1/* 2 * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org> 3 * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org> 4 * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved. 5 * Copyright (C) 2011 Torch Mobile (Beijing) Co. Ltd. All rights reserved. 6 * Copyright (C) 2012 University of Szeged 7 * Copyright (C) 2012 Renata Hodovan <reni@webkit.org> 8 * 9 * This library is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU Library General Public 11 * License as published by the Free Software Foundation; either 12 * version 2 of the License, or (at your option) any later version. 13 * 14 * This library is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * Library General Public License for more details. 18 * 19 * You should have received a copy of the GNU Library General Public License 20 * along with this library; see the file COPYING.LIB. If not, write to 21 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 22 * Boston, MA 02110-1301, USA. 23 */ 24 25#include "config.h" 26#include "SVGUseElement.h" 27 28#include "CachedResourceLoader.h" 29#include "CachedResourceRequest.h" 30#include "CachedSVGDocument.h" 31#include "Document.h" 32#include "ElementIterator.h" 33#include "Event.h" 34#include "EventListener.h" 35#include "HTMLNames.h" 36#include "NodeRenderStyle.h" 37#include "RegisteredEventListener.h" 38#include "RenderSVGResource.h" 39#include "RenderSVGTransformableContainer.h" 40#include "ShadowRoot.h" 41#include "SVGElementInstance.h" 42#include "SVGElementRareData.h" 43#include "SVGElementInstanceList.h" 44#include "SVGGElement.h" 45#include "SVGLengthContext.h" 46#include "SVGNames.h" 47#include "SVGSMILElement.h" 48#include "SVGSVGElement.h" 49#include "SVGSymbolElement.h" 50#include "StyleResolver.h" 51#include "XLinkNames.h" 52#include "XMLDocumentParser.h" 53#include "XMLSerializer.h" 54#include <wtf/NeverDestroyed.h> 55 56// Dump SVGElementInstance object tree - useful to debug instanceRoot problems 57// #define DUMP_INSTANCE_TREE 58 59// Dump the deep-expanded shadow tree (where the renderers are built from) 60// #define DUMP_SHADOW_TREE 61 62namespace WebCore { 63 64// Animated property definitions 65DEFINE_ANIMATED_LENGTH(SVGUseElement, SVGNames::xAttr, X, x) 66DEFINE_ANIMATED_LENGTH(SVGUseElement, SVGNames::yAttr, Y, y) 67DEFINE_ANIMATED_LENGTH(SVGUseElement, SVGNames::widthAttr, Width, width) 68DEFINE_ANIMATED_LENGTH(SVGUseElement, SVGNames::heightAttr, Height, height) 69DEFINE_ANIMATED_STRING(SVGUseElement, XLinkNames::hrefAttr, Href, href) 70DEFINE_ANIMATED_BOOLEAN(SVGUseElement, SVGNames::externalResourcesRequiredAttr, ExternalResourcesRequired, externalResourcesRequired) 71 72BEGIN_REGISTER_ANIMATED_PROPERTIES(SVGUseElement) 73 REGISTER_LOCAL_ANIMATED_PROPERTY(x) 74 REGISTER_LOCAL_ANIMATED_PROPERTY(y) 75 REGISTER_LOCAL_ANIMATED_PROPERTY(width) 76 REGISTER_LOCAL_ANIMATED_PROPERTY(height) 77 REGISTER_LOCAL_ANIMATED_PROPERTY(href) 78 REGISTER_LOCAL_ANIMATED_PROPERTY(externalResourcesRequired) 79 REGISTER_PARENT_ANIMATED_PROPERTIES(SVGGraphicsElement) 80END_REGISTER_ANIMATED_PROPERTIES 81 82inline SVGUseElement::SVGUseElement(const QualifiedName& tagName, Document& document, bool wasInsertedByParser) 83 : SVGGraphicsElement(tagName, document) 84 , m_x(LengthModeWidth) 85 , m_y(LengthModeHeight) 86 , m_width(LengthModeWidth) 87 , m_height(LengthModeHeight) 88 , m_wasInsertedByParser(wasInsertedByParser) 89 , m_haveFiredLoadEvent(false) 90 , m_needsShadowTreeRecreation(false) 91 , m_svgLoadEventTimer(this, &SVGElement::svgLoadEventTimerFired) 92{ 93 ASSERT(hasCustomStyleResolveCallbacks()); 94 ASSERT(hasTagName(SVGNames::useTag)); 95 registerAnimatedPropertiesForSVGUseElement(); 96} 97 98PassRefPtr<SVGUseElement> SVGUseElement::create(const QualifiedName& tagName, Document& document, bool wasInsertedByParser) 99{ 100 // Always build a #shadow-root for SVGUseElement. 101 RefPtr<SVGUseElement> use = adoptRef(new SVGUseElement(tagName, document, wasInsertedByParser)); 102 use->ensureUserAgentShadowRoot(); 103 return use.release(); 104} 105 106SVGUseElement::~SVGUseElement() 107{ 108 setCachedDocument(0); 109 110 clearResourceReferences(); 111} 112 113SVGElementInstance* SVGUseElement::instanceRoot() 114{ 115 // If there is no element instance tree, force immediate SVGElementInstance tree 116 // creation by asking the document to invoke our recalcStyle function - as we can't 117 // wait for the lazy creation to happen if e.g. JS wants to access the instanceRoot 118 // object right after creating the element on-the-fly 119 if (!m_targetElementInstance) 120 document().updateLayoutIgnorePendingStylesheets(); 121 122 return m_targetElementInstance.get(); 123} 124 125SVGElementInstance* SVGUseElement::animatedInstanceRoot() const 126{ 127 // FIXME: Implement me. 128 return 0; 129} 130 131bool SVGUseElement::isSupportedAttribute(const