Changeset 271191 in webkit

Timestamp:

Jan 5, 2021, 7:55:01 PM (6 years ago)

Author:

Simon Fraser

Message:

REGRESSION: animated iframe painted blank
​https://bugs.webkit.org/show_bug.cgi?id=220231
Source/WebCore:

<rdar://problem/72793724>

Reviewed by Zalan Bujtas.

When an <iframe> on a fractional pixel boundary, on a non-Retina display, with
composited contents had its visibility toggled from 'hidden' to 'visible' we could
fail to parent the iframe content compositing layers, resulting in missing iframe
content.

This happened when the iframe's GraphicsLayer had a m_contentsClippingLayer (which
acts as the parent for the content layers) due to the fractional pixel offset.
When GraphicsLayerCA::setContentsVisible(true) was called, it would fail to call
noteSublayersChanged() because the iframe host layer has no m_contentsLayer,
but we do need to rebuild sublayers in this case.

Test: compositing/iframes/content-visibility-with-clipping.html

• platform/graphics/ca/GraphicsLayerCA.cpp:

(WebCore::GraphicsLayerCA::setContentsVisible):

LayoutTests:

Reviewed by Zalan Bujtas.

• compositing/iframes/content-visibility-with-clipping-expected.html: Added.
• compositing/iframes/content-visibility-with-clipping.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/compositing/iframes/content-visibility-with-clipping-expected.html (added)
• LayoutTests/compositing/iframes/content-visibility-with-clipping.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/platform/graphics/ca/GraphicsLayerCA.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2021-01-05  Simon Fraser  <simon.fraser@apple.com>
+
+        REGRESSION: animated iframe painted blank
+        https://bugs.webkit.org/show_bug.cgi?id=220231
+
+        Reviewed by Zalan Bujtas.
+
+        * compositing/iframes/content-visibility-with-clipping-expected.html: Added.
+        * compositing/iframes/content-visibility-with-clipping.html: Added.
+
 2021-01-05  Peng Liu  <peng.liu6@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-01-05  Simon Fraser  <simon.fraser@apple.com>
+
+        REGRESSION: animated iframe painted blank
+        https://bugs.webkit.org/show_bug.cgi?id=220231
+        <rdar://problem/72793724>
+
+        Reviewed by Zalan Bujtas.
+
+        When an <iframe> on a fractional pixel boundary, on a non-Retina display, with
+        composited contents had its visibility toggled from 'hidden' to 'visible' we could
+        fail to parent the iframe content compositing layers, resulting in missing iframe
+        content.
+
+        This happened when the iframe's GraphicsLayer had a m_contentsClippingLayer (which
+        acts as the parent for the content layers) due to the fractional pixel offset.
+        When GraphicsLayerCA::setContentsVisible(true) was called, it would fail to call
+        noteSublayersChanged() because the iframe host layer has no m_contentsLayer,
+        but we do need to rebuild sublayers in this case.
+
+        Test: compositing/iframes/content-visibility-with-clipping.html
+
+        * platform/graphics/ca/GraphicsLayerCA.cpp:
+        (WebCore::GraphicsLayerCA::setContentsVisible):
+
 2021-01-05  Megan Gardner  <megan_gardner@apple.com>
 

trunk/Source/WebCore/platform/graphics/ca/GraphicsLayerCA.cpp

@@ -742 +742 @@
     GraphicsLayer::setContentsVisible(contentsVisible);
     noteLayerPropertyChanged(ContentsVisibilityChanged);
+
     // Visibility affects whether the contentsLayer is parented.
-    if (m_contentsLayer)
+    if (m_contentsLayer || m_contentsClippingLayer)
         noteSublayersChanged();
 }