Changeset 135071 in webkit

Timestamp:

Nov 18, 2012, 10:06:58 AM (13 years ago)

Author:

Simon Fraser

Message:

<rdar://problem/12725980> Fix overlay scrollbar painting in compositing layers (102442)
Merge r135029

2012-11-16 Simon Fraser <Simon Fraser>

Fix overlay scrollbar painting in compositing layers
​https://bugs.webkit.org/show_bug.cgi?id=102442

Reviewed by Beth Dakin.

There were two issues with overlay scrollbar painting in
compositing layers.

First, we'd only ever call setContainsDirtyOverlayScrollbars()
on the RenderView's layer, even when encountering an overlay scrollbar
in some descendant compositing layer. This meant that we'd never
run the paintOverlayScrollbars() code for those child compositing
layers, so sometimes scrollbars were missing there.

Even after fixing that, we would fail to render scrollbars that
were not in the composited RenderLayer itself. This happened because
we called into RenderLayer::paintOverlayScrollbars(), which called
paintLayer() with flags that only said to paint the overlay scrollbars
but not any descendants, so this paint path would not walk child
RenderLayers.

Also remove the containsScrollableAreaWithOverlayScrollbars() flag on
ScrollView which is no longer used.

• platform/ScrollView.cpp: (WebCore::ScrollView::ScrollView): Remove containsScrollableAreaWithOverlayScrollbars(). (WebCore::ScrollView::paint): Remove setting of m_containsScrollableAreaWithOverlayScrollbars.
• platform/ScrollView.h:
• rendering/RenderLayer.cpp: (WebCore::RenderLayer::paintOverflowControls): Call setContainsDirtyOverlayScrollbars() on the compositing ancestor or the root. Remove call to setContainsScrollableAreaWithOverlayScrollbars(). (WebCore::RenderLayer::paintOverlayScrollbars): When painting overlay scrollbars, no need to say we have transparency, and no need to use temporary clip rects. (WebCore::RenderLayer::paintLayer): The PaintLayerPaintingOverlayScrollbars check here was only needed because the compositing entrypoint to painting overlay scrollbars went via paintLayer(), which isn't normally used as a composited painting entry point. Now that we no longer call that, we don't need this special check.
• rendering/RenderLayerBacking.cpp: (WebCore::RenderLayerBacking::paintIntoLayer): Jump into overlay scrollbar painting via paintLayerContents(), not paintOverlayScrollbars(), since the latter does not traverse sublayers.

Location:

branches/safari-536.28-branch/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/ScrollView.cpp (modified) (2 diffs)
• platform/ScrollView.h (modified) (2 diffs)
• rendering/RenderLayer.cpp (modified) (3 diffs)
• rendering/RenderLayerBacking.cpp (modified) (1 diff)

branches/safari-536.28-branch/Source/WebCore/ChangeLog

@@ +1 @@
+2012-11-18  Simon Fraser  <simon.fraser@apple.com>
+
+        <rdar://problem/12725980> Fix overlay scrollbar painting in compositing layers (102442)
+        Merge r135029
+
+    2012-11-16  Simon Fraser  <simon.fraser@apple.com>
+    
+            Fix overlay scrollbar painting in compositing layers
+            https://bugs.webkit.org/show_bug.cgi?id=102442
+    
+            Reviewed by Beth Dakin.
+    
+            There were two issues with overlay scrollbar painting in
+            compositing layers.
+            
+            First, we'd only ever call setContainsDirtyOverlayScrollbars()
+            on the RenderView's layer, even when encountering an overlay scrollbar
+            in some descendant compositing layer. This meant that we'd never
+            run the paintOverlayScrollbars() code for those child compositing
+            layers, so sometimes scrollbars were missing there.
+            
+            Even after fixing that, we would fail to render scrollbars that
+            were not in the composited RenderLayer itself. This happened because
+            we called into RenderLayer::paintOverlayScrollbars(), which called
+            paintLayer() with flags that only said to paint the overlay scrollbars
+            but not any descendants, so this paint path would not walk child
+            RenderLayers.
+            
+            Also remove the containsScrollableAreaWithOverlayScrollbars() flag on
+            ScrollView which is no longer used.
+    
+            * platform/ScrollView.cpp:
+            (WebCore::ScrollView::ScrollView): Remove containsScrollableAreaWithOverlayScrollbars().
+            (WebCore::ScrollView::paint): Remove setting of m_containsScrollableAreaWithOverlayScrollbars.
+            * platform/ScrollView.h:
+            * rendering/RenderLayer.cpp:
+            (WebCore::RenderLayer::paintOverflowControls): Call setContainsDirtyOverlayScrollbars()
+            on the compositing ancestor or the root.
+            Remove call to setContainsScrollableAreaWithOverlayScrollbars().
+            (WebCore::RenderLayer::paintOverlayScrollbars): When painting overlay
+            scrollbars, no need to say we have transparency, and no need to use 
+            temporary clip rects.
+            (WebCore::RenderLayer::paintLayer): The PaintLayerPaintingOverlayScrollbars
+            check here was only needed because the compositing entrypoint to painting
+            overlay scrollbars went via paintLayer(), which isn't normally used as
+            a composited painting entry point. Now that we no longer call that, we
+            don't need this special check.
+            * rendering/RenderLayerBacking.cpp:
+            (WebCore::RenderLayerBacking::paintIntoLayer): Jump into overlay scrollbar
+            painting via paintLayerContents(), not paintOverlayScrollbars(), since
+            the latter does not traverse sublayers.
+
 2012-11-18  Simon Fraser  <simon.fraser@apple.com>
 

