Stricter treatment of SVGSVGElement::m_useCurrentView

third_party/WebKit/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 81 matching lines @@
 {
     // FIXME: This method doesn't follow the spec and is basically untested. Parent documents are not considered here.
     // As we have no test coverage for this, we're going to disable it completly for now.
     return SVGRectTearOff::create(SVGRect::create(), 0, PropertyIsNotAnimVal);
 }
 
 SVGViewSpec* SVGSVGElement::currentView()
 {
     if (!m_viewSpec)
         m_viewSpec = SVGViewSpec::create(this);
-    return m_viewSpec.get();
+    return m_viewSpec;
 }
 
 float SVGSVGElement::currentScale() const
 {
     if (!isConnected() || !isOutermostSVGSVGElement())
         return 1;
 
     return m_currentScale;
 }
 
@@ skipping 41 matching lines @@
 void SVGSVGElement::updateUserTransform()
 {
     if (LayoutObject* object = layoutObject())
         object->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::Unknown);
 }
 
 bool SVGSVGElement::zoomAndPanEnabled() const
 {
     const SVGZoomAndPan* currentViewSpec = this;
     if (m_useCurrentView)
-        currentViewSpec = m_viewSpec.get();
-    return currentViewSpec && currentViewSpec->zoomAndPan() == SVGZoomAndPanMagnify;
+        currentViewSpec = m_viewSpec;
+    DCHECK(currentViewSpec);
+    return currentViewSpec->zoomAndPan() == SVGZoomAndPanMagnify;
 }
 
 void SVGSVGElement::parseAttribute(const QualifiedName& name, const AtomicString& oldValue, const AtomicString& value)
 {
     if (!nearestViewportElement()) {
         bool setListener = true;
 
         // Only handle events if we're the outermost <svg> element
         if (name == HTMLNames::onunloadAttr) {
             document().setWindowAttributeEventListener(EventTypeNames::unload, createAttributeEventListener(document().frame(), name, value, eventParameterName()));
@@ skipping 385 matching lines @@
 bool SVGSVGElement::selfHasRelativeLengths() const
 {
     return m_x->currentValue()->isRelative()
         || m_y->currentValue()->isRelative()
         || m_width->currentValue()->isRelative()
         || m_height->currentValue()->isRelative();
 }
 
 FloatRect SVGSVGElement::currentViewBoxRect() const
 {
-    if (m_useCurrentView)
-        return m_viewSpec ? m_viewSpec->viewBox()->currentValue()->value() : FloatRect();
+    if (m_useCurrentView) {
+        DCHECK(m_viewSpec);
+        return m_viewSpec->viewBox()->currentValue()->value();
+    }
 
     FloatRect useViewBox = viewBox()->currentValue()->value();
     if (!useViewBox.isEmpty())
         return useViewBox;
     if (!layoutObject() || !layoutObject()->isSVGRoot())
         return FloatRect();
     if (!toLayoutSVGRoot(layoutObject())->isEmbeddedThroughSVGImage())
         return FloatRect();
 
     // If no viewBox is specified but non-relative width/height values, then we
@@ skipping 38 matching lines @@
 {
     if (height()->currentValue()->typeWithCalcResolved() == CSSPrimitiveValue::UnitType::Percentage)
         return 0;
 
     SVGLengthContext lengthContext(this);
     return height()->currentValue()->value(lengthContext);
 }
 
 AffineTransform SVGSVGElement::viewBoxToViewTransform(float viewWidth, float viewHeight) const
 {
-    if (!m_useCurrentView || !m_viewSpec)
+    if (!m_useCurrentView)
         return SVGFitToViewBox::viewBoxToViewTransform(currentViewBoxRect(), preserveAspectRatio()->currentValue(), viewWidth, viewHeight);
+    DCHECK(m_viewSpec);
 
     AffineTransform ctm = SVGFitToViewBox::viewBoxToViewTransform(currentViewBoxRect(), m_viewSpec->preserveAspectRatio()->currentValue(), viewWidth, viewHeight);
     SVGTransformList* transformList = m_viewSpec->transform();
     if (transformList->isEmpty())
         return ctm;
 
     AffineTransform transform;
     if (transformList->concatenate(transform))
         ctm *= transform;
 
     return ctm;
 }
 
 void SVGSVGElement::setupInitialView(const String& fragmentIdentifier, Element* anchorNode)
 {
-    LayoutObject* layoutObject = this->layoutObject();
-    SVGViewSpec* view = m_viewSpec.get();
-    if (view)
-        view->reset();
+    if (m_viewSpec)
+        m_viewSpec->reset();
 
-    bool hadUseCurrentView = m_useCurrentView;
+    // If we previously had a view, we need to layout again, regardless of the
+    // state after setting.
+    bool needsViewUpdate = m_useCurrentView;
     m_useCurrentView = false;
 
     if (fragmentIdentifier.startsWith("svgView(")) {
-        if (!view)
-            view = currentView(); // Create the SVGViewSpec.
+        SVGViewSpec* view = currentView(); // Ensure the SVGViewSpec has been created.
 
         view->inheritViewAttributesFromElement(this);
 
         if (view->parseViewSpec(fragmentIdentifier)) {
             UseCounter::count(document(), UseCounter::SVGSVGElementFragmentSVGView);
             m_useCurrentView = true;
+            needsViewUpdate = true;
         } else {
             view->reset();
         }
-
-        if (layoutObject && (hadUseCurrentView || m_useCurrentView))
-            markForLayoutAndParentResourceInvalidation(layoutObject);
-        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.
-    // TODO(ed): The spec text above is a bit unclear.
-    // Should the transform from outermost svg to nested svg be applied to "display"
-    // the inner svg in the viewport, then let the view element override the inner
-    // svg's view specification attributes. Should it fill/override the outer viewport?
-    if (isSVGViewElement(anchorNode)) {
+    } else if (isSVGViewElement(anchorNode)) {
+        // 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.
+        // TODO(ed): The spec text above is a bit unclear.
+        // Should the transform from outermost svg to nested svg be applied to
+        // "display" the inner svg in the viewport, then let the view element
+        // override the inner svg's view specification attributes. Should it
+        // fill/override the outer viewport?
         SVGViewElement& viewElement = toSVGViewElement(*anchorNode);
 
         if (SVGSVGElement* svg = viewElement.ownerSVGElement()) {
             svg->inheritViewAttributes(&viewElement);
 
             if (LayoutObject* layoutObject = svg->layoutObject())
                 markForLayoutAndParentResourceInvalidation(layoutObject);
 
             return;
         }
     }
 
-    // If we previously had a view and didn't get a new one, we need to
-    // layout again.
-    if (layoutObject && hadUseCurrentView)
+    LayoutObject* layoutObject = this->layoutObject();
+    if (layoutObject && needsViewUpdate)
         markForLayoutAndParentResourceInvalidation(layoutObject);
 
+    // If m_useCurrentView is true we should have a view-spec.
+    DCHECK(!m_useCurrentView || m_viewSpec);
+
     // 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;
     UseCounter::count(document(), UseCounter::SVGSVGElementFragmentSVGViewElement);
     view->inheritViewAttributesFromElement(this);
     view->inheritViewAttributesFromElement(viewElement);
+    DCHECK(!m_useCurrentView || m_viewSpec);
 }
 
 void SVGSVGElement::finishParsingChildren()
 {
     SVGGraphicsElement::finishParsingChildren();
 
     // The outermost SVGSVGElement SVGLoad event is fired through
     // LocalDOMWindow::dispatchWindowLoadEvent.
     if (isOutermostSVGSVGElement())
         return;
@@ skipping 10 matching lines @@
     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