C++ SVGUseElement类代码示例

static void updateContainerOffset(SVGElementInstance* targetInstance)
{
    // Depth-first used to write the method in early exit style, no particular other reason.
    for (SVGElementInstance* instance = targetInstance->firstChild(); instance; instance = instance->nextSibling())
        updateContainerOffset(instance);

    SVGElement* correspondingElement = targetInstance->correspondingElement();
    ASSERT(correspondingElement);

    if (!correspondingElement->hasTagName(SVGNames::useTag))
        return;

    SVGElement* shadowTreeElement = targetInstance->shadowTreeElement();
    ASSERT(shadowTreeElement);
    ASSERT(shadowTreeElement->hasTagName(SVGNames::gTag));

    if (!static_cast<SVGGElement*>(shadowTreeElement)->isShadowTreeContainerElement())
        return;

    // Spec: An additional transformation translate(x,y) is appended to the end
    // (i.e., right-side) of the transform attribute on the generated 'g', where x
    // and y represent the values of the x and y attributes on the 'use' element. 
    SVGUseElement* useElement = static_cast<SVGUseElement*>(correspondingElement);
    SVGShadowTreeContainerElement* containerElement = static_cast<SVGShadowTreeContainerElement*>(shadowTreeElement);
    containerElement->setContainerOffset(useElement->x(), useElement->y());
}

void SVGUseElement::expandUseElementsInShadowTree(SVGShadowTreeRootElement* shadowRoot, Node* element)
{
    // Why expand the <use> elements in the shadow tree here, and not just
    // do this directly in buildShadowTree, if we encounter a <use> element?
    //
    // Short answer: Because we may miss to expand some elements. Ie. if a <symbol>
    // contains <use> tags, we'd miss them. So once we're done with settin' up the
    // actual shadow tree (after the special case modification for svg/symbol) we have
    // to walk it completely and expand all <use> elements.
    if (element->hasTagName(SVGNames::useTag)) {
        SVGUseElement* use = static_cast<SVGUseElement*>(element);

        String id = SVGURIReference::getTarget(use->href());
        Element* targetElement = document()->getElementById(id); 
        SVGElement* target = 0;
        if (targetElement && targetElement->isSVGElement())
            target = static_cast<SVGElement*>(targetElement);

        // Don't ASSERT(target) here, it may be "pending", too.
        // Setup sub-shadow tree root node
        RefPtr<SVGShadowTreeContainerElement> cloneParent = new SVGShadowTreeContainerElement(document());

        // 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());

        ExceptionCode ec = 0;
        if (target && !isDisallowedElement(target)) {
            RefPtr<Element> newChild = target->cloneElementWithChildren();

            // 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(newChild.get()))
                removeDisallowedElementsFromSubtree(newChild.get());

            SVGElement* newChildPtr = 0;
            if (newChild->isSVGElement())
                newChildPtr = static_cast<SVGElement*>(newChild.get());
            ASSERT(newChildPtr);

            cloneParent->appendChild(newChild.release(), ec);
            ASSERT(!ec);
        }

        // Replace <use> with referenced content.
        ASSERT(use->parentNode()); 
        use->parentNode()->replaceChild(cloneParent.release(), use, ec);
        ASSERT(!ec);

        // Immediately stop here, and restart expanding.
        expandUseElementsInShadowTree(shadowRoot, shadowRoot);
        return;
    }

    for (RefPtr<Node> child = element->firstChild(); child; child = child->nextSibling())
        expandUseElementsInShadowTree(shadowRoot, child.get());
}

String SVGStyledElement::title() const
{
    // According to spec, we should not return titles when hovering over root <svg> elements (those
    // <title> elements are the title of the document, not a tooltip) so we instantly return.
    if (isOutermostSVGSVGElement())
        return String();

    // Walk up the tree, to find out whether we're inside a <use> shadow tree, to find the right title.
    if (isInShadowTree()) {
        SVGUseElement* useElement = static_cast<SVGUseElement*>(treeScope()->rootNode()->shadowHost());
        ASSERT(useElement);

