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/*
* Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
* Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
* Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
* Copyright (C) 2011 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
* Copyright (C) 2012 University of Szeged
* Copyright (C) 2012 Renata Hodovan <reni@webkit.org>
* Copyright (C) 2015-2019 Apple Inc. All rights reserved.
*
* 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.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include "SVGUseElement.h"
#include "CachedResourceLoader.h"
#include "CachedSVGDocument.h"
#include "ElementIterator.h"
#include "Event.h"
#include "EventNames.h"
#include "RenderSVGResource.h"
#include "RenderSVGTransformableContainer.h"
#include "SVGDocumentExtensions.h"
#include "SVGGElement.h"
#include "SVGSVGElement.h"
#include "SVGSymbolElement.h"
#include "ScriptDisallowedScope.h"
#include "ShadowRoot.h"
#include "XLinkNames.h"
#include <wtf/IsoMallocInlines.h>
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(SVGUseElement);
inline SVGUseElement::SVGUseElement(const QualifiedName& tagName, Document& document)
: SVGGraphicsElement(tagName, document)
, SVGExternalResourcesRequired(this)
, SVGURIReference(this)
, m_svgLoadEventTimer(*this, &SVGElement::svgLoadEventTimerFired)
{
ASSERT(hasCustomStyleResolveCallbacks());
ASSERT(hasTagName(SVGNames::useTag));
static std::once_flag onceFlag;
std::call_once(onceFlag, [] {
PropertyRegistry::registerProperty<SVGNames::xAttr, &SVGUseElement::m_x>();
PropertyRegistry::registerProperty<SVGNames::yAttr, &SVGUseElement::m_y>();
PropertyRegistry::registerProperty<SVGNames::widthAttr, &SVGUseElement::m_width>();
PropertyRegistry::registerProperty<SVGNames::heightAttr, &SVGUseElement::m_height>();
});
}
Ref<SVGUseElement> SVGUseElement::create(const QualifiedName& tagName, Document& document)
{
return adoptRef(*new SVGUseElement(tagName, document));
}
SVGUseElement::~SVGUseElement()
{
if (m_externalDocument)
m_externalDocument->removeClient(*this);
}
void SVGUseElement::parseAttribute(const QualifiedName& name, const AtomString& value)
{
SVGParsingError parseError = NoError;
if (name == SVGNames::xAttr)
m_x->setBaseValInternal(SVGLengthValue::construct(SVGLengthMode::Width, value, parseError));
else if (name == SVGNames::yAttr)
m_y->setBaseValInternal(SVGLengthValue::construct(SVGLengthMode::Height, value, parseError));
else if (name == SVGNames::widthAttr)
m_width->setBaseValInternal(SVGLengthValue::construct(SVGLengthMode::Width, value, parseError, SVGLengthNegativeValuesMode::Forbid));
else if (name == SVGNames::heightAttr)
m_height->setBaseValInternal(SVGLengthValue::construct(SVGLengthMode::Height, value, parseError, SVGLengthNegativeValuesMode::Forbid));
reportAttributeParsingError(parseError, name, value);
SVGExternalResourcesRequired::parseAttribute(name, value);
SVGGraphicsElement::parseAttribute(name, value);
SVGURIReference::parseAttribute(name, value);
}
Node::InsertedIntoAncestorResult SVGUseElement::insertedIntoAncestor(InsertionType insertionType, ContainerNode& parentOfInsertedTree)
{
SVGGraphicsElement::insertedIntoAncestor(insertionType, parentOfInsertedTree);
if (insertionType.connectedToDocument) {
if (m_shadowTreeNeedsUpdate)
document().addSVGUseElement(*this);
SVGExternalResourcesRequired::insertedIntoDocument();
invalidateShadowTree();
// FIXME: Move back the call to updateExternalDocument() here once notifyFinished is made always async.
