1 /*

     2  * Copyright (C) 2008 Apple Inc. All Rights Reserved.

     3  * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/

     4  * Copyright (C) 2010 Google Inc. All Rights Reserved.

     5  *

     6  * Redistribution and use in source and binary forms, with or without

     7  * modification, are permitted provided that the following conditions

     8  * are met:

     9  * 1. Redistributions