void GraphicsLayerTreeBuilder::rebuild(PaintLayer& layer, AncestorInfo info)
{
// Make the layer compositing if necessary, and set up clipping and content layers.
// Note that we can only do work here that is independent of whether the descendant layers
// have been processed. computeCompositingRequirements() will already have done the paint invalidation if necessary.
layer.stackingNode()->updateLayerListsIfNeeded();
const bool hasCompositedLayerMapping = layer.hasCompositedLayerMapping();
CompositedLayerMapping* currentCompositedLayerMapping = layer.compositedLayerMapping();
// If this layer has a compositedLayerMapping, then that is where we place subsequent children GraphicsLayers.
// Otherwise children continue to append to the child list of the enclosing layer.
GraphicsLayerVector layerChildren;
AncestorInfo infoForChildren(info);
if (hasCompositedLayerMapping) {
infoForChildren.childLayersOfEnclosingCompositedLayer = &layerChildren;
infoForChildren.enclosingCompositedLayer = &layer;
}
#if ENABLE(ASSERT)
LayerListMutationDetector mutationChecker(layer.stackingNode());
#endif
if (layer.stackingNode()->isStackingContext()) {
PaintLayerStackingNodeIterator iterator(*layer.stackingNode(), NegativeZOrderChildren);
while (PaintLayerStackingNode* curNode = iterator.next())
rebuild(*curNode->layer(), infoForChildren);
// If a negative z-order child is compositing, we get a foreground layer which needs to get parented.
if (hasCompositedLayerMapping && currentCompositedLayerMapping->foregroundLayer())
infoForChildren.childLayersOfEnclosingCompositedLayer->append(currentCompositedLayerMapping->foregroundLayer());
}
PaintLayerStackingNodeIterator iterator(*layer.stackingNode(), NormalFlowChildren | PositiveZOrderChildren);
while (PaintLayerStackingNode* curNode = iterator.next())
rebuild(*curNode->layer(), infoForChildren);
if (hasCompositedLayerMapping) {
bool parented = false;
if (layer.layoutObject()->isLayoutPart())
parented = PaintLayerCompositor::attachFrameContentLayersToIframeLayer(toLayoutPart(layer.layoutObject()));
if (!parented)
currentCompositedLayerMapping->setSublayers(layerChildren);
if (shouldAppendLayer(layer))
info.childLayersOfEnclosingCompositedLayer->append(currentCompositedLayerMapping->childForSuperlayers());
}
if (layer.scrollParent()
&& layer.scrollParent()->hasCompositedLayerMapping()
&& layer.scrollParent()->compositedLayerMapping()->needsToReparentOverflowControls()
&& layer.scrollParent()->getScrollableArea()->topmostScrollChild() == &layer)
info.childLayersOfEnclosingCompositedLayer->append(layer.scrollParent()->compositedLayerMapping()->detachLayerForOverflowControls(*info.enclosingCompositedLayer));
}
static CompositedLayerMapping* mappingFromElement(Element* element) {
if (!element)
return nullptr;
LayoutObject* layoutObject = element->layoutObject();
if (!layoutObject || !layoutObject->isBoxModelObject())
return nullptr;
PaintLayer* layer = toLayoutBoxModelObject(layoutObject)->layer();
if (!layer)
return nullptr;
if (!layer->hasCompositedLayerMapping())
return nullptr;
return layer->compositedLayerMapping();
}
bool PaintLayerCompositor::attachFrameContentLayersToIframeLayer(LayoutPart* layoutObject)
{
PaintLayerCompositor* innerCompositor = frameContentsCompositor(layoutObject);
if (!innerCompositor || !innerCompositor->staleInCompositingMode() || innerCompositor->rootLayerAttachment() != RootLayerAttachedViaEnclosingFrame)
return false;
PaintLayer* layer = layoutObject->layer();
if (!layer->hasCompositedLayerMapping())
return false;
layer->compositedLayerMapping()->setSublayers(GraphicsLayerVector(1, innerCompositor->rootGraphicsLayer()));
return true;
}
static WebLayer* webLayerFromElement(Element* element)
{
if (!element)
return 0;
LayoutObject* layoutObject = element->layoutObject();
if (!layoutObject || !layoutObject->isBoxModelObject())
return 0;
PaintLayer* layer = toLayoutBoxModelObject(layoutObject)->layer();
if (!layer)
return 0;
if (!layer->hasCompositedLayerMapping())
return 0;
CompositedLayerMapping* compositedLayerMapping = layer->compositedLayerMapping();
GraphicsLayer* graphicsLayer = compositedLayerMapping->mainGraphicsLayer();
if (!graphicsLayer)
return 0;
return graphicsLayer->platformLayer();
}
bool PaintLayerCompositor::allocateOrClearCompositedLayerMapping(PaintLayer* layer, const CompositingStateTransitionType compositedLayerUpdate)
{
bool compositedLayerMappingChanged = false;
// FIXME: It would be nice to directly use the layer's compositing reason,
// but allocateOrClearCompositedLayerMapping also gets called without having updated compositing
// requirements fully.
