Add SVGUseElement::createInstanceTree helper

third_party/WebKit/Source/core/svg/SVGUseElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  * Copyright (C) 2011 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012 University of Szeged
  * Copyright (C) 2012 Renata Hodovan <reni@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 227 matching lines @@
         }
 
         invalidateShadowTree();
 
         return;
     }
 
     SVGGraphicsElement::svgAttributeChanged(attrName);
 }
 
-static bool isDisallowedElement(const Node& node)
+static bool isDisallowedElement(const Element& element)
 {
     // Spec: "Any 'svg', 'symbol', 'g', graphics element or other 'use' is potentially a template object that can be re-used
     // (i.e., "instanced") in the SVG document via a 'use' element."
     // "Graphics Element" is defined as 'circle', 'ellipse', 'image', 'line', 'path', 'polygon', 'polyline', 'rect', 'text'
     // Excluded are anything that is used by reference or that only make sense to appear once in a document.
-    // We must also allow the shadow roots of other use elements.
-    if (node.isShadowRoot() || node.isTextNode())
-        return false;
-
-    if (!node.isSVGElement())
+    if (!element.isSVGElement())
         return true;
 
-    const Element& element = toElement(node);
-
     DEFINE_STATIC_LOCAL(HashSet<QualifiedName>, allowedElementTags, ());
     if (allowedElementTags.isEmpty()) {
         allowedElementTags.add(SVGNames::aTag);
         allowedElementTags.add(SVGNames::circleTag);
         allowedElementTags.add(SVGNames::descTag);
         allowedElementTags.add(SVGNames::ellipseTag);
         allowedElementTags.add(SVGNames::gTag);
         allowedElementTags.add(SVGNames::imageTag);
         allowedElementTags.add(SVGNames::lineTag);
         allowedElementTags.add(SVGNames::metadataTag);
@@ skipping 106 matching lines @@
             Element* next = ElementTraversal::nextSkippingChildren(*element, &subtree);
             // The subtree is not in document so this won't generate events that could mutate the tree.
             element->parentNode()->removeChild(element);
             element = next;
         } else {
             element = ElementTraversal::next(*element, &subtree);
         }
     }
 }
 
+PassRefPtrWillBeRawPtr<Element> SVGUseElement::createInstanceTree(SVGElement& targetRoot) const
+{
+    RefPtrWillBeRawPtr<Element> instanceRoot = targetRoot.cloneElementWithChildren();
+    ASSERT(instanceRoot->isSVGElement());
+    associateCorrespondingElements(targetRoot, toSVGElement(*instanceRoot));
+    removeDisallowedElementsFromSubtree(toSVGElement(*instanceRoot));
+    return instanceRoot.release();
+}
+
 void SVGUseElement::buildShadowAndInstanceTree(SVGElement& target)
 {
     ASSERT(!m_targetElementInstance);
     ASSERT(!m_needsShadowTreeRecreation);
 
     // <use> creates a "user agent" shadow root. Do not build the shadow/instance tree for <use>
     // elements living in a user agent shadow tree because they will get expanded in a second
     // pass -- see expandUseElementsInShadowTree().
     if (inUseShadowTree())
         return;
 
     // Do not allow self-referencing.
     if (&target == this || isDisallowedElement(target))
         return;
 
     // Set up root SVG element in shadow tree.
     // Clone the target subtree into the shadow tree, not handling <use> and <symbol> yet.
-    RefPtrWillBeRawPtr<Element> instanceRoot = target.cloneElementWithChildren();
-    ASSERT(instanceRoot->isSVGElement());
-    associateCorrespondingElements(target, toSVGElement(*instanceRoot));
-    removeDisallowedElementsFromSubtree(toSVGElement(*instanceRoot));
-
+    RefPtrWillBeRawPtr<Element> instanceRoot = createInstanceTree(target);
     m_targetElementInstance = toSVGElement(instanceRoot.get());
     ShadowRoot* shadowTreeRootElement = userAgentShadowRoot();
     shadowTreeRootElement->appendChild(instanceRoot.release());
 
     addReferencesToFirstDegreeNestedUseElements(target);
 
     if (instanceTreeIsLoading()) {
         cloneNonMarkupEventListeners();
         return;
     }
@@ skipping 178 matching lines @@
         // Transfer all data (attributes, etc.) from <use> to the new <g> element.
         cloneParent->cloneDataFromElement(*use);
         cloneParent->setCorrespondingElement(&originalUse);
 
         removeAttributesFromReplacementElement(*cloneParent);
 
         // Move already cloned elements to the new <g> element.
         moveChildrenToReplacementElement(*use, *cloneParent);
 
         if (target) {
-            RefPtrWillBeRawPtr<Element> instanceRoot = target->cloneElementWithChildren();
-            ASSERT(instanceRoot->isSVGElement());
-            associateCorrespondingElements(*target, toSVGElement(*instanceRoot));
+            RefPtrWillBeRawPtr<Element> instanceRoot = use->createInstanceTree(*target);
             transferUseWidthAndHeightIfNeeded(*use, toSVGElement(*instanceRoot), *target);
-            removeDisallowedElementsFromSubtree(toSVGElement(*instanceRoot));
             cloneParent->appendChild(instanceRoot.release());
         }
 
         RefPtrWillBeRawPtr<SVGElement> replacingElement(cloneParent.get());
 
         // Replace <use> with referenced content.
         use->parentNode()->replaceChild(cloneParent.release(), use);
 
         use = Traversal<SVGUseElement>::next(*replacingElement, shadowRoot);
     }
@@ skipping 12 matching lines @@
         // 'svg' element will use values of 100% for these attributes.
         SVGElement& originalSymbol = *symbol->correspondingElement();
         RefPtrWillBeRawPtr<SVGSVGElement> svgElement = SVGSVGElement::create(originalSymbol.document());
         // Transfer all data (attributes, etc.) from <symbol> to the new <svg> element.
         svgElement->cloneDataFromElement(*symbol);
         svgElement->setCorrespondingElement(&originalSymbol);
 
         // Move already cloned elements to the new <svg> element.
         moveChildrenToReplacementElement(*symbol, *svgElement);
 
-        removeDisallowedElementsFromSubtree(*svgElement);
-
         RefPtrWillBeRawPtr<SVGElement> replacingElement(svgElement.get());
 
         // Replace <symbol> with <svg>.
         symbol->parentNode()->replaceChild(svgElement.release(), symbol);
 
         symbol = Traversal<SVGSymbolElement>::next(*replacingElement, shadowRoot);
     }
 }
 
 void SVGUseElement::invalidateShadowTree()
@@ skipping 112 matching lines @@
 
     if (m_resource)
         m_resource->removeClient(this);
 
     m_resource = resource;
     if (m_resource)
         m_resource->addClient(this);
 }
 
 } // namespace blink