Source/WebCore/html/HTMLLinkElement.cpp - platform/external/webkit - Git at Google

 /*
  * 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)
  *
  * 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 "HTMLLinkElement.h"

 #include "Attribute.h"
 #include "CachedCSSStyleSheet.h"
 #include "CachedResource.h"
 #include "CachedResourceLoader.h"
 #include "CSSStyleSelector.h"
 #include "Document.h"
 #include "Frame.h"
 #include "FrameLoader.h"
 #include "FrameLoaderClient.h"
 #include "FrameTree.h"
 #include "FrameView.h"
 #include "HTMLNames.h"
 #include "HTMLParserIdioms.h"
 #include "MediaList.h"
 #include "MediaQueryEvaluator.h"
 #include "Page.h"
 #include "ResourceHandle.h"
 #include "ScriptEventListener.h"
 #include "Settings.h"
 #include <wtf/StdLibExtras.h>

 namespace WebCore {

 using namespace HTMLNames;

 inline HTMLLinkElement::HTMLLinkElement(const QualifiedName& tagName, Document* document, bool createdByParser)
     : HTMLElement(tagName, document)
 #if ENABLE(LINK_PREFETCH)
     , m_onloadTimer(this, &HTMLLinkElement::onloadTimerFired)
 #endif
     , m_disabledState(Unset)
     , m_loading(false)
     , m_createdByParser(createdByParser)
     , m_isInShadowTree(false)
     , m_pendingSheetType(None)
 {
     ASSERT(hasTagName(linkTag));
 }

 PassRefPtr<HTMLLinkElement> HTMLLinkElement::create(const QualifiedName& tagName, Document* document, bool createdByParser)
 {
     return adoptRef(new HTMLLinkElement(tagName, document, createdByParser));
 }

 HTMLLinkElement::~HTMLLinkElement()
 {
     if (m_sheet)
         m_sheet->clearOwnerNode();

     if (m_cachedSheet) {
         m_cachedSheet->removeClient(this);
         removePendingSheet();
     }

 #if ENABLE(LINK_PREFETCH)
     if (m_cachedLinkResource)
         m_cachedLinkResource->removeClient(this);
 #endif
 }

 void HTMLLinkElement::setDisabledState(bool _disabled)
 {
     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 (isLoading()) {
             // 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_relAttribute.m_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_relAttribute.m_isAlternate && m_disabledState == EnabledViaScript && oldDisabledState == Disabled)
                 addPendingSheet(Blocking);

             // If the sheet is already loading just bail.
             return;
         }

         // Load the sheet, since it's never been loaded before.
         if (!m_sheet && m_disabledState == EnabledViaScript)
             process();
         else
             document()->styleSelectorChanged(DeferRecalcStyle); // Update the style selector.
     }
 }

 StyleSheet* HTMLLinkElement::sheet() const
 {
     return m_sheet.get();
 }

 void HTMLLinkElement::parseMappedAttribute(Attribute* attr)
 {
     if (attr->name() == relAttr) {
         tokenizeRelAttribute(attr->value(), m_relAttribute);
         process();
     } else if (attr->name() == hrefAttr) {
         m_url = document()->completeURL(stripLeadingAndTrailingHTMLSpaces(attr->value()));
         process();
     } else if (attr->name() == typeAttr) {
         m_type = attr->value();
         process();
     } else if (attr->name() == mediaAttr) {
         m_media = attr->value().string().lower();
         process();
     } else if (attr->name() == disabledAttr)
         setDisabledState(!attr->isNull());
     else if (attr->name() == onbeforeloadAttr)
         setAttributeEventListener(eventNames().beforeloadEvent, createAttributeEventListener(this, attr));
 #if ENABLE(LINK_PREFETCH)
     else if (attr->name() == onloadAttr)
         setAttributeEventListener(eventNames().loadEvent, createAttributeEventListener(this, attr));
     else if (attr->name() == onerrorAttr)
         setAttributeEventListener(eventNames().errorEvent, createAttributeEventListener(this, attr));
 #endif
     else {
         if (attr->name() == titleAttr && m_sheet)
             m_sheet->setTitle(attr->value());
         HTMLElement::parseMappedAttribute(attr);
     }
 }