switch (compositedLayerUpdate) {
case AllocateOwnCompositedLayerMapping:
ASSERT(!layer->hasCompositedLayerMapping());
setCompositingModeEnabled(true);
// If we need to issue paint invalidations, do so before allocating the compositedLayerMapping and clearing out the groupedMapping.
paintInvalidationOnCompositingChange(layer);
// If this layer was previously squashed, we need to remove its reference to a groupedMapping right away, so
// that computing paint invalidation rects will know the layer's correct compositingState.
// FIXME: do we need to also remove the layer from it's location in the squashing list of its groupedMapping?
// Need to create a test where a squashed layer pops into compositing. And also to cover all other
// sorts of compositingState transitions.
layer->setLostGroupedMapping(false);
layer->setGroupedMapping(nullptr, PaintLayer::InvalidateLayerAndRemoveFromMapping);
layer->ensureCompositedLayerMapping();
compositedLayerMappingChanged = true;
// At this time, the ScrollingCooridnator only supports the top-level frame.
if (layer->isRootLayer() && m_layoutView.frame()->isLocalRoot()) {
if (ScrollingCoordinator* scrollingCoordinator = this->scrollingCoordinator())
scrollingCoordinator->frameViewRootLayerDidChange(m_layoutView.frameView());
}
break;
case RemoveOwnCompositedLayerMapping:
// PutInSquashingLayer means you might have to remove the composited layer mapping first.
case PutInSquashingLayer:
if (layer->hasCompositedLayerMapping()) {
// If we're removing the compositedLayerMapping from a reflection, clear the source GraphicsLayer's pointer to
// its replica GraphicsLayer. In practice this should never happen because reflectee and reflection
// are both either composited, or not composited.
if (layer->isReflection()) {
PaintLayer* sourceLayer = toLayoutBoxModelObject(layer->layoutObject()->parent())->layer();
if (sourceLayer->hasCompositedLayerMapping()) {
ASSERT(sourceLayer->compositedLayerMapping()->mainGraphicsLayer()->replicaLayer() == layer->compositedLayerMapping()->mainGraphicsLayer());
sourceLayer->compositedLayerMapping()->mainGraphicsLayer()->setReplicatedByLayer(nullptr);
}
}
layer->clearCompositedLayerMapping();
compositedLayerMappingChanged = true;
}
break;
case RemoveFromSquashingLayer:
case NoCompositingStateChange:
// Do nothing.
break;
}
if (compositedLayerMappingChanged && layer->layoutObject()->isLayoutPart()) {
PaintLayerCompositor* innerCompositor = frameContentsCompositor(toLayoutPart(layer->layoutObject()));
if (innerCompositor && innerCompositor->staleInCompositingMode())
innerCompositor->updateRootLayerAttachment();
}
if (compositedLayerMappingChanged)
layer->clipper().clearClipRectsIncludingDescendants(PaintingClipRects);
// If a fixed position layer gained/lost a compositedLayerMapping or the reason not compositing it changed,
// the scrolling coordinator needs to recalculate whether it can do fast scrolling.
if (compositedLayerMappingChanged) {
if (ScrollingCoordinator* scrollingCoordinator = this->scrollingCoordinator())
scrollingCoordinator->frameViewFixedObjectsDidChange(m_layoutView.frameView());
}
return compositedLayerMappingChanged;
}