return InsertedIntoAncestorResult::NeedsPostInsertionCallback;
}
return InsertedIntoAncestorResult::Done;
}
void SVGUseElement::didFinishInsertingNode()
{
updateExternalDocument();
}
void SVGUseElement::removedFromAncestor(RemovalType removalType, ContainerNode& oldParentOfRemovedTree)
{
// Check m_shadowTreeNeedsUpdate before calling SVGElement::removedFromAncestor which calls SVGElement::invalidateInstances
// and SVGUseElement::updateExternalDocument which calls invalidateShadowTree().
if (removalType.disconnectedFromDocument) {
if (m_shadowTreeNeedsUpdate)
document().removeSVGUseElement(*this);
}
SVGGraphicsElement::removedFromAncestor(removalType, oldParentOfRemovedTree);
if (removalType.disconnectedFromDocument) {
clearShadowTree();
updateExternalDocument();
}
}
inline Document* SVGUseElement::externalDocument() const
{
return m_externalDocument ? m_externalDocument->document() : nullptr;
}
void SVGUseElement::transferSizeAttributesToTargetClone(SVGElement& shadowElement) const
{
// FIXME: The check for valueInSpecifiedUnits being non-zero below is a workaround for the fact
// that we currently have no good way to tell whether a particular animatable attribute is a value
// indicating it was unspecified, or specified but could not be parsed. Would be nice to fix that some day.
if (is<SVGSymbolElement>(shadowElement)) {
// 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.
shadowElement.setAttribute(SVGNames::widthAttr, width().valueInSpecifiedUnits() ? AtomString(width().valueAsString()) : "100%");
shadowElement.setAttribute(SVGNames::heightAttr, height().valueInSpecifiedUnits() ? AtomString(height().valueAsString()) : "100%");
} else if (is<SVGSVGElement>(shadowElement)) {
// 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.
auto correspondingElement = makeRefPtr(shadowElement.correspondingElement());
shadowElement.setAttribute(SVGNames::widthAttr, width().valueInSpecifiedUnits() ? AtomString(width().valueAsString()) : (correspondingElement ? correspondingElement->getAttribute(SVGNames::widthAttr) : nullAtom()));
shadowElement.setAttribute(SVGNames::heightAttr, height().valueInSpecifiedUnits() ? AtomString(height().valueAsString()) : (correspondingElement ? correspondingElement->getAttribute(SVGNames::heightAttr) : nullAtom()));
}
}
void SVGUseElement::svgAttributeChanged(const QualifiedName& attrName)
{
InstanceInvalidationGuard guard(*this);
if (PropertyRegistry::isKnownAttribute(attrName)) {
updateRelativeLengthsInformation();
if (attrName == SVGNames::widthAttr || attrName == SVGNames::heightAttr) {
// FIXME: It's unnecessarily inefficient to update both width and height each time either is changed.
if (auto targetClone = this->targetClone())
transferSizeAttributesToTargetClone(*targetClone);
}
if (auto* renderer = this->renderer())
RenderSVGResource::markForLayoutAndParentResourceInvalidation(*renderer);
return;
}
if (SVGURIReference::isKnownAttribute(attrName)) {
updateExternalDocument();
invalidateShadowTree();
return;
}
if (SVGLangSpace::isKnownAttribute(attrName) || SVGExternalResourcesRequired::isKnownAttribute(attrName))
invalidateShadowTree();
SVGGraphicsElement::svgAttributeChanged(attrName);
SVGExternalResourcesRequired::svgAttributeChanged(attrName);
}
static HashSet<AtomString> createAllowedElementSet()
{
// Spec: "Any 'svg', 'symbol', 'g', graphics element or other 'use' is potentially a template object that can be re-used
// (i.e., "instanced") in the SVG document via a 'use' element."
