svguseelement.cpp

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}

#if ENABLE(SVG) && ENABLE(SVG_USE)
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 = 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.
        if (target) {
            // Setup sub-shadow tree root node
            RefPtr<SVGElement> cloneParent = new SVGGElement(SVGNames::gTag, 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());

            // 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.
            if (use->x().value(this) != 0.0 || use->y().value(this) != 0.0) {
                if (!cloneParent->hasAttribute(SVGNames::transformAttr)) {
                    String transformString = String::format("translate(%f, %f)", use->x().value(this), use->y().value(this));
                    cloneParent->setAttribute(SVGNames::transformAttr, transformString);
                } else {
                    String transformString = String::format(" translate(%f, %f)", use->x().value(this), use->y().value(this));
                    const AtomicString& transformAttribute = cloneParent->getAttribute(SVGNames::transformAttr);
                    cloneParent->setAttribute(SVGNames::transformAttr, transformAttribute + transformString); 
                }
            }

            ExceptionCode ec = 0;
 
            // For instance <use> on <foreignObject> (direct case).
            if (isDisallowedElement(target)) {
                // We still have to setup the <use> replacment (<g>). Otherwhise
                // associateInstancesWithShadowTreeElements() makes wrong assumptions.
                // Replace <use> with referenced content.
                ASSERT(use->parentNode()); 
                use->parentNode()->replaceChild(cloneParent.release(), use, ec);
                ASSERT(ec == 0);
                return;
            }

            RefPtr<Node> newChild = target->cloneNode(true);

            // We don't walk the target tree element-by-element, and clone each element,
            // but instead use cloneNode(deep=true). 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 == 0);

            // Replace <use> with referenced content.
            ASSERT(use->parentNode()); 
            use->parentNode()->replaceChild(cloneParent.release(), use, ec);
            ASSERT(ec == 0);

            // Handle use referencing <svg> special case
            if (target->hasTagName(SVGNames::svgTag))
                alterShadowTreeForSVGTag(newChildPtr);

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

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

void SVGUseElement::expandSymbolElementsInShadowTree(Node* element)
{
    if (element->hasTagName(SVGNames::symbolTag)) {
        // Spec: The referenced 'symbol' and its contents are deep-cloned into the generated tree,
        // with the exception that the 'symbol' is replaced by an 'svg'. 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.
        RefPtr<SVGSVGElement> svgElement = new SVGSVGElement(SVGNames::svgTag, document());

        // Transfer all attributes from <symbol> to the new <svg> element
        svgElement->attributes()->setAttributes(*element->attributes());

        // Explicitly re-set width/height values
        String widthString = String::number(width().value(this));
        String heightString = String::number(height().value(this)); 

        svgElement->setAttribute(SVGNames::widthAttr, hasAttribute(SVGNames::widthAttr) ? widthString : "100%");
        svgElement->setAttribute(SVGNames::heightAttr, hasAttribute(SVGNames::heightAttr) ? heightString : "100%");

        ExceptionCode ec = 0;

        // Only clone symbol children, and add them to the new <svg> element    
        for (Node* child = element->firstChild(); child; child = child->nextSibling()) {
            RefPtr<Node> newChild = child->cloneNode(true);
            svgElement->appendChild(newChild.release(), ec);
            ASSERT(ec == 0);
        }
    
        // We don't walk the target tree element-by-element, and clone each element,
        // but instead use cloneNode(deep=true). 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(svgElement.get()))
            removeDisallowedElementsFromSubtree(svgElement.get());

        // Replace <symbol> with <svg>.
        ASSERT(element->parentNode()); 
        element->parentNode()->replaceChild(svgElement.release(), element, ec);
        ASSERT(ec == 0);

        // Immediately stop here, and restart expanding.
        expandSymbolElementsInShadowTree(m_shadowTreeRootElement.get());
        return;
    }

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

#endif
    
void SVGUseElement::attachShadowTree()
{
    if (!m_shadowTreeRootElement || m_shadowTreeRootElement->attached() || !document()->shouldCreateRenderers() || !attached() || !renderer())
        return;

    // Inspired by RenderTextControl::createSubtreeIfNeeded(). 
    if (renderer()->canHaveChildren() && childShouldCreateRenderer(m_shadowTreeRootElement.get())) {
        RefPtr<RenderStyle> style = m_shadowTreeRootElement->styleForRenderer();

        if (m_shadowTreeRootElement->rendererIsNeeded(style.get())) {
            m_shadowTreeRootElement->setRenderer(m_shadowTreeRootElement->createRenderer(document()->renderArena(), style.get()));
            if (RenderObject* shadowRenderer = m_shadowTreeRootElement->renderer()) {
                shadowRenderer->setStyle(style.release());
                renderer()->addChild(shadowRenderer, m_shadowTreeRootElement->nextRenderer());
                m_shadowTreeRootElement->setAttached();
            }
        }

