Tracking filter mutation via SVGElementProxy

third_party/WebKit/Source/core/paint/PaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights
  * reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 170 matching lines @@
   if (!layoutObject->slowFirstChild() && layoutObject->style()) {
     m_isVisibleContentDirty = false;
     m_hasVisibleContent =
         layoutObject->style()->visibility() == EVisibility::Visible;
   }
 
   updateScrollableArea();
 }
 
 PaintLayer::~PaintLayer() {
-  if (m_rareData && m_rareData->filterInfo)
+  if (m_rareData && m_rareData->filterInfo) {
+    layoutObject()->styleRef().filter().removeClient(m_rareData->filterInfo);
     m_rareData->filterInfo->clearLayer();
+  }
   if (layoutObject()->frame() && layoutObject()->frame()->page()) {
     if (ScrollingCoordinator* scrollingCoordinator =
             layoutObject()->frame()->page()->scrollingCoordinator())
       scrollingCoordinator->willDestroyLayer(this);
   }
 
   if (groupedMapping()) {
     DisableCompositingQueryAsserts disabler;
     setGroupedMapping(0, InvalidateLayerAndRemoveFromMapping);
   }
@@ skipping 2444 matching lines @@
 
 void PaintLayer::ensureCompositedLayerMapping() {
   if (m_rareData && m_rareData->compositedLayerMapping)
     return;
 
   ensureRareData().compositedLayerMapping =
       wrapUnique(new CompositedLayerMapping(*this));
   m_rareData->compositedLayerMapping->setNeedsGraphicsLayerUpdate(
       GraphicsLayerUpdateSubtree);
 
-  updateOrRemoveFilterEffect();
+  if (PaintLayerFilterInfo* filterInfo = this->filterInfo())
+    filterInfo->invalidateFilterChain();
 }
 
 void PaintLayer::clearCompositedLayerMapping(bool layerBeingDestroyed) {
   if (!layerBeingDestroyed) {
     // We need to make sure our decendants get a geometry update. In principle,
     // we could call setNeedsGraphicsLayerUpdate on our children, but that would
     // require walking the z-order lists to find them. Instead, we
     // over-invalidate by marking our parent as needing a geometry update.
     if (PaintLayer* compositingParent =
             enclosingLayerWithCompositedLayerMapping(ExcludeSelf))
       compositingParent->compositedLayerMapping()->setNeedsGraphicsLayerUpdate(
           GraphicsLayerUpdateSubtree);
   }
 
   if (m_rareData)
     m_rareData->compositedLayerMapping.reset();
 
-  if (!layerBeingDestroyed)
-    updateOrRemoveFilterEffect();
+  if (layerBeingDestroyed)
+    return;
+
+  if (PaintLayerFilterInfo* filterInfo = this->filterInfo())
+    filterInfo->invalidateFilterChain();
 }
 
 void PaintLayer::setGroupedMapping(CompositedLayerMapping* groupedMapping,
                                    SetGroupMappingOptions options) {
   CompositedLayerMapping* oldGroupedMapping = this->groupedMapping();
   if (groupedMapping == oldGroupedMapping)
     return;
 
   if (options == InvalidateLayerAndRemoveFromMapping && oldGroupedMapping) {
     oldGroupedMapping->setNeedsGraphicsLayerUpdate(GraphicsLayerUpdateSubtree);
@@ skipping 174 matching lines @@
     return false;
 
   return hasBoxDecorationsOrBackground() || hasOverflowControls();
 }
 
 void PaintLayer::updateFilters(const ComputedStyle* oldStyle,
                                const ComputedStyle& newStyle) {
   if (!newStyle.hasFilterInducingProperty() &&
       (!oldStyle || !oldStyle->hasFilterInducingProperty()))
     return;
-
-  updateOrRemoveFilterClients();
-  updateOrRemoveFilterEffect();
+  const bool hadFilterInfo = filterInfo();
+  if (newStyle.hasFilterInducingProperty())
+    newStyle.filter().addClient(&ensureFilterInfo());
+  if (hadFilterInfo && oldStyle)
+    oldStyle->filter().removeClient(filterInfo());
+  if (!newStyle.hasFilterInducingProperty()) {
+    removeFilterInfo();
+    return;
+  }
+  if (PaintLayerFilterInfo* filterInfo = this->filterInfo())
+    filterInfo->invalidateFilterChain();
 }
 
 bool PaintLayer::attemptDirectCompositingUpdate(StyleDifference diff,
                                                 const ComputedStyle* oldStyle) {
   CompositingReasons oldPotentialCompositingReasonsFromStyle =
       potentialCompositingReasonsFromStyle();
   compositor()->updatePotentialCompositingReasonsFromStyle(this);
 
   // This function implements an optimization for transforms and opacity.
   // A common pattern is for a touchmove handler to update the transform
@@ skipping 124 matching lines @@
   return builder.buildFilterOperations(style.backdropFilter());
 }
 
 PaintLayerFilterInfo& PaintLayer::ensureFilterInfo() {
   PaintLayerRareData& rareData = ensureRareData();
   if (!rareData.filterInfo)
     rareData.filterInfo = new PaintLayerFilterInfo(this);
   return *rareData.filterInfo;
 }
 
