Changeset 140593 in webkit

Timestamp:

Jan 23, 2013 2:24:49 PM (11 years ago)

Author:

wangxianzhu@chromium.org

Message:

Should update compositing state when an out-of-view fixed position element becomes in-view
​https://bugs.webkit.org/show_bug.cgi?id=107410

Reviewed by Simon Fraser.

Source/WebCore:

When a non-compositing page contains some not-composited fixed position element because of bounds out-of-view, when the element changes position and RenderLayerCompositor::updateCompositingLayers() is called, the function may return early because of "if (!m_reevaluateCompositingAfterLayout && !m_compositing)" without updating the compositing layers.

Set m_reevaluateCompositingAfterLayout when a fixed position element is not composited because of bounds out-of-view.

Test: compositing/layer-creation/fixed-position-change-out-of-view-in-view.html

• rendering/RenderLayerCompositor.cpp:

(WebCore::RenderLayerCompositor::requiresCompositingForPosition):

LayoutTests:

Tests if compositing status is properly updated when fixed position elements change from out-of-view to in-view and back.

• compositing/layer-creation/fixed-position-change-out-of-view-in-view-expected.txt: Added.
• compositing/layer-creation/fixed-position-change-out-of-view-in-view.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/compositing/layer-creation/fixed-position-change-out-of-view-in-view-expected.txt (added)
• LayoutTests/compositing/layer-creation/fixed-position-change-out-of-view-in-view.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayerCompositor.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2013-01-23  Xianzhu Wang  <wangxianzhu@chromium.org>
+
+        Should update compositing state when an out-of-view fixed position element becomes in-view
+        https://bugs.webkit.org/show_bug.cgi?id=107410
+
+        Reviewed by Simon Fraser.
+
+        Tests if compositing status is properly updated when fixed position elements change from out-of-view to in-view and back.
+
+        * compositing/layer-creation/fixed-position-change-out-of-view-in-view-expected.txt: Added.
+        * compositing/layer-creation/fixed-position-change-out-of-view-in-view.html: Added.
+
 2013-01-23  Erik Arvidsson  <arv@chromium.org>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-01-23  Xianzhu Wang  <wangxianzhu@chromium.org>
+
+        Should update compositing state when an out-of-view fixed position element becomes in-view
+        https://bugs.webkit.org/show_bug.cgi?id=107410
+
+        Reviewed by Simon Fraser.
+
+        When a non-compositing page contains some not-composited fixed position element because of bounds out-of-view, when the element changes position and RenderLayerCompositor::updateCompositingLayers() is called, the function may return early because of "if (!m_reevaluateCompositingAfterLayout && !m_compositing)" without updating the compositing layers.
+
+        Set m_reevaluateCompositingAfterLayout when a fixed position element is not composited because of bounds out-of-view.
+
+        Test: compositing/layer-creation/fixed-position-change-out-of-view-in-view.html
+
+        * rendering/RenderLayerCompositor.cpp:
+        (WebCore::RenderLayerCompositor::requiresCompositingForPosition):
+
 2013-01-23  Tony Chang  <tony@chromium.org>
 

trunk/Source/WebCore/rendering/RenderLayerCompositor.cpp

@@ -2073 +2073 @@
             if (viewportConstrainedNotCompositedReason)
                 *viewportConstrainedNotCompositedReason = RenderLayer::NotCompositedForBoundsOutOfView;
+            // Reevaluate compositing after layout because the layer bounds may change and become composited.
+            m_reevaluateCompositingAfterLayout = true;
             return false;
         }