 void HTMLLinkElement::tokenizeRelAttribute(const AtomicString& rel, RelAttribute& relAttribute)
 {
     relAttribute.m_isStyleSheet = false;
     relAttribute.m_isIcon = false;
     relAttribute.m_isAlternate = false;
     relAttribute.m_isDNSPrefetch = false;
 #if ENABLE(LINK_PREFETCH)
     relAttribute.m_isLinkPrefetch = false;
     relAttribute.m_isLinkSubresource = false;
 #endif
 #ifdef ANDROID_APPLE_TOUCH_ICON
     relAttribute.m_isTouchIcon = false;
     relAttribute.m_isPrecomposedTouchIcon = false;
 #endif
     if (equalIgnoringCase(rel, "stylesheet"))
         relAttribute.m_isStyleSheet = true;
     else if (equalIgnoringCase(rel, "icon") || equalIgnoringCase(rel, "shortcut icon"))
         relAttribute.m_isIcon = true;
 #ifdef ANDROID_APPLE_TOUCH_ICON
     else if (equalIgnoringCase(rel, "apple-touch-icon"))
         relAttribute.m_isTouchIcon = true;
     else if (equalIgnoringCase(rel, "apple-touch-icon-precomposed"))
         relAttribute.m_isPrecomposedTouchIcon = true;
 #endif
     else if (equalIgnoringCase(rel, "dns-prefetch"))
         relAttribute.m_isDNSPrefetch = true;
     else if (equalIgnoringCase(rel, "alternate stylesheet") || equalIgnoringCase(rel, "stylesheet alternate")) {
         relAttribute.m_isStyleSheet = true;
         relAttribute.m_isAlternate = true;
     } else {
         // Tokenize the rel attribute and set bits based on specific keywords that we find.
         String relString = rel.string();
         relString.replace('\n', ' ');
         Vector<String> list;
         relString.split(' ', list);
         Vector<String>::const_iterator end = list.end();
         for (Vector<String>::const_iterator it = list.begin(); it != end; ++it) {
             if (equalIgnoringCase(*it, "stylesheet"))
                 relAttribute.m_isStyleSheet = true;
             else if (equalIgnoringCase(*it, "alternate"))
                 relAttribute.m_isAlternate = true;
             else if (equalIgnoringCase(*it, "icon"))
                 relAttribute.m_isIcon = true;
 #if ENABLE(LINK_PREFETCH)
             else if (equalIgnoringCase(*it, "prefetch"))
               relAttribute.m_isLinkPrefetch = true;
             else if (equalIgnoringCase(*it, "subresource"))
               relAttribute.m_isLinkSubresource = true;
 #endif
         }
     }
 }

 bool HTMLLinkElement::checkBeforeLoadEvent()
 {
     RefPtr<Document> originalDocument = document();
     if (!dispatchBeforeLoadEvent(m_url))
         return false;
     // A beforeload handler might have removed us from the document or changed the document.
     if (!inDocument() || document() != originalDocument)
         return false;
     return true;
 }

 void HTMLLinkElement::process()
 {
     if (!inDocument() || m_isInShadowTree) {
         ASSERT(!m_sheet);
         return;
     }

     String type = m_type.lower();

     // IE extension: location of small icon for locationbar / bookmarks
     // We'll record this URL per document, even if we later only use it in top level frames
     if (m_relAttribute.m_isIcon && m_url.isValid() && !m_url.isEmpty()) {
         if (!checkBeforeLoadEvent())
             return;
         document()->setIconURL(m_url.string(), type);
     }

 #ifdef ANDROID_APPLE_TOUCH_ICON
     if ((m_relAttribute.m_isTouchIcon || m_relAttribute.m_isPrecomposedTouchIcon) && m_url.isValid()
         && !m_url.isEmpty() && document()->frame())
         document()->frame()->loader()->client()
                 ->dispatchDidReceiveTouchIconURL(m_url.string(),
                         m_relAttribute.m_isPrecomposedTouchIcon);
 #endif

     if (m_relAttribute.m_isDNSPrefetch) {
         Settings* settings = document()->settings();
         // FIXME: The href attribute of the link element can be in "//hostname" form, and we shouldn't attempt
         // to complete that as URL <https://bugs.webkit.org/show_bug.cgi?id=48857>.
         if (settings && settings->dnsPrefetchingEnabled() && m_url.isValid() && !m_url.isEmpty())
             ResourceHandle::prepareForURL(m_url);
     }

 #if ENABLE(LINK_PREFETCH)
     if ((m_relAttribute.m_isLinkPrefetch || m_relAttribute.m_isLinkSubresource) && m_url.isValid() && document()->frame()) {
         if (!checkBeforeLoadEvent())
             return;
         ResourceLoadPriority priority = ResourceLoadPriorityUnresolved;
         if (m_relAttribute.m_isLinkSubresource)
             priority = ResourceLoadPriorityLow;

         m_cachedLinkResource = document()->cachedResourceLoader()->requestLinkResource(m_url, priority);
         if (m_cachedLinkResource)
             m_cachedLinkResource->addClient(this);
     }
 #endif

     bool acceptIfTypeContainsTextCSS = document()->page() && document()->page()->settings() && document()->page()->settings()->treatsAnyTextCSSLinkAsStylesheet();

     if (m_disabledState != Disabled && (m_relAttribute.m_isStyleSheet || (acceptIfTypeContainsTextCSS && type.contains("text/css")))
         && document()->frame() && m_url.isValid()) {