+void PaintLayer::removeFilterInfo() {
+  if (!m_rareData || !m_rareData->filterInfo)
+    return;
+  m_rareData->filterInfo->clearLayer();
+  m_rareData->filterInfo = nullptr;
+}
+
 void PaintLayer::removeAncestorOverflowLayer(const PaintLayer* removedLayer) {
   // If the current ancestor overflow layer does not match the removed layer
   // the ancestor overflow layer has changed so we can stop searching.
   if (ancestorOverflowLayer() && ancestorOverflowLayer() != removedLayer)
     return;
 
   if (ancestorOverflowLayer()) {
     // TODO(pdr): When slimming paint v2 is enabled, we will need to
     // invalidate the scroll paint property subtree for this so main
     // thread scroll reasons are recomputed.
     ancestorOverflowLayer()
         ->getScrollableArea()
         ->invalidateStickyConstraintsFor(this);
   }
   updateAncestorOverflowLayer(nullptr);
   PaintLayer* current = m_first;
   while (current) {
     current->removeAncestorOverflowLayer(removedLayer);
     current = current->nextSibling();
   }
 }
 
-void PaintLayer::updateOrRemoveFilterClients() {
-  const auto& filter = layoutObject()->style()->filter();
-  if (filter.isEmpty() && m_rareData && m_rareData->filterInfo) {
-    m_rareData->filterInfo->clearLayer();
-    m_rareData->filterInfo = nullptr;
-  } else if (filter.hasReferenceFilter()) {
-    ensureFilterInfo().updateReferenceFilterClients(filter);
-  } else if (filterInfo()) {
-    filterInfo()->clearFilterReferences();
-  }
-}
-
-FilterEffect* PaintLayer::updateFilterEffect() const {
+FilterEffect* PaintLayer::lastFilterEffect() const {
   // TODO(chrishtr): ensure (and assert) that compositing is clean here.
-
   if (!paintsWithFilters())
     return nullptr;
-
   PaintLayerFilterInfo* filterInfo = this->filterInfo();
-
-  // Should have been added by updateOrRemoveFilterEffect().
   DCHECK(filterInfo);
 
   if (filterInfo->lastEffect())
     return filterInfo->lastEffect();
 
   const ComputedStyle& style = layoutObject()->styleRef();
   FloatRect zoomedReferenceBox;
   if (style.filter().hasReferenceFilter())
     zoomedReferenceBox = boxForFilter();
   FilterEffectBuilder builder(enclosingNode(), zoomedReferenceBox,
                               style.effectiveZoom());
   filterInfo->setLastEffect(
       builder.buildFilterEffect(addReflectionToFilterOperations(style)));
   return filterInfo->lastEffect();
 }
 
-FilterEffect* PaintLayer::lastFilterEffect() const {
-  return updateFilterEffect();
-}
-
 FloatRect PaintLayer::mapRectForFilter(const FloatRect& rect) const {
   if (!hasFilterThatMovesPixels())
     return rect;
 
   // Ensure the filter-chain is refreshed wrt reference filters.
-  updateFilterEffect();
+  lastFilterEffect();

[esprehn, 2016/10/25 01:18:42]

This is strange that it has side effects. Can we refactor it to call whatever
code has the side effects directly instead?

[fs, 2016/10/25 15:00:53]

Sure. That would mean that every time this is called we'd have to redo it
though. lastFilterEffect() has some notion of validity, so it can avoid that.
Note that this is nothing new in this CL though, rather just removing the
indirection.

Another option would be to call mapRect on the FilterEffect returned by
lastFilterEffect().

 
   FilterOperations filterOperations =
       addReflectionToFilterOperations(layoutObject()->styleRef());
   return filterOperations.mapRect(rect);
 }
 
 LayoutRect PaintLayer::mapLayoutRectForFilter(const LayoutRect& rect) const {
   if (!hasFilterThatMovesPixels())
     return rect;
   return enclosingLayoutRect(mapRectForFilter(FloatRect(rect)));
 }
 
 bool PaintLayer::hasFilterThatMovesPixels() const {
   if (!hasFilterInducingProperty())
     return false;
   const ComputedStyle& style = layoutObject()->styleRef();
   if (style.hasFilter() && style.filter().hasFilterThatMovesPixels())
     return true;
   if (style.hasBoxReflect())
     return true;
   return false;
 }
 
-void PaintLayer::updateOrRemoveFilterEffect() {
-  // FilterEffectBuilder is only used to render the filters in software mode,
-  // so we always need to run updateOrRemoveFilterEffect after the composited
-  // mode might have changed for this layer.
-  if (!paintsWithFilters()) {
-    if (PaintLayerFilterInfo* filterInfo = this->filterInfo())
-      filterInfo->setLastEffect(nullptr);
-    return;
-  }
-
-  ensureFilterInfo().setLastEffect(nullptr);
-}
-
 void PaintLayer::filterNeedsPaintInvalidation() {
   {
     DeprecatedScheduleStyleRecalcDuringLayout marker(
         layoutObject()->document().lifecycle());
     // It's possible for scheduleSVGFilterLayerUpdateHack to schedule a style
     // recalc, which is a problem because this function can be called right
     // before performing layout but after style recalc.
     //
     // See LayoutView::layout() and the call to
     // invalidateSVGRootsWithRelativeLengthDescendents(). This violation is
@@ skipping 136 matching lines @@
 }
 
 void showLayerTree(const blink::LayoutObject* layoutObject) {
   if (!layoutObject) {
     fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
     return;
   }
   showLayerTree(layoutObject->enclosingLayer());
 }
 #endif