        // If the <use> title is not empty we found the title to use.
        String useTitle(useElement->title());
        if (!useTitle.isEmpty())
            return useTitle;
    }

    // If we aren't an instance in a <use> or the <use> title was not found, then find the first
    // <title> child of this element.
    Element* titleElement = firstElementChild();
    for (; titleElement; titleElement = titleElement->nextElementSibling()) {
        if (titleElement->hasTagName(SVGNames::titleTag) && titleElement->isSVGElement())
            break;
    }

    // If a title child was found, return the text contents.
    if (titleElement)
        return titleElement->innerText();
    
    // Otherwise return a null/empty string.
    return String();
}

inline EventTarget& eventTargetRespectingTargetRules(Node& referenceNode)
{
    if (referenceNode.isPseudoElement()) {
        EventTarget* hostElement = toPseudoElement(referenceNode).hostElement();
        ASSERT(hostElement);
        return *hostElement;
    }

#if ENABLE(SVG)
    if (!referenceNode.isSVGElement() || !referenceNode.isInShadowTree())
        return referenceNode;

    // Spec: The event handling for the non-exposed tree works as if the referenced element had been textually included
    // as a deeply cloned child of the 'use' element, except that events are dispatched to the SVGElementInstance objects
    Node* rootNode = referenceNode.treeScope().rootNode();
    Element* shadowHostElement = rootNode->isShadowRoot() ? toShadowRoot(rootNode)->hostElement() : 0;
    // At this time, SVG nodes are not supported in non-<use> shadow trees.
    if (!shadowHostElement || !shadowHostElement->hasTagName(SVGNames::useTag))
        return referenceNode;
    SVGUseElement* useElement = toSVGUseElement(shadowHostElement);
    if (SVGElementInstance* instance = useElement->instanceForShadowTreeElement(&referenceNode))
        return *instance;
#endif

    return referenceNode;
}

bool RenderSVGTransformableContainer::calculateLocalTransform()
{
    SVGGraphicsElement& element = graphicsElement();

    // If we're either the renderer for a <use> element, or for any <g> element inside the shadow
    // tree, that was created during the use/symbol/svg expansion in SVGUseElement. These containers
    // need to respect the translations induced by their corresponding use elements x/y attributes.
    SVGUseElement* useElement = nullptr;
    if (is<SVGUseElement>(element))
        useElement = &downcast<SVGUseElement>(element);
    else if (element.isInShadowTree() && is<SVGGElement>(element)) {
        SVGElement* correspondingElement = element.correspondingElement();
        if (is<SVGUseElement>(correspondingElement))
            useElement = downcast<SVGUseElement>(correspondingElement);
    }

    if (useElement) {
        SVGLengthContext lengthContext(useElement);
        FloatSize translation(useElement->x().value(lengthContext), useElement->y().value(lengthContext));
        if (translation != m_lastTranslation)
            m_needsTransformUpdate = true;
        m_lastTranslation = translation;
    }

    m_didTransformToRootUpdate = m_needsTransformUpdate || SVGRenderSupport::transformToRootChanged(parent());
    if (!m_needsTransformUpdate)
        return false;

    m_localTransform = element.animatedLocalTransform();
    m_localTransform.translate(m_lastTranslation.width(), m_lastTranslation.height());
    m_needsTransformUpdate = false;
    return true;
}

void RenderSVGViewportContainer::calcViewport()
{
    SVGSVGElement& svg = svgSVGElement();
    FloatRect oldViewport = m_viewport;

    SVGLengthContext lengthContext(&svg);
    m_viewport = FloatRect(svg.x().value(lengthContext), svg.y().value(lengthContext), svg.width().value(lengthContext), svg.height().value(lengthContext));

    SVGElement* correspondingElement = svg.correspondingElement();
    if (correspondingElement && svg.isInShadowTree()) {
        const HashSet<SVGElementInstance*>& instances = correspondingElement->instancesForElement();
        ASSERT(!instances.isEmpty());

