void SVGUseElement::buildInstanceTree(SVGElement* target, SVGElementInstance* targetInstance, bool& foundProblem, bool foundUse)
{
ASSERT(target);
ASSERT(targetInstance);
// Spec: If the referenced object is itself a 'use', or if there are 'use' subelements within the referenced
// object, the instance tree will contain recursive expansion of the indirect references to form a complete tree.
bool targetHasUseTag = target->hasTagName(SVGNames::useTag);
SVGElement* newTarget = 0;
if (targetHasUseTag) {
foundProblem = hasCycleUseReferencing(toSVGUseElement(target), targetInstance, newTarget);
if (foundProblem)
return;
// We only need to track first degree <use> dependencies. Indirect references are handled
// as the invalidation bubbles up the dependency chain.
if (!foundUse) {
document().accessSVGExtensions()->addElementReferencingTarget(this, target);
foundUse = true;
}
} else if (isDisallowedElement(*target)) {
foundProblem = true;
return;
}
// A general description from the SVG spec, describing what buildInstanceTree() actually does.
//
// Spec: If the 'use' element references a 'g' which contains two 'rect' elements, then the instance tree
// contains three SVGElementInstance objects, a root SVGElementInstance object whose correspondingElement
// is the SVGGElement object for the 'g', and then two child SVGElementInstance objects, each of which has
// its correspondingElement that is an SVGRectElement object.
for (auto& element : childrenOfType<SVGElement>(*target)) {
// Skip any non-svg nodes or any disallowed element.
if (isDisallowedElement(element))
continue;
// Create SVGElementInstance object, for both container/non-container nodes.
RefPtr<SVGElementInstance> instance = SVGElementInstance::create(this, 0, &element);
SVGElementInstance* instancePtr = instance.get();
targetInstance->appendChild(instance.release());
// Enter recursion, appending new instance tree nodes to the "instance" object.
buildInstanceTree(&element, instancePtr, foundProblem, foundUse);
if (foundProblem)
return;
}
if (!targetHasUseTag || !newTarget)
return;
RefPtr<SVGElementInstance> newInstance = SVGElementInstance::create(this, toSVGUseElement(target), newTarget);
SVGElementInstance* newInstancePtr = newInstance.get();
targetInstance->appendChild(newInstance.release());
buildInstanceTree(newTarget, newInstancePtr, foundProblem, foundUse);
}
void SVGUseElement::buildInstanceTree(SVGElement* target, SVGElementInstance* targetInstance, bool& foundProblem)
{
ASSERT(target);
ASSERT(targetInstance);
// Spec: If the referenced object is itself a 'use', or if there are 'use' subelements within the referenced
// object, the instance tree will contain recursive expansion of the indirect references to form a complete tree.
bool targetHasUseTag = target->hasTagName(SVGNames::useTag);
SVGElement* newTarget = 0;
if (targetHasUseTag) {
foundProblem = hasCycleUseReferencing(static_cast<SVGUseElement*>(target), targetInstance, newTarget);
if (foundProblem)
return;
}
// A general description from the SVG spec, describing what buildInstanceTree() actually does.
//
// Spec: If the 'use' element references a 'g' which contains two 'rect' elements, then the instance tree
// contains three SVGElementInstance objects, a root SVGElementInstance object whose correspondingElement
// is the SVGGElement object for the 'g', and then two child SVGElementInstance objects, each of which has
// its correspondingElement that is an SVGRectElement object.
for (Node* node = target->firstChild(); node; node = node->nextSibling()) {
SVGElement* element = 0;
if (node->isSVGElement())
element = static_cast<SVGElement*>(node);
// Skip any non-svg nodes or any disallowed element.
if (!element || isDisallowedElement(element))
continue;
// Create SVGElementInstance object, for both container/non-container nodes.
RefPtr<SVGElementInstance> instance = SVGElementInstance::create(this, element);
SVGElementInstance* instancePtr = instance.get();
targetInstance->appendChild(instance.release());
// Enter recursion, appending new instance tree nodes to the "instance" object.
buildInstanceTree(element, instancePtr, foundProblem);
if (foundProblem)
return;
}
if (!targetHasUseTag || !newTarget)
return;
RefPtr<SVGElementInstance> newInstance = SVGElementInstance::create(this, newTarget);
SVGElementInstance* newInstancePtr = newInstance.get();
targetInstance->appendChild(newInstance.release());
buildInstanceTree(newTarget, newInstancePtr, foundProblem);
}
void SVGUseElement::handleDeepUseReferencing(SVGUseElement* use, SVGElementInstance* targetInstance, bool& foundProblem)
{
String id = SVGURIReference::getTarget(use->href());
Element* targetElement = document()->getElementById(id);
SVGElement* target = 0;
if (targetElement && targetElement->isSVGElement())
target = static_cast<SVGElement*>(targetElement);
if (!target)
return;
// Cycle detection first!
