Changeset 127620 in webkit

Timestamp:

Sep 5, 2012 11:53:29 AM (12 years ago)

Author:

commit-queue@webkit.org

Message:

Enable/disable composited scrolling based on overflow
​https://bugs.webkit.org/show_bug.cgi?id=95323

Patch by Sami Kyostila <​skyostil@google.com> on 2012-09-05
Reviewed by Simon Fraser.

Source/WebCore:

When an overflow:{auto,overlay} and -webkit-overflow-scrolling:touch
element gains or loses overflow, we should correspondingly enable and
disable composited scrolling depending on whether the element can be
scrolled or not.

The previous logic in RenderLayer::usesCompositedScrolling() already
checked for actual overflow, but we also need to recompute the
compositing requirements when the amount of overflow changes during
layout. Additionally, layers using composited scrolling are marked as
self-painting to ensure they are always promoted to composited layers
when needed.

Test: compositing/overflow/overflow-auto-with-touch-toggle.html

Note that the behavior for maintaining a stacking context even without
the presense of overflow is covered by platform/chromium/compositing/overflow/overflow-scrolling-touch-stacking-context.html.

• rendering/RenderLayer.cpp:

(WebCore::RenderLayer::updateScrollInfoAfterLayout):
(WebCore::RenderLayer::shouldBeSelfPaintingLayer):

LayoutTests:

Added a new test for making sure composited scrolling is enabled when overflow
is introduced.

Note that this test will pass only if OVERFLOW_SCROLLING is enabled.

• compositing/overflow/overflow-auto-with-touch-toggle-expected.txt: Added.
• compositing/overflow/overflow-auto-with-touch-toggle.html: Added.
• platform/chromium/TestExpectations:

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/compositing/overflow/overflow-auto-with-touch-toggle-expected.txt (added)
• LayoutTests/compositing/overflow/overflow-auto-with-touch-toggle.html (added)
• LayoutTests/platform/chromium/TestExpectations (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayer.cpp (modified) (2 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2012-09-05  Sami Kyostila  <skyostil@google.com>
+
+        Enable/disable composited scrolling based on overflow
+        https://bugs.webkit.org/show_bug.cgi?id=95323
+
+        Reviewed by Simon Fraser.
+
+        Added a new test for making sure composited scrolling is enabled when overflow
+        is introduced.
+
+        Note that this test will pass only if OVERFLOW_SCROLLING is enabled.
+
+        * compositing/overflow/overflow-auto-with-touch-toggle-expected.txt: Added.
+        * compositing/overflow/overflow-auto-with-touch-toggle.html: Added.
+        * platform/chromium/TestExpectations:
+
 2012-09-05  Max Vujovic  <mvujovic@adobe.com>
 

trunk/LayoutTests/platform/chromium/TestExpectations

@@ -3454 +3454 @@
 BUGWK94353 LINUX ANDROID : compositing/overflow/nested-scrolling.html = IMAGE+TEXT PASS
 BUGWK94353 : compositing/overflow/overflow-auto-with-touch.html = TEXT
+BUGWK94353 : compositing/overflow/overflow-auto-with-touch-toggle.html = TEXT
 BUGWK94353 : compositing/overflow/overflow-overlay-with-touch.html = TEXT
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2012-09-05  Sami Kyostila  <skyostil@google.com>
+
+        Enable/disable composited scrolling based on overflow
+        https://bugs.webkit.org/show_bug.cgi?id=95323
+
+        Reviewed by Simon Fraser.
+
+        When an overflow:{auto,overlay} and -webkit-overflow-scrolling:touch
+        element gains or loses overflow, we should correspondingly enable and
+        disable composited scrolling depending on whether the element can be
+        scrolled or not.
+
+        The previous logic in RenderLayer::usesCompositedScrolling() already
+        checked for actual overflow, but we also need to recompute the
+        compositing requirements when the amount of overflow changes during
+        layout. Additionally, layers using composited scrolling are marked as
+        self-painting to ensure they are always promoted to composited layers
+        when needed.
+
+        Test: compositing/overflow/overflow-auto-with-touch-toggle.html
+
+        Note that the behavior for maintaining a stacking context even without
+        the presense of overflow is covered by platform/chromium/compositing/overflow/overflow-scrolling-touch-stacking-context.html.
+
+        * rendering/RenderLayer.cpp:
+        (WebCore::RenderLayer::updateScrollInfoAfterLayout):
+        (WebCore::RenderLayer::shouldBeSelfPaintingLayer):
+
 2012-09-05  Mike Fenton  <mifenton@rim.com>
 

trunk/Source/WebCore/rendering/RenderLayer.cpp

@@ -2656 +2656 @@
     if (originalScrollOffset != scrollOffset())
         scrollToOffsetWithoutAnimation(toPoint(scrollOffset()));
+
+#if USE(ACCELERATED_COMPOSITING)
+    // Composited scrolling may need to be enabled or disabled if the amount of overflow changed.
+    if (renderer()->view() && compositor()->updateLayerCompositingState(this))
+        compositor()->setCompositingLayersNeedRebuild();
+#endif
 }
 
@@ -4848 +4854 @@
     return !isNormalFlowOnly()
         || hasOverlayScrollbars()
+        || usesCompositedScrolling()
         || renderer()->hasReflection()
         || renderer()->hasMask()