// "Graphics Element" is defined as 'circle', 'ellipse', 'image', 'line', 'path', 'polygon', 'polyline', 'rect', 'text'
// Excluded are anything that is used by reference or that only make sense to appear once in a document.
using namespace SVGNames;
HashSet<AtomString> set;
for (auto& tag : { aTag.get(), circleTag.get(), descTag.get(), ellipseTag.get(), gTag.get(), imageTag.get(), lineTag.get(), metadataTag.get(), pathTag.get(), polygonTag.get(), polylineTag.get(), rectTag.get(), svgTag.get(), switchTag.get(), symbolTag.get(), textTag.get(), textPathTag.get(), titleTag.get(), trefTag.get(), tspanTag.get(), useTag.get() })
set.add(tag.localName());
return set;
}
static inline bool isDisallowedElement(const SVGElement& element)
{
static NeverDestroyed<HashSet<AtomString>> set = createAllowedElementSet();
return !set.get().contains(element.localName());
}
static inline bool isDisallowedElement(const Element& element)
{
return !element.isSVGElement() || isDisallowedElement(downcast<SVGElement>(element));
}
void SVGUseElement::clearShadowTree()
{
if (auto root = userAgentShadowRoot()) {
// Safe because SVG use element's shadow tree is never used to fire synchronous events during layout or DOM mutations.
ScriptDisallowedScope::EventAllowedScope scope(*root);
root->removeChildren();
}
}
void SVGUseElement::buildPendingResource()
{
invalidateShadowTree();
}
void SVGUseElement::updateShadowTree()
{
m_shadowTreeNeedsUpdate = false;
// FIXME: It's expensive to re-clone the entire tree every time. We should find a more efficient way to handle this.
clearShadowTree();
if (!isConnected())
return;
document().removeSVGUseElement(*this);
String targetID;
auto* target = findTarget(&targetID);
if (!target) {
document().accessSVGExtensions().addPendingResource(targetID, *this);
return;
}
RELEASE_ASSERT(!isDescendantOf(target));
{
auto& shadowRoot = ensureUserAgentShadowRoot();
cloneTarget(shadowRoot, *target);
expandUseElementsInShadowTree();
expandSymbolElementsInShadowTree();
updateRelativeLengthsInformation();
}
transferEventListenersToShadowTree();
// When we invalidate the other shadow trees, it's important that we don't
// follow any cycles and invalidate ourselves. To avoid that, we temporarily
// set m_shadowTreeNeedsUpdate to true so invalidateShadowTree will
// quickly return and do nothing.
ASSERT(!m_shadowTreeNeedsUpdate);
m_shadowTreeNeedsUpdate = true;
invalidateDependentShadowTrees();
m_shadowTreeNeedsUpdate = false;
}
RefPtr<SVGElement> SVGUseElement::targetClone() const
{
auto root = userAgentShadowRoot();
if (!root)
return nullptr;
return childrenOfType<SVGElement>(*root).first();
}
RenderPtr<RenderElement> SVGUseElement::createElementRenderer(RenderStyle&& style, const RenderTreePosition&)
{
return createRenderer<RenderSVGTransformableContainer>(*this, WTFMove(style));
}
static bool isDirectReference(const SVGElement& element)
{
using namespace SVGNames;
return element.hasTagName(circleTag)
|| element.hasTagName(ellipseTag)
|| element.hasTagName(pathTag)
|| element.hasTagName(polygonTag)
|| element.hasTagName(polylineTag)
|| element.hasTagName(rectTag)
|| element.hasTagName(textTag);
}
Path SVGUseElement::toClipPath()
{
auto targetClone = this->targetClone();
if (!is<SVGGraphicsElement>(targetClone))
return { };
if (!isDirectReference(*targetClone)) {
// Spec: Indirect references are an error (14.3.5)
document().accessSVGExtensions().reportError("Not allowed to use indirect reference in <clip-path>"_s);
return { };
}
Path path = downcast<SVGGraphicsElement>(*targetClone).toClipPath();
SVGLengthContext lengthContext(this);
// FIXME: Find a way to do this without manual resolution of x/y here. It's potentially incorrect.