        SVGUseElement* useElement = 0;
        const HashSet<SVGElementInstance*>::const_iterator end = instances.end();
        for (HashSet<SVGElementInstance*>::const_iterator it = instances.begin(); it != end; ++it) {
            const SVGElementInstance* instance = (*it);
            ASSERT(instance->correspondingElement()->hasTagName(SVGNames::svgTag) || instance->correspondingElement()->hasTagName(SVGNames::symbolTag));
            if (instance->shadowTreeElement() == &svg) {
                ASSERT(correspondingElement == instance->correspondingElement());
                useElement = instance->directUseElement();
                if (!useElement)
                    useElement = instance->correspondingUseElement();
                break;
            }
        }

        ASSERT(useElement);
        bool isSymbolElement = correspondingElement->hasTagName(SVGNames::symbolTag);

        // 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.

        // 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.

        SVGLengthContext lengthContext(&svg);
        if (useElement->hasAttribute(SVGNames::widthAttr))
            m_viewport.setWidth(useElement->width().value(lengthContext));
        else if (isSymbolElement && svg.hasAttribute(SVGNames::widthAttr)) {
            SVGLength containerWidth(LengthModeWidth, "100%");
            m_viewport.setWidth(containerWidth.value(lengthContext));
        }

        if (useElement->hasAttribute(SVGNames::heightAttr))
            m_viewport.setHeight(useElement->height().value(lengthContext));
        else if (isSymbolElement && svg.hasAttribute(SVGNames::heightAttr)) {
            SVGLength containerHeight(LengthModeHeight, "100%");
            m_viewport.setHeight(containerHeight.value(lengthContext));
        }
    }

    if (oldViewport != m_viewport) {
        setNeedsBoundariesUpdate();
        setNeedsTransformUpdate();
    }
}

PassRefPtr<DisplayList> RenderSVGResourceClipper::asDisplayList(GraphicsContext* context,
    const AffineTransform& contentTransformation)
{
    ASSERT(context);
    ASSERT(frame());

    context->beginRecording(repaintRectInLocalCoordinates());

    // Switch to a paint behavior where all children of this <clipPath> will be rendered using special constraints:
    // - fill-opacity/stroke-opacity/opacity set to 1
    // - masker/filter not applied when rendering the children
    // - fill is set to the initial fill paint server (solid, black)
    // - stroke is set to the initial stroke paint server (none)
    PaintBehavior oldBehavior = frame()->view()->paintBehavior();
    frame()->view()->setPaintBehavior(oldBehavior | PaintBehaviorRenderingSVGMask);

    for (Node* childNode = element()->firstChild(); childNode; childNode = childNode->nextSibling()) {
        RenderObject* renderer = childNode->renderer();
        if (!childNode->isSVGElement() || !renderer)
            continue;

        RenderStyle* style = renderer->style();
        if (!style || style->display() == NONE || style->visibility() != VISIBLE)
            continue;

        WindRule newClipRule = style->svgStyle()->clipRule();
        bool isUseElement = childNode->hasTagName(SVGNames::useTag);
        if (isUseElement) {
            SVGUseElement* useElement = toSVGUseElement(childNode);
            renderer = useElement->rendererClipChild();
            if (!renderer)
                continue;
            if (!useElement->hasAttribute(SVGNames::clip_ruleAttr))
                newClipRule = renderer->style()->svgStyle()->clipRule();
        }

        // Only shapes, paths and texts are allowed for clipping.
        if (!renderer->isSVGShape() && !renderer->isSVGText())
            continue;

        context->setFillRule(newClipRule);

        if (isUseElement)
            renderer = childNode->renderer();

        SVGRenderingContext::renderSubtree(context, renderer, contentTransformation);
    }

    frame()->view()->setPaintBehavior(oldBehavior);

    return context->endRecording();
}

static void dumpInstanceTree(unsigned int& depth, String& text, SVGElementInstance* targetInstance)
{
    SVGElement* element = targetInstance->correspondingElement();
    ASSERT(element);

    if (element->hasTagName(SVGNames::useTag)) {
        if (toSVGUseElement(element)->cachedDocumentIsStillLoading())
            return;
    }

