Changeset 182743 in webkit

Timestamp:

Apr 13, 2015 10:55:07 AM (9 years ago)

Author:

Simon Fraser

Message:

Fixed position element is truncated if moved onscreen by a transform
​https://bugs.webkit.org/show_bug.cgi?id=143655
Source/WebCore:

rdar://problem/15020044

Reviewed by Darin Adler.

Our "don't do layout if transform changes" code was too aggressive.
If an element changes between having a transform and not having one, we
really need to do a layout since so much else depends on transforms. In
this particular case, we clip position:fixed elements to the viewport if
they are not transformed, and were failing to re-evaluate this when a
transform was added. Doing a layout fixes this.

Test: compositing/geometry/fixed-transformed.html

• rendering/style/RenderStyle.cpp:

(WebCore::RenderStyle::changeRequiresLayout):

• rendering/style/StyleTransformData.h:

(WebCore::StyleTransformData::hasTransform):

LayoutTests:

Reviewed by Darin Adler.

Test that moves a position:fixed element on-screen using a transform.

• compositing/geometry/fixed-transformed.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/compositing/geometry/fixed-transformed.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/style/RenderStyle.cpp (modified) (1 diff)
• Source/WebCore/rendering/style/StyleTransformData.h (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2015-04-13  Simon Fraser  <simon.fraser@apple.com>
+
+        Fixed position element is truncated if moved onscreen by a transform
+        https://bugs.webkit.org/show_bug.cgi?id=143655
+
+        Reviewed by Darin Adler.
+        
+        Test that moves a position:fixed element on-screen using a transform.
+
+        * compositing/geometry/fixed-transformed.html: Added.
+
 2015-04-13  Alexey Proskuryakov  <ap@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2015-04-13  Simon Fraser  <simon.fraser@apple.com>
+
+        Fixed position element is truncated if moved onscreen by a transform
+        https://bugs.webkit.org/show_bug.cgi?id=143655
+        rdar://problem/15020044
+
+        Reviewed by Darin Adler.
+        
+        Our "don't do layout if transform changes" code was too aggressive.
+        If an element changes between having a transform and not having one, we
+        really need to do a layout since so much else depends on transforms. In
+        this particular case, we clip position:fixed elements to the viewport if
+        they are not transformed, and were failing to re-evaluate this when a
+        transform was added. Doing a layout fixes this.
+
+        Test: compositing/geometry/fixed-transformed.html
+
+        * rendering/style/RenderStyle.cpp:
+        (WebCore::RenderStyle::changeRequiresLayout):
+        * rendering/style/StyleTransformData.h:
+        (WebCore::StyleTransformData::hasTransform):
+
 2015-04-12  Darin Adler  <darin@apple.com>
 

trunk/Source/WebCore/rendering/style/RenderStyle.cpp

@@ -483 +483 @@
             return true;
 
-        if (rareNonInheritedData->m_transform.get() != other.rareNonInheritedData->m_transform.get()
-            && *rareNonInheritedData->m_transform.get() != *other.rareNonInheritedData->m_transform.get()) {
-            changedContextSensitiveProperties |= ContextSensitivePropertyTransform;
-            // Don't return; keep looking for another change
+        if (rareNonInheritedData->m_transform != other.rareNonInheritedData->m_transform) {
+            if (rareNonInheritedData->m_transform->hasTransform() != other.rareNonInheritedData->m_transform->hasTransform())
+                return true;
+            if (*rareNonInheritedData->m_transform != *other.rareNonInheritedData->m_transform) {
+                changedContextSensitiveProperties |= ContextSensitivePropertyTransform;
+                // Don't return; keep looking for another change
+            }
         }
 

trunk/Source/WebCore/rendering/style/StyleTransformData.h

@@ -43 +43 @@
         return !(*this == o);
     }
+    
+    bool hasTransform() const { return m_operations.size(); }
 
     TransformOperations m_operations;