[svg] Make svgView override existing data selectively

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.
  * Copyright (C) 2014 Google, Inc.
  *
  * 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 695 matching lines @@
         // FIXME: XPointer references are ignored (https://bugs.webkit.org/show_bug.cgi?id=17491)
         if (renderer && hadUseCurrentView)
             markForLayoutAndParentResourceInvalidation(renderer);
         return;
     }
 
     if (fragmentIdentifier.startsWith("svgView(")) {
         if (!view)
             view = currentView(); // Create the SVGViewSpec.
 
+        view->inheritViewAttributesFromElement(this);
+
         if (view->parseViewSpec(fragmentIdentifier))
             m_useCurrentView = true;
         else
             view->reset();
 
         if (renderer && (hadUseCurrentView || m_useCurrentView))
             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 (isSVGViewElement(anchorNode)) {
         SVGViewElement& viewElement = toSVGViewElement(*anchorNode);
 
         if (SVGSVGElement* svg = viewElement.ownerSVGElement()) {
-            svg->inheritViewAttributes(&viewElement);
+            if (!view)
+                view = currentView();
+            m_useCurrentView = true;

[fs, 2015/03/19 10:16:30]

Maybe we should tread more carefully here, since viewElement.ownerSVGElement()
is not actually guaranteed to return 'this'.

+
+            view->inheritViewAttributesFromElement(svg);
+            view->inheritViewAttributesFromElement(&viewElement);
 
             if (LayoutObject* renderer = svg->layoutObject())
                 markForLayoutAndParentResourceInvalidation(renderer);
 
             return;
         }
     }
 
     // If we previously had a view and didn't get a new one, we need to
     // layout again.
     if (renderer && hadUseCurrentView)
         markForLayoutAndParentResourceInvalidation(renderer);
 
     // 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;
-
-    if (viewElement->hasAttribute(SVGNames::viewBoxAttr))
-        view->viewBox()->baseValue()->setValue(viewElement->viewBox()->currentValue()->value());
-    else
-        view->viewBox()->baseValue()->setValue(viewBox()->currentValue()->value());
-
-    if (viewElement->hasAttribute(SVGNames::preserveAspectRatioAttr)) {
-        view->preserveAspectRatio()->baseValue()->setAlign(viewElement->preserveAspectRatio()->currentValue()->align());
-        view->preserveAspectRatio()->baseValue()->setMeetOrSlice(viewElement->preserveAspectRatio()->currentValue()->meetOrSlice());
-    } else {
-        view->preserveAspectRatio()->baseValue()->setAlign(preserveAspectRatio()->currentValue()->align());
-        view->preserveAspectRatio()->baseValue()->setMeetOrSlice(preserveAspectRatio()->currentValue()->meetOrSlice());
-    }
-
-    if (viewElement->hasAttribute(SVGNames::zoomAndPanAttr))
-        view->setZoomAndPan(viewElement->zoomAndPan());
-    else
-        view->setZoomAndPan(zoomAndPan());
-}
-
 void SVGSVGElement::finishParsingChildren()
 {
     SVGGraphicsElement::finishParsingChildren();
 
     // The outermost SVGSVGElement SVGLoad event is fired through Document::dispatchWindowLoadEvent.
     if (isOutermostSVGSVGElement())
         return;
 
     // finishParsingChildren() is called when the close tag is reached for an element (e.g. </svg>)
     // we send SVGLoad events here if we can, otherwise they'll be sent when any required loads finish
     sendSVGLoadEventIfPossible();
 }
 
 DEFINE_TRACE(SVGSVGElement)
 {
     visitor->trace(m_x);
     visitor->trace(m_y);
     visitor->trace(m_width);
     visitor->trace(m_height);
     visitor->trace(m_translation);
     visitor->trace(m_timeContainer);
     visitor->trace(m_viewSpec);
     SVGGraphicsElement::trace(visitor);
     SVGFitToViewBox::trace(visitor);
 }
 
 } // namespace blink