Recompute overflow after transform changes

Source/core/rendering/RenderObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1779 matching lines @@
             RenderBlock* block = toRenderBlock(parent())->createAnonymousBlock();
             RenderObjectChildList* childlist = parent()->virtualChildren();
             childlist->insertChildNode(parent(), block, this);
             block->children()->appendChildNode(block, childlist->removeChildNode(parent(), this));
         }
     }
 }
 
 StyleDifference RenderObject::adjustStyleDifference(StyleDifference diff, unsigned contextSensitiveProperties) const
 {
-    // If transform changed, and the layer does not paint into its own separate backing, then we need to do a layout.
-    // FIXME: The comment above is what the code does, but it is technically not following spec. This means we will
-    // not to layout for 3d transforms, but we should be invoking a simplified relayout. Is it possible we are avoiding
-    // doing this for some performance reason at this time?
-    if (contextSensitiveProperties & ContextSensitivePropertyTransform) {
+    if (contextSensitiveProperties & ContextSensitivePropertyTransform && isSVG())
+        diff = StyleDifferenceLayout;

[esprehn, 2014/04/10 23:46:14]

Why the special case for SVG?

[trchen, 2014/04/11 22:04:55]

Because SVG is special. They do rely on layout to update transform correctly.
This behavior is the same as before. The logic was somehow obfuscated in the big
if-block we just removed.

+
+    // If transform changed, and the layer does not paint into its own separate backing, then we need to repaint.
+    if (contextSensitiveProperties & ContextSensitivePropertyTransform  && diff <= StyleDifferenceRepaintLayer) {
         // Text nodes share style with their parents but transforms don't apply to them,
         // hence the !isText() check.
-        // FIXME: when transforms are taken into account for overflow, we will need to do a layout.
-        if (!isText() && (!hasLayer() || !toRenderLayerModelObject(this)->layer()->hasDirectReasonsForCompositing())) {
-            // We need to set at least SimplifiedLayout, but if PositionedMovementOnly is already set
-            // then we actually need SimplifiedLayoutAndPositionedMovement.
-            if (!hasLayer())
-                diff = StyleDifferenceLayout; // FIXME: Do this for now since SimplifiedLayout cannot handle updating floating objects lists.
-            else if (diff < StyleDifferenceLayoutPositionedMovementOnly)
-                diff = StyleDifferenceSimplifiedLayout;
-            else if (diff < StyleDifferenceSimplifiedLayout)
-                diff = StyleDifferenceSimplifiedLayoutAndPositionedMovement;
-        } else if (diff < StyleDifferenceRecompositeLayer)
+        if (!isText() && (!hasLayer() || !toRenderLayerModelObject(this)->layer()->hasDirectReasonsForCompositing()))
+            diff = StyleDifferenceRepaintLayer;
+        else if (diff < StyleDifferenceRecompositeLayer)
             diff = StyleDifferenceRecompositeLayer;
     }
 
     // If opacity or filters changed, and the layer does not paint into its own separate backing, then we need to repaint (also
     // ignoring text nodes)
     if (contextSensitiveProperties & ContextSensitivePropertyOpacity && diff <= StyleDifferenceRepaintLayer) {
         if (!isText() && (!hasLayer() || !toRenderLayerModelObject(this)->layer()->hasDirectReasonsForCompositing()))
             diff = StyleDifferenceRepaintLayer;
         else if (diff < StyleDifferenceRecompositeLayer)
             diff = StyleDifferenceRecompositeLayer;
@@ skipping 57 matching lines @@
             return true;
     }
     return false;
 }
 
 inline bool RenderObject::shouldRepaintForStyleDifference(StyleDifference diff) const
 {
     return diff == StyleDifferenceRepaint || (diff == StyleDifferenceRepaintIfTextOrColorChange && hasImmediateNonWhitespaceTextChildOrPropertiesDependentOnColor());
 }
 
+void RenderObject::markContainingBlocksForOverflowRecalc()
+{
+    for (RenderBlock* container = containingBlock(); container && !container->childNeedsOverflowRecalcAfterStyleChange(); container = container->containingBlock())
+        container->setChildNeedsOverflowRecalcAfterStyleChange(true);
+}
+
+void RenderObject::setNeedsOverflowRecalcAfterStyleChange()
+{
+    setSelfNeedsOverflowRecalcAfterStyleChange(true);
+    markContainingBlocksForOverflowRecalc();
+}
+
 void RenderObject::setStyle(PassRefPtr<RenderStyle> style)
 {
     if (m_style == style) {
         // We need to run through adjustStyleDifference() for iframes, plugins, and canvas so
         // style sharing is disabled for them. That should ensure that we never hit this code path.
         ASSERT(!isRenderIFrame() && !isEmbeddedObject() && !isCanvas());
         return;
     }
 
