Changeset 136452 in webkit

Timestamp:

Dec 3, 2012, 4:04:52 PM (12 years ago)

Author:

kenneth@webkit.org

Message:

[EFL][Qt][WK2] Fixed position elements are not always fixed
​https://bugs.webkit.org/show_bug.cgi?id=103452

Reviewed by Simon Fraser.

The code figuring out whether fixed position layers are inside
the visible viewport, assumes that the visible viewport is always
the size of the layout viewport. This assumption doesn't hold with
how the Qt and EFL tiled backing store and coordinated graphics
works, so instead using the visibleContentsRect(), which provides
the right values in all cases.

• rendering/RenderLayerCompositor.cpp:

(WebCore::RenderLayerCompositor::requiresCompositingForPosition):

Use visibleContentsRect instead of scrollOffsetForFixedPosition().

scrollOffsetForFixedPosition() is needed sometimes in the Mac code
because visibleContentRect() will return negative offsets when you
are in the rubber-band phase of a scroll on the Mac.

However that is not an issue here.

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• rendering/RenderLayerCompositor.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2012-12-03  Kenneth Rohde Christiansen  <kenneth@webkit.org>
+
+        [EFL][Qt][WK2] Fixed position elements are not always fixed
+        https://bugs.webkit.org/show_bug.cgi?id=103452
+
+        Reviewed by Simon Fraser.
+
+        The code figuring out whether fixed position layers are inside
+        the visible viewport, assumes that the visible viewport is always
+        the size of the layout viewport. This assumption doesn't hold with
+        how the Qt and EFL tiled backing store and coordinated graphics
+        works, so instead using the visibleContentsRect(), which provides
+        the right values in all cases.
+
+        * rendering/RenderLayerCompositor.cpp:
+        (WebCore::RenderLayerCompositor::requiresCompositingForPosition):
+
+            Use visibleContentsRect instead of scrollOffsetForFixedPosition().
+
+            scrollOffsetForFixedPosition() is needed sometimes in the Mac code
+            because visibleContentRect() will return negative offsets when you
+            are in the rubber-band phase of a scroll on the Mac.
+
+            However that is not an issue here.
+
 2012-12-03  Sheriff Bot  <webkit.review.bot@gmail.com>
 

trunk/Source/WebCore/rendering/RenderLayerCompositor.cpp

@@ -1975 +1975 @@
     // Fixed position elements that are invisible in the current view don't get their own layer.
     if (FrameView* frameView = m_renderView->frameView()) {
-        IntRect viewBounds = IntRect(IntPoint(frameView->scrollOffsetForFixedPosition()), frameView->layoutSize());
+        IntRect viewBounds = frameView->visibleContentRect();
         IntRect layerBounds = calculateCompositedBounds(layer, rootRenderLayer());
         if (!viewBounds.intersects(layerBounds))