QualifiedName& attrName) 132{ 133 static NeverDestroyed<HashSet<QualifiedName>> supportedAttributes; 134 if (supportedAttributes.get().isEmpty()) { 135 SVGLangSpace::addSupportedAttributes(supportedAttributes); 136 SVGExternalResourcesRequired::addSupportedAttributes(supportedAttributes); 137 SVGURIReference::addSupportedAttributes(supportedAttributes); 138 supportedAttributes.get().add(SVGNames::xAttr); 139 supportedAttributes.get().add(SVGNames::yAttr); 140 supportedAttributes.get().add(SVGNames::widthAttr); 141 supportedAttributes.get().add(SVGNames::heightAttr); 142 } 143 return supportedAttributes.get().contains<SVGAttributeHashTranslator>(attrName); 144} 145 146void SVGUseElement::parseAttribute(const QualifiedName& name, const AtomicString& value) 147{ 148 SVGParsingError parseError = NoError; 149 150 if (!isSupportedAttribute(name)) 151 SVGGraphicsElement::parseAttribute(name, value); 152 else if (name == SVGNames::xAttr) 153 setXBaseValue(SVGLength::construct(LengthModeWidth, value, parseError)); 154 else if (name == SVGNames::yAttr) 155 setYBaseValue(SVGLength::construct(LengthModeHeight, value, parseError)); 156 else if (name == SVGNames::widthAttr) 157 setWidthBaseValue(SVGLength::construct(LengthModeWidth, value, parseError, ForbidNegativeLengths)); 158 else if (name == SVGNames::heightAttr) 159 setHeightBaseValue(SVGLength::construct(LengthModeHeight, value, parseError, ForbidNegativeLengths)); 160 else if (SVGLangSpace::parseAttribute(name, value) 161 || SVGExternalResourcesRequired::parseAttribute(name, value) 162 || SVGURIReference::parseAttribute(name, value)) { 163 } else 164 ASSERT_NOT_REACHED(); 165 166 reportAttributeParsingError(parseError, name, value); 167} 168 169#if !ASSERT_DISABLED 170static inline bool isWellFormedDocument(Document& document) 171{ 172 if (document.isSVGDocument() || document.isXHTMLDocument()) 173 return static_cast<XMLDocumentParser*>(document.parser())->wellFormed(); 174 return true; 175} 176#endif 177 178Node::InsertionNotificationRequest SVGUseElement::insertedInto(ContainerNode& rootParent) 179{ 180 // This functions exists to assure assumptions made in the code regarding SVGElementInstance creation/destruction are satisfied. 181 SVGGraphicsElement::insertedInto(rootParent); 182 if (!rootParent.inDocument()) 183 return InsertionDone; 184 ASSERT(!m_targetElementInstance || !isWellFormedDocument(document())); 185 ASSERT(!hasPendingResources() || !isWellFormedDocument(document())); 186 SVGExternalResourcesRequired::insertedIntoDocument(this); 187 if (!m_wasInsertedByParser) 188 return InsertionShouldCallDidNotifySubtreeInsertions; 189 return InsertionDone; 190} 191 192void SVGUseElement::didNotifySubtreeInsertions(ContainerNode*) 193{ 194 buildPendingResource(); 195} 196 197void SVGUseElement::removedFrom(ContainerNode& rootParent) 198{ 199 SVGGraphicsElement::removedFrom(rootParent); 200 if (rootParent.inDocument()) 201 clearResourceReferences(); 202} 203 204Document* SVGUseElement::referencedDocument() const 205{ 206 if (!isExternalURIReference(href(), document())) 207 return &document(); 208 return externalDocument(); 209} 210 211Document* SVGUseElement::externalDocument() const 212{ 213 if (m_cachedDocument && m_cachedDocument->isLoaded()) { 214 // Gracefully handle error condition. 215 if (m_cachedDocument->errorOccurred()) 216 return 0; 217 ASSERT(m_cachedDocument->document()); 218 return m_cachedDocument->document(); 219 } 220 return 0; 221} 222 223void SVGUseElement::svgAttributeChanged(const QualifiedName& attrName) 224{ 225 if (!isSupportedAttribute(attrName)) { 226 SVGGraphicsElement::svgAttributeChanged(attrName); 227 return; 228 } 229 230 SVGElementInstance::InvalidationGuard invalidationGuard(this); 231 232 auto renderer = this->renderer(); 233 if (attrName == SVGNames::xAttr 234 || attrName == SVGNames::yAttr 235 || attrName == SVGNames::widthAttr 236 || attrName == SVGNames::heightAttr) { 237 updateRelativeLengthsInformation(); 238 if (renderer) 239 RenderSVGResource::markForLayoutAndParentResourceInvalidation(*renderer); 240 return; 241 } 242 243 if (SVGExternalResourcesRequired::handleAttributeChange(this, attrName)) 244 return; 245 246 if (SVGURIReference::isKnownAttribute(attrName)) { 247 bool isExternalReference = isExternalURIReference(href(), document()); 248 if (isExternalReference) { 249 URL url = document().completeURL(href()); 250 if (url.hasFragmentIdentifier()) { 251 CachedResourceRequest request(ResourceRequest(url.string())); 252 request.setInitiator(this); 253 setCachedDocument(document().cachedResourceLoader()->requestSVGDocument(request)); 254 } 255 } else 256 setCachedDocument(0); 257 258 if (!m_wasInsertedByParser) 259 buildPendingResource(); 260 261 return; 262 } 263 264 if (SVGLangSpace::isKnownAttribute(attrName) 265 || SVGExternalResourcesRequired::isKnownAttribute(attrName)) { 