Refactor LinkStyle out of HTMLLinkElement

third_party/WebKit/Source/core/html/HTMLLinkElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google 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 "core/html/HTMLLinkElement.h"
 
 #include "bindings/core/v8/ScriptEventListener.h"
 #include "core/HTMLNames.h"
-#include "core/css/MediaList.h"
-#include "core/css/MediaQueryEvaluator.h"
-#include "core/css/StyleSheetContents.h"
-#include "core/css/resolver/StyleResolver.h"
 #include "core/dom/Attribute.h"
 #include "core/dom/Document.h"
-#include "core/dom/StyleEngine.h"
 #include "core/dom/TaskRunnerHelper.h"
 #include "core/events/Event.h"
-#include "core/fetch/CSSStyleSheetResource.h"
-#include "core/fetch/FetchRequest.h"
-#include "core/fetch/ResourceFetcher.h"
-#include "core/frame/FrameView.h"
-#include "core/frame/LocalFrame.h"
-#include "core/frame/SubresourceIntegrity.h"
 #include "core/frame/UseCounter.h"
-#include "core/frame/csp/ContentSecurityPolicy.h"
 #include "core/html/CrossOriginAttribute.h"
 #include "core/html/LinkManifest.h"
 #include "core/html/imports/LinkImport.h"
 #include "core/inspector/ConsoleMessage.h"
-#include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "core/loader/NetworkHintsInterface.h"
 #include "core/origin_trials/OriginTrials.h"
-#include "core/style/StyleInheritedData.h"
-#include "platform/ContentType.h"
-#include "platform/Histogram.h"
-#include "platform/MIMETypeRegistry.h"
-#include "platform/RuntimeEnabledFeatures.h"
 #include "public/platform/WebIconSizesParser.h"
 #include "public/platform/WebSize.h"
-#include "wtf/StdLibExtras.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
-static bool styleSheetTypeIsSupported(const String& type) {
-  String trimmedType = ContentType(type).type();
-  return trimmedType.isEmpty() ||
-         MIMETypeRegistry::isSupportedStyleSheetMIMEType(trimmedType);
-}
-
 inline HTMLLinkElement::HTMLLinkElement(Document& document,
                                         bool createdByParser)
     : HTMLElement(linkTag, document),
       m_linkLoader(LinkLoader::create(this)),
       m_sizes(DOMTokenList::create(this)),
       m_relList(RelList::create(this)),
       m_createdByParser(createdByParser) {}
 
 HTMLLinkElement* HTMLLinkElement::create(Document& document,
                                          bool createdByParser) {
@@ skipping 292 matching lines @@
   HTMLElement::trace(visitor);
   LinkLoaderClient::trace(visitor);
   DOMTokenListObserver::trace(visitor);
 }
 
 DEFINE_TRACE_WRAPPERS(HTMLLinkElement) {
   visitor->traceWrappers(m_relList);
   HTMLElement::traceWrappers(visitor);
 }
 
-LinkStyle* LinkStyle::create(HTMLLinkElement* owner) {
-  return new LinkStyle(owner);
-}
-
-LinkStyle::LinkStyle(HTMLLinkElement* owner)
-    : LinkResource(owner),
-      m_disabledState(Unset),
-      m_pendingSheetType(None),
-      m_loading(false),
-      m_firedLoad(false),
-      m_loadedSheet(false),
-      m_fetchFollowingCORS(false) {}
-
-LinkStyle::~LinkStyle() {}
-
-Document& LinkStyle::document() {
-  return m_owner->document();
-}
-
-enum StyleSheetCacheStatus {
-  StyleSheetNewEntry,
-  StyleSheetInDiskCache,
-  StyleSheetInMemoryCache,
-  StyleSheetCacheStatusCount,
-};
-
-void LinkStyle::setCSSStyleSheet(
-    const String& href,
-    const KURL& baseURL,
-    const String& charset,
-    const CSSStyleSheetResource* cachedStyleSheet) {
-  if (!m_owner->isConnected()) {
-    // While the stylesheet is asynchronously loading, the owner can be disconnected from a document.
-    // In that case, cancel any processing on the loaded content.
-    m_loading = false;
-    removePendingSheet();
-    if (m_sheet)
-      clearSheet();
-    return;
-  }
-
-  // See the comment in PendingScript.cpp about why this check is necessary
-  // here, instead of in the resource fetcher. https://crbug.com/500701.
