Current work-in-progress crbug.com/567021

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/StyleSheetContents.h"
 #include "core/css/resolver/StyleResolver.h"
+#include "core/css/resolver/ViewportStyleResolver.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)
+void DocumentStyleSheetCollection::updateViewport()
+{
+    ViewportStyleResolver& resolver = document().styleEngine().ensureViewportStyleResolver();
+
+    resolver.reset();
+    resolver.collectViewportRulesFromUASheets();
+
+    for (Node* node : m_styleSheetCandidateNodes) {
+        StyleSheetCandidate candidate(*node);
+
+        if (candidate.isImport())
+            continue;
+        StyleSheet* sheet = candidate.sheet();
+        if (!sheet)
+            continue;
+        if (!candidate.canBeActivated(document().styleEngine().preferredStylesheetSetName()))
+            continue;
+        resolver.collectViewportRulesFromAuthorSheet(*toCSSStyleSheet(sheet));
+    }
+
+    resolver.resolve();
+}
+
+void DocumentStyleSheetCollection::collectStyleSheetsFromCandidates(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()) {
-            // it is loading but we should still decide which style sheet set to use
-            if (candidate.hasPreferrableName())
-                engine.setPreferredStylesheetSetNameIfNotSet(candidate.title());
+        if (candidate.isEnabledAndLoading())
             continue;
-        }
 
         StyleSheet* sheet = candidate.sheet();
         if (!sheet)
             continue;
 
-        if (candidate.hasPreferrableName())
-            engine.setPreferredStylesheetSetNameIfNotSet(candidate.title());
         collector.appendSheetForList(sheet);
-        if (candidate.canBeActivated(engine.preferredStylesheetSetName()))
-            collector.appendActiveStyleSheet(toCSSStyleSheet(sheet));
+
+        if (!candidate.canBeActivated(document().styleEngine().preferredStylesheetSetName()))
+            continue;
+
+        CSSStyleSheet* cssSheet = toCSSStyleSheet(sheet);
+        collector.appendActiveStyleSheet(std::make_pair(cssSheet, &document().styleEngine().ensureRuleSetForSheet(*cssSheet)));
     }
 }
 
-void DocumentStyleSheetCollection::collectStyleSheets(StyleEngine& engine, DocumentStyleSheetCollector& collector)
+void DocumentStyleSheetCollection::collectStyleSheets(DocumentStyleSheetCollector& collector)
 {
-    DCHECK_EQ(&document().styleEngine(), &engine);
-    collector.appendActiveStyleSheets(engine.injectedAuthorStyleSheets());
-    collectStyleSheetsFromCandidates(engine, collector);
+    for (auto& sheet : document().styleEngine().injectedAuthorStyleSheets())
+        collector.appendActiveStyleSheet(std::make_pair(sheet, &document().styleEngine().ensureRuleSetForSheet(*sheet)));
+
+    collectStyleSheetsFromCandidates(collector);
 }
 
-void DocumentStyleSheetCollection::updateActiveStyleSheets(StyleEngine& engine, StyleResolverUpdateMode updateMode)
+void DocumentStyleSheetCollection::updateActiveStyleSheets()
 {
     StyleSheetCollection collection;
     ActiveDocumentStyleSheetCollector collector(collection);
-    collectStyleSheets(engine, collector);
-
-    StyleSheetChange change;
-    analyzeStyleSheetChange(updateMode, collection, 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);
+    collectStyleSheets(collector);
+    applyActiveStyleSheetChanges(collection);
 }
 
 DEFINE_TRACE_WRAPPERS(DocumentStyleSheetCollection)
 {
     for (auto sheet : m_styleSheetsForStyleSheetList) {
         visitor->traceWrappers(sheet);
     }
 }
 } // namespace blink