foundProblem = (target == this);
// Shortcut for self-references
if (foundProblem)
return;
SVGElementInstance* instance = targetInstance->parentNode();
while (instance) {
SVGElement* element = instance->correspondingElement();
if (element->getIDAttribute() == id) {
foundProblem = true;
return;
}
instance = instance->parentNode();
}
// Create an instance object, even if we're dealing with a cycle
RefPtr<SVGElementInstance> newInstance = SVGElementInstance::create(this, target);
SVGElementInstance* newInstancePtr = newInstance.get();
targetInstance->appendChild(newInstance.release());
// Eventually enter recursion to build SVGElementInstance objects for the sub-tree children
buildInstanceTree(target, newInstancePtr, foundProblem);
}
void SVGUseElement::buildShadowAndInstanceTree(SVGShadowTreeRootElement* shadowRoot)
{
String id = SVGURIReference::getTarget(href());
Element* targetElement = document()->getElementById(id);
if (!targetElement) {
// The only time we should get here is when the use element has not been
// given a resource to target.
ASSERT(m_resourceId.isEmpty());
return;
}
// Do not build the shadow/instance tree for <use> elements living in a shadow tree.
// The will be expanded soon anyway - see expandUseElementsInShadowTree().
Node* parent = parentNode();
while (parent) {
if (parent->isShadowNode())
return;
parent = parent->parentNode();
}
SVGElement* target = 0;
if (targetElement && targetElement->isSVGElement())
target = static_cast<SVGElement*>(targetElement);
if (m_targetElementInstance)
m_targetElementInstance = 0;
// Do not allow self-referencing.
// 'target' may be null, if it's a non SVG namespaced element.
if (!target || target == this)
return;
// Why a seperated instance/shadow tree? SVG demands it:
// The instance tree is accesable from JavaScript, and has to
// expose a 1:1 copy of the referenced tree, whereas internally we need
// to alter the tree for correct "use-on-symbol", "use-on-svg" support.
// Build instance tree. Create root SVGElementInstance object for the first sub-tree node.
//
// Spec: If the 'use' element references a simple graphics element such as a 'rect', then there is only a
// single SVGElementInstance object, and the correspondingElement attribute on this SVGElementInstance object
// is the SVGRectElement that corresponds to the referenced 'rect' element.
m_targetElementInstance = SVGElementInstance::create(this, target);
// Eventually enter recursion to build SVGElementInstance objects for the sub-tree children
bool foundProblem = false;
buildInstanceTree(target, m_targetElementInstance.get(), foundProblem);
// 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 (foundProblem) {
m_targetElementInstance = 0;
return;
}
// Assure instance tree building was successfull
ASSERT(m_targetElementInstance);
ASSERT(!m_targetElementInstance->shadowTreeElement());
ASSERT(m_targetElementInstance->correspondingUseElement() == this);
ASSERT(m_targetElementInstance->correspondingElement() == target);
// Build shadow tree from instance tree
// This also handles the special cases: <use> on <symbol>, <use> on <svg>.
buildShadowTree(shadowRoot, target, m_targetElementInstance.get());
#if ENABLE(SVG) && ENABLE(SVG_USE)
// Expand all <use> elements in the shadow tree.
// Expand means: replace the actual <use> element by what it references.
expandUseElementsInShadowTree(shadowRoot, shadowRoot);
// Expand all <symbol> elements in the shadow tree.
// Expand means: replace the actual <symbol> element by the <svg> element.
expandSymbolElementsInShadowTree(shadowRoot, shadowRoot);
#endif
// Now that the shadow tree is completly expanded, we can associate
// shadow tree elements <-> instances in the instance tree.
associateInstancesWithShadowTreeElements(shadowRoot->firstChild(), m_targetElementInstance.get());
// If no shadow tree element is present, this means that the reference root
// element was removed, as it is disallowed (ie. <use> on <foreignObject>)
// Do NOT leave an inconsistent instance tree around, instead destruct it.
if (!m_targetElementInstance->shadowTreeElement()) {
shadowRoot->removeAllChildren();
m_targetElementInstance = 0;
return;
}
// Consistency checks - this is assumed in updateContainerOffset().
