void SVGUseElement::buildShadowAndInstanceTree(SVGElement* target)
{
ASSERT(!m_targetElementInstance);
ASSERT(!m_needsShadowTreeRecreation);
// <use> creates a "user agent" shadow root. Do not build the shadow/instance tree for <use>
// elements living in a user agent shadow tree because they will get expanded in a second
// pass -- see expandUseElementsInShadowTree().
if (inUseShadowTree())
return;
// Do not allow self-referencing.
// 'target' may be null, if it's a non SVG namespaced element.
if (!target || target == this || isDisallowedElement(target))
return;
// Set up root SVG element in shadow tree.
RefPtrWillBeRawPtr<Element> newChild = target->cloneElementWithoutChildren();
m_targetElementInstance = toSVGElement(newChild.get());
ShadowRoot* shadowTreeRootElement = userAgentShadowRoot();
shadowTreeRootElement->appendChild(newChild.release());
// Clone the target subtree into the shadow tree, not handling <use> and <symbol> yet.
// SVG specification does not say a word about <use> & cycles. My view on this is: just ignore it!
// Non-appearing <use> content is easier to debug, then half-appearing content.
if (!buildShadowTree(target, m_targetElementInstance.get(), false)) {
clearShadowTree();
return;
}
if (instanceTreeIsLoading(m_targetElementInstance.get()))
return;
// Assure shadow tree building was successfull
ASSERT(m_targetElementInstance);
ASSERT(m_targetElementInstance->correspondingUseElement() == this);
ASSERT(m_targetElementInstance->correspondingElement() == target);
// Expand all <use> elements in the shadow tree.
// Expand means: replace the actual <use> element by what it references.
if (!expandUseElementsInShadowTree(m_targetElementInstance.get())) {
clearShadowTree();
return;
}
// Expand all <symbol> elements in the shadow tree.
// Expand means: replace the actual <symbol> element by the <svg> element.
expandSymbolElementsInShadowTree(toSVGElement(shadowTreeRootElement->firstChild()));
m_targetElementInstance = toSVGElement(shadowTreeRootElement->firstChild());
transferUseWidthAndHeightIfNeeded(*this, m_targetElementInstance.get(), *m_targetElementInstance->correspondingElement());
ASSERT(m_targetElementInstance->parentNode() == shadowTreeRootElement);
// Update relative length information.
updateRelativeLengthsInformation();
}
void SVGUseElement::removedFrom(ContainerNode* rootParent) {
SVGGraphicsElement::removedFrom(rootParent);
if (rootParent->isConnected()) {
clearShadowTree();
cancelShadowTreeRecreation();
}
}
void SVGUseElement::buildPendingResource()
{
if (inUseShadowTree())
return;
clearShadowTree();
cancelShadowTreeRecreation();
if (!referencedScope() || !inDocument())
return;
AtomicString id;
Element* target = SVGURIReference::targetElementFromIRIString(hrefString(), treeScope(), &id, externalDocument());
if (!target || !target->inDocument()) {
// If we can't find the target of an external element, just give up.
// We can't observe if the target somewhen enters the external document, nor should we do it.
if (externalDocument())
return;
if (id.isEmpty())
return;
referencedScope()->document().accessSVGExtensions().addPendingResource(id, this);
ASSERT(hasPendingResources());
return;
}
if (target->isSVGElement()) {
buildShadowAndInstanceTree(toSVGElement(target));
invalidateDependentShadowTrees();
}
ASSERT(!m_needsShadowTreeRecreation);
}
SVGUseElement::~SVGUseElement()
{
#if !ENABLE(OILPAN)
clearShadowTree();
cancelShadowTreeRecreation();
svgUseLoadEventSender().cancelEvent(this);
dispose();
#endif
}
SVGUseElement::~SVGUseElement()
{
setDocumentResource(0);
#if !ENABLE(OILPAN)
clearShadowTree();
cancelShadowTreeRecreation();
svgUseLoadEventSender().cancelEvent(this);
#endif
}