266 invalidateShadowTree(); 267 return; 268 } 269 270 ASSERT_NOT_REACHED(); 271} 272 273void SVGUseElement::willAttachRenderers() 274{ 275 if (m_needsShadowTreeRecreation) 276 buildPendingResource(); 277} 278 279#ifdef DUMP_INSTANCE_TREE 280static void dumpInstanceTree(unsigned int& depth, String& text, SVGElementInstance* targetInstance) 281{ 282 SVGElement* element = targetInstance->correspondingElement(); 283 ASSERT(element); 284 285 if (element->hasTagName(SVGNames::useTag)) { 286 if (toSVGUseElement(element)->cachedDocumentIsStillLoading()) 287 return; 288 } 289 290 SVGElement* shadowTreeElement = targetInstance->shadowTreeElement(); 291 ASSERT(shadowTreeElement); 292 293 SVGUseElement* directUseElement = targetInstance->directUseElement(); 294 String directUseElementName = directUseElement ? directUseElement->nodeName() : "null"; 295 296 String elementId = element->getIdAttribute(); 297 String elementNodeName = element->nodeName(); 298 String shadowTreeElementNodeName = shadowTreeElement->nodeName(); 299 String parentNodeName = element->parentNode() ? element->parentNode()->nodeName() : "null"; 300 String firstChildNodeName = element->firstChild() ? element->firstChild()->nodeName() : "null"; 301 302 for (unsigned int i = 0; i < depth; ++i) 303 text += " "; 304 305 text += String::format("SVGElementInstance this=%p, (parentNode=%s (%p), firstChild=%s (%p), correspondingElement=%s (%p), directUseElement=%s (%p), shadowTreeElement=%s (%p), id=%s)\n", 306 targetInstance, parentNodeName.latin1().data(), element->parentNode(), firstChildNodeName.latin1().data(), element->firstChild(), 307 elementNodeName.latin1().data(), element, directUseElementName.latin1().data(), directUseElement, shadowTreeElementNodeName.latin1().data(), shadowTreeElement, elementId.latin1().data()); 308 309 for (unsigned int i = 0; i < depth; ++i) 310 text += " "; 311 312 const HashSet<SVGElementInstance*>& elementInstances = element->instancesForElement(); 313 text += "Corresponding element is associated with " + String::number(elementInstances.size()) + " instance(s):\n"; 314 315 const HashSet<SVGElementInstance*>::const_iterator end = elementInstances.end(); 316 for (HashSet<SVGElementInstance*>::const_iterator it = elementInstances.begin(); it != end; ++it) { 317 for (unsigned int i = 0; i < depth; ++i) 318 text += " "; 319 320 text += String::format(" -> SVGElementInstance this=%p, (refCount: %i, shadowTreeElement in document? %i)\n", 321 *it, (*it)->refCount(), (*it)->shadowTreeElement()->inDocument()); 322 } 323 324 ++depth; 325 326 for (SVGElementInstance* instance = targetInstance->firstChild(); instance; instance = instance->nextSibling()) 327 dumpInstanceTree(depth, text, instance); 328 329 --depth; 330} 331#endif 332 333static bool isDisallowedElement(const Element& element) 334{ 335 // Spec: "Any 'svg', 'symbol', 'g', graphics element or other 'use' is potentially a template object that can be re-used 336 // (i.e., "instanced") in the SVG document via a 'use' element." 337 // "Graphics Element" is defined as 'circle', 'ellipse', 'image', 'line', 'path', 'polygon', 'polyline', 'rect', 'text' 338 // Excluded are anything that is used by reference or that only make sense to appear once in a document. 339 340 if (!element.isSVGElement()) 341 return true; 342 343 static NeverDestroyed<HashSet<QualifiedName>> allowedElementTags; 344 if (allowedElementTags.get().isEmpty()) { 345 allowedElementTags.get().add(SVGNames::aTag); 346 allowedElementTags.get().add(SVGNames::circleTag); 347 allowedElementTags.get().add(SVGNames::descTag); 348 allowedElementTags.get().add(SVGNames::ellipseTag); 349 allowedElementTags.get().add(SVGNames::gTag); 350 allowedElementTags.get().add(SVGNames::imageTag); 351 allowedElementTags.get().add(SVGNames::lineTag); 352 allowedElementTags.get().add(SVGNames::metadataTag); 353 allowedElementTags.get().add(SVGNames::pathTag); 354 allowedElementTags.get().add(SVGNames::polygonTag); 355 allowedElementTags.get().add(SVGNames::polylineTag); 356 allowedElementTags.get().add(SVGNames::rectTag); 357 allowedElementTags.get().add(SVGNames::svgTag); 358 allowedElementTags.get().add(SVGNames::switchTag); 359 allowedElementTags.get().add(SVGNames::symbolTag); 360 allowedElementTags.get().add(SVGNames::textTag); 361 allowedElementTags.get().add(SVGNames::textPathTag); 362 allowedElementTags.get().add(SVGNames::titleTag); 363 allowedElementTags.get().add(SVGNames::trefTag); 364 allowedElementTags.get().add(SVGNames::tspanTag); 365 allowedElementTags.get().add(SVGNames::useTag); 366 } 367 return !allowedElementTags.get().contains<SVGAttributeHashTranslator>(element.tagQName()); 368} 369 370static bool subtreeContainsDisallowedElement(SVGElement& start) 371{ 372 for (auto& element : descendantsOfType<Element>(start)) { 373 if (isDisallowedElement(element)) 374 return true; 375 } 376 377 return false; 378} 379 380void SVGUseElement::clearResourceReferences() 381{ 382 // FIXME: We should try to optimize this, to at least allow partial reclones. 