ASSERT(m_targetElementInstance->shadowTreeElement()->parentNode() == shadowRoot);
// Eventually dump instance tree
#ifdef DUMP_INSTANCE_TREE
String text;
unsigned int depth = 0;
dumpInstanceTree(depth, text, m_targetElementInstance.get());
fprintf(stderr, "\nDumping <use> instance tree:\n%s\n", text.latin1().data());
#endif
// Eventually dump shadow tree
#ifdef DUMP_SHADOW_TREE
ExceptionCode ec = 0;
PassRefPtr<XMLSerializer> serializer = XMLSerializer::create();
String markup = serializer->serializeToString(shadowRoot, ec);
ASSERT(!ec);
fprintf(stderr, "Dumping <use> shadow tree markup:\n%s\n", markup.latin1().data());
#endif
// Transfer event listeners assigned to the referenced element to our shadow tree elements.
transferEventListenersToShadowTree(m_targetElementInstance.get());
// Update container offset/size
updateContainerOffsets();
updateContainerSizes();
}
void SVGUseElement::buildShadowAndInstanceTree(SVGElement* target)
{
ASSERT(!m_targetElementInstance);
// Do not build the shadow/instance tree for <use> elements living in a shadow tree.
// The will be expanded soon anyway - see expandUseElementsInShadowTree().
if (isInShadowTree())
return;
// Do not allow self-referencing.
// 'target' may be null, if it's a non SVG namespaced element.
if (!target || target == this)
return;
// Why a seperated instance/shadow tree? SVG demands it:
// The instance tree is accesable from JavaScript, and has to
// expose a 1:1 copy of the referenced tree, whereas internally we need
// to alter the tree for correct "use-on-symbol", "use-on-svg" support.
// Build instance tree. Create root SVGElementInstance object for the first sub-tree node.
//
// Spec: If the 'use' element references a simple graphics element such as a 'rect', then there is only a
// single SVGElementInstance object, and the correspondingElement attribute on this SVGElementInstance object
// is the SVGRectElement that corresponds to the referenced 'rect' element.
m_targetElementInstance = SVGElementInstance::create(this, this, target);
// Eventually enter recursion to build SVGElementInstance objects for the sub-tree children
bool foundProblem = false;
buildInstanceTree(target, m_targetElementInstance.get(), foundProblem, false);
if (instanceTreeIsLoading(m_targetElementInstance.get()))
return;
// 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 (foundProblem) {
clearResourceReferences();
return;
}
// Assure instance tree building was successfull
ASSERT(m_targetElementInstance);
ASSERT(!m_targetElementInstance->shadowTreeElement());
ASSERT(m_targetElementInstance->correspondingUseElement() == this);
ASSERT(m_targetElementInstance->directUseElement() == this);
ASSERT(m_targetElementInstance->correspondingElement() == target);
ShadowRoot* shadowTreeRootElement = shadowRoot();
ASSERT(shadowTreeRootElement);
// Build shadow tree from instance tree
// This also handles the special cases: <use> on <symbol>, <use> on <svg>.
buildShadowTree(target, m_targetElementInstance.get());
// Expand all <use> elements in the shadow tree.
// Expand means: replace the actual <use> element by what it references.
expandUseElementsInShadowTree(shadowTreeRootElement);
// Expand all <symbol> elements in the shadow tree.
// Expand means: replace the actual <symbol> element by the <svg> element.
expandSymbolElementsInShadowTree(shadowTreeRootElement);
// Now that the shadow tree is completly expanded, we can associate
// shadow tree elements <-> instances in the instance tree.
associateInstancesWithShadowTreeElements(shadowTreeRootElement->firstChild(), m_targetElementInstance.get());
// If no shadow tree element is present, this means that the reference root
// element was removed, as it is disallowed (ie. <use> on <foreignObject>)
// Do NOT leave an inconsistent instance tree around, instead destruct it.
if (!m_targetElementInstance->shadowTreeElement()) {
clearResourceReferences();
return;
}
ASSERT(m_targetElementInstance->shadowTreeElement()->parentNode() == shadowTreeRootElement);
// Transfer event listeners assigned to the referenced element to our shadow tree elements.
transferEventListenersToShadowTree(m_targetElementInstance.get());
// Update relative length information.
updateRelativeLengthsInformation();
// Eventually dump instance tree
#ifdef DUMP_INSTANCE_TREE
String text;
unsigned int depth = 0;
dumpInstanceTree(depth, text, m_targetElementInstance.get());
fprintf(stderr, "\nDumping <use> instance tree:\n%s\n", text.latin1().data());
#endif
// Eventually dump shadow tree
#ifdef DUMP_SHADOW_TREE
RefPtr<XMLSerializer> serializer = XMLSerializer::create();
String markup = serializer->serializeToString(shadowTreeRootElement, ASSERT_NO_EXCEPTION);
fprintf(stderr, "Dumping <use> shadow tree markup:\n%s\n", markup.latin1().data());
#endif
}
void SVGUseElement::buildPendingResource()
{
String id = SVGURIReference::getTarget(href());
Element* targetElement = document()->getElementById(id);
if (!targetElement) {
// TODO: We want to deregister as pending resource, if our href() changed!