         String charset = getAttribute(charsetAttr);
         if (charset.isEmpty() && document()->frame())
             charset = document()->charset();

         if (m_cachedSheet) {
             removePendingSheet();
             m_cachedSheet->removeClient(this);
             m_cachedSheet = 0;
         }

         if (!checkBeforeLoadEvent())
             return;

         m_loading = true;

         bool mediaQueryMatches = true;
         if (!m_media.isEmpty()) {
             RefPtr<RenderStyle> documentStyle = CSSStyleSelector::styleForDocument(document());
             RefPtr<MediaList> media = MediaList::createAllowingDescriptionSyntax(m_media);
             MediaQueryEvaluator evaluator(document()->frame()->view()->mediaType(), document()->frame(), documentStyle.get());
             mediaQueryMatches = evaluator.eval(media.get());
         }

         // Don't hold up render tree construction and script execution on stylesheets
         // that are not needed for the rendering at the moment.
         bool blocking = mediaQueryMatches && !isAlternate();
         addPendingSheet(blocking ? Blocking : NonBlocking);

         // Load stylesheets that are not needed for the rendering immediately with low priority.
         ResourceLoadPriority priority = blocking ? ResourceLoadPriorityUnresolved : ResourceLoadPriorityVeryLow;
         m_cachedSheet = document()->cachedResourceLoader()->requestCSSStyleSheet(m_url, charset, priority);

         if (m_cachedSheet)
             m_cachedSheet->addClient(this);
         else {
             // The request may have been denied if (for example) the stylesheet is local and the document is remote.
             m_loading = false;
             removePendingSheet();
         }
     } else if (m_sheet) {
         // we no longer contain a stylesheet, e.g. perhaps rel or type was changed
         m_sheet = 0;
         document()->styleSelectorChanged(DeferRecalcStyle);
     }
 }

 void HTMLLinkElement::insertedIntoDocument()
 {
     HTMLElement::insertedIntoDocument();

     m_isInShadowTree = isInShadowTree();
     if (m_isInShadowTree)
         return;

     document()->addStyleSheetCandidateNode(this, m_createdByParser);

     process();
 }

 void HTMLLinkElement::removedFromDocument()
 {
     HTMLElement::removedFromDocument();

     if (m_isInShadowTree) {
         ASSERT(!m_sheet);
         return;
     }
     document()->removeStyleSheetCandidateNode(this);

     if (m_sheet) {
         ASSERT(m_sheet->ownerNode() == this);
         m_sheet->clearOwnerNode();
         m_sheet = 0;
     }

     if (document()->renderer())
         document()->styleSelectorChanged(DeferRecalcStyle);
 }

 void HTMLLinkElement::finishParsingChildren()
 {
     m_createdByParser = false;
     HTMLElement::finishParsingChildren();
 }

 void HTMLLinkElement::setCSSStyleSheet(const String& href, const KURL& baseURL, const String& charset, const CachedCSSStyleSheet* sheet)
 {
     if (!inDocument()) {
         ASSERT(!m_sheet);
         return;
     }

     m_sheet = CSSStyleSheet::create(this, href, baseURL, charset);

     bool strictParsing = !document()->inQuirksMode();
     bool enforceMIMEType = strictParsing;
     bool crossOriginCSS = false;
     bool validMIMEType = false;
     bool needsSiteSpecificQuirks = document()->page() && document()->page()->settings()->needsSiteSpecificQuirks();

     // Check to see if we should enforce the MIME type of the CSS resource in strict mode.
     // Running in iWeb 2 is one example of where we don't want to - <rdar://problem/6099748>
     if (enforceMIMEType && document()->page() && !document()->page()->settings()->enforceCSSMIMETypeInNoQuirksMode())
         enforceMIMEType = false;

 #if defined(BUILDING_ON_TIGER) || defined(BUILDING_ON_LEOPARD)
     if (enforceMIMEType && needsSiteSpecificQuirks) {
         // Covers both http and https, with or without "www."
         if (baseURL.string().contains("mcafee.com/japan/", false))
             enforceMIMEType = false;
     }
 #endif

     String sheetText = sheet->sheetText(enforceMIMEType, &validMIMEType);
     m_sheet->parseString(sheetText, strictParsing);