-  if (!cachedStyleSheet->errorOccurred() &&
-      m_owner->fastHasAttribute(HTMLNames::integrityAttr) &&
-      cachedStyleSheet->resourceBuffer() &&
-      !SubresourceIntegrity::CheckSubresourceIntegrity(
-          *m_owner, cachedStyleSheet->resourceBuffer()->data(),
-          cachedStyleSheet->resourceBuffer()->size(), KURL(baseURL, href),
-          *cachedStyleSheet)) {
-    m_loading = false;
-    removePendingSheet();
-    notifyLoadedSheetAndAllCriticalSubresources(
-        Node::ErrorOccurredLoadingSubresource);
-    return;
-  }
-
-  CSSParserContext parserContext(m_owner->document(), nullptr, baseURL,
-                                 charset);
-
-  DEFINE_STATIC_LOCAL(EnumerationHistogram, restoredCachedStyleSheetHistogram,
-                      ("Blink.RestoredCachedStyleSheet", 2));
-  DEFINE_STATIC_LOCAL(
-      EnumerationHistogram, restoredCachedStyleSheet2Histogram,
-      ("Blink.RestoredCachedStyleSheet2", StyleSheetCacheStatusCount));
-
-  if (StyleSheetContents* restoredSheet =
-          const_cast<CSSStyleSheetResource*>(cachedStyleSheet)
-              ->restoreParsedStyleSheet(parserContext)) {
-    DCHECK(restoredSheet->isCacheableForResource());
-    DCHECK(!restoredSheet->isLoading());
-
-    if (m_sheet)
-      clearSheet();
-    m_sheet = CSSStyleSheet::create(restoredSheet, *m_owner);
-    m_sheet->setMediaQueries(MediaQuerySet::create(m_owner->media()));
-    if (m_owner->isInDocumentTree())
-      setSheetTitle(m_owner->title());
-    setCrossOriginStylesheetStatus(m_sheet.get());
-
-    m_loading = false;
-    restoredSheet->checkLoaded();
-
-    restoredCachedStyleSheetHistogram.count(true);
-    restoredCachedStyleSheet2Histogram.count(StyleSheetInMemoryCache);
-    return;
-  }
-  restoredCachedStyleSheetHistogram.count(false);
-  StyleSheetCacheStatus cacheStatus = cachedStyleSheet->response().wasCached()
-                                          ? StyleSheetInDiskCache
-                                          : StyleSheetNewEntry;
-  restoredCachedStyleSheet2Histogram.count(cacheStatus);
-
-  StyleSheetContents* styleSheet =
-      StyleSheetContents::create(href, parserContext);
-
-  if (m_sheet)
-    clearSheet();
-
-  m_sheet = CSSStyleSheet::create(styleSheet, *m_owner);
-  m_sheet->setMediaQueries(MediaQuerySet::create(m_owner->media()));
-  if (m_owner->isInDocumentTree())
-    setSheetTitle(m_owner->title());
-  setCrossOriginStylesheetStatus(m_sheet.get());
-
-  styleSheet->parseAuthorStyleSheet(cachedStyleSheet,
-                                    m_owner->document().getSecurityOrigin());
-
-  m_loading = false;
-  styleSheet->notifyLoadedSheet(cachedStyleSheet);
-  styleSheet->checkLoaded();
-
-  if (styleSheet->isCacheableForResource())
-    const_cast<CSSStyleSheetResource*>(cachedStyleSheet)
-        ->saveParsedStyleSheet(styleSheet);
-  clearResource();
-}
-
-bool LinkStyle::sheetLoaded() {
-  if (!styleSheetIsLoading()) {
-    removePendingSheet();
-    return true;
-  }
-  return false;
-}
-
-void LinkStyle::notifyLoadedSheetAndAllCriticalSubresources(
-    Node::LoadedSheetErrorStatus errorStatus) {
-  if (m_firedLoad)
-    return;
-  m_loadedSheet = (errorStatus == Node::NoErrorLoadingSubresource);
-  if (m_owner)
-    m_owner->scheduleEvent();
-  m_firedLoad = true;
-}
-
-void LinkStyle::startLoadingDynamicSheet() {
-  DCHECK_LT(m_pendingSheetType, Blocking);
-  addPendingSheet(Blocking);
-}
-
-void LinkStyle::clearSheet() {
-  DCHECK(m_sheet);
-  DCHECK_EQ(m_sheet->ownerNode(), m_owner);
-  m_sheet.release()->clearOwnerNode();
-}
-
-bool LinkStyle::styleSheetIsLoading() const {
-  if (m_loading)
-    return true;
-  if (!m_sheet)
-    return false;
-  return m_sheet->contents()->isLoading();
-}
-
-void LinkStyle::addPendingSheet(PendingSheetType type) {
-  if (type <= m_pendingSheetType)
-    return;
-  m_pendingSheetType = type;
-
-  if (m_pendingSheetType == NonBlocking)
-    return;
-  m_owner->document().styleEngine().addPendingSheet(m_styleEngineContext);
-}
-
-void LinkStyle::removePendingSheet() {
-  DCHECK(m_owner);
-  PendingSheetType type = m_pendingSheetType;
-  m_pendingSheetType = None;
-
-  if (type == None)
-    return;
-  if (type == NonBlocking) {
-    // Tell StyleEngine to re-compute styleSheets of this m_owner's treescope.
