Move toClipPath to SVGGeometryElement.

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 426 matching lines @@
         || isSVGEllipseElement(element)
         || isSVGPolygonElement(element)
         || isSVGPolylineElement(element)
         || isSVGTextElement(element);
 }
 
 void SVGUseElement::toClipPath(Path& path)
 {
     ASSERT(path.isEmpty());
 
-    Node* n = userAgentShadowRoot()->firstChild();
-    if (!n || !n->isSVGElement())
+    const SVGGraphicsElement* element = targetGraphicsElementForClipping();
+
+    if (!element)
         return;
-    SVGElement& element = toSVGElement(*n);
 
-    if (element.isSVGGraphicsElement()) {
-        if (!isDirectReference(element)) {
-            // Spec: Indirect references are an error (14.3.5)
-            document().accessSVGExtensions().reportError("Not allowed to use indirect reference in <clip-path>");
-        } else {
-            toSVGGraphicsElement(element).toClipPath(path);
-            // FIXME: Avoid manual resolution of x/y here. Its potentially harmful.
-            SVGLengthContext lengthContext(this);
-            path.translate(FloatSize(m_x->currentValue()->value(lengthContext), m_y->currentValue()->value(lengthContext)));
-            path.transform(calculateAnimatedLocalTransform());
-        }
+    if (!isDirectReference(*element)) {
+        // Spec: Indirect references are an error (14.3.5)
+        document().accessSVGExtensions().reportError("Not allowed to use indirect reference in <clip-path>");
+    } else if (element->isSVGGeometryElement()) {
+        toSVGGeometryElement(*element).toClipPath(path);
+        // FIXME: Avoid manual resolution of x/y here. Its potentially harmful.
+        SVGLengthContext lengthContext(this);
+        path.translate(FloatSize(m_x->currentValue()->value(lengthContext), m_y->currentValue()->value(lengthContext)));
+        path.transform(calculateAnimatedLocalTransform());
     }
 }
 
-LayoutObject* SVGUseElement::layoutObjectClipChild() const
+SVGGraphicsElement* SVGUseElement::targetGraphicsElementForClipping() const
 {
-    if (Node* n = userAgentShadowRoot()->firstChild()) {
-        if (n->isSVGElement() && isDirectReference(toSVGElement(*n)))
-            return n->layoutObject();
+    Node* n = userAgentShadowRoot()->firstChild();
+    if (!n || !n->isSVGElement())
+        return nullptr;
+
+    SVGElement& element = toSVGElement(*n);
+    if (element.isSVGGraphicsElement()) {
+        if (isSVGTextElement(element) || isSVGTSpanElement(element) || element.isSVGGeometryElement())

[pdr., 2015/06/17 04:42:13]

Lets add a link to the spec here.
// Spec: "If a <use> element is a child of a clipPath element, it must directly
// reference <path>, <text> or basic shapes elements. Indirect references are an
// error and the clipPath element must be ignored."
// http://dev.w3.org/fxtf/css-masking-1/#the-clip-path

Can you also move the isDirectReference check and reportError call here instead
of in toClipPath?

+            return &toSVGGraphicsElement(element);
     }
 
     return nullptr;
 }
 
+LayoutObject* SVGUseElement::layoutObjectClipChild() const

[pdr., 2015/06/17 04:42:13]

This function is pretty simple now, can you move this logic into
LayoutSVGResourceClipper::createContentPicture and remove
SVGUseElement::layoutObjectClipChild?

+{
+    const SVGGraphicsElement* element = targetGraphicsElementForClipping();
+
+    if (!element)
+        return nullptr;
+
+    return element->layoutObject();
+}
+
 bool SVGUseElement::buildShadowTree(SVGElement* target, SVGElement* targetInstance, bool foundUse)
 {
     ASSERT(target);
     ASSERT(targetInstance);
 
     // Spec: If the referenced object is itself a 'use', or if there are 'use' subelements within the referenced
     // object, the instance tree will contain recursive expansion of the indirect references to form a complete tree.
     if (isSVGUseElement(*target)) {
         // We only need to track first degree <use> dependencies. Indirect references are handled
         // as the invalidation bubbles up the dependency chain.
@@ skipping 288 matching lines @@
 
     if (m_resource)
         m_resource->removeClient(this);
 
     m_resource = resource;
     if (m_resource)
         m_resource->addClient(this);
 }
 
 }