383 if (ShadowRoot* shadowTreeRootElement = shadowRoot()) 384 shadowTreeRootElement->removeChildren(); 385 386 if (m_targetElementInstance) { 387 m_targetElementInstance->detach(); 388 m_targetElementInstance = 0; 389 } 390 391 m_needsShadowTreeRecreation = false; 392 393 document().accessSVGExtensions()->removeAllTargetReferencesForElement(this); 394} 395 396void SVGUseElement::buildPendingResource() 397{ 398 if (!referencedDocument() || isInShadowTree()) 399 return; 400 clearResourceReferences(); 401 if (!inDocument()) 402 return; 403 404 String id; 405 Element* target = SVGURIReference::targetElementFromIRIString(href(), document(), &id, externalDocument()); 406 if (!target || !target->inDocument()) { 407 // If we can't find the target of an external element, just give up. 408 // We can't observe if the target somewhen enters the external document, nor should we do it. 409 if (externalDocument()) 410 return; 411 if (id.isEmpty()) 412 return; 413 414 referencedDocument()->accessSVGExtensions()->addPendingResource(id, this); 415 ASSERT(hasPendingResources()); 416 return; 417 } 418 419 if (target->isSVGElement()) { 420 buildShadowAndInstanceTree(toSVGElement(target)); 421 invalidateDependentShadowTrees(); 422 } 423 424 ASSERT(!m_needsShadowTreeRecreation); 425} 426 427void SVGUseElement::buildShadowAndInstanceTree(SVGElement* target) 428{ 429 ASSERT(!m_targetElementInstance); 430 431 // Do not build the shadow/instance tree for <use> elements living in a shadow tree. 432 // The will be expanded soon anyway - see expandUseElementsInShadowTree(). 433 if (isInShadowTree()) 434 return; 435 436 // Do not allow self-referencing. 437 // 'target' may be null, if it's a non SVG namespaced element. 438 if (!target || target == this) 439 return; 440 441 // Why a seperated instance/shadow tree? SVG demands it: 442 // The instance tree is accesable from JavaScript, and has to 443 // expose a 1:1 copy of the referenced tree, whereas internally we need 444 // to alter the tree for correct "use-on-symbol", "use-on-svg" support. 445 446 // Build instance tree. Create root SVGElementInstance object for the first sub-tree node. 447 // 448 // Spec: If the 'use' element references a simple graphics element such as a 'rect', then there is only a 449 // single SVGElementInstance object, and the correspondingElement attribute on this SVGElementInstance object 450 // is the SVGRectElement that corresponds to the referenced 'rect' element. 451 m_targetElementInstance = SVGElementInstance::create(this, this, target); 452 453 // Eventually enter recursion to build SVGElementInstance objects for the sub-tree children 454 bool foundProblem = false; 455 buildInstanceTree(target, m_targetElementInstance.get(), foundProblem, false); 456 457 if (instanceTreeIsLoading(m_targetElementInstance.get())) 458 return; 459 460 // SVG specification does not say a word about <use> & cycles. My view on this is: just ignore it! 461 // Non-appearing <use> content is easier to debug, then half-appearing content. 462 if (foundProblem) { 463 clearResourceReferences(); 464 return; 465 } 466 467 // Assure instance tree building was successfull 468 ASSERT(m_targetElementInstance); 469 ASSERT(!m_targetElementInstance->shadowTreeElement()); 470 ASSERT(m_targetElementInstance->correspondingUseElement() == this); 471 ASSERT(m_targetElementInstance->directUseElement() == this); 472 ASSERT(m_targetElementInstance->correspondingElement() == target); 473 474 ShadowRoot* shadowTreeRootElement = shadowRoot(); 475 ASSERT(shadowTreeRootElement); 476 477 // Build shadow tree from instance tree 478 // This also handles the special cases: <use> on <symbol>, <use> on <svg>. 479 buildShadowTree(target, m_targetElementInstance.get()); 480 481 // Expand all <use> elements in the shadow tree. 482 // Expand means: replace the actual <use> element by what it references. 483 expandUseElementsInShadowTree(shadowTreeRootElement); 484 485 // Expand all <symbol> elements in the shadow tree. 486 // Expand means: replace the actual <symbol> element by the <svg> element. 487 expandSymbolElementsInShadowTree(shadowTreeRootElement); 488 489 // Now that the shadow tree is completly expanded, we can associate 490 // shadow tree elements <-> instances in the instance tree. 491 associateInstancesWithShadowTreeElements(shadowTreeRootElement->firstChild(), m_targetElementInstance.get()); 492 493 // If no shadow tree element is present, this means that the reference root 494 // element was removed, as it is disallowed (ie. <use> on <foreignObject>) 495 // Do NOT leave an inconsistent instance tree around, instead destruct it. 496 if (!m_targetElementInstance->shadowTreeElement()) { 497 clearResourceReferences(); 498 return; 499 } 500 501 ASSERT(m_targetElementInstance->shadowTreeElement()->parentNode() == shadowTreeRootElement); 502 503 // Transfer event listeners assigned to the referenced element to our shadow tree elements. 