     // If we're loading a stylesheet cross-origin, and the MIME type is not
     // standard, require the CSS to at least start with a syntactically
     // valid CSS rule.
     // This prevents an attacker playing games by injecting CSS strings into
     // HTML, XML, JSON, etc. etc.
     if (!document()->securityOrigin()->canRequest(baseURL))
         crossOriginCSS = true;

     if (crossOriginCSS && !validMIMEType && !m_sheet->hasSyntacticallyValidCSSHeader())
         m_sheet = CSSStyleSheet::create(this, href, baseURL, charset);

     if (strictParsing && needsSiteSpecificQuirks) {
         // Work around <https://bugs.webkit.org/show_bug.cgi?id=28350>.
         DEFINE_STATIC_LOCAL(const String, slashKHTMLFixesDotCss, ("/KHTMLFixes.css"));
         DEFINE_STATIC_LOCAL(const String, mediaWikiKHTMLFixesStyleSheet, ("/* KHTML fix stylesheet */\n/* work around the horizontal scrollbars */\n#column-content { margin-left: 0; }\n\n"));
         // There are two variants of KHTMLFixes.css. One is equal to mediaWikiKHTMLFixesStyleSheet,
         // while the other lacks the second trailing newline.
         if (baseURL.string().endsWith(slashKHTMLFixesDotCss) && !sheetText.isNull() && mediaWikiKHTMLFixesStyleSheet.startsWith(sheetText)
                 && sheetText.length() >= mediaWikiKHTMLFixesStyleSheet.length() - 1) {
             ASSERT(m_sheet->length() == 1);
             ExceptionCode ec;
             m_sheet->deleteRule(0, ec);
         }
     }

     m_sheet->setTitle(title());

     RefPtr<MediaList> media = MediaList::createAllowingDescriptionSyntax(m_media);
     m_sheet->setMedia(media.get());

     m_loading = false;
     m_sheet->checkLoaded();
 }

 bool HTMLLinkElement::isLoading() const
 {
     if (m_loading)
         return true;
     if (!m_sheet)
         return false;
     return static_cast<CSSStyleSheet *>(m_sheet.get())->isLoading();
 }

 #if ENABLE(LINK_PREFETCH)
 void HTMLLinkElement::onloadTimerFired(Timer<HTMLLinkElement>* timer)
 {
     ASSERT_UNUSED(timer, timer == &m_onloadTimer);
     if (m_cachedLinkResource->errorOccurred())
         dispatchEvent(Event::create(eventNames().errorEvent, false, false));
     else
         dispatchEvent(Event::create(eventNames().loadEvent, false, false));

     m_cachedLinkResource->removeClient(this);
     m_cachedLinkResource = 0;
 }

 void HTMLLinkElement::notifyFinished(CachedResource* resource)
 {
     m_onloadTimer.startOneShot(0);
     ASSERT(m_cachedLinkResource.get() == resource);
 }
 #endif

 bool HTMLLinkElement::sheetLoaded()
 {
     if (!isLoading()) {
         removePendingSheet();
         return true;
     }
     return false;
 }

 bool HTMLLinkElement::isURLAttribute(Attribute *attr) const
 {
     return attr->name() == hrefAttr;
 }

 KURL HTMLLinkElement::href() const
 {
     return document()->completeURL(getAttribute(hrefAttr));
 }

 String HTMLLinkElement::rel() const
 {
     return getAttribute(relAttr);
 }

 String HTMLLinkElement::target() const
 {
     return getAttribute(targetAttr);
 }

 String HTMLLinkElement::type() const
 {
     return getAttribute(typeAttr);
 }

 void HTMLLinkElement::addSubresourceAttributeURLs(ListHashSet<KURL>& urls) const
 {
     HTMLElement::addSubresourceAttributeURLs(urls);

     // Favicons are handled by a special case in LegacyWebArchive::create()
     if (m_relAttribute.m_isIcon)
         return;

     if (!m_relAttribute.m_isStyleSheet)
         return;

     // Append the URL of this link element.
     addSubresourceURL(urls, href());

     // Walk the URLs linked by the linked-to stylesheet.
     if (StyleSheet* styleSheet = const_cast<HTMLLinkElement*>(this)->sheet())
         styleSheet->addSubresourceStyleURLs(urls);
 }

 #ifdef ANDROID_INSTRUMENT
 void* HTMLLinkElement::operator new(size_t size)
 {
     return Node::operator new(size);
 }

 void* HTMLLinkElement::operator new[](size_t size)
 {
     return Node::operator new[](size);
 }

 void HTMLLinkElement::operator delete(void* p, size_t size)
 {
     Node::operator delete(p, size);
 }

 void HTMLLinkElement::operator delete[](void* p, size_t size)
 {
     Node::operator delete[](p, size);
 }
 #endif

 void HTMLLinkElement::addPendingSheet(PendingSheetType type)
 {
     if (type <= m_pendingSheetType)
         return;
     m_pendingSheetType = type;

     if (m_pendingSheetType == NonBlocking)
         return;
     document()->addPendingSheet();
 }

 void HTMLLinkElement::removePendingSheet()
 {
     PendingSheetType type = m_pendingSheetType;
     m_pendingSheetType = None;

     if (type == None)
         return;
     if (type == NonBlocking) {
         // Document::removePendingSheet() triggers the style selector recalc for blocking sheets.
         document()->styleSelectorChanged(RecalcStyleImmediately);
         return;
     }
     document()->removePendingSheet();
 }

