Changeset 167489 in webkit

Timestamp:

Apr 18, 2014 6:07:48 AM (10 years ago)

Author:

stavila@adobe.com

Message:

[CSSRegions] Incorrect background paint on positioned element hover
​https://bugs.webkit.org/show_bug.cgi?id=131617

Reviewed by Andrei Bucur.

Source/WebCore:
When computing the repaint rect for absolute elements flowed into regions, the Y location of the
region within the flow thread must no longer be added to the repaint rect's location because absolute
positioned elements get pushed down through the regions by their absolute top. So adding the region's
position in the flow thread and then adding the element's absolute top would cause us to add
something twice.

Tests: fast/regions/repaint/repaint-absolute-pushed-to-next-region.html

• rendering/RenderBox.cpp:

(WebCore::RenderBox::computeRectForRepaint):

LayoutTests:
Added test for the proper repainting of absolute positioned elements in regions when the
absolute top of the elements causes it to be pushed to the next region.

• fast/regions/repaint/repaint-absolute-pushed-to-next-region-expected.txt: Added.
• fast/regions/repaint/repaint-absolute-pushed-to-next-region.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/regions/repaint/repaint-absolute-pushed-to-next-region-expected.txt (added)
• LayoutTests/fast/regions/repaint/repaint-absolute-pushed-to-next-region.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderBox.cpp (modified) (2 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2014-04-18  Radu Stavila  <stavila@adobe.com>
+
+        [CSSRegions] Incorrect background paint on positioned element hover
+        https://bugs.webkit.org/show_bug.cgi?id=131617
+
+        Reviewed by Andrei Bucur.
+
+        Added test for the proper repainting of absolute positioned elements in regions when the
+        absolute top of the elements causes it to be pushed to the next region.
+
+        * fast/regions/repaint/repaint-absolute-pushed-to-next-region-expected.txt: Added.
+        * fast/regions/repaint/repaint-absolute-pushed-to-next-region.html: Added.
+
 2014-04-18  Philippe Normand  <pnormand@igalia.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2014-04-18  Radu Stavila  <stavila@adobe.com>
+
+        [CSSRegions] Incorrect background paint on positioned element hover
+        https://bugs.webkit.org/show_bug.cgi?id=131617
+
+        Reviewed by Andrei Bucur.
+
+        When computing the repaint rect for absolute elements flowed into regions, the Y location of the
+        region within the flow thread must no longer be added to the repaint rect's location because absolute
+        positioned elements get pushed down through the regions by their absolute top. So adding the region's
+        position in the flow thread and then adding the element's absolute top would cause us to add
+        something twice.
+
+        Tests: fast/regions/repaint/repaint-absolute-pushed-to-next-region.html
+
+        * rendering/RenderBox.cpp:
+        (WebCore::RenderBox::computeRectForRepaint):
+
 2014-04-18  Philippe Normand  <pnormand@igalia.com>
 

trunk/Source/WebCore/rendering/RenderBox.cpp

@@ -2109 +2109 @@
         return;
     
+    EPosition position = styleToUse.position();
+
     // This code isn't necessary for in-flow RenderFlowThreads.
-    if (o->isOutOfFlowRenderFlowThread()) {
+    // Don't add the location of the region in the flow thread for absolute positioned
+    // elements because their absolute position already pushes them down through
+    // the regions so adding this here and then adding the topLeft again would cause
+    // us to add the height twice.
+    if (o->isOutOfFlowRenderFlowThread() && position != AbsolutePosition) {
         RenderRegion* firstRegion = nullptr;
         RenderRegion* lastRegion = nullptr;
@@ -2122 +2128 @@
     LayoutPoint topLeft = rect.location();
     topLeft.move(locationOffset());
-
-    EPosition position = styleToUse.position();
 
     // We are now in our parent container's coordinate space.  Apply our transform to obtain a bounding box