[CSS Regions] Elements in a region should be assignable to a named flow

Source/core/dom/PseudoElement.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 28 matching lines @@
     static PassRefPtr<PseudoElement> create(Element* parent, PseudoId pseudoId)
     {
         return adoptRef(new PseudoElement(parent, pseudoId));
     }
     ~PseudoElement();
 
     virtual PassRefPtr<RenderStyle> customStyleForRenderer() OVERRIDE;
     virtual void attach() OVERRIDE;
     virtual bool rendererIsNeeded(const NodeRenderingContext&) OVERRIDE;
 
+    // As per http://dev.w3.org/csswg/css3-regions/#flow-into, pseudo-elements such as ::first-line, ::first-letter, ::before or ::after
+    // cannot be directly collected into a named flow.
+    virtual bool moveToFlowThreadIsNeeded(RefPtr<RenderStyle>& cachedStyle) OVERRIDE

[Julien - ping for review, 2013/05/09 15:30:18]

I am really not a huge fan of this function naming. Usually such functions
starts with "should" and here it would make IMO a better name:
shouldMoveElementToFlowThread

[Mihai Maerean, 2013/05/09 16:25:55]

Ok, I will rename it.
PS: it may be possible in a future spec version to also flow nodes, not just
elements. So I would drop the "Element" word from the suggested name.

+    {
+        UNUSED_PARAM(cachedStyle);

[Julien - ping for review, 2013/05/09 15:30:18]

If you didn't put the argument in the function signature, you wouldn't need this
line.

[Mihai Maerean, 2013/05/09 16:25:55]

That's true when declaring the function. When the implementation is written in
the header at the declaration point, a missing argument would make the compiler
think it's a different method signature.

[Julien - ping for review, 2013/05/10 00:13:05]

I don't think you are right (argument names don't impact the signature, only the
number of arguments and their types). See among other example RenderBlock.h:

virtual void adjustInlineDirectionLineBounds(int /* expansionOpportunityCount
*/, float& /* logicalLeft */, float& /* logicalWidth */) const { }

+        return false;
+    }
+
     virtual bool canStartSelection() const OVERRIDE { return false; }
     virtual bool canContainRangeEndPoint() const OVERRIDE { return false; }
 
     static String pseudoElementNameForEvents(PseudoId);
 
 private:
     PseudoElement(Element*, PseudoId);
 
     virtual void didRecalcStyle(StyleChange) OVERRIDE;
     virtual PseudoId customPseudoId() const OVERRIDE { return m_pseudoId; }
 
     PseudoId m_pseudoId;
 };
 
 const QualifiedName& pseudoElementTagName();
 
 inline bool pseudoElementRendererIsNeeded(const RenderStyle* style)
 {
     return style && style->display() != NONE && (style->contentData() || !style->regionThread().isEmpty());
 }
 
 } // namespace
 
 #endif