third_party/WebKit/Source/core/css/StyleRuleImport.cpp

/*
 * (C) 1999-2003 Lars Knoll (knoll@kde.org)
 * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2002, 2005, 2006, 2008, 2009, 2010, 2012 Apple Inc. All rights
 * reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "core/css/StyleRuleImport.h"

#include "core/css/StyleSheetContents.h"
#include "core/dom/Document.h"
#include "core/fetch/CSSStyleSheetResource.h"
#include "core/fetch/FetchInitiatorTypeNames.h"
#include "core/fetch/FetchRequest.h"
#include "core/fetch/ResourceFetcher.h"

namespace blink {

StyleRuleImport* StyleRuleImport::create(const String& href,
                                         MediaQuerySet* media) {
  return new StyleRuleImport(href, media);
}

StyleRuleImport::StyleRuleImport(const String& href, MediaQuerySet* media)
    : StyleRuleBase(Import),
      m_parentStyleSheet(nullptr),
      m_styleSheetClient(new ImportedStyleSheetClient(this)),
      m_strHref(href),
      m_mediaQueries(media),
      m_loading(false) {
  if (!m_mediaQueries)
    m_mediaQueries = MediaQuerySet::create(String());

  ThreadState::current()->registerPreFinalizer(this);
}

StyleRuleImport::~StyleRuleImport() {}

void StyleRuleImport::dispose() {
  if (m_resource)
    m_resource->removeClient(m_styleSheetClient);
  m_resource = nullptr;
}

DEFINE_TRACE_AFTER_DISPATCH(StyleRuleImport) {
  visitor->trace(m_styleSheetClient);
  visitor->trace(m_parentStyleSheet);
  visitor->trace(m_mediaQueries);
  visitor->trace(m_styleSheet);
  visitor->trace(m_resource);
  StyleRuleBase::traceAfterDispatch(visitor);
}

void StyleRuleImport::setCSSStyleSheet(
    const String& href,
    const KURL& baseURL,
    const String& charset,
    const CSSStyleSheetResource* cachedStyleSheet) {
  if (m_styleSheet)
    m_styleSheet->clearOwnerRule();

  CSSParserContext context = m_parentStyleSheet
                                 ? m_parentStyleSheet->parserContext()
                                 : strictCSSParserContext();
  context.setCharset(charset);
  Document* document =
      m_parentStyleSheet ? m_parentStyleSheet->singleOwnerDocument() : nullptr;
  if (!baseURL.isNull()) {
    context.setBaseURL(baseURL);
    if (document)
      context.setReferrer(Referrer(baseURL.strippedForUseAsReferrer(),
                                   document->getReferrerPolicy()));
  }

  m_styleSheet = StyleSheetContents::create(this, href, context);

  m_styleSheet->parseAuthorStyleSheet(
      cachedStyleSheet, document ? document->getSecurityOrigin() : 0);

  m_loading = false;

  if (m_parentStyleSheet) {
    m_parentStyleSheet->notifyLoadedSheet(cachedStyleSheet);
    m_parentStyleSheet->checkLoaded();
  }
}

bool StyleRuleImport::isLoading() const {
  return m_loading || (m_styleSheet && m_styleSheet->isLoading());
}

void StyleRuleImport::requestStyleSheet() {
  if (!m_parentStyleSheet)
    return;
  Document* document = m_parentStyleSheet->singleOwnerDocument();
  if (!document)
    return;

  ResourceFetcher* fetcher = document->fetcher();
  if (!fetcher)
    return;

  KURL absURL;
  if (!m_parentStyleSheet->baseURL().isNull()) {
    // use parent styleheet's URL as the base URL
    absURL = KURL(m_parentStyleSheet->baseURL(), m_strHref);
  } else {
    absURL = document->completeURL(m_strHref);
  }

  // Check for a cycle in our import chain.  If we encounter a stylesheet
  // in our parent chain with the same URL, then just bail.
  StyleSheetContents* rootSheet = m_parentStyleSheet;
  for (StyleSheetContents* sheet = m_parentStyleSheet; sheet;
       sheet = sheet->parentStyleSheet()) {
    if (equalIgnoringFragmentIdentifier(absURL, sheet->baseURL()) ||
        equalIgnoringFragmentIdentifier(
            absURL, document->completeURL(sheet->originalURL())))
      return;
    rootSheet = sheet;
  }

  FetchRequest request(ResourceRequest(absURL), FetchInitiatorTypeNames::css,
                       m_parentStyleSheet->charset());
  m_resource = CSSStyleSheetResource::fetch(request, fetcher);
  if (m_resource) {
    // if the import rule is issued dynamically, the sheet may be
    // removed from the pending sheet count, so let the doc know
    // the sheet being imported is pending.
    if (m_parentStyleSheet && m_parentStyleSheet->loadCompleted() &&
        rootSheet == m_parentStyleSheet)
      m_parentStyleSheet->startLoadingDynamicSheet();
    m_loading = true;
    m_resource->addClient(m_styleSheetClient);
  }
}

}  // namespace blink