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      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2001 Dirk Mueller (mueller (at) kde.org)
      5  *           (C) 2006 Alexey Proskuryakov (ap (at) webkit.org)
      6  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
      7  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
      8  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
      9  * Copyright (C) 2013 Google Inc. All rights reserved.
     10  *
     11  * This library is free software; you can redistribute it and/or
     12  * modify it under the terms of the GNU Library General Public
     13  * License as published by the Free Software Foundation; either
     14  * version 2 of the License, or (at your option) any later version.
     15  *
     16  * This library is distributed in the hope that it will be useful,
     17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     19  * Library General Public License for more details.
     20  *
     21  * You should have received a copy of the GNU Library General Public License
     22  * along with this library; see the file COPYING.LIB.  If not, write to
     23  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     24  * Boston, MA 02110-1301, USA.
     25  */
     26 
     27 #include "config.h"
     28 #include "core/dom/StyleSheetCollection.h"
     29 
     30 #include "core/css/CSSStyleSheet.h"
     31 #include "core/css/StyleInvalidationAnalysis.h"
     32 #include "core/css/StyleRuleImport.h"
     33 #include "core/css/StyleSheetContents.h"
     34 #include "core/css/resolver/StyleResolver.h"
     35 #include "core/dom/Element.h"
     36 #include "core/dom/StyleEngine.h"
     37 #include "core/html/HTMLStyleElement.h"
     38 #include "core/frame/Settings.h"
     39 
     40 namespace WebCore {
     41 
     42 StyleSheetCollectionBase::StyleSheetCollectionBase()
     43 {
     44 }
     45 
     46 StyleSheetCollectionBase::~StyleSheetCollectionBase()
     47 {
     48 }
     49 
     50 void StyleSheetCollectionBase::swap(StyleSheetCollectionBase& other)
     51 {
     52     m_styleSheetsForStyleSheetList.swap(other.m_styleSheetsForStyleSheetList);
     53     m_activeAuthorStyleSheets.swap(other.m_activeAuthorStyleSheets);
     54 }
     55 
     56 void StyleSheetCollectionBase::appendActiveStyleSheets(const Vector<RefPtr<CSSStyleSheet> >& sheets)
     57 {
     58     m_activeAuthorStyleSheets.append(sheets);
     59 }
     60 
     61 void StyleSheetCollectionBase::appendActiveStyleSheet(CSSStyleSheet* sheet)
     62 {
     63     m_activeAuthorStyleSheets.append(sheet);
     64 }
     65 
     66 void StyleSheetCollectionBase::appendSheetForList(StyleSheet* sheet)
     67 {
     68     m_styleSheetsForStyleSheetList.append(sheet);
     69 }
     70 
     71 
     72 StyleSheetCollection::StyleSheetCollection(TreeScope& treeScope)
     73     : m_treeScope(treeScope)
     74     , m_hadActiveLoadingStylesheet(false)
     75     , m_usesRemUnits(false)
     76 {
     77 }
     78 
     79 void StyleSheetCollection::addStyleSheetCandidateNode(Node* node, bool createdByParser)
     80 {
     81     if (!node->inDocument())
     82         return;
     83 
     84     // Until the <body> exists, we have no choice but to compare document positions,
     85     // since styles outside of the body and head continue to be shunted into the head
     86     // (and thus can shift to end up before dynamically added DOM content that is also
     87     // outside the body).