branches/safari-536.28-branch/Source/WebCore/platform/ScrollView.cpp

@@ -58 +58 @@
     , m_clipsRepaints(true)
     , m_delegatesScrolling(false)
-    , m_containsScrollableAreaWithOverlayScrollbars(false)
 {
     platformInit();
@@ -1040 +1039 @@
 
     notifyPageThatContentAreaWillPaint();
-
-    // If we encounter any overlay scrollbars as we paint, this will be set to true.
-    m_containsScrollableAreaWithOverlayScrollbars = false;
 
     IntRect clipRect = frameRect();

branches/safari-536.28-branch/Source/WebCore/platform/ScrollView.h

@@ -280 +280 @@
     virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar*, const IntPoint&) const;
 
-    bool containsScrollableAreaWithOverlayScrollbars() const { return m_containsScrollableAreaWithOverlayScrollbars; }
-    void setContainsScrollableAreaWithOverlayScrollbars(bool contains) { m_containsScrollableAreaWithOverlayScrollbars = contains; }
-
     void calculateAndPaintOverhangAreas(GraphicsContext*, const IntRect& dirtyRect);
 
@@ -352 +349 @@
     bool m_clipsRepaints;
     bool m_delegatesScrolling;
-
-    bool m_containsScrollableAreaWithOverlayScrollbars;
 
     void init();

branches/safari-536.28-branch/Source/WebCore/rendering/RenderLayer.cpp

@@ -2531 +2531 @@
 #endif
         RenderView* renderView = renderer()->view();
-        renderView->layer()->setContainsDirtyOverlayScrollbars(true);
-        renderView->frameView()->setContainsScrollableAreaWithOverlayScrollbars(true);
+
+        RenderLayer* paintingRoot = enclosingCompositingLayer();
+        if (!paintingRoot)
+            paintingRoot = renderView->layer();
+
+        paintingRoot->setContainsDirtyOverlayScrollbars(true);
         return;
     }
@@ -2752 +2756 @@
 
     LayerPaintingInfo paintingInfo(this, enclosingIntRect(damageRect), paintBehavior, paintingRoot);
-    paintLayer(context, paintingInfo, PaintLayerHaveTransparency | PaintLayerTemporaryClipRects | PaintLayerPaintingOverlayScrollbars);
+    paintLayer(context, paintingInfo, PaintLayerPaintingOverlayScrollbars);
 
     m_containsDirtyOverlayScrollbars = false;
@@ -2857 +2861 @@
             paintFlags |= PaintLayerTemporaryClipRects;
         else if (!backing()->paintsIntoWindow()
-            && !shouldDoSoftwarePaint(this, paintFlags & PaintLayerPaintingReflection)
-            && !(paintingInfo.rootLayer->containsDirtyOverlayScrollbars()
-            && (paintFlags & PaintLayerPaintingOverlayScrollbars))) {
+            && !shouldDoSoftwarePaint(this, paintFlags & PaintLayerPaintingReflection)) {
             // If this RenderLayer should paint into its backing, that will be done via RenderLayerBacking::paintIntoLayer().
             return;

branches/safari-536.28-branch/Source/WebCore/rendering/RenderLayerBacking.cpp

@@ -1214 +1214 @@
 
     if (m_owningLayer->containsDirtyOverlayScrollbars())
-        m_owningLayer->paintOverlayScrollbars(context, paintDirtyRect, paintBehavior);
+        m_owningLayer->paintLayerContents(context, paintingInfo, paintFlags | RenderLayer::PaintLayerPaintingOverlayScrollbars);
 
     ASSERT(!m_owningLayer->m_usedTransparency);