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      1 /*
      2  * Copyright (C) 2006, 2007 Rob Buis
      3  * Copyright (C) 2008 Apple, Inc. All rights reserved.
      4  *
      5  * This library is free software; you can redistribute it and/or
      6  * modify it under the terms of the GNU Library General Public
      7  * License as published by the Free Software Foundation; either
      8  * version 2 of the License, or (at your option) any later version.
      9  *
     10  * This library is distributed in the hope that it will be useful,
     11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13  * Library General Public License for more details.
     14  *
     15  * You should have received a copy of the GNU Library General Public License
     16  * along with this library; see the file COPYING.LIB.  If not, write to
     17  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     18  * Boston, MA 02110-1301, USA.
     19  */
     20 
     21 #include "config.h"
     22 #include "core/dom/StyleElement.h"
     23 
     24 #include "core/css/MediaList.h"
     25 #include "core/css/MediaQueryEvaluator.h"
     26 #include "core/css/StyleSheetContents.h"
     27 #include "core/dom/Document.h"
     28 #include "core/dom/Element.h"
     29 #include "core/dom/ScriptableDocumentParser.h"
     30 #include "core/dom/StyleEngine.h"
     31 #include "core/html/HTMLStyleElement.h"
     32 #include "core/frame/ContentSecurityPolicy.h"
     33 #include "wtf/text/StringBuilder.h"
     34 
     35 namespace WebCore {
     36 
     37 static bool isCSS(Element* element, const AtomicString& type)
     38 {
     39     return type.isEmpty() || (element->isHTMLElement() ? equalIgnoringCase(type, "text/css") : (type == "text/css"));
     40 }
     41 
     42 StyleElement::StyleElement(Document* document, bool createdByParser)
     43     : m_createdByParser(createdByParser)
     44     , m_loading(false)
     45     , m_startPosition(TextPosition::belowRangePosition())
     46 {
     47     if (createdByParser && document && document->scriptableDocumentParser() && !document->isInDocumentWrite())
     48         m_startPosition = document->scriptableDocumentParser()->textPosition();
     49 }
     50 
     51 StyleElement::~StyleElement()
     52 {
     53     if (m_sheet)
     54         clearSheet();
     55 }
     56 
     57 void StyleElement::processStyleSheet(Document& document, Element* element)
     58 {
     59     ASSERT(element);
     60     document.styleEngine()->addStyleSheetCandidateNode(element, m_createdByParser);
     61     if (m_createdByParser)
     62         return;
     63 
     64     process(element);
     65 }
     66 
     67 void StyleElement::removedFromDocument(Document& document, Element* element, ContainerNode* scopingNode)
     68 {
     69     ASSERT(element);
     70     document.styleEngine()->removeStyleSheetCandidateNode(element, scopingNode);
     71 
     72     RefPtr<StyleSheet> removedSheet = m_sheet;
     73 
     74     if (m_sheet)
     75         clearSheet();
     76 
     77     document.removedStyleSheet(removedSheet.get(), RecalcStyleDeferred, AnalyzedStyleUpdate);
     78 }
     79 
     80 void StyleElement::clearDocumentData(Document& document, Element* element)
     81 {
     82     if (m_sheet)
     83         m_sheet->clearOwnerNode();
     84 
     85     if (element->inDocument())
     86         document.styleEngine()->removeStyleSheetCandidateNode(element, isHTMLStyleElement(element) ? toHTMLStyleElement(element)->scopingNode() :  0);
     87 }
     88 
     89 void StyleElement::childrenChanged(Element* element)
     90 {
     91     ASSERT(element);
     92     if (m_createdByParser)
     93         return;
     94 
     95     process(element);
     96 }
     97 
     98 void StyleElement::finishParsingChildren(Element* element)
     99 {
    100     ASSERT(element);
    101     process(element);
    102     m_createdByParser = false;
    103 }
    104 
    105 void StyleElement::process(Element* element)
    106 {
    107     if (!element || !element->inDocument())
    108         return;
    109     createSheet(element, element->textFromChildren());
    110 }
    111 
    112 void StyleElement::clearSheet()
    113 {
    114     ASSERT(m_sheet);
    115     m_sheet.release()->clearOwnerNode();
    116 }
    117 
    118 void StyleElement::createSheet(Element* e, const String& text)
    119 {
    120     ASSERT(e);
    121     ASSERT(e->inDocument());
    122     Document& document = e->document();
    123     if (m_sheet) {
    124         if (m_sheet->isLoading())
    125             document.styleEngine()->removePendingSheet(e);
    126         clearSheet();
    127     }
    128 
    129     // If type is empty or CSS, this is a CSS style sheet.
    130     const AtomicString& type = this->type();
    131     bool passesContentSecurityPolicyChecks = document.contentSecurityPolicy()->allowStyleNonce(e->fastGetAttribute(HTMLNames::nonceAttr)) || document.contentSecurityPolicy()->allowInlineStyle(e->document().url(), m_startPosition.m_line);
    132     if (isCSS(e, type) && passesContentSecurityPolicyChecks) {
    133         RefPtr<MediaQuerySet> mediaQueries = MediaQuerySet::create(media());
    134 
    135         MediaQueryEvaluator screenEval("screen", true);
    136         MediaQueryEvaluator printEval("print", true);
    137         if (screenEval.eval(mediaQueries.get()) || printEval.eval(mediaQueries.get())) {
    138             document.styleEngine()->addPendingSheet();
    139             m_loading = true;
    140 
    141             TextPosition startPosition = m_startPosition == TextPosition::belowRangePosition() ? TextPosition::minimumPosition() : m_startPosition;
    142             m_sheet = CSSStyleSheet::createInline(e, KURL(), startPosition, document.inputEncoding());
    143             m_sheet->setMediaQueries(mediaQueries.release());
    144             m_sheet->setTitle(e->title());
    145             m_sheet->contents()->parseStringAtPosition(text, startPosition, m_createdByParser);
    146 
    147             m_loading = false;
    148         }
    149     }
    150 
    151     if (m_sheet)
    152         m_sheet->contents()->checkLoaded();
    153 }
    154 
    155 bool StyleElement::isLoading() const
    156 {
    157     if (m_loading)
    158         return true;
    159     return m_sheet ? m_sheet->isLoading() : false;
    160 }
    161 
    162 bool StyleElement::sheetLoaded(Document& document)
    163 {
    164     if (isLoading())
    165         return false;
    166 
    167     document.styleEngine()->removePendingSheet(m_sheet->ownerNode());
    168     return true;
    169 }
    170 
    171 void StyleElement::startLoadingDynamicSheet(Document& document)
    172 {
    173     document.styleEngine()->addPendingSheet();
    174 }
    175 
    176 }
    177