 }
	/*
	* 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)
	*
	* 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 "HTMLLinkElement.h"

	#include "Attribute.h"
	#include "CachedCSSStyleSheet.h"
	#include "CachedResource.h"
	#include "CachedResourceLoader.h"
	#include "CSSStyleSelector.h"
	#include "Document.h"
	#include "Frame.h"
	#include "FrameLoader.h"
	#include "FrameLoaderClient.h"
	#include "FrameTree.h"
	#include "FrameView.h"
	#include "HTMLNames.h"
	#include "HTMLParserIdioms.h"
	#include "MediaList.h"
	#include "MediaQueryEvaluator.h"
	#include "Page.h"
	#include "ResourceHandle.h"
	#include "ScriptEventListener.h"
	#include "Settings.h"
	#include <wtf/StdLibExtras.h>

	namespace WebCore {

	using namespace HTMLNames;

	inline HTMLLinkElement::HTMLLinkElement(const QualifiedName& tagName, Document* document, bool createdByParser)
	: HTMLElement(tagName, document)
	#if ENABLE(LINK_PREFETCH)
	, m_onloadTimer(this, &HTMLLinkElement::onloadTimerFired)
	#endif
	, m_disabledState(Unset)
	, m_loading(false)
	, m_createdByParser(createdByParser)
	, m_isInShadowTree(false)
	, m_pendingSheetType(None)
	{
	ASSERT(hasTagName(linkTag));
	}

	PassRefPtr<HTMLLinkElement> HTMLLinkElement::create(const QualifiedName& tagName, Document* document, bool createdByParser)
	{
	return adoptRef(new HTMLLinkElement(tagName, document, createdByParser));
	}

	HTMLLinkElement::~HTMLLinkElement()
	{
	if (m_sheet)
	m_sheet->clearOwnerNode();

	if (m_cachedSheet) {
	m_cachedSheet->removeClient(this);
	removePendingSheet();
	}

	#if ENABLE(LINK_PREFETCH)
	if (m_cachedLinkResource)
	m_cachedLinkResource->removeClient(this);
	#endif
	}

	void HTMLLinkElement::setDisabledState(bool _disabled)
	{
	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 (isLoading()) {
	// 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_relAttribute.m_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_relAttribute.m_isAlternate && m_disabledState == EnabledViaScript && oldDisabledState == Disabled)
	addPendingSheet(Blocking);

	// If the sheet is already loading just bail.
	return;
	}

	// Load the sheet, since it's never been loaded before.
	if (!m_sheet && m_disabledState == EnabledViaScript)
	process();
	else
	document()->styleSelectorChanged(DeferRecalcStyle); // Update the style selector.
	}
	}

	StyleSheet* HTMLLinkElement::sheet() const
	{
	return m_sheet.get();
	}

	void HTMLLinkElement::parseMappedAttribute(Attribute* attr)
	{
	if (attr->name() == relAttr) {
	tokenizeRelAttribute(attr->value(), m_relAttribute);
	process();
	} else if (attr->name() == hrefAttr) {
	m_url = document()->completeURL(stripLeadingAndTrailingHTMLSpaces(attr->value()));
	process();
	} else if (attr->name() == typeAttr) {
	m_type = attr->value();
	process();
	} else if (attr->name() == mediaAttr) {
	m_media = attr->value().string().lower();
	process();
	} else if (attr->name() == disabledAttr)
	setDisabledState(!attr->isNull());
	else if (attr->name() == onbeforeloadAttr)
	setAttributeEventListener(eventNames().beforeloadEvent, createAttributeEventListener(this, attr));
	#if ENABLE(LINK_PREFETCH)
	else if (attr->name() == onloadAttr)
	setAttributeEventListener(eventNames().loadEvent, createAttributeEventListener(this, attr));
	else if (attr->name() == onerrorAttr)
	setAttributeEventListener(eventNames().errorEvent, createAttributeEventListener(this, attr));
	#endif
	else {
	if (attr->name() == titleAttr && m_sheet)
	m_sheet->setTitle(attr->value());
	HTMLElement::parseMappedAttribute(attr);
	}
	}

