Changeset 246019 in webkit

Timestamp:

Jun 1, 2019, 8:01:47 PM (7 years ago)

Author:

Simon Fraser

Message:

[Async overflow scroll] Flashing content when scrolling async overflow with a negative z-index child
​https://bugs.webkit.org/show_bug.cgi?id=198458

Reviewed by Dean Jackson.

Source/WebCore:

Set the GraphicsLayerPaintOverflowContents phase on the foreground layer in a composited overflow scroller,
which prevents clipping to the visible region, fixing scrolling flashes.

Tested by compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases.html

• rendering/RenderLayerBacking.cpp:

(WebCore::RenderLayerBacking::updatePaintingPhases):

LayoutTests:

• compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:
• platform/ios-wk2/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt (modified) (1 diff)
• LayoutTests/platform/ios-wk2/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayerBacking.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2019-06-01  Simon Fraser  <simon.fraser@apple.com>
+
+        [Async overflow scroll] Flashing content when scrolling async overflow with a negative z-index child
+        https://bugs.webkit.org/show_bug.cgi?id=198458
+
+        Reviewed by Dean Jackson.
+
+        * compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:
+        * platform/ios-wk2/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt:
+
 2019-06-01  Simon Fraser  <simon.fraser@apple.com>
 

trunk/LayoutTests/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt

@@ -55 +55 @@
                       (paintingPhases
                         GraphicsLayerPaintForeground
+                        GraphicsLayerPaintOverflowContents
                         )
                     )

trunk/LayoutTests/platform/ios-wk2/compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases-expected.txt

@@ -55 +55 @@
                       (paintingPhases
                         GraphicsLayerPaintForeground
+                        GraphicsLayerPaintOverflowContents
                         )
                     )

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-06-01  Simon Fraser  <simon.fraser@apple.com>
+
+        [Async overflow scroll] Flashing content when scrolling async overflow with a negative z-index child
+        https://bugs.webkit.org/show_bug.cgi?id=198458
+
+        Reviewed by Dean Jackson.
+
+        Set the GraphicsLayerPaintOverflowContents phase on the foreground layer in a composited overflow scroller,
+        which prevents clipping to the visible region, fixing scrolling flashes.
+
+        Tested by compositing/overflow/stacking-context-composited-scroller-with-foreground-paint-phases.html
+
+        * rendering/RenderLayerBacking.cpp:
+        (WebCore::RenderLayerBacking::updatePaintingPhases):
+
 2019-06-01  Simon Fraser  <simon.fraser@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayerBacking.cpp

@@ -2103 +2103 @@
     if (m_foregroundLayer) {
         OptionSet<GraphicsLayerPaintingPhase> foregroundLayerPhases { GraphicsLayerPaintingPhase::Foreground };
+        
+        if (m_scrolledContentsLayer)
+            foregroundLayerPhases.add(GraphicsLayerPaintingPhase::OverflowContents);
+
         m_foregroundLayer->setPaintingPhase(foregroundLayerPhases);
         primaryLayerPhases.remove(GraphicsLayerPaintingPhase::Foreground);