Introduce toSVGViewElement(), and refactor setupInitialView() using it

Source/core/svg/SVGSVGElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 698 matching lines @@
         if (renderer && (hadUseCurrentView || m_useCurrentView))
             RenderSVGResource::markForLayoutAndParentResourceInvalidation(renderer);
         return;
     }
 
     // Spec: If the SVG fragment identifier addresses a ‘view’ element within an SVG document (e.g., MyDrawing.svg#MyView
     // or MyDrawing.svg#xpointer(id('MyView'))) then the closest ancestor ‘svg’ element is displayed in the viewport.
     // Any view specification attributes included on the given ‘view’ element override the corresponding view specification
     // attributes on the closest ancestor ‘svg’ element.
     if (anchorNode && anchorNode->hasTagName(SVGNames::viewTag)) {
-        if (SVGViewElement* viewElement = anchorNode->hasTagName(SVGNames::viewTag) ? static_cast<SVGViewElement*>(anchorNode) : 0) {
-            SVGElement* element = SVGLocatable::nearestViewportElement(viewElement);
-            if (element->hasTagName(SVGNames::svgTag)) {
-                SVGSVGElement* svg = toSVGSVGElement(element);
-                svg->inheritViewAttributes(viewElement);
+        SVGViewElement* viewElement = toSVGViewElement(anchorNode);
+        if (!viewElement)
+            return;
 
-                if (RenderObject* renderer = svg->renderer())
-                    RenderSVGResource::markForLayoutAndParentResourceInvalidation(renderer);
-            }
+        SVGElement* element = SVGLocatable::nearestViewportElement(viewElement);
+        if (element->hasTagName(SVGNames::svgTag)) {
+            SVGSVGElement* svg = toSVGSVGElement(element);
+            svg->inheritViewAttributes(viewElement);
+
+            if (RenderObject* renderer = svg->renderer())
+                RenderSVGResource::markForLayoutAndParentResourceInvalidation(renderer);
         }
-        return;
     }
 
     // FIXME: We need to decide which <svg> to focus on, and zoom to it.
     // FIXME: We need to actually "highlight" the viewTarget(s).
 }
 
 void SVGSVGElement::inheritViewAttributes(SVGViewElement* viewElement)
 {
     SVGViewSpec* view = currentView();
     m_useCurrentView = true;
@@ skipping 29 matching lines @@
             continue;
 
         Element* element = toElement(node);
         if (element->getIdAttribute() == id)
             return element;
     }
     return 0;
 }
 
 }