1 /* 2 * (C) 1999-2003 Lars Knoll (knoll (at) kde.org) 3 * Copyright (C) 2004, 2006, 2010 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 #include "config.h" 21 #include "MediaList.h" 22 23 #include "CSSImportRule.h" 24 #include "CSSParser.h" 25 #include "CSSStyleSheet.h" 26 #include "ExceptionCode.h" 27 #include "MediaQuery.h" 28 #include "MediaQueryExp.h" 29 30 namespace WebCore { 31 32 /* MediaList is used to store 3 types of media related entities which mean the same: 33 * Media Queries, Media Types and Media Descriptors. 34 * Currently MediaList always tries to parse media queries and if parsing fails, 35 * tries to fallback to Media Descriptors if m_fallback flag is set. 36 * Slight problem with syntax error handling: 37 * CSS 2.1 Spec (http://www.w3.org/TR/CSS21/media.html) 38 * specifies that failing media type parsing is a syntax error 39 * CSS 3 Media Queries Spec (http://www.w3.org/TR/css3-mediaqueries/) 40 * specifies that failing media query is a syntax error 41 * HTML 4.01 spec (http://www.w3.org/TR/REC-html40/present/styles.html#adef-media) 42 * specifies that Media Descriptors should be parsed with forward-compatible syntax 43 * DOM Level 2 Style Sheet spec (http://www.w3.org/TR/DOM-Level-2-Style/) 44 * talks about MediaList.mediaText and refers 45 * - to Media Descriptors of HTML 4.0 in context of StyleSheet 46 * - to Media Types of CSS 2.0 in context of CSSMediaRule and CSSImportRule 47 * 48 * These facts create situation where same (illegal) media specification may result in 49 * different parses depending on whether it is media attr of style element or part of 50 * css @media rule. 51 * <style media="screen and resolution > 40dpi"> ..</style> will be enabled on screen devices where as 52 * @media screen and resolution > 40dpi {..} will not. 53 * This gets more counter-intuitive in JavaScript: 54 * document.styleSheets[0].media.mediaText = "screen and resolution > 40dpi" will be ok and 55 * enabled, while 56 * document.styleSheets[0].cssRules[0].media.mediaText = "screen and resolution > 40dpi" will 57 * throw SYNTAX_ERR exception. 58 */ 59 60 MediaList::MediaList(CSSStyleSheet* parentSheet, bool fallbackToDescriptor) 61 : StyleBase(parentSheet) 62 , m_fallback(fallbackToDescriptor) 63 { 64 } 65 66 MediaList::MediaList(CSSStyleSheet* parentSheet, const String& media, bool fallbackToDescriptor) 67 : StyleBase(parentSheet) 68 , m_fallback(fallbackToDescriptor) 69 { 70 ExceptionCode ec = 0; 71 setMediaText(media, ec); 72 // FIXME: parsing can fail. The problem with failing constructor is that 73 // we would need additional flag saying MediaList is not valid 74 // Parse can fail only when fallbackToDescriptor == false, i.e when HTML4 media descriptor 75 // forward-compatible syntax is not in use. 76 // DOMImplementationCSS seems to mandate that media descriptors are used 77 // for both html and svg, even though svg:style doesn't use media descriptors 78 // Currently the only places where parsing can fail are 79 // creating <svg:style>, creating css media / import rules from js 80 if (ec) 81 setMediaText("invalid", ec); 82 } 83 84 MediaList::MediaList(CSSImportRule* parentRule, const String& media) 85 : StyleBase(parentRule) 86 , m_fallback(false) 87 { 88 ExceptionCode ec = 0; 89 setMediaText(media, ec); 90 if (ec) 91 setMediaText("invalid", ec); 92 } 93 94 MediaList::~MediaList() 95 { 96 deleteAllValues(m_queries); 97 } 98 99 static String parseMediaDescriptor(const String& s) 100 { 101 int len = s.length(); 102 103 // http://www.w3.org/TR/REC-html40/types.html#type-media-descriptors 104 // "Each entry is truncated just before the first character that isn't a 105 // US ASCII letter [a-zA-Z] (ISO 10646 hex 41-5a, 61-7a), digit [0-9] (hex 30-39), 106 // or hyphen (hex 2d)." 