    SVGElement* shadowTreeElement = targetInstance->shadowTreeElement();
    ASSERT(shadowTreeElement);

    SVGUseElement* directUseElement = targetInstance->directUseElement();
    String directUseElementName = directUseElement ? directUseElement->nodeName() : "null";

    String elementId = element->getIdAttribute();
    String elementNodeName = element->nodeName();
    String shadowTreeElementNodeName = shadowTreeElement->nodeName();
    String parentNodeName = element->parentNode() ? element->parentNode()->nodeName() : "null";
    String firstChildNodeName = element->firstChild() ? element->firstChild()->nodeName() : "null";

    for (unsigned int i = 0; i < depth; ++i)
        text += "  ";

    text += String::format("SVGElementInstance this=%p, (parentNode=%s (%p), firstChild=%s (%p), correspondingElement=%s (%p), directUseElement=%s (%p), shadowTreeElement=%s (%p), id=%s)\n",
                           targetInstance, parentNodeName.latin1().data(), element->parentNode(), firstChildNodeName.latin1().data(), element->firstChild(),
                           elementNodeName.latin1().data(), element, directUseElementName.latin1().data(), directUseElement, shadowTreeElementNodeName.latin1().data(), shadowTreeElement, elementId.latin1().data());

    for (unsigned int i = 0; i < depth; ++i)
        text += "  ";

    const HashSet<SVGElementInstance*>& elementInstances = element->instancesForElement();
    text += "Corresponding element is associated with " + String::number(elementInstances.size()) + " instance(s):\n";

    const HashSet<SVGElementInstance*>::const_iterator end = elementInstances.end();
    for (HashSet<SVGElementInstance*>::const_iterator it = elementInstances.begin(); it != end; ++it) {
        for (unsigned int i = 0; i < depth; ++i)
            text += "  ";

        text += String::format(" -> SVGElementInstance this=%p, (refCount: %i, shadowTreeElement in document? %i)\n",
                               *it, (*it)->refCount(), (*it)->shadowTreeElement()->inDocument());
    }

    ++depth;

    for (SVGElementInstance* instance = targetInstance->firstChild(); instance; instance = instance->nextSibling())
        dumpInstanceTree(depth, text, instance);

    --depth;
}

String SVGStyledElement::title() const
{
    // According to spec, we should not return titles when hovering over root <svg> elements (those
    // <title> elements are the title of the document, not a tooltip) so we instantly return.
    if (hasTagName(SVGNames::svgTag)) {
        const SVGSVGElement* svg = static_cast<const SVGSVGElement*>(this);
        if (svg->isOutermostSVG())
            return String();
    }
    
    // Walk up the tree, to find out whether we're inside a <use> shadow tree, to find the right title.
    Node* parent = const_cast<SVGStyledElement*>(this);
    while (parent) {
        if (!parent->isSVGShadowRoot()) {
            parent = parent->parentNodeGuaranteedHostFree();
            continue;
        }
        
        // Get the <use> element.
        Element* shadowParent = parent->svgShadowHost();
        if (shadowParent && shadowParent->isSVGElement() && shadowParent->hasTagName(SVGNames::useTag)) {
            SVGUseElement* useElement = static_cast<SVGUseElement*>(shadowParent);
            // If the <use> title is not empty we found the title to use.
            String useTitle(useElement->title());
            if (useTitle.isEmpty())
                break;
            return useTitle;
        }
        parent = parent->parentNode();
    }
    
    // If we aren't an instance in a <use> or the <use> title was not found, then find the first
    // <title> child of this element.
    Element* titleElement = firstElementChild();
    for (; titleElement; titleElement = titleElement->nextElementSibling()) {
        if (titleElement->hasTagName(SVGNames::titleTag) && titleElement->isSVGElement())
            break;
    }

    // If a title child was found, return the text contents.
    if (titleElement)
        return titleElement->innerText();
    