     StyleDifference diff = StyleDifferenceEqual;
@@ skipping 29 matching lines @@
 
     // Now that the layer (if any) has been updated, we need to adjust the diff again,
     // check whether we should layout now, and decide if we need to repaint.
     StyleDifference updatedDiff = adjustStyleDifference(diff, contextSensitiveProperties);
 
     if (diff <= StyleDifferenceLayoutPositionedMovementOnly) {
         if (updatedDiff == StyleDifferenceLayout)
             setNeedsLayoutAndPrefWidthsRecalc();
         else if (updatedDiff == StyleDifferenceLayoutPositionedMovementOnly)
             setNeedsPositionedMovementLayout();
-        else if (updatedDiff == StyleDifferenceSimplifiedLayoutAndPositionedMovement) {
-            setNeedsPositionedMovementLayout();
-            setNeedsSimplifiedNormalFlowLayout();
-        } else if (updatedDiff == StyleDifferenceSimplifiedLayout)
-            setNeedsSimplifiedNormalFlowLayout();
+    }
+
+    if (contextSensitiveProperties & ContextSensitivePropertyTransform && !needsLayout()) {
+        if (RenderBlock* container = containingBlock())
+            container->setNeedsOverflowRecalcAfterStyleChange();
+        if (isBox())
+            toRenderBox(this)->updateLayerTransform();
     }
 
     if (updatedDiff == StyleDifferenceRepaintLayer || shouldRepaintForStyleDifference(updatedDiff)) {
         // Do a repaint with the new style now, e.g., for example if we go from
         // not having an outline to having an outline.
         repaint();
     }
 }
 
 static inline bool rendererHasBackground(const RenderObject* renderer)
@@ skipping 114 matching lines @@
 }
 
 void RenderObject::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 {
     if (s_affectsParentBlock)
         handleDynamicFloatPositionChange();
 
     if (!m_parent)
         return;
 
-    if (diff == StyleDifferenceLayout || diff == StyleDifferenceSimplifiedLayout) {
+    if (diff == StyleDifferenceLayout) {
         RenderCounter::rendererStyleChanged(*this, oldStyle, m_style.get());
 
         // If the object already needs layout, then setNeedsLayout won't do
         // any work. But if the containing block has changed, then we may need
         // to mark the new containing blocks for layout. The change that can
         // directly affect the containing block of this object is a change to
         // the position style.
         if (needsLayout() && oldStyle->position() != m_style->position())
             markContainingBlocksForLayout();
 
+        // Ditto.
+        if (needsOverflowRecalcAfterStyleChange() && oldStyle->position() != m_style->position()) {
+            if (RenderBlock* container = containingBlock())
+                container->markContainingBlocksForOverflowRecalc();

[esprehn, 2014/04/10 23:46:14]

This doesn't look right, you want to call
markContainingBlocksForOverflowRecalc() on yourself like we do above, not go up
one level from there.

[trchen, 2014/04/11 22:04:55]

Done.

+        }
+
         if (diff == StyleDifferenceLayout)
             setNeedsLayoutAndPrefWidthsRecalc();
-        else
-            setNeedsSimplifiedNormalFlowLayout();
-    } else if (diff == StyleDifferenceSimplifiedLayoutAndPositionedMovement) {
-        setNeedsPositionedMovementLayout();
-        setNeedsSimplifiedNormalFlowLayout();
     } else if (diff == StyleDifferenceLayoutPositionedMovementOnly)
         setNeedsPositionedMovementLayout();
 
     // Don't check for repaint here; we need to wait until the layer has been
     // updated by subclasses before we know if we have to repaint (in setStyle()).
 
     if (oldStyle && !areCursorsEqual(oldStyle, style())) {
         if (LocalFrame* frame = this->frame())
             frame->eventHandler().scheduleCursorUpdate();
     }
@@ skipping 1217 matching lines @@
 {
     if (object1) {
         const WebCore::RenderObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showRenderTreeAndMark(object1, "*", object2, "-", 0);
     }
 }
 
 #endif