504 transferEventListenersToShadowTree(m_targetElementInstance.get()); 505 506 // Update relative length information. 507 updateRelativeLengthsInformation(); 508 509 // Eventually dump instance tree 510#ifdef DUMP_INSTANCE_TREE 511 String text; 512 unsigned int depth = 0; 513 514 dumpInstanceTree(depth, text, m_targetElementInstance.get()); 515 fprintf(stderr, "\nDumping <use> instance tree:\n%s\n", text.latin1().data()); 516#endif 517 518 // Eventually dump shadow tree 519#ifdef DUMP_SHADOW_TREE 520 RefPtr<XMLSerializer> serializer = XMLSerializer::create(); 521 String markup = serializer->serializeToString(shadowTreeRootElement, ASSERT_NO_EXCEPTION); 522 fprintf(stderr, "Dumping <use> shadow tree markup:\n%s\n", markup.latin1().data()); 523#endif 524} 525 526RenderPtr<RenderElement> SVGUseElement::createElementRenderer(PassRef<RenderStyle> style) 527{ 528 return createRenderer<RenderSVGTransformableContainer>(*this, WTF::move(style)); 529} 530 531static bool isDirectReference(const SVGElement& element) 532{ 533 return element.hasTagName(SVGNames::pathTag) 534 || element.hasTagName(SVGNames::rectTag) 535 || element.hasTagName(SVGNames::circleTag) 536 || element.hasTagName(SVGNames::ellipseTag) 537 || element.hasTagName(SVGNames::polygonTag) 538 || element.hasTagName(SVGNames::polylineTag) 539 || element.hasTagName(SVGNames::textTag); 540} 541 542void SVGUseElement::toClipPath(Path& path) 543{ 544 ASSERT(path.isEmpty()); 545 546 Node* n = m_targetElementInstance ? m_targetElementInstance->shadowTreeElement() : 0; 547 if (!n) 548 return; 549 550 if (n->isSVGElement() && toSVGElement(*n).isSVGGraphicsElement()) { 551 if (!isDirectReference(toSVGElement(*n))) { 552 // Spec: Indirect references are an error (14.3.5) 553 document().accessSVGExtensions()->reportError("Not allowed to use indirect reference in <clip-path>"); 554 } else { 555 toSVGGraphicsElement(*n).toClipPath(path); 556 // FIXME: Avoid manual resolution of x/y here. Its potentially harmful. 557 SVGLengthContext lengthContext(this); 558 path.translate(FloatSize(x().value(lengthContext), y().value(lengthContext))); 559 path.transform(animatedLocalTransform()); 560 } 561 } 562} 563 564RenderElement* SVGUseElement::rendererClipChild() const 565{ 566 if (!m_targetElementInstance) 567 return nullptr; 568 569 auto* element = m_targetElementInstance->shadowTreeElement(); 570 if (!element) 571 return nullptr; 572 573 if (!isDirectReference(*element)) 574 return nullptr; 575 576 return element->renderer(); 577} 578 579void SVGUseElement::buildInstanceTree(SVGElement* target, SVGElementInstance* targetInstance, bool& foundProblem, bool foundUse) 580{ 581 ASSERT(target); 582 ASSERT(targetInstance); 583 584 // Spec: If the referenced object is itself a 'use', or if there are 'use' subelements within the referenced 585 // object, the instance tree will contain recursive expansion of the indirect references to form a complete tree. 586 bool targetHasUseTag = target->hasTagName(SVGNames::useTag); 587 SVGElement* newTarget = 0; 588 if (targetHasUseTag) { 589 foundProblem = hasCycleUseReferencing(toSVGUseElement(target), targetInstance, newTarget); 590 if (foundProblem) 591 return; 592 593 // We only need to track first degree <use> dependencies. Indirect references are handled 594 // as the invalidation bubbles up the dependency chain. 595 if (!foundUse) { 596 document().accessSVGExtensions()->addElementReferencingTarget(this, target); 597 foundUse = true; 598 } 599 } else if (isDisallowedElement(*target)) { 600 foundProblem = true; 601 return; 602 } 603 604 // A general description from the SVG spec, describing what buildInstanceTree() actually does. 605 // 606 // Spec: If the 'use' element references a 'g' which contains two 'rect' elements, then the instance tree 607 // contains three SVGElementInstance objects, a root SVGElementInstance object whose correspondingElement 608 // is the SVGGElement object for the 'g', and then two child SVGElementInstance objects, each of which has 609 // its correspondingElement that is an SVGRectElement object. 610 611 for (auto& element : childrenOfType<SVGElement>(*target)) { 612 // Skip any non-svg nodes or any disallowed element. 613 if (isDisallowedElement(element)) 614 continue; 615 616 // Create SVGElementInstance object, for both container/non-container nodes. 617 RefPtr<SVGElementInstance> instance = SVGElementInstance::create(this, 0, &element); 618 SVGElementInstance* instancePtr = instance.get(); 619 targetInstance->appendChild(instance.release()); 620 621 // Enter recursion, appending new instance tree nodes to the "instance" object. 