path.translate(FloatSize(x().value(lengthContext), y().value(lengthContext)));
path.transform(animatedLocalTransform());
return path;
}
RenderElement* SVGUseElement::rendererClipChild() const
{
auto targetClone = this->targetClone();
if (!targetClone)
return nullptr;
if (!isDirectReference(*targetClone))
return nullptr;
return targetClone->renderer();
}
static inline void disassociateAndRemoveClones(const Vector<Element*>& clones)
{
for (auto& clone : clones) {
for (auto& descendant : descendantsOfType<SVGElement>(*clone))
descendant.setCorrespondingElement(nullptr);
if (is<SVGElement>(clone))
downcast<SVGElement>(*clone).setCorrespondingElement(nullptr);
clone->parentNode()->removeChild(*clone);
}
}
static void removeDisallowedElementsFromSubtree(SVGElement& subtree)
{
// Remove disallowed elements after the fact rather than not cloning them in the first place.
// This optimizes for the normal case where none of those elements are present.
// This function is used only on elements in subtrees that are not yet in documents, so
// mutation events are not a factor; there are no event listeners to handle those events.
// Assert that it's not in a document to make sure callers are still using it this way.
ASSERT(!subtree.isConnected());
Vector<Element*> disallowedElements;
auto descendants = descendantsOfType<Element>(subtree);
for (auto it = descendants.begin(), end = descendants.end(); it != end; ) {
if (isDisallowedElement(*it)) {
disallowedElements.append(&*it);
it.traverseNextSkippingChildren();
continue;
}
++it;
}
disassociateAndRemoveClones(disallowedElements);
}
static void removeSymbolElementsFromSubtree(SVGElement& subtree)
{
// Symbol elements inside the subtree should not be cloned for two reasons: 1) They are invisible and
// don't need to be cloned to get correct rendering. 2) expandSymbolElementsInShadowTree will turn them
// into <svg> elements, which is correct for symbol elements directly referenced by use elements,
// but incorrect for ones that just happen to be in a subtree.
Vector<Element*> symbolElements;
for (auto& descendant : descendantsOfType<SVGSymbolElement>(subtree))
symbolElements.append(&descendant);
disassociateAndRemoveClones(symbolElements);
}
static void associateClonesWithOriginals(SVGElement& clone, SVGElement& original)
{
// This assertion checks that we don't call this with the arguments backwards.
// The clone is new and so it's not installed in a parent yet.
ASSERT(!clone.parentNode());
// The loop below works because we are associating these clones immediately, before
// doing transformations like removing disallowed elements or expanding elements.
clone.setCorrespondingElement(&original);
for (auto pair : descendantsOfType<SVGElement>(clone, original))
pair.first.setCorrespondingElement(&pair.second);
}
static void associateReplacementCloneWithOriginal(SVGElement& replacementClone, SVGElement& originalClone)
{
auto* correspondingElement = originalClone.correspondingElement();
ASSERT(correspondingElement);
originalClone.setCorrespondingElement(nullptr);
replacementClone.setCorrespondingElement(correspondingElement);
}
static void associateReplacementClonesWithOriginals(SVGElement& replacementClone, SVGElement& originalClone)
{
// This assertion checks that we don't call this with the arguments backwards.
// The replacement clone is new and so it's not installed in a parent yet.
ASSERT(!replacementClone.parentNode());
// The loop below works because we are associating these clones immediately, before
// doing transformations like removing disallowed elements or expanding elements.
associateReplacementCloneWithOriginal(replacementClone, originalClone);
for (auto pair : descendantsOfType<SVGElement>(replacementClone, originalClone))
associateReplacementCloneWithOriginal(pair.first, pair.second);
}
SVGElement* SVGUseElement::findTarget(String* targetID) const
{
auto* correspondingElement = this->correspondingElement();
auto& original = correspondingElement ? downcast<SVGUseElement>(*correspondingElement) : *this;
auto targetResult = targetElementFromIRIString(original.href(), original.treeScope(), original.externalDocument());
if (targetID) {
*targetID = WTFMove(targetResult.identifier);
// If the reference is external, don't return the target ID to the caller.