-    m_owner->document().styleEngine().modifiedStyleSheetCandidateNode(*m_owner);
-    return;
-  }
-
-  m_owner->document().styleEngine().removePendingSheet(*m_owner,
-                                                       m_styleEngineContext);
-}
-
-void LinkStyle::setDisabledState(bool disabled) {
-  LinkStyle::DisabledState oldDisabledState = m_disabledState;
-  m_disabledState = disabled ? Disabled : EnabledViaScript;
-  if (oldDisabledState != m_disabledState) {
-    // If we change the disabled state while the sheet is still loading, then we have to
-    // perform three checks:
-    if (styleSheetIsLoading()) {
-      // Check #1: The sheet becomes disabled while loading.
-      if (m_disabledState == Disabled)
-        removePendingSheet();
-
-      // Check #2: An alternate sheet becomes enabled while it is still loading.
-      if (m_owner->relAttribute().isAlternate() &&
-          m_disabledState == EnabledViaScript)
-        addPendingSheet(Blocking);
-
-      // Check #3: A main sheet becomes enabled while it was still loading and
-      // after it was disabled via script. It takes really terrible code to make this
-      // happen (a double toggle for no reason essentially). This happens on
-      // virtualplastic.net, which manages to do about 12 enable/disables on only 3
-      // sheets. :)
-      if (!m_owner->relAttribute().isAlternate() &&
-          m_disabledState == EnabledViaScript && oldDisabledState == Disabled)
-        addPendingSheet(Blocking);
-
-      // If the sheet is already loading just bail.
-      return;
-    }
-
-    if (m_sheet) {
-      m_sheet->setDisabled(disabled);
-      return;
-    }
-
-    if (m_disabledState == EnabledViaScript && m_owner->shouldProcessStyle())
-      process();
-  }
-}
-
-void LinkStyle::setCrossOriginStylesheetStatus(CSSStyleSheet* sheet) {
-  if (m_fetchFollowingCORS && resource() && !resource()->errorOccurred()) {
-    // Record the security origin the CORS access check succeeded at, if cross origin.
-    // Only origins that are script accessible to it may access the stylesheet's rules.
-    sheet->setAllowRuleAccessFromOrigin(
-        m_owner->document().getSecurityOrigin());
-  }
-  m_fetchFollowingCORS = false;
-}
-
-void LinkStyle::process() {
-  DCHECK(m_owner->shouldProcessStyle());
-  String type = m_owner->typeValue().lower();
-  String as = m_owner->asValue().lower();
-  String media = m_owner->media().lower();
-  LinkRequestBuilder builder(m_owner);
-
-  if (m_owner->relAttribute().getIconType() != InvalidIcon &&
-      builder.url().isValid() && !builder.url().isEmpty()) {
-    if (!m_owner->shouldLoadLink())
-      return;
-    if (!document().getSecurityOrigin()->canDisplay(builder.url()))
-      return;
-    if (!document().contentSecurityPolicy()->allowImageFromSource(
-            builder.url()))
-      return;
-    if (document().frame() && document().frame()->loader().client())
-      document().frame()->loader().client()->dispatchDidChangeIcons(
-          m_owner->relAttribute().getIconType());
-  }
-
-  if (!m_owner->loadLink(type, as, media, builder.url()))
-    return;
-
-  if (m_disabledState != Disabled && m_owner->relAttribute().isStyleSheet() &&
-      styleSheetTypeIsSupported(type) && shouldLoadResource() &&
-      builder.url().isValid()) {
-    if (resource()) {
-      removePendingSheet();
-      clearResource();
-      clearFetchFollowingCORS();
-    }
-
-    if (!m_owner->shouldLoadLink())
-      return;
-
-    m_loading = true;
-
-    String title = m_owner->title();
-    if (!title.isEmpty() && !m_owner->isAlternate() &&
-        m_disabledState != EnabledViaScript && m_owner->isInDocumentTree())
-      document().styleEngine().setPreferredStylesheetSetNameIfNotSet(
-          title, StyleEngine::DontUpdateActiveSheets);
-
-    bool mediaQueryMatches = true;
-    LocalFrame* frame = loadingFrame();
-    if (!m_owner->media().isEmpty() && frame) {
-      MediaQuerySet* media = MediaQuerySet::create(m_owner->media());
-      MediaQueryEvaluator evaluator(frame);
-      mediaQueryMatches = evaluator.eval(media);
-    }
-
-    // Don't hold up layout tree construction and script execution on stylesheets
-    // that are not needed for the layout at the moment.