622 buildInstanceTree(&element, instancePtr, foundProblem, foundUse); 623 if (foundProblem) 624 return; 625 } 626 627 if (!targetHasUseTag || !newTarget) 628 return; 629 630 RefPtr<SVGElementInstance> newInstance = SVGElementInstance::create(this, toSVGUseElement(target), newTarget); 631 SVGElementInstance* newInstancePtr = newInstance.get(); 632 targetInstance->appendChild(newInstance.release()); 633 buildInstanceTree(newTarget, newInstancePtr, foundProblem, foundUse); 634} 635 636bool SVGUseElement::hasCycleUseReferencing(SVGUseElement* use, SVGElementInstance* targetInstance, SVGElement*& newTarget) 637{ 638 ASSERT(referencedDocument()); 639 Element* targetElement = SVGURIReference::targetElementFromIRIString(use->href(), *referencedDocument()); 640 newTarget = 0; 641 if (targetElement && targetElement->isSVGElement()) 642 newTarget = toSVGElement(targetElement); 643 644 if (!newTarget) 645 return false; 646 647 // Shortcut for self-references 648 if (newTarget == this) 649 return true; 650 651 AtomicString targetId = newTarget->getIdAttribute(); 652 SVGElementInstance* instance = targetInstance->parentNode(); 653 while (instance) { 654 SVGElement* element = instance->correspondingElement(); 655 656 if (element->hasID() && element->getIdAttribute() == targetId && &element->document() == &newTarget->document()) 657 return true; 658 659 instance = instance->parentNode(); 660 } 661 return false; 662} 663 664static inline void removeDisallowedElementsFromSubtree(SVGElement& subtree) 665{ 666 ASSERT(!subtree.inDocument()); 667 Vector<Element*> toRemove; 668 auto it = descendantsOfType<Element>(subtree).begin(); 669 auto end = descendantsOfType<Element>(subtree).end(); 670 while (it != end) { 671 if (isDisallowedElement(*it)) { 672 toRemove.append(&*it); 673 it.traverseNextSkippingChildren(); 674 continue; 675 } 676 ++it; 677 } 678 // The subtree is not in document so this won't generate events that could mutate the tree. 679 for (unsigned i = 0; i < toRemove.size(); ++i) 680 toRemove[i]->parentNode()->removeChild(toRemove[i]); 681} 682 683void SVGUseElement::buildShadowTree(SVGElement* target, SVGElementInstance* targetInstance) 684{ 685 ASSERT(target); // FIXME: Don't be a pointer! 686 687 // For instance <use> on <foreignObject> (direct case). 688 if (isDisallowedElement(*target)) 689 return; 690 691 RefPtr<SVGElement> newChild = static_pointer_cast<SVGElement>(targetInstance->correspondingElement()->cloneElementWithChildren()); 692 693 // We don't walk the target tree element-by-element, and clone each element, 694 // but instead use cloneElementWithChildren(). This is an optimization for the common 695 // case where <use> doesn't contain disallowed elements (ie. <foreignObject>). 696 // Though if there are disallowed elements in the subtree, we have to remove them. 697 // For instance: <use> on <g> containing <foreignObject> (indirect case). 698 if (subtreeContainsDisallowedElement(*newChild)) 699 removeDisallowedElementsFromSubtree(*newChild); 700 701 shadowRoot()->appendChild(newChild.release()); 702} 703 704void SVGUseElement::expandUseElementsInShadowTree(Node* element) 705{ 706 // Why expand the <use> elements in the shadow tree here, and not just 707 // do this directly in buildShadowTree, if we encounter a <use> element? 708 // 709 // Short answer: Because we may miss to expand some elements. Ie. if a <symbol> 710 // contains <use> tags, we'd miss them. So once we're done with settin' up the 711 // actual shadow tree (after the special case modification for svg/symbol) we have 712 // to walk it completely and expand all <use> elements. 713 if (element->hasTagName(SVGNames::useTag)) { 714 SVGUseElement* use = toSVGUseElement(element); 715 ASSERT(!use->cachedDocumentIsStillLoading()); 716 717 ASSERT(referencedDocument()); 718 Element* targetElement = SVGURIReference::targetElementFromIRIString(use->href(), *referencedDocument()); 719 SVGElement* target = 0; 720 if (targetElement && targetElement->isSVGElement()) 721 target = toSVGElement(targetElement); 722 723 // Don't ASSERT(target) here, it may be "pending", too. 724 // Setup sub-shadow tree root node 725 RefPtr<SVGGElement> cloneParent = SVGGElement::create(SVGNames::gTag, *referencedDocument()); 726 use->cloneChildNodes(cloneParent.get()); 727 728 // Spec: In the generated content, the 'use' will be replaced by 'g', where all attributes from the 729 // 'use' element except for x, y, width, height and xlink:href are transferred to the generated 'g' element. 730 transferUseAttributesToReplacedElement(use, cloneParent.get()); 731 732 if (target && !isDisallowedElement(*target)) { 733 RefPtr<Element> newChild = target->cloneElementWithChildren(); 734 ASSERT(newChild->isSVGElement()); 735 cloneParent->appendChild(newChild.release()); 736 } 737 738 // We don't walk the target tree element-by-element, and clone each element, 739 // but instead use cloneElementWithChildren(). This is an optimization for the common 740 // case where <use> doesn't contain disallowed elements (ie. <foreignObject>). 