewport.
if (!flowRenderer->hasRegions())
continue;
// Iterate over the fixed positioned elements in the flow thread
TrackedRendererListHashSet* positionedDescendants = flowRenderer->positionedObjects();
if (positionedDescendants) {
for (auto it = positionedDescendants->begin(), end = positionedDescendants->end(); it != end; ++it) {
RenderBox* box = *it;
if (!box->fixedPositionedWithNamedFlowContainingBlock())
continue;
fixedPosLayers.append(box->layer());
}
}
}
}
