Avoid using SVGElementInstance in calcViewport

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 176 matching lines @@
     if (m_resource && m_resource->isLoaded()) {
         // Gracefully handle error condition.
         if (m_resource->errorOccurred())
             return 0;
         ASSERT(m_resource->document());
         return m_resource->document();
     }
     return 0;
 }
 
+inline void transferUseWidthAndHeightIfNeeded(const SVGUseElement& use, SVGElement* shadowElement, SVGElement* originalElement)

[pdr., 2014/05/02 23:03:51]

I still don't understand why this is inline.

[pdr., 2014/05/02 23:03:51]

Nit: can originalElement be a const reference?

+{
+    ASSERT(shadowElement);
+    ASSERT(originalElement);
+    if (isSVGSymbolElement(*shadowElement)) {
+        // Spec (<use> on <symbol>): This generated 'svg' will always have explicit values for attributes width and height.
+        // If attributes width and/or height are provided on the 'use' element, then these attributes
+        // will be transferred to the generated 'svg'. If attributes width and/or height are not specified,
+        // the generated 'svg' element will use values of 100% for these attributes.
+        shadowElement->setAttribute(SVGNames::widthAttr, use.width()->isSpecified() ? AtomicString(use.width()->currentValue()->valueAsString()) : "100%");
+        shadowElement->setAttribute(SVGNames::heightAttr, use.height()->isSpecified() ? AtomicString(use.height()->currentValue()->valueAsString()) : "100%");
+    } else if (isSVGSVGElement(*shadowElement)) {
+        // Spec (<use> on <svg>): If attributes width and/or height are provided on the 'use' element, then these
+        // values will override the corresponding attributes on the 'svg' in the generated tree.
+        if (use.width()->isSpecified())
+            shadowElement->setAttribute(SVGNames::widthAttr, AtomicString(use.width()->currentValue()->valueAsString()));
+        else
+            shadowElement->setAttribute(SVGNames::widthAttr, originalElement->getAttribute(SVGNames::widthAttr));
+        if (use.height()->isSpecified())
+            shadowElement->setAttribute(SVGNames::heightAttr, AtomicString(use.height()->currentValue()->valueAsString()));
+        else
+            shadowElement->setAttribute(SVGNames::heightAttr, originalElement->getAttribute(SVGNames::heightAttr));
+    }
+}
+
 void SVGUseElement::svgAttributeChanged(const QualifiedName& attrName)
 {
     if (!isSupportedAttribute(attrName)) {
         SVGGraphicsElement::svgAttributeChanged(attrName);
         return;
     }
 
     SVGElementInstance::InvalidationGuard invalidationGuard(this);
 
     RenderObject* renderer = this->renderer();
     if (attrName == SVGNames::xAttr
         || attrName == SVGNames::yAttr
         || attrName == SVGNames::widthAttr
         || attrName == SVGNames::heightAttr) {
         updateRelativeLengthsInformation();
+        if (m_targetElementInstance)
+            transferUseWidthAndHeightIfNeeded(*this, m_targetElementInstance->shadowTreeElement(), m_targetElementInstance->correspondingElement());
         if (renderer)
             RenderSVGResource::markForLayoutAndParentResourceInvalidation(renderer);
         return;
     }
 
     if (SVGURIReference::isKnownAttribute(attrName)) {
         bool isExternalReference = isExternalURIReference(hrefString(), document());
         if (isExternalReference) {
             KURL url = document().completeURL(hrefString());
             if (url.hasFragmentIdentifier()) {
@@ skipping 238 matching lines @@
     expandUseElementsInShadowTree(shadowTreeRootElement);
 
     // Expand all <symbol> elements in the shadow tree.
     // Expand means: replace the actual <symbol> element by the <svg> element.
     expandSymbolElementsInShadowTree(shadowTreeRootElement);
 
     // Now that the shadow tree is completly expanded, we can associate
     // shadow tree elements <-> instances in the instance tree.
     associateInstancesWithShadowTreeElements(shadowTreeRootElement->firstChild(), m_targetElementInstance.get());
 
+    transferUseWidthAndHeightIfNeeded(*this, m_targetElementInstance->shadowTreeElement(), m_targetElementInstance->correspondingElement());
+
     // If no shadow tree element is present, this means that the reference root
     // element was removed, as it is disallowed (ie. <use> on <foreignObject>)
     // Do NOT leave an inconsistent instance tree around, instead destruct it.
     if (!m_targetElementInstance->shadowTreeElement()) {
         clearResourceReferences();
         return;
     }
 
     ASSERT(m_targetElementInstance->shadowTreeElement()->parentNode() == shadowTreeRootElement);
 
@@ skipping 215 matching lines @@
         RefPtr<SVGGElement> cloneParent = SVGGElement::create(referencedScope()->document());
         use->cloneChildNodes(cloneParent.get());
 
         // Spec: In the generated content, the 'use' will be replaced by 'g', where all attributes from the
         // 'use' element except for x, y, width, height and xlink:href are transferred to the generated 'g' element.
         transferUseAttributesToReplacedElement(use, cloneParent.get());
 
         if (target && !isDisallowedElement(target)) {
             RefPtr<Element> newChild = target->cloneElementWithChildren();
             ASSERT(newChild->isSVGElement());
+            transferUseWidthAndHeightIfNeeded(*use, toSVGElement(newChild.get()), target);
             cloneParent->appendChild(newChild.release());
         }
 
         // We don't walk the target tree element-by-element, and clone each element,
         // but instead use cloneElementWithChildren(). This is an optimization for the common
         // case where <use> doesn't contain disallowed elements (ie. <foreignObject>).
         // Though if there are disallowed elements in the subtree, we have to remove them.
         // For instance: <use> on <g> containing <foreignObject> (indirect case).
         if (subtreeContainsDisallowedElement(cloneParent.get()))
             removeDisallowedElementsFromSubtree(*cloneParent);
@@ skipping 250 matching lines @@
 
     if (m_resource)
         m_resource->removeClient(this);
 
     m_resource = resource;
     if (m_resource)
         m_resource->addClient(this);
 }
 
 }