741 // Though if there are disallowed elements in the subtree, we have to remove them. 742 // For instance: <use> on <g> containing <foreignObject> (indirect case). 743 if (subtreeContainsDisallowedElement(*cloneParent)) 744 removeDisallowedElementsFromSubtree(*cloneParent); 745 746 RefPtr<Node> replacingElement(cloneParent.get()); 747 748 // Replace <use> with referenced content. 749 ASSERT(use->parentNode()); 750 use->parentNode()->replaceChild(cloneParent.release(), use); 751 752 // Expand the siblings because the *element* is replaced and we will 753 // lose the sibling chain when we are back from recursion. 754 element = replacingElement.get(); 755 for (RefPtr<Node> sibling = element->nextSibling(); sibling; sibling = sibling->nextSibling()) 756 expandUseElementsInShadowTree(sibling.get()); 757 } 758 759 for (RefPtr<Node> child = element->firstChild(); child; child = child->nextSibling()) 760 expandUseElementsInShadowTree(child.get()); 761} 762 763void SVGUseElement::expandSymbolElementsInShadowTree(Node* element) 764{ 765 if (element->hasTagName(SVGNames::symbolTag)) { 766 // Spec: The referenced 'symbol' and its contents are deep-cloned into the generated tree, 767 // with the exception that the 'symbol' is replaced by an 'svg'. This generated 'svg' will 768 // always have explicit values for attributes width and height. If attributes width and/or 769 // height are provided on the 'use' element, then these attributes will be transferred to 770 // the generated 'svg'. If attributes width and/or height are not specified, the generated 771 // 'svg' element will use values of 100% for these attributes. 772 RefPtr<SVGSVGElement> svgElement = SVGSVGElement::create(SVGNames::svgTag, *referencedDocument()); 773 774 // Transfer all data (attributes, etc.) from <symbol> to the new <svg> element. 775 svgElement->cloneDataFromElement(*toElement(element)); 776 777 // Only clone symbol children, and add them to the new <svg> element 778 for (Node* child = element->firstChild(); child; child = child->nextSibling()) { 779 RefPtr<Node> newChild = child->cloneNode(true); 780 svgElement->appendChild(newChild.release()); 781 } 782 783 // We don't walk the target tree element-by-element, and clone each element, 784 // but instead use cloneNode(deep=true). This is an optimization for the common 785 // case where <use> doesn't contain disallowed elements (ie. <foreignObject>). 786 // Though if there are disallowed elements in the subtree, we have to remove them. 787 // For instance: <use> on <g> containing <foreignObject> (indirect case). 788 if (subtreeContainsDisallowedElement(*svgElement)) 789 removeDisallowedElementsFromSubtree(*svgElement); 790 791 RefPtr<Node> replacingElement(svgElement.get()); 792 793 // Replace <symbol> with <svg>. 794 element->parentNode()->replaceChild(svgElement.release(), element); 795 796 // Expand the siblings because the *element* is replaced and we will 797 // lose the sibling chain when we are back from recursion. 798 element = replacingElement.get(); 799 for (RefPtr<Node> sibling = element->nextSibling(); sibling; sibling = sibling->nextSibling()) 800 expandSymbolElementsInShadowTree(sibling.get()); 801 } 802 803 for (RefPtr<Node> child = element->firstChild(); child; child = child->nextSibling()) 804 expandSymbolElementsInShadowTree(child.get()); 805} 806 807void SVGUseElement::transferEventListenersToShadowTree(SVGElementInstance* target) 808{ 809 if (!target) 810 return; 811 812 SVGElement* originalElement = target->correspondingElement(); 813 ASSERT(originalElement); 814 815 if (SVGElement* shadowTreeElement = target->shadowTreeElement()) { 816 if (EventTargetData* data = originalElement->eventTargetData()) 817 data->eventListenerMap.copyEventListenersNotCreatedFromMarkupToTarget(shadowTreeElement); 818 } 819 820 for (SVGElementInstance* instance = target->firstChild(); instance; instance = instance->nextSibling()) 821 transferEventListenersToShadowTree(instance); 822} 823 824void SVGUseElement::associateInstancesWithShadowTreeElements(Node* target, SVGElementInstance* targetInstance) 825{ 826 if (!target || !targetInstance) 827 return; 828 829 SVGElement* originalElement = targetInstance->correspondingElement(); 830 831 if (originalElement->hasTagName(SVGNames::useTag)) { 832 // <use> gets replaced by <g> 833 ASSERT(target->nodeName() == SVGNames::gTag); 834 } else if (originalElement->hasTagName(SVGNames::symbolTag)) { 835 // <symbol> gets replaced by <svg> 836 ASSERT(target->nodeName() == SVGNames::svgTag); 837 } else 838 ASSERT(target->nodeName() == originalElement->nodeName()); 839 840 