third_party/WebKit/Source/core/dom/DocumentStyleSheetCollection.cpp

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All
 * rights reserved.
 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
 * (http://www.torchmobile.com/)
 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
 * Copyright (C) 2013 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/dom/DocumentStyleSheetCollection.h"

#include "core/css/resolver/StyleResolver.h"
#include "core/dom/Document.h"
#include "core/dom/DocumentStyleSheetCollector.h"
#include "core/dom/ProcessingInstruction.h"
#include "core/dom/StyleChangeReason.h"
#include "core/dom/StyleEngine.h"
#include "core/dom/StyleSheetCandidate.h"
#include "platform/RuntimeEnabledFeatures.h"

namespace blink {

DocumentStyleSheetCollection::DocumentStyleSheetCollection(TreeScope& treeScope)
    : TreeScopeStyleSheetCollection(treeScope) {
  DCHECK_EQ(treeScope.rootNode(), treeScope.rootNode().document());
}

void DocumentStyleSheetCollection::collectStyleSheetsFromCandidates(
    StyleEngine& engine,
    DocumentStyleSheetCollector& collector) {
  for (Node* n : m_styleSheetCandidateNodes) {
    StyleSheetCandidate candidate(*n);

    DCHECK(!candidate.isXSL());
    if (candidate.isImport()) {
      Document* document = candidate.importedDocument();
      if (!document)
        continue;
      if (collector.hasVisited(document))
        continue;
      collector.willVisit(document);
      document->styleEngine().updateStyleSheetsInImport(collector);
      continue;
    }

    if (candidate.isEnabledAndLoading())
      continue;

    StyleSheet* sheet = candidate.sheet();
    if (!sheet)
      continue;

    collector.appendSheetForList(sheet);
    if (candidate.canBeActivated(engine.preferredStylesheetSetName()))
      collector.appendActiveStyleSheet(toCSSStyleSheet(sheet));
  }
}

void DocumentStyleSheetCollection::collectStyleSheets(
    StyleEngine& engine,
    DocumentStyleSheetCollector& collector) {
  DCHECK_EQ(&document().styleEngine(), &engine);
  collector.appendActiveStyleSheets(engine.injectedAuthorStyleSheets());
  collectStyleSheetsFromCandidates(engine, collector);
  if (engine.inspectorStyleSheet())
    collector.appendActiveStyleSheet(engine.inspectorStyleSheet());
}

void DocumentStyleSheetCollection::updateActiveStyleSheets(
    StyleEngine& engine,
    StyleResolverUpdateMode updateMode) {
  // StyleSheetCollection is GarbageCollected<>, allocate it on the heap.
  StyleSheetCollection* collection = StyleSheetCollection::create();
  ActiveDocumentStyleSheetCollector collector(*collection);
  collectStyleSheets(engine, collector);

  StyleSheetChange change;
  analyzeStyleSheetChange(updateMode, collection->activeAuthorStyleSheets(),
                          change);

  if (change.styleResolverUpdateType == Reconstruct) {
    engine.clearMasterResolver();
    // TODO(rune@opera.com): The following depends on whether StyleRuleFontFace
    // was modified or not.  We should only remove modified/removed @font-face
    // rules, or @font-face rules from removed stylesheets. We currently avoid
    // clearing the font cache when we have had an analyzed update and no
    // @font-face rules were removed, in which case requiresFullStyleRecalc will
    // be false.
    if (change.requiresFullStyleRecalc)
      engine.clearFontCache();
  } else if (StyleResolver* styleResolver = engine.resolver()) {
    if (change.styleResolverUpdateType != Additive) {
      DCHECK_EQ(change.styleResolverUpdateType, Reset);
      styleResolver->resetAuthorStyle(treeScope());
      engine.removeFontFaceRules(change.fontFaceRulesToRemove);
      styleResolver->removePendingAuthorStyleSheets(m_activeAuthorStyleSheets);
      styleResolver->lazyAppendAuthorStyleSheets(
          0, collection->activeAuthorStyleSheets());
    } else {
      styleResolver->lazyAppendAuthorStyleSheets(
          m_activeAuthorStyleSheets.size(),
          collection->activeAuthorStyleSheets());
    }
  }
  if (change.requiresFullStyleRecalc)
    document().setNeedsStyleRecalc(
        SubtreeStyleChange, StyleChangeReasonForTracing::create(
                                StyleChangeReason::ActiveStylesheetsUpdate));

  collection->swap(*this);
  collection->dispose();
}

DEFINE_TRACE_WRAPPERS(DocumentStyleSheetCollection) {
  for (auto sheet : m_styleSheetsForStyleSheetList) {
    visitor->traceWrappers(sheet);
  }
}
}  // namespace blink