     88     if (createdByParser && document()->body())
     89         m_styleSheetCandidateNodes.parserAdd(node);
     90     else
     91         m_styleSheetCandidateNodes.add(node);
     92 
     93     if (!isHTMLStyleElement(node))
     94         return;
     95 
     96     ContainerNode* scopingNode = toHTMLStyleElement(node)->scopingNode();
     97     if (!isTreeScopeRoot(scopingNode))
     98         m_scopingNodesForStyleScoped.add(scopingNode);
     99 }
    100 
    101 void StyleSheetCollection::removeStyleSheetCandidateNode(Node* node, ContainerNode* scopingNode)
    102 {
    103     m_styleSheetCandidateNodes.remove(node);
    104 
    105     if (!isTreeScopeRoot(scopingNode))
    106         m_scopingNodesForStyleScoped.remove(scopingNode);
    107 }
    108 
    109 StyleSheetCollection::StyleResolverUpdateType StyleSheetCollection::compareStyleSheets(const Vector<RefPtr<CSSStyleSheet> >& oldStyleSheets, const Vector<RefPtr<CSSStyleSheet> >& newStylesheets, Vector<StyleSheetContents*>& addedSheets)
    110 {
    111     unsigned newStyleSheetCount = newStylesheets.size();
    112     unsigned oldStyleSheetCount = oldStyleSheets.size();
    113     ASSERT(newStyleSheetCount >= oldStyleSheetCount);
    114 
    115     if (!newStyleSheetCount)
    116         return Reconstruct;
    117 
    118     unsigned newIndex = 0;
    119     for (unsigned oldIndex = 0; oldIndex < oldStyleSheetCount; ++oldIndex) {
    120         while (oldStyleSheets[oldIndex] != newStylesheets[newIndex]) {
    121             addedSheets.append(newStylesheets[newIndex]->contents());
    122             if (++newIndex == newStyleSheetCount)
    123                 return Reconstruct;
    124         }
    125         if (++newIndex == newStyleSheetCount)
    126             return Reconstruct;
    127     }
    128     bool hasInsertions = !addedSheets.isEmpty();
    129     while (newIndex < newStyleSheetCount) {
    130         addedSheets.append(newStylesheets[newIndex]->contents());
    131         ++newIndex;
    132     }
    133     // If all new sheets were added at the end of the list we can just add them to existing StyleResolver.
    134     // If there were insertions we need to re-add all the stylesheets so rules are ordered correctly.
    135     return hasInsertions ? Reset : Additive;
    136 }
    137 
    138 bool StyleSheetCollection::activeLoadingStyleSheetLoaded(const Vector<RefPtr<CSSStyleSheet> >& newStyleSheets)
    139 {
    140     // StyleSheets of <style> elements that @import stylesheets are active but loading. We need to trigger a full recalc when such loads are done.
    141     bool hasActiveLoadingStylesheet = false;
    142     unsigned newStylesheetCount = newStyleSheets.size();
    143     for (unsigned i = 0; i < newStylesheetCount; ++i) {
    144         if (newStyleSheets[i]->isLoading())
    145             hasActiveLoadingStylesheet = true;
    146     }
    147     if (m_hadActiveLoadingStylesheet && !hasActiveLoadingStylesheet) {
    148         m_hadActiveLoadingStylesheet = false;
    149         return true;
    150     }
    151     m_hadActiveLoadingStylesheet = hasActiveLoadingStylesheet;
    152     return false;
    153 }
    154 
    155 static bool styleSheetContentsHasFontFaceRule(Vector<StyleSheetContents*> sheets)
    156 {
    157     for (unsigned i = 0; i < sheets.size(); ++i) {
    158         ASSERT(sheets[i]);
    159         if (sheets[i]->hasFontFaceRule())
    160             return true;
    161     }
    162     return false;
    163 }
    164 
    165 static bool cssStyleSheetHasFontFaceRule(const Vector<RefPtr<CSSStyleSheet> > sheets)
    166 {
    167     for (unsigned i = 0; i < sheets.size(); ++i) {
    168         ASSERT(sheets[i]);
    169         if (sheets[i]->contents()->hasFontFaceRule())
    170             return true;
    171     }
    172     return false;
    173 }
    174 
    175 void StyleSheetCollection::analyzeStyleSheetChange(StyleResolverUpdateMode updateMode, const StyleSheetCollectionBase& newCollection, StyleSheetChange& change)
    176 {
    177     if (activeLoadingStyleSheetLoaded(newCollection.activeAuthorStyleSheets()))
    178         return;
    179 
    180     if (updateMode != AnalyzedStyleUpdate)
    181         return;
    182 
    183     // Find out which stylesheets are new.