	void HTMLLinkElement::tokenizeRelAttribute(const AtomicString& rel, RelAttribute& relAttribute)
	{
	relAttribute.m_isStyleSheet = false;
	relAttribute.m_isIcon = false;
	relAttribute.m_isAlternate = false;
	relAttribute.m_isDNSPrefetch = false;
	#if ENABLE(LINK_PREFETCH)
	relAttribute.m_isLinkPrefetch = false;
	relAttribute.m_isLinkSubresource = false;
	#endif
	#ifdef ANDROID_APPLE_TOUCH_ICON
	relAttribute.m_isTouchIcon = false;
	relAttribute.m_isPrecomposedTouchIcon = false;
	#endif
	if (equalIgnoringCase(rel, "stylesheet"))
	relAttribute.m_isStyleSheet = true;
	else if (equalIgnoringCase(rel, "icon") \|\| equalIgnoringCase(rel, "shortcut icon"))
	relAttribute.m_isIcon = true;
	#ifdef ANDROID_APPLE_TOUCH_ICON
	else if (equalIgnoringCase(rel, "apple-touch-icon"))
	relAttribute.m_isTouchIcon = true;
	else if (equalIgnoringCase(rel, "apple-touch-icon-precomposed"))
	relAttribute.m_isPrecomposedTouchIcon = true;
	#endif
	else if (equalIgnoringCase(rel, "dns-prefetch"))
	relAttribute.m_isDNSPrefetch = true;
	else if (equalIgnoringCase(rel, "alternate stylesheet") \|\| equalIgnoringCase(rel, "stylesheet alternate")) {
	relAttribute.m_isStyleSheet = true;
	relAttribute.m_isAlternate = true;
	} else {
	// Tokenize the rel attribute and set bits based on specific keywords that we find.
	String relString = rel.string();
	relString.replace('\n', ' ');
	Vector<String> list;
	relString.split(' ', list);
	Vector<String>::const_iterator end = list.end();
	for (Vector<String>::const_iterator it = list.begin(); it != end; ++it) {
	if (equalIgnoringCase(*it, "stylesheet"))
	relAttribute.m_isStyleSheet = true;
	else if (equalIgnoringCase(*it, "alternate"))
	relAttribute.m_isAlternate = true;
	else if (equalIgnoringCase(*it, "icon"))
	relAttribute.m_isIcon = true;
	#if ENABLE(LINK_PREFETCH)
	else if (equalIgnoringCase(*it, "prefetch"))
	relAttribute.m_isLinkPrefetch = true;
	else if (equalIgnoringCase(*it, "subresource"))
	relAttribute.m_isLinkSubresource = true;
	#endif
	}
	}
	}

	bool HTMLLinkElement::checkBeforeLoadEvent()
	{
	RefPtr<Document> originalDocument = document();
	if (!dispatchBeforeLoadEvent(m_url))
	return false;
	// A beforeload handler might have removed us from the document or changed the document.
	if (!inDocument() \|\| document() != originalDocument)
	return false;
	return true;
	}

	void HTMLLinkElement::process()
	{
	if (!inDocument() \|\| m_isInShadowTree) {
	ASSERT(!m_sheet);
	return;
	}

	String type = m_type.lower();

	// IE extension: location of small icon for locationbar / bookmarks
	// We'll record this URL per document, even if we later only use it in top level frames
	if (m_relAttribute.m_isIcon && m_url.isValid() && !m_url.isEmpty()) {
	if (!checkBeforeLoadEvent())
	return;
	document()->setIconURL(m_url.string(), type);
	}

	#ifdef ANDROID_APPLE_TOUCH_ICON
	if ((m_relAttribute.m_isTouchIcon \|\| m_relAttribute.m_isPrecomposedTouchIcon) && m_url.isValid()
	&& !m_url.isEmpty() && document()->frame())
	document()->frame()->loader()->client()
	->dispatchDidReceiveTouchIconURL(m_url.string(),
	m_relAttribute.m_isPrecomposedTouchIcon);
	#endif

	if (m_relAttribute.m_isDNSPrefetch) {
	Settings* settings = document()->settings();
	// FIXME: The href attribute of the link element can be in "//hostname" form, and we shouldn't attempt
	// to complete that as URL <https://bugs.webkit.org/show_bug.cgi?id=48857>.
	if (settings && settings->dnsPrefetchingEnabled() && m_url.isValid() && !m_url.isEmpty())
	ResourceHandle::prepareForURL(m_url);
	}

	#if ENABLE(LINK_PREFETCH)
	if ((m_relAttribute.m_isLinkPrefetch \|\| m_relAttribute.m_isLinkSubresource) && m_url.isValid() && document()->frame()) {
	if (!checkBeforeLoadEvent())
	return;
	ResourceLoadPriority priority = ResourceLoadPriorityUnresolved;
	if (m_relAttribute.m_isLinkSubresource)
	priority = ResourceLoadPriorityLow;

	m_cachedLinkResource = document()->cachedResourceLoader()->requestLinkResource(m_url, priority);
	if (m_cachedLinkResource)
	m_cachedLinkResource->addClient(this);
	}
	#endif

	bool acceptIfTypeContainsTextCSS = document()->page() && document()->page()->settings() && document()->page()->settings()->treatsAnyTextCSSLinkAsStylesheet();

	if (m_disabledState != Disabled && (m_relAttribute.m_isStyleSheet \|\| (acceptIfTypeContainsTextCSS && type.contains("text/css")))
	&& document()->frame() && m_url.isValid()) {

