void FlowThreadController::updateFlowThreadsIntoOverflowPhase()
{
for (auto iter = m_renderNamedFlowThreadList->rbegin(), end = m_renderNamedFlowThreadList->rend(); iter != end; ++iter) {
RenderNamedFlowThread* flowRenderer = *iter;
ASSERT(!flowRenderer->hasRegions() || flowRenderer->hasValidRegionInfo());
ASSERT(!flowRenderer->needsTwoPhasesLayout());
// In the overflow computation phase the flow threads start in the constrained phase even though optimizations didn't set the state before.
flowRenderer->setLayoutPhase(RenderFlowThread::LayoutPhaseConstrained);
flowRenderer->layoutIfNeeded();
flowRenderer->markRegionsForOverflowLayoutIfNeeded();
flowRenderer->setLayoutPhase(RenderFlowThread::LayoutPhaseOverflow);
}
}
void FlowThreadController::updateFlowThreadsIntoConstrainedPhase()
{
// Walk the flow chain in reverse order to update the auto-height regions and compute correct sizes for the containing regions. Only after this we can
// set the flow in the constrained layout phase.
for (RenderNamedFlowThreadList::reverse_iterator iter = m_renderNamedFlowThreadList->rbegin(); iter != m_renderNamedFlowThreadList->rend(); ++iter) {
RenderNamedFlowThread* flowRenderer = *iter;
ASSERT(!flowRenderer->hasRegions() || flowRenderer->hasValidRegionInfo());
flowRenderer->layoutIfNeeded();
if (flowRenderer->hasAutoLogicalHeightRegions()) {
ASSERT(flowRenderer->needsTwoPhasesLayout());
flowRenderer->markAutoLogicalHeightRegionsForLayout();
}
flowRenderer->setInConstrainedLayoutPhase(true);
flowRenderer->clearNeedsTwoPhasesLayout();
}
}
// 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());
}
}
}
}