// The caller would use the target ID to wait for a pending resource on the wrong document.
// If we ever want the change that and let the caller to wait on the external document,
// we should change this function so it returns the appropriate document to go with the ID.
if (!targetID->isNull() && isExternalURIReference(original.href(), original.document()))
*targetID = String { };
}
if (!is<SVGElement>(targetResult.element))
return nullptr;
auto& target = downcast<SVGElement>(*targetResult.element);
if (!target.isConnected() || isDisallowedElement(target))
return nullptr;
if (correspondingElement) {
for (auto& ancestor : lineageOfType<SVGElement>(*this)) {
if (ancestor.correspondingElement() == &target)
return nullptr;
}
} else {
if (target.contains(this))
return nullptr;
// Target should only refer to a node in the same tree or a node in another document.
ASSERT(!isDescendantOrShadowDescendantOf(&target));
}
return &target;
}
void SVGUseElement::cloneTarget(ContainerNode& container, SVGElement& target) const
{
Ref<SVGElement> targetClone = static_cast<SVGElement&>(target.cloneElementWithChildren(document()).get());
associateClonesWithOriginals(targetClone.get(), target);
removeDisallowedElementsFromSubtree(targetClone.get());
removeSymbolElementsFromSubtree(targetClone.get());
transferSizeAttributesToTargetClone(targetClone.get());
container.appendChild(targetClone);
}
static void cloneDataAndChildren(SVGElement& replacementClone, SVGElement& originalClone)
{
// This assertion checks that we don't call this with the arguments backwards.
// The replacement clone is new and so it's not installed in a parent yet.
ASSERT(!replacementClone.parentNode());
replacementClone.cloneDataFromElement(originalClone);
originalClone.cloneChildNodes(replacementClone);
associateReplacementClonesWithOriginals(replacementClone, originalClone);
removeDisallowedElementsFromSubtree(replacementClone);
}
void SVGUseElement::expandUseElementsInShadowTree() const
{
auto descendants = descendantsOfType<SVGUseElement>(*userAgentShadowRoot());
for (auto it = descendants.begin(), end = descendants.end(); it != end; ) {
SVGUseElement& originalClone = *it;
it = end; // Efficiently quiets assertions due to the outstanding iterator.
auto* target = originalClone.findTarget();
// 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.
auto replacementClone = SVGGElement::create(document());
cloneDataAndChildren(replacementClone.get(), originalClone);
replacementClone->removeAttribute(SVGNames::xAttr);
replacementClone->removeAttribute(SVGNames::yAttr);
replacementClone->removeAttribute(SVGNames::widthAttr);
replacementClone->removeAttribute(SVGNames::heightAttr);
replacementClone->removeAttribute(SVGNames::hrefAttr);
replacementClone->removeAttribute(XLinkNames::hrefAttr);
if (target)
originalClone.cloneTarget(replacementClone.get(), *target);
originalClone.parentNode()->replaceChild(replacementClone, originalClone);
// Resume iterating, starting just inside the replacement clone.
it = descendants.from(replacementClone.get());
}
}
void SVGUseElement::expandSymbolElementsInShadowTree() const
{
auto descendants = descendantsOfType<SVGSymbolElement>(*userAgentShadowRoot());
for (auto it = descendants.begin(), end = descendants.end(); it != end; ) {
SVGSymbolElement& originalClone = *it;
it = end; // Efficiently quiets assertions due to the outstanding iterator.