    // Otherwise return a null/empty string.
    return String();
}

void JSSVGUseElement::putValueProperty(ExecState* exec, int token, JSValue* value, int /*attr*/)
{
    switch (token) {
    case XmllangAttrNum: {
        SVGUseElement* imp = static_cast<SVGUseElement*>(impl());

        imp->setXmllang(value->toString(exec));
        break;
    }
    case XmlspaceAttrNum: {
        SVGUseElement* imp = static_cast<SVGUseElement*>(impl());

        imp->setXmlspace(value->toString(exec));
        break;
    }
    }
}

void RenderSVGShadowTreeRootContainer::updateFromElement()
{
    bool hadExistingTree = m_shadowRoot;

    SVGUseElement* useElement = static_cast<SVGUseElement*>(node());
    if (!m_shadowRoot) {
        ASSERT(!m_recreateTree);
        m_shadowRoot = new SVGShadowTreeRootElement(document(), useElement);
        useElement->buildPendingResource();
    }

    ASSERT(m_shadowRoot->shadowParentNode() == useElement);

    bool shouldRecreateTree = m_recreateTree;
    if (m_recreateTree) {
        ASSERT(hadExistingTree);

        if (m_shadowRoot->attached())
            m_shadowRoot->detach();

        m_shadowRoot->removeAllChildren();
        m_recreateTree = false;
    }

    // Only rebuild the shadow tree, if we a) never had a tree or b) we were specifically asked to do so
    // If the use element is a pending resource, and a) or b) is true, do nothing, and wait for the use
    // element to be asked to buildPendingResource(), this will call us again, with m_recreateTrue=true.
    if ((shouldRecreateTree || !hadExistingTree) && !useElement->isPendingResource()) {
        useElement->buildShadowAndInstanceTree(m_shadowRoot.get());

        // Attach shadow root element
        m_shadowRoot->attachElement(style(), renderArena());

        // Attach subtree, as if it was a regular non-shadow tree
        for (Node* child = m_shadowRoot->firstChild(); child; child = child->nextSibling())
            child->attach();
    }

    ASSERT(!m_recreateTree);
    RenderSVGTransformableContainer::updateFromElement();
}

inline static EventTarget* eventTargetRespectingSVGTargetRules(Node* referenceNode)
{
    ASSERT(referenceNode);

#if ENABLE(SVG)
    if (!referenceNode->isSVGElement() || !referenceNode->isInShadowTree())
        return referenceNode;

    // Spec: The event handling for the non-exposed tree works as if the referenced element had been textually included
    // as a deeply cloned child of the 'use' element, except that events are dispatched to the SVGElementInstance objects
    Element* shadowHostElement = toShadowRoot(referenceNode->treeScope()->rootNode())->host();
    // At this time, SVG nodes are not supported in non-<use> shadow trees.
    if (!shadowHostElement || !shadowHostElement->hasTagName(SVGNames::useTag))
        return referenceNode;
    SVGUseElement* useElement = static_cast<SVGUseElement*>(shadowHostElement);
    if (SVGElementInstance* instance = useElement->instanceForShadowTreeElement(referenceNode))
        return instance;
#endif

    return referenceNode;
}

String SVGElement::title() const
{
    // According to spec, we should not return titles when hovering over root <svg> elements (those
    // <title> elements are the title of the document, not a tooltip) so we instantly return.
    if (isOutermostSVGSVGElement())
        return String();

    // Walk up the tree, to find out whether we're inside a <use> shadow tree, to find the right title.
    if (isInShadowTree()) {
        Element* shadowHostElement = toShadowRoot(treeScope().rootNode()).host();
        // At this time, SVG nodes are not allowed in non-<use> shadow trees, so any shadow root we do
        // have should be a use. The assert and following test is here to catch future shadow DOM changes
        // that do enable SVG in a shadow tree.
        ASSERT(!shadowHostElement || shadowHostElement->hasTagName(SVGNames::useTag));
        if (shadowHostElement && shadowHostElement->hasTagName(SVGNames::useTag)) {
            SVGUseElement* useElement = toSVGUseElement(shadowHostElement);

            // If the <use> title is not empty we found the title to use.
            String useTitle(useElement->title());
            if (!useTitle.isEmpty())
                return useTitle;
        }
    }