	String charset = getAttribute(charsetAttr);
	if (charset.isEmpty() && document()->frame())
	charset = document()->charset();

	if (m_cachedSheet) {
	removePendingSheet();
	m_cachedSheet->removeClient(this);
	m_cachedSheet = 0;
	}

	if (!checkBeforeLoadEvent())
	return;

	m_loading = true;

	bool mediaQueryMatches = true;
	if (!m_media.isEmpty()) {
	RefPtr<RenderStyle> documentStyle = CSSStyleSelector::styleForDocument(document());
	RefPtr<MediaList> media = MediaList::createAllowingDescriptionSyntax(m_media);
	MediaQueryEvaluator evaluator(document()->frame()->view()->mediaType(), document()->frame(), documentStyle.get());
	mediaQueryMatches = evaluator.eval(media.get());
	}

	// Don't hold up render tree construction and script execution on stylesheets
	// that are not needed for the rendering at the moment.
	bool blocking = mediaQueryMatches && !isAlternate();
	addPendingSheet(blocking ? Blocking : NonBlocking);

	// Load stylesheets that are not needed for the rendering immediately with low priority.
	ResourceLoadPriority priority = blocking ? ResourceLoadPriorityUnresolved : ResourceLoadPriorityVeryLow;
	m_cachedSheet = document()->cachedResourceLoader()->requestCSSStyleSheet(m_url, charset, priority);

	if (m_cachedSheet)
	m_cachedSheet->addClient(this);
	else {
	// The request may have been denied if (for example) the stylesheet is local and the document is remote.
	m_loading = false;
	removePendingSheet();
	}
	} else if (m_sheet) {
	// we no longer contain a stylesheet, e.g. perhaps rel or type was changed
	m_sheet = 0;
	document()->styleSelectorChanged(DeferRecalcStyle);
	}
	}

	void HTMLLinkElement::insertedIntoDocument()
	{
	HTMLElement::insertedIntoDocument();

	m_isInShadowTree = isInShadowTree();
	if (m_isInShadowTree)
	return;

	document()->addStyleSheetCandidateNode(this, m_createdByParser);

	process();
	}

	void HTMLLinkElement::removedFromDocument()
	{
	HTMLElement::removedFromDocument();

	if (m_isInShadowTree) {
	ASSERT(!m_sheet);
	return;
	}
	document()->removeStyleSheetCandidateNode(this);

	if (m_sheet) {
	ASSERT(m_sheet->ownerNode() == this);
	m_sheet->clearOwnerNode();
	m_sheet = 0;
	}

	if (document()->renderer())
	document()->styleSelectorChanged(DeferRecalcStyle);
	}

	void HTMLLinkElement::finishParsingChildren()
	{
	m_createdByParser = false;
	HTMLElement::finishParsingChildren();
	}

	void HTMLLinkElement::setCSSStyleSheet(const String& href, const KURL& baseURL, const String& charset, const CachedCSSStyleSheet* sheet)
	{
	if (!inDocument()) {
	ASSERT(!m_sheet);
	return;
	}

	m_sheet = CSSStyleSheet::create(this, href, baseURL, charset);

	bool strictParsing = !document()->inQuirksMode();
	bool enforceMIMEType = strictParsing;
	bool crossOriginCSS = false;
	bool validMIMEType = false;
	bool needsSiteSpecificQuirks = document()->page() && document()->page()->settings()->needsSiteSpecificQuirks();

	// Check to see if we should enforce the MIME type of the CSS resource in strict mode.
	// Running in iWeb 2 is one example of where we don't want to - <rdar://problem/6099748>
	if (enforceMIMEType && document()->page() && !document()->page()->settings()->enforceCSSMIMETypeInNoQuirksMode())
	enforceMIMEType = false;

	#if defined(BUILDING_ON_TIGER) \|\| defined(BUILDING_ON_LEOPARD)
	if (enforceMIMEType && needsSiteSpecificQuirks) {
	// Covers both http and https, with or without "www."
	if (baseURL.string().contains("mcafee.com/japan/", false))
	enforceMIMEType = false;
	}
	#endif

	String sheetText = sheet->sheetText(enforceMIMEType, &validMIMEType);
	m_sheet->parseString(sheetText, strictParsing);