    184     Vector<StyleSheetContents*> addedSheets;
    185     if (m_activeAuthorStyleSheets.size() <= newCollection.activeAuthorStyleSheets().size()) {
    186         change.styleResolverUpdateType = compareStyleSheets(m_activeAuthorStyleSheets, newCollection.activeAuthorStyleSheets(), addedSheets);
    187     } else {
    188         StyleResolverUpdateType updateType = compareStyleSheets(newCollection.activeAuthorStyleSheets(), m_activeAuthorStyleSheets, addedSheets);
    189         if (updateType != Additive) {
    190             change.styleResolverUpdateType = updateType;
    191         } else {
    192             if (styleSheetContentsHasFontFaceRule(addedSheets)) {
    193                 change.styleResolverUpdateType = ResetStyleResolverAndFontSelector;
    194                 return;
    195             }
    196             // FIXME: since currently all stylesheets are re-added after reseting styleresolver,
    197             // fontSelector should be always reset. After creating RuleSet for each StyleSheetContents,
    198             // we can avoid appending all stylesheetcontents in reset case.
    199             // So we can remove "styleSheetContentsHasFontFaceRule(newSheets)".
    200             if (cssStyleSheetHasFontFaceRule(newCollection.activeAuthorStyleSheets()))
    201                 change.styleResolverUpdateType = ResetStyleResolverAndFontSelector;
    202             else
    203                 change.styleResolverUpdateType = Reset;
    204         }
    205     }
    206 
    207     // FIXME: If styleResolverUpdateType is Reconstruct, we should return early here since
    208     // we need to recalc the whole document. It's wrong to use StyleInvalidationAnalysis since
    209     // it only looks at the addedSheets.
    210 
    211     // No point in doing the analysis work if we're just going to recalc the whole document anyways.
    212     // This needs to be done after the compareStyleSheets calls above to ensure we don't throw away
    213     // the StyleResolver if we don't need to.
    214     if (document()->hasPendingForcedStyleRecalc())
    215         return;
    216 
    217     // If we are already parsing the body and so may have significant amount of elements, put some effort into trying to avoid style recalcs.
    218     if (!document()->body() || document()->hasNodesWithPlaceholderStyle())
    219         return;
    220     StyleInvalidationAnalysis invalidationAnalysis(addedSheets);
    221     if (invalidationAnalysis.dirtiesAllStyle())
    222         return;
    223     invalidationAnalysis.invalidateStyle(*document());
    224     change.requiresFullStyleRecalc = false;
    225     return;
    226 }
    227 
    228 void StyleSheetCollection::clearMediaQueryRuleSetStyleSheets()
    229 {
    230     for (size_t i = 0; i < m_activeAuthorStyleSheets.size(); ++i) {
    231         StyleSheetContents* contents = m_activeAuthorStyleSheets[i]->contents();
    232         if (contents->hasMediaQueries())
    233             contents->clearRuleSet();
    234     }
    235 }
    236 
    237 void StyleSheetCollection::resetAllRuleSetsInTreeScope(StyleResolver* styleResolver)
    238 {
    239     // FIXME: If many web developers use style scoped, implement reset RuleSets in per-scoping node manner.
    240     if (DocumentOrderedList* styleScopedScopingNodes = scopingNodesForStyleScoped()) {
    241         for (DocumentOrderedList::iterator it = styleScopedScopingNodes->begin(); it != styleScopedScopingNodes->end(); ++it)
    242             styleResolver->resetAuthorStyle(toContainerNode(*it));
    243     }
    244     if (ListHashSet<Node*, 4>* removedNodes = scopingNodesRemoved()) {
    245         for (ListHashSet<Node*, 4>::iterator it = removedNodes->begin(); it != removedNodes->end(); ++it)
    246             styleResolver->resetAuthorStyle(toContainerNode(*it));
    247     }
    248     styleResolver->resetAuthorStyle(toContainerNode(m_treeScope.rootNode()));
    249 }
    250 
    251 static bool styleSheetsUseRemUnits(const Vector<RefPtr<CSSStyleSheet> >& sheets)
    252 {
    253     for (unsigned i = 0; i < sheets.size(); ++i) {
    254         if (sheets[i]->contents()->usesRemUnits())
    255             return true;
    256     }
    257     return false;
    258 }
    259 
    260 void StyleSheetCollection::updateUsesRemUnits()
    261 {
    262     m_usesRemUnits = styleSheetsUseRemUnits(m_activeAuthorStyleSheets);
    263 }
    264 
    265 }
    266