107 int i; 108 unsigned short c; 109 for (i = 0; i < len; ++i) { 110 c = s[i]; 111 if (! ((c >= 'a' && c <= 'z') 112 || (c >= 'A' && c <= 'Z') 113 || (c >= '1' && c <= '9') 114 || (c == '-'))) 115 break; 116 } 117 return s.left(i); 118 } 119 120 void MediaList::deleteMedium(const String& oldMedium, ExceptionCode& ec) 121 { 122 RefPtr<MediaList> tempMediaList = MediaList::create(); 123 CSSParser p(true); 124 125 MediaQuery* oldQuery = 0; 126 OwnPtr<MediaQuery> createdQuery; 127 128 if (p.parseMediaQuery(tempMediaList.get(), oldMedium)) { 129 if (tempMediaList->m_queries.size() > 0) 130 oldQuery = tempMediaList->m_queries[0]; 131 } else if (m_fallback) { 132 String medium = parseMediaDescriptor(oldMedium); 133 if (!medium.isNull()) { 134 createdQuery = adoptPtr(new MediaQuery(MediaQuery::None, medium, 0)); 135 oldQuery = createdQuery.get(); 136 } 137 } 138 139 // DOM Style Sheets spec doesn't allow SYNTAX_ERR to be thrown in deleteMedium 140 ec = NOT_FOUND_ERR; 141 142 if (oldQuery) { 143 for (size_t i = 0; i < m_queries.size(); ++i) { 144 MediaQuery* a = m_queries[i]; 145 if (*a == *oldQuery) { 146 m_queries.remove(i); 147 delete a; 148 ec = 0; 149 break; 150 } 151 } 152 } 153 154 if (!ec) 155 notifyChanged(); 156 } 157 158 String MediaList::mediaText() const 159 { 160 String text(""); 161 162 bool first = true; 163 for (size_t i = 0; i < m_queries.size(); ++i) { 164 if (!first) 165 text += ", "; 166 else 167 first = false; 168 text += m_queries[i]->cssText(); 169 } 170 171 return text; 172 } 173 174 void MediaList::setMediaText(const String& value, ExceptionCode& ec) 175 { 176 RefPtr<MediaList> tempMediaList = MediaList::create(); 177 CSSParser p(true); 178 179 Vector<String> list; 180 value.split(',', list); 181 Vector<String>::const_iterator end = list.end(); 182 for (Vector<String>::const_iterator it = list.begin(); it != end; ++it) { 183 String medium = (*it).stripWhiteSpace(); 184 if (!medium.isEmpty()) { 185 if (!p.parseMediaQuery(tempMediaList.get(), medium)) { 186 if (m_fallback) { 187 String mediaDescriptor = parseMediaDescriptor(medium); 188 if (!mediaDescriptor.isNull()) 189 tempMediaList->m_queries.append(new MediaQuery(MediaQuery::None, mediaDescriptor, 0)); 190 } else { 191 ec = SYNTAX_ERR; 192 return; 193 } 194 } 195 } else if (!m_fallback) { 196 ec = SYNTAX_ERR; 197 return; 198 } 199 } 200 // ",,,," falls straight through, but is not valid unless fallback 201 if (!m_fallback && list.begin() == list.end()) { 202 String s = value.stripWhiteSpace(); 203 if (!s.isEmpty()) { 204 ec = SYNTAX_ERR; 205 return; 206 } 207 } 208 209 ec = 0; 210 deleteAllValues(m_queries); 211 m_queries = tempMediaList->m_queries; 212 tempMediaList->m_queries.clear(); 213 notifyChanged(); 214 } 215 216 String MediaList::item(unsigned index) const 217 { 218 if (index < m_queries.size()) { 219 MediaQuery* query = m_queries[index]; 220 return query->cssText(); 221 } 222 223 return String(); 224 } 225 226 void MediaList::appendMedium(const String& newMedium, ExceptionCode& ec) 227 { 228 ec = INVALID_CHARACTER_ERR; 229 CSSParser p(true); 230 if (p.parseMediaQuery(this, newMedium)) { 231 ec = 0; 232 } else if (m_fallback) { 233 String medium = parseMediaDescriptor(newMedium); 234 if (!medium.isNull()) { 235 m_queries.append(new MediaQuery(MediaQuery::None, medium, 0)); 236 ec = 0; 237 } 238 } 239 240 if (!ec) 241 notifyChanged(); 242 } 243 244 void MediaList::appendMediaQuery(PassOwnPtr<MediaQuery> mediaQuery) 245 { 246 m_queries.append(mediaQuery.leakPtr()); 247 } 248 249 void MediaList::notifyChanged() 250 { 251 for (StyleBase* p = parent(); p; p = p->parent()) { 252 if (p->isCSSStyleSheet()) 253 return static_cast<CSSStyleSheet*>(p)->styleSheetChanged(); 254 } 255 } 256 257 } 258