SVGElement* element = 0; 841 if (target->isSVGElement()) 842 element = toSVGElement(target); 843 844 ASSERT(!targetInstance->shadowTreeElement()); 845 targetInstance->setShadowTreeElement(element); 846 element->setCorrespondingElement(originalElement); 847 848 Node* node = target->firstChild(); 849 for (SVGElementInstance* instance = targetInstance->firstChild(); node && instance; instance = instance->nextSibling()) { 850 // Skip any non-svg elements in shadow tree 851 while (node && !node->isSVGElement()) 852 node = node->nextSibling(); 853 854 if (!node) 855 break; 856 857 associateInstancesWithShadowTreeElements(node, instance); 858 node = node->nextSibling(); 859 } 860} 861 862SVGElementInstance* SVGUseElement::instanceForShadowTreeElement(Node* element) const 863{ 864 if (!m_targetElementInstance) { 865 ASSERT(!inDocument()); 866 return 0; 867 } 868 869 return instanceForShadowTreeElement(element, m_targetElementInstance.get()); 870} 871 872SVGElementInstance* SVGUseElement::instanceForShadowTreeElement(Node* element, SVGElementInstance* instance) const 873{ 874 ASSERT(element); 875 ASSERT(instance); 876 877 // We're dispatching a mutation event during shadow tree construction 878 // this instance hasn't yet been associated to a shadowTree element. 879 if (!instance->shadowTreeElement()) 880 return 0; 881 882 if (element == instance->shadowTreeElement()) 883 return instance; 884 885 for (SVGElementInstance* current = instance->firstChild(); current; current = current->nextSibling()) { 886 if (SVGElementInstance* search = instanceForShadowTreeElement(element, current)) 887 return search; 888 } 889 890 return 0; 891} 892 893void SVGUseElement::invalidateShadowTree() 894{ 895 if (m_needsShadowTreeRecreation) 896 return; 897 m_needsShadowTreeRecreation = true; 898 setNeedsStyleRecalc(ReconstructRenderTree); 899 invalidateDependentShadowTrees(); 900} 901 902void SVGUseElement::invalidateDependentShadowTrees() 903{ 904 // Recursively invalidate dependent <use> shadow trees 905 const HashSet<SVGElementInstance*>& instances = instancesForElement(); 906 const HashSet<SVGElementInstance*>::const_iterator end = instances.end(); 907 for (HashSet<SVGElementInstance*>::const_iterator it = instances.begin(); it != end; ++it) { 908 if (SVGUseElement* element = (*it)->correspondingUseElement()) { 909 ASSERT(element->inDocument()); 910 element->invalidateShadowTree(); 911 } 912 } 913} 914 915void SVGUseElement::transferUseAttributesToReplacedElement(SVGElement* from, SVGElement* to) const 916{ 917 ASSERT(from); 918 ASSERT(to); 919 920 to->cloneDataFromElement(*from); 921 922 to->removeAttribute(SVGNames::xAttr); 923 to->removeAttribute(SVGNames::yAttr); 924 to->removeAttribute(SVGNames::widthAttr); 925 to->removeAttribute(SVGNames::heightAttr); 926 to->removeAttribute(XLinkNames::hrefAttr); 927} 928 929bool SVGUseElement::selfHasRelativeLengths() const 930{ 931 if (x().isRelative() 932 || y().isRelative() 933 || width().isRelative() 934 || height().isRelative()) 935 return true; 936 937 if (!m_targetElementInstance) 938 return false; 939 940 SVGElement* element = m_targetElementInstance->correspondingElement(); 941 if (!element) 942 return false; 943 944 return element->hasRelativeLengths(); 945} 946 947void SVGUseElement::notifyFinished(CachedResource* resource) 948{ 949 if (!inDocument()) 950 return; 951 952 invalidateShadowTree(); 953 if (resource->errorOccurred()) 954 dispatchEvent(Event::create(eventNames().errorEvent, false, false)); 955 else if (!resource->wasCanceled()) 956 SVGExternalResourcesRequired::dispatchLoadEvent(this); 957} 958 959bool SVGUseElement::cachedDocumentIsStillLoading() 960{ 961 if (m_cachedDocument && m_cachedDocument->isLoading()) 962 return true; 963 return false; 964} 965 966bool SVGUseElement::instanceTreeIsLoading(SVGElementInstance* targetElementInstance) 967{ 968 for (SVGElementInstance* instance = targetElementInstance->firstChild(); instance; instance = instance->nextSibling()) { 969 if (SVGUseElement* use = instance->correspondingUseElement()) { 970 if (use->cachedDocumentIsStillLoading()) 971 return true; 972 } 973 if (instance->hasChildNodes()) 974 instanceTreeIsLoading(instance); 975 } 976 return false; 977} 978 979void SVGUseElement::finishParsingChildren() 980{ 981 SVGGraphicsElement::finishParsingChildren(); 982 SVGExternalResourcesRequired::finishParsingChildren(); 983 if (m_wasInsertedByParser) { 984 buildPendingResource(); 985 m_wasInsertedByParser = false; 986 } 987} 988 989void SVGUseElement::setCachedDocument(CachedResourceHandle<CachedSVGDocument> cachedDocument) 990{ 991 if (m_cachedDocument == cachedDocument) 992 return; 993 994 if (m_cachedDocument) 995 m_cachedDocument->removeClient(this); 996 997 m_cachedDocument = cachedDocument; 998 if (m_cachedDocument) 999 m_cachedDocument->addClient(this); 1000} 1001 1002} 1003