	// If we're loading a stylesheet cross-origin, and the MIME type is not
	// standard, require the CSS to at least start with a syntactically
	// valid CSS rule.
	// This prevents an attacker playing games by injecting CSS strings into
	// HTML, XML, JSON, etc. etc.
	if (!document()->securityOrigin()->canRequest(baseURL))
	crossOriginCSS = true;

	if (crossOriginCSS && !validMIMEType && !m_sheet->hasSyntacticallyValidCSSHeader())
	m_sheet = CSSStyleSheet::create(this, href, baseURL, charset);

	if (strictParsing && needsSiteSpecificQuirks) {
	// Work around <https://bugs.webkit.org/show_bug.cgi?id=28350>.
	DEFINE_STATIC_LOCAL(const String, slashKHTMLFixesDotCss, ("/KHTMLFixes.css"));
	DEFINE_STATIC_LOCAL(const String, mediaWikiKHTMLFixesStyleSheet, ("/* KHTML fix stylesheet /\n/ work around the horizontal scrollbars */\n#column-content { margin-left: 0; }\n\n"));
	// There are two variants of KHTMLFixes.css. One is equal to mediaWikiKHTMLFixesStyleSheet,
	// while the other lacks the second trailing newline.
	if (baseURL.string().endsWith(slashKHTMLFixesDotCss) && !sheetText.isNull() && mediaWikiKHTMLFixesStyleSheet.startsWith(sheetText)
	&& sheetText.length() >= mediaWikiKHTMLFixesStyleSheet.length() - 1) {
	ASSERT(m_sheet->length() == 1);
	ExceptionCode ec;
	m_sheet->deleteRule(0, ec);
	}
	}

	m_sheet->setTitle(title());

	RefPtr<MediaList> media = MediaList::createAllowingDescriptionSyntax(m_media);
	m_sheet->setMedia(media.get());

	m_loading = false;
	m_sheet->checkLoaded();
	}

	bool HTMLLinkElement::isLoading() const
	{
	if (m_loading)
	return true;
	if (!m_sheet)
	return false;
	return static_cast<CSSStyleSheet *>(m_sheet.get())->isLoading();
	}

	#if ENABLE(LINK_PREFETCH)
	void HTMLLinkElement::onloadTimerFired(Timer<HTMLLinkElement>* timer)
	{
	ASSERT_UNUSED(timer, timer == &m_onloadTimer);
	if (m_cachedLinkResource->errorOccurred())
	dispatchEvent(Event::create(eventNames().errorEvent, false, false));
	else
	dispatchEvent(Event::create(eventNames().loadEvent, false, false));

	m_cachedLinkResource->removeClient(this);
	m_cachedLinkResource = 0;
	}

	void HTMLLinkElement::notifyFinished(CachedResource* resource)
	{
	m_onloadTimer.startOneShot(0);
	ASSERT(m_cachedLinkResource.get() == resource);
	}
	#endif

	bool HTMLLinkElement::sheetLoaded()
	{
	if (!isLoading()) {
	removePendingSheet();
	return true;
	}
	return false;
	}

	bool HTMLLinkElement::isURLAttribute(Attribute *attr) const
	{
	return attr->name() == hrefAttr;
	}

	KURL HTMLLinkElement::href() const
	{
	return document()->completeURL(getAttribute(hrefAttr));
	}

	String HTMLLinkElement::rel() const
	{
	return getAttribute(relAttr);
	}

	String HTMLLinkElement::target() const
	{
	return getAttribute(targetAttr);
	}

	String HTMLLinkElement::type() const
	{
	return getAttribute(typeAttr);
	}

	void HTMLLinkElement::addSubresourceAttributeURLs(ListHashSet<KURL>& urls) const
	{
	HTMLElement::addSubresourceAttributeURLs(urls);

	// Favicons are handled by a special case in LegacyWebArchive::create()
	if (m_relAttribute.m_isIcon)
	return;

	if (!m_relAttribute.m_isStyleSheet)
	return;

	// Append the URL of this link element.
	addSubresourceURL(urls, href());

	// Walk the URLs linked by the linked-to stylesheet.
	if (StyleSheet* styleSheet = const_cast<HTMLLinkElement*>(this)->sheet())
	styleSheet->addSubresourceStyleURLs(urls);
	}

	#ifdef ANDROID_INSTRUMENT
	void* HTMLLinkElement::operator new(size_t size)
	{
	return Node::operator new(size);
	}

	void* HTMLLinkElement::operator new[](size_t size)
	{
	return Node::operator new[](size);
	}

	void HTMLLinkElement::operator delete(void* p, size_t size)
	{
	Node::operator delete(p, size);
	}

	void HTMLLinkElement::operator delete[](void* p, size_t size)
	{
	Node::operator delete[](p, size);
	}
	#endif

	void HTMLLinkElement::addPendingSheet(PendingSheetType type)
	{
	if (type <= m_pendingSheetType)
	return;
	m_pendingSheetType = type;

	if (m_pendingSheetType == NonBlocking)
	return;
	document()->addPendingSheet();
	}

	void HTMLLinkElement::removePendingSheet()
	{
	PendingSheetType type = m_pendingSheetType;
	m_pendingSheetType = None;

	if (type == None)
	return;
	if (type == NonBlocking) {
	// Document::removePendingSheet() triggers the style selector recalc for blocking sheets.
	document()->styleSelectorChanged(RecalcStyleImmediately);
	return;
	}
	document()->removePendingSheet();
	}

	}