    // If we aren't an instance in a <use> or the <use> title was not found, then find the first
    // <title> child of this element.
    Element* titleElement = ElementTraversal::firstWithin(*this);
    for (; titleElement; titleElement = ElementTraversal::nextSkippingChildren(*titleElement, this)) {
        if (titleElement->hasTagName(SVGNames::titleTag) && titleElement->isSVGElement())
            break;
    }

    // If a title child was found, return the text contents.
    if (titleElement)
        return titleElement->innerText();

    // Otherwise return a null/empty string.
    return String();
}

void SVGUseElement::expandUseElementsInShadowTree(Node* element)
{
    // Why expand the <use> elements in the shadow tree here, and not just
    // do this directly in buildShadowTree, if we encounter a <use> element?
    //
    // Short answer: Because we may miss to expand some elements. Ie. if a <symbol>
    // contains <use> tags, we'd miss them. So once we're done with settin' up the
    // actual shadow tree (after the special case modification for svg/symbol) we have
    // to walk it completely and expand all <use> elements.
    if (element->hasTagName(SVGNames::useTag)) {
        SVGUseElement* use = toSVGUseElement(element);
        ASSERT(!use->cachedDocumentIsStillLoading());

        ASSERT(referencedDocument());
        Element* targetElement = SVGURIReference::targetElementFromIRIString(use->href(), *referencedDocument());
        SVGElement* target = 0;
        if (targetElement && targetElement->isSVGElement())
            target = toSVGElement(targetElement);

        // Don't ASSERT(target) here, it may be "pending", too.
        // Setup sub-shadow tree root node
        RefPtr<SVGGElement> cloneParent = SVGGElement::create(SVGNames::gTag, *referencedDocument());
        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());
            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))
            removeDisallowedElementsFromSubtree(*cloneParent);

        RefPtr<Node> replacingElement(cloneParent.get());

        // Replace <use> with referenced content.
        ASSERT(use->parentNode());
        use->parentNode()->replaceChild(cloneParent.release(), use);

        // Expand the siblings because the *element* is replaced and we will
        // lose the sibling chain when we are back from recursion.
        element = replacingElement.get();
        for (RefPtr<Node> sibling = element->nextSibling(); sibling; sibling = sibling->nextSibling())
            expandUseElementsInShadowTree(sibling.get());
    }

    for (RefPtr<Node> child = element->firstChild(); child; child = child->nextSibling())
        expandUseElementsInShadowTree(child.get());
}

bool LayoutSVGTransformableContainer::calculateLocalTransform()
{
    SVGGraphicsElement* element = toSVGGraphicsElement(this->element());
    ASSERT(element);

    // If we're either the layoutObject for a <use> element, or for any <g> element inside the shadow
    // tree, that was created during the use/symbol/svg expansion in SVGUseElement. These containers
    // need to respect the translations induced by their corresponding use elements x/y attributes.
    SVGUseElement* useElement = nullptr;
    if (isSVGUseElement(*element)) {
        useElement = toSVGUseElement(element);
    } else if (isSVGGElement(*element) && toSVGGElement(element)->inUseShadowTree()) {
        SVGElement* correspondingElement = element->correspondingElement();
        if (isSVGUseElement(correspondingElement))
            useElement = toSVGUseElement(correspondingElement);
    }

    if (useElement) {
        SVGLengthContext lengthContext(useElement);
        FloatSize translation(
            useElement->x()->currentValue()->value(lengthContext),
            useElement->y()->currentValue()->value(lengthContext));
        if (translation != m_additionalTranslation)
            m_needsTransformUpdate = true;
        m_additionalTranslation = translation;
    }

    m_didTransformToRootUpdate = m_needsTransformUpdate || SVGLayoutSupport::transformToRootChanged(parent());
    if (!m_needsTransformUpdate)
        return false;

    m_localTransform = element->calculateAnimatedLocalTransform();
    m_localTransform.translate(m_additionalTranslation.width(), m_additionalTranslation.height());
    m_needsTransformUpdate = false;
    return true;
}