Changeset 217748 in webkit

Timestamp:

Jun 2, 2017 7:27:27 PM (7 years ago)

Author:

Wenson Hsieh

Message:

REGRESSION(r216212): RenderReplaced::paint() should not save and restore the context unless it has to
​https://bugs.webkit.org/show_bug.cgi?id=172883
<rdar://problem/32548614>

Reviewed by Tim Horton.

After implementing dragged content fading, RenderReplace::paint is now always guarded by unnecessary calls to
GraphicsContext::save and GraphicsContext::restore, even when there is no dragged content being rendered. To
address this, we initialize our GraphicsContextStateSaver with saveAndRestore = false, indicating that we don't
want to immediately try and save the context.

If we are in a dragged content range, we will then call GraphicsContextStateSaver::save, which saves the
graphics context and also causes the GraphicsContextStateSaver to eventually try and restore() when it is
destroyed. Otherwise, in the common codepath where the renderer is not in a dragged content range, the
constructor and destructor of GraphicsContextStateSaver will be no-ops with respect to saving and restoring the
graphics context.

• rendering/RenderReplaced.cpp:

(WebCore::RenderReplaced::paint):

Location:

trunk/Source/WebCore

Files:

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

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2017-06-02  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        REGRESSION(r216212): RenderReplaced::paint() should not save and restore the context unless it has to
+        https://bugs.webkit.org/show_bug.cgi?id=172883
+        <rdar://problem/32548614>
+
+        Reviewed by Tim Horton.
+
+        After implementing dragged content fading, RenderReplace::paint is now always guarded by unnecessary calls to
+        GraphicsContext::save and GraphicsContext::restore, even when there is no dragged content being rendered. To
+        address this, we initialize our GraphicsContextStateSaver with saveAndRestore = false, indicating that we don't
+        want to immediately try and save the context.
+
+        If we are in a dragged content range, we will then call GraphicsContextStateSaver::save, which saves the
+        graphics context and also causes the GraphicsContextStateSaver to eventually try and restore() when it is
+        destroyed. Otherwise, in the common codepath where the renderer is not in a dragged content range, the
+        constructor and destructor of GraphicsContextStateSaver will be no-ops with respect to saving and restoring the
+        graphics context.
+
+        * rendering/RenderReplaced.cpp:
+        (WebCore::RenderReplaced::paint):
+
 2017-06-02  Myles C. Maxfield  <mmaxfield@apple.com>
 

trunk/Source/WebCore/rendering/RenderReplaced.cpp

@@ -160 +160 @@
 #endif
 
-    GraphicsContextStateSaver savedGraphicsContext(paintInfo.context());
+    GraphicsContextStateSaver savedGraphicsContext(paintInfo.context(), false);
     if (element() && element()->parentOrShadowHostElement()) {
         auto* parentContainer = element()->parentOrShadowHostElement();
-        if (draggedContentContainsReplacedElement(document().markers().markersFor(parentContainer, DocumentMarker::DraggedContent), *element()))
+        if (draggedContentContainsReplacedElement(document().markers().markersFor(parentContainer, DocumentMarker::DraggedContent), *element())) {
+            savedGraphicsContext.save();
             paintInfo.context().setAlpha(0.25);
+        }
     }