-    bool blocking = mediaQueryMatches && !m_owner->isAlternate() &&
-                    m_owner->isCreatedByParser();
-    addPendingSheet(blocking ? Blocking : NonBlocking);
-
-    // Load stylesheets that are not needed for the layout immediately with low priority.
-    // When the link element is created by scripts, load the stylesheets asynchronously but in high priority.
-    bool lowPriority = !mediaQueryMatches || m_owner->isAlternate();
-    FetchRequest request = builder.build(lowPriority);
-    CrossOriginAttributeValue crossOrigin = crossOriginAttributeValue(
-        m_owner->fastGetAttribute(HTMLNames::crossoriginAttr));
-    if (crossOrigin != CrossOriginAttributeNotSet) {
-      request.setCrossOriginAccessControl(document().getSecurityOrigin(),
-                                          crossOrigin);
-      setFetchFollowingCORS();
-    }
-
-    String integrityAttr = m_owner->fastGetAttribute(HTMLNames::integrityAttr);
-    if (!integrityAttr.isEmpty()) {
-      IntegrityMetadataSet metadataSet;
-      SubresourceIntegrity::parseIntegrityAttribute(integrityAttr, metadataSet);
-      request.setIntegrityMetadata(metadataSet);
-    }
-    setResource(CSSStyleSheetResource::fetch(request, document().fetcher()));
-
-    if (m_loading && !resource()) {
-      // The request may have been denied if (for example) the stylesheet is local and the document is remote, or if there was a Content Security Policy Failure.
-      // setCSSStyleSheet() can be called synchronuosly in setResource() and thus resource() is null and |m_loading| is false in such cases even if the request succeeds.
-      m_loading = false;
-      removePendingSheet();
-      notifyLoadedSheetAndAllCriticalSubresources(
-          Node::ErrorOccurredLoadingSubresource);
-    }
-  } else if (m_sheet) {
-    // we no longer contain a stylesheet, e.g. perhaps rel or type was changed
-    StyleSheet* removedSheet = m_sheet.get();
-    clearSheet();
-    document().styleEngine().setNeedsActiveStyleUpdate(removedSheet,
-                                                       FullStyleUpdate);
-  }
-}
-
-void LinkStyle::setSheetTitle(
-    const String& title,
-    StyleEngine::ActiveSheetsUpdate updateActiveSheets) {
-  if (!m_owner->isInDocumentTree() || !m_owner->relAttribute().isStyleSheet())
-    return;
-
-  if (m_sheet)
-    m_sheet->setTitle(title);
-
-  if (title.isEmpty() || !isUnset() || m_owner->isAlternate())
-    return;
-
-  KURL href = m_owner->getNonEmptyURLAttribute(hrefAttr);
-  if (href.isValid() && !href.isEmpty())
-    document().styleEngine().setPreferredStylesheetSetNameIfNotSet(
-        title, updateActiveSheets);
-}
-
-void LinkStyle::ownerRemoved() {
-  if (m_sheet)
-    clearSheet();
-
-  if (styleSheetIsLoading())
-    removePendingSheet();
-}
-
 DEFINE_TRACE(LinkStyle) {
   visitor->trace(m_sheet);
   LinkResource::trace(visitor);
   ResourceOwner<StyleSheetResource>::trace(visitor);
 }
 
 }  // namespace blink