// 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.
auto replacementClone = SVGSVGElement::create(document());
cloneDataAndChildren(replacementClone.get(), originalClone);
originalClone.parentNode()->replaceChild(replacementClone, originalClone);
// Resume iterating, starting just inside the replacement clone.
it = descendants.from(replacementClone.get());
}
}
void SVGUseElement::transferEventListenersToShadowTree() const
{
// FIXME: Don't directly add event listeners on each descendant. Copy event listeners on the use element instead.
for (auto& descendant : descendantsOfType<SVGElement>(*userAgentShadowRoot())) {
if (EventTargetData* data = descendant.correspondingElement()->eventTargetData())
data->eventListenerMap.copyEventListenersNotCreatedFromMarkupToTarget(&descendant);
}
}
void SVGUseElement::invalidateShadowTree()
{
if (m_shadowTreeNeedsUpdate)
return;
m_shadowTreeNeedsUpdate = true;
invalidateStyleAndRenderersForSubtree();
invalidateDependentShadowTrees();
if (isConnected())
document().addSVGUseElement(*this);
}
void SVGUseElement::invalidateDependentShadowTrees()
{
for (auto* instance : instances()) {
if (auto element = instance->correspondingUseElement())
element->invalidateShadowTree();
}
}
bool SVGUseElement::selfHasRelativeLengths() const
{
if (x().isRelative() || y().isRelative() || width().isRelative() || height().isRelative())
return true;
auto targetClone = this->targetClone();
return targetClone && targetClone->hasRelativeLengths();
}
void SVGUseElement::notifyFinished(CachedResource& resource)
{
ASSERT(ScriptDisallowedScope::InMainThread::isScriptAllowed());
invalidateShadowTree();
if (resource.errorOccurred())
dispatchEvent(Event::create(eventNames().errorEvent, Event::CanBubble::No, Event::IsCancelable::No));
else if (!resource.wasCanceled())
SVGExternalResourcesRequired::dispatchLoadEvent();
}
void SVGUseElement::finishParsingChildren()
{
SVGGraphicsElement::finishParsingChildren();
SVGExternalResourcesRequired::finishParsingChildren();
}
void SVGUseElement::updateExternalDocument()
{
URL externalDocumentURL;
if (isConnected() && isExternalURIReference(href(), document())) {
externalDocumentURL = document().completeURL(href());
if (!externalDocumentURL.hasFragmentIdentifier())
externalDocumentURL = URL();
}
if (externalDocumentURL == (m_externalDocument ? m_externalDocument->url() : URL()))
return;
if (m_externalDocument)
m_externalDocument->removeClient(*this);
if (externalDocumentURL.isNull())
m_externalDocument = nullptr;
else {
ResourceLoaderOptions options = CachedResourceLoader::defaultCachedResourceOptions();
options.contentSecurityPolicyImposition = isInUserAgentShadowTree() ? ContentSecurityPolicyImposition::SkipPolicyCheck : ContentSecurityPolicyImposition::DoPolicyCheck;
options.mode = FetchOptions::Mode::SameOrigin;
CachedResourceRequest request { ResourceRequest { externalDocumentURL }, options };
request.setInitiator(*this);
m_externalDocument = document().cachedResourceLoader().requestSVGDocument(WTFMove(request)).value_or(nullptr);
if (m_externalDocument)
m_externalDocument->addClient(*this);
}
invalidateShadowTree();
}
bool SVGUseElement::isValid() const
{
return SVGTests::isValid();
}
bool SVGUseElement::haveLoadedRequiredResources()
{
return SVGExternalResourcesRequired::haveLoadedRequiredResources();
}
void SVGUseElement::setHaveFiredLoadEvent(bool haveFiredLoadEvent)
{
m_haveFiredLoadEvent = haveFiredLoadEvent;
}
bool SVGUseElement::haveFiredLoadEvent() const
{
return m_haveFiredLoadEvent;
}
Timer* SVGUseElement::svgLoadEventTimer()
{
return &m_svgLoadEventTimer;
}
}