Changeset 130692 in webkit

Timestamp:

Oct 8, 2012, 3:15:44 PM (14 years ago)

Author:

commit-queue@webkit.org

Message:

Some non-scrollable elements are added to non-fast-scrollable region
​https://bugs.webkit.org/show_bug.cgi?id=97927

Patch by Sami Kyostila <​skyostil@chromium.org> on 2012-10-08
Reviewed by James Robinson.

Source/WebCore:

Only RenderLayers that can actually be scrolled should be added to the
ScrollingCoordinator's non-fast scrollable region. Otherwise we may
needlessly fall back to main thread scrolling.

Test: ScrollingCoordinatorChromiumTest.clippedBodyTest

• rendering/RenderLayer.cpp:

(WebCore::RenderLayer::updateScrollbarsAfterLayout):
(WebCore::RenderLayer::updateScrollbarsAfterStyleChange):

Source/WebKit/chromium:

Test that a non-scrollable RenderLayer isn't added to the non-fast scrollable
region.

The test in this patch consists of a web page where both the html and
body elements clip horizontal overflow. This results in a hierarchy
where the body element gets a scrollable RenderLayer. However, that
layer isn't (interactively) scrollable because while the scroll geometry
is calculated based on the amount of overflow, the scroll bars are
hidden because of the "overflow-x: hidden" style.

Previously this layer would have made the entire page part of the
non-fast scrollable region. With this patch,
RenderLayer::allowScrolling() is used as a pre-requisite for expanding
the region, thus avoiding the problem.

• tests/ScrollingCoordinatorChromiumTest.cpp:

(WebKit::TEST_F):
(WebKit):

• tests/data/clipped-body.html: Added.

Location:

trunk/Source

Files:

• WebCore/ChangeLog (modified) (1 diff)
• WebCore/rendering/RenderLayer.cpp (modified) (2 diffs)
• WebKit/chromium/ChangeLog (modified) (1 diff)
• WebKit/chromium/tests/ScrollingCoordinatorChromiumTest.cpp (modified) (1 diff)
• WebKit/chromium/tests/data/clipped-body.html (added)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2012-10-08  Sami Kyostila  <skyostil@chromium.org>
+
+        Some non-scrollable elements are added to non-fast-scrollable region
+        https://bugs.webkit.org/show_bug.cgi?id=97927
+
+        Reviewed by James Robinson.
+
+        Only RenderLayers that can actually be scrolled should be added to the
+        ScrollingCoordinator's non-fast scrollable region. Otherwise we may
+        needlessly fall back to main thread scrolling.
+
+        Test: ScrollingCoordinatorChromiumTest.clippedBodyTest
+
+        * rendering/RenderLayer.cpp:
+        (WebCore::RenderLayer::updateScrollbarsAfterLayout):
+        (WebCore::RenderLayer::updateScrollbarsAfterStyleChange):
+
 2012-10-08  Simon Fraser  <simon.fraser@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayer.cpp

@@ -2630 +2630 @@
     }
 
-    updateScrollableAreaSet((hasHorizontalOverflow || hasVerticalOverflow) && scrollsOverflow());
+    updateScrollableAreaSet((hasHorizontalOverflow || hasVerticalOverflow) && scrollsOverflow() && allowsScrolling());
 }
 
@@ -4848 +4848 @@
 
     if (!m_scrollDimensionsDirty)
-        updateScrollableAreaSet((hasHorizontalOverflow() || hasVerticalOverflow()) && scrollsOverflow());
+        updateScrollableAreaSet((hasHorizontalOverflow() || hasVerticalOverflow()) && scrollsOverflow() && allowsScrolling());
 }
 

trunk/Source/WebKit/chromium/ChangeLog

@@ +1 @@
+2012-10-08  Sami Kyostila  <skyostil@chromium.org>
+
+        Some non-scrollable elements are added to non-fast-scrollable region
+        https://bugs.webkit.org/show_bug.cgi?id=97927
+
+        Reviewed by James Robinson.
+
+        Test that a non-scrollable RenderLayer isn't added to the non-fast scrollable
+        region.
+
+        The test in this patch consists of a web page where both the html and
+        body elements clip horizontal overflow. This results in a hierarchy
+        where the body element gets a scrollable RenderLayer. However, that
+        layer isn't (interactively) scrollable because while the scroll geometry
+        is calculated based on the amount of overflow, the scroll bars are
+        hidden because of the "overflow-x: hidden" style.
+
+        Previously this layer would have made the entire page part of the
+        non-fast scrollable region. With this patch,
+        RenderLayer::allowScrolling() is used as a pre-requisite for expanding
+        the region, thus avoiding the problem.
+
+        * tests/ScrollingCoordinatorChromiumTest.cpp:
+        (WebKit::TEST_F):
+        (WebKit):
+        * tests/data/clipped-body.html: Added.
+
 2012-10-08  Sailesh Agrawal  <sail@chromium.org>
 

trunk/Source/WebKit/chromium/tests/ScrollingCoordinatorChromiumTest.cpp

@@ -184 +184 @@
 }
 
+TEST_F(ScrollingCoordinatorChromiumTest, clippedBodyTest)
+{
+    registerMockedHttpURLLoad("clipped-body.html");
+    navigateTo(m_baseURL + "clipped-body.html");
+
+    WebLayer* rootScrollLayer = getRootScrollLayer();
+    ASSERT_EQ(0u, rootScrollLayer->nonFastScrollableRegion().size());
+}
+
 #if ENABLE(ACCELERATED_OVERFLOW_SCROLLING)
 TEST_F(ScrollingCoordinatorChromiumTest, touchOverflowScrolling)