// TODO: Move to svgAttributeChanged, once we're fixing use & the new dynamic update concept.
document()->accessSVGExtensions()->addPendingResource(id, this);
return;
}
// Do not build the shadow/instance tree for <use> elements living in a shadow tree.
// The will be expanded soon anyway - see expandUseElementsInShadowTree().
Node* parent = parentNode();
while (parent) {
if (parent->isShadowNode())
return;
parent = parent->parentNode();
}
SVGElement* target = 0;
if (targetElement && targetElement->isSVGElement())
target = static_cast<SVGElement*>(targetElement);
// Do not allow self-referencing.
// 'target' may be null, if it's a non SVG namespaced element.
if (!target || target == this) {
m_targetElementInstance = 0;
m_shadowTreeRootElement = 0;
return;
}
// Why a seperated instance/shadow tree? SVG demands it:
// The instance tree is accesable from JavaScript, and has to
// expose a 1:1 copy of the referenced tree, whereas internally we need
// to alter the tree for correct "use-on-symbol", "use-on-svg" support.
// Build instance tree. Create root SVGElementInstance object for the first sub-tree node.
//
// Spec: If the 'use' element references a simple graphics element such as a 'rect', then there is only a
// single SVGElementInstance object, and the correspondingElement attribute on this SVGElementInstance object
// is the SVGRectElement that corresponds to the referenced 'rect' element.
m_targetElementInstance = new SVGElementInstance(this, target);
// Eventually enter recursion to build SVGElementInstance objects for the sub-tree children
bool foundProblem = false;
buildInstanceTree(target, m_targetElementInstance.get(), foundProblem);
// 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 (foundProblem) {
m_targetElementInstance = 0;
m_shadowTreeRootElement = 0;
return;
}
// Assure instance tree building was successfull
ASSERT(m_targetElementInstance);
ASSERT(m_targetElementInstance->correspondingUseElement() == this);
// Setup shadow tree root node
m_shadowTreeRootElement = new SVGGElement(SVGNames::gTag, document());
m_shadowTreeRootElement->setInDocument();
m_shadowTreeRootElement->setShadowParentNode(this);
// 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 (x().value() != 0.0 || y().value() != 0.0) {
String transformString = String::format("translate(%f, %f)", x().value(), y().value());
m_shadowTreeRootElement->setAttribute(SVGNames::transformAttr, transformString);
}
// Build shadow tree from instance tree
// This also handles the special cases: <use> on <symbol>, <use> on <svg>.
buildShadowTree(target, m_targetElementInstance.get());
#if ENABLE(SVG) && ENABLE(SVG_USE)
// Expand all <use> elements in the shadow tree.
// Expand means: replace the actual <use> element by what it references.
expandUseElementsInShadowTree(m_shadowTreeRootElement.get());
// Expand all <symbol> elements in the shadow tree.
// Expand means: replace the actual <symbol> element by the <svg> element.
expandSymbolElementsInShadowTree(m_shadowTreeRootElement.get());
#endif
// Now that the shadow tree is completly expanded, we can associate
// shadow tree elements <-> instances in the instance tree.
associateInstancesWithShadowTreeElements(m_shadowTreeRootElement->firstChild(), m_targetElementInstance.get());
// Eventually dump instance tree
#ifdef DUMP_INSTANCE_TREE
String text;
unsigned int depth = 0;
dumpInstanceTree(depth, text, m_targetElementInstance.get());
fprintf(stderr, "\nDumping <use> instance tree:\n%s\n", text.latin1().data());
#endif
// Eventually dump shadow tree
#ifdef DUMP_SHADOW_TREE
ExceptionCode ec = 0;
PassRefPtr<XMLSerializer> serializer = XMLSerializer::create();
String markup = serializer->serializeToString(m_shadowTreeRootElement.get(), ec);
ASSERT(ec == 0);
fprintf(stderr, "Dumping <use> shadow tree markup:\n%s\n", markup.latin1().data());
#endif
// The DOM side is setup properly. Now we have to attach the root shadow
// tree element manually - using attach() won't work for "shadow nodes".
attachShadowTree();
}