        // This will take care of attaching all shadow tree child nodes.
        for (Node* child = m_shadowTreeRootElement->firstChild(); child; child = child->nextSibling())
            child->attach();
    }
}
 
void SVGUseElement::transferEventListenersToShadowTree(SVGElementInstance* target)
{
    if (!target)
        return;

    SVGElement* originalElement = target->correspondingElement();
    ASSERT(originalElement);

    if (SVGElement* shadowTreeElement = target->shadowTreeElement()) {
        const RegisteredEventListenerVector& listeners = originalElement->eventListeners();
        size_t size = listeners.size();
        for (size_t i = 0; i < size; ++i) {
            const RegisteredEventListener& r = *listeners[i];
            EventListener* listener = r.listener();
            ASSERT(listener);

            // Event listeners created from markup have already been transfered to the shadow tree during cloning!
            if (listener->wasCreatedFromMarkup())
                continue;

            shadowTreeElement->addEventListener(r.eventType(), listener, r.useCapture());
        }
    }

    for (SVGElementInstance* instance = target->firstChild(); instance; instance = instance->nextSibling())
        transferEventListenersToShadowTree(instance);
}

void SVGUseElement::associateInstancesWithShadowTreeElements(Node* target, SVGElementInstance* targetInstance)
{
    if (!target || !targetInstance)
        return;

    SVGElement* originalElement = targetInstance->correspondingElement();

    if (originalElement->hasTagName(SVGNames::useTag)) {
#if ENABLE(SVG) && ENABLE(SVG_USE)
        // <use> gets replaced by <g>
        ASSERT(target->nodeName() == SVGNames::gTag);
#else 
        ASSERT(target->nodeName() == SVGNames::gTag || target->nodeName() == SVGNames::useTag);
#endif
    } else if (originalElement->hasTagName(SVGNames::symbolTag)) {
        // <symbol> gets replaced by <svg>
#if ENABLE(SVG) && ENABLE(SVG_USE) && ENABLE(SVG_FOREIGN_OBJECT)
        ASSERT(target->nodeName() == SVGNames::svgTag);
#endif
    } else
        ASSERT(target->nodeName() == originalElement->nodeName());

    SVGElement* element = 0;
    if (target->isSVGElement())
        element = static_cast<SVGElement*>(target);

    ASSERT(!targetInstance->shadowTreeElement());
    targetInstance->setShadowTreeElement(element);

    Node* node = target->firstChild();
    for (SVGElementInstance* instance = targetInstance->firstChild(); node && instance; instance = instance->nextSibling()) {
        // Skip any non-svg elements in shadow tree
        while (node && !node->isSVGElement())
           node = node->nextSibling();

        associateInstancesWithShadowTreeElements(node, instance);
        node = node->nextSibling();
    }
}

SVGElementInstance* SVGUseElement::instanceForShadowTreeElement(Node* element) const
{
    return instanceForShadowTreeElement(element, m_targetElementInstance.get());
}

SVGElementInstance* SVGUseElement::instanceForShadowTreeElement(Node* element, SVGElementInstance* instance) const
{
    ASSERT(element);
    ASSERT(instance);
    ASSERT(instance->shadowTreeElement());

    if (element == instance->shadowTreeElement())
        return instance;

    for (SVGElementInstance* current = instance->firstChild(); current; current = current->nextSibling()) {
        SVGElementInstance* search = instanceForShadowTreeElement(element, current);
        if (search)
            return search;
    }

    return 0;
}

void SVGUseElement::transferUseAttributesToReplacedElement(SVGElement* from, SVGElement* to) const
{
    ASSERT(from);
    ASSERT(to);

    to->attributes()->setAttributes(*from->attributes());

    ExceptionCode ec = 0;

    to->removeAttribute(SVGNames::xAttr, ec);
    ASSERT(ec == 0);

    to->removeAttribute(SVGNames::yAttr, ec);
    ASSERT(ec == 0);

    to->removeAttribute(SVGNames::widthAttr, ec);
    ASSERT(ec == 0);

    to->removeAttribute(SVGNames::heightAttr, ec);
    ASSERT(ec == 0);

    to->removeAttribute(XLinkNames::hrefAttr, ec);
    ASSERT(ec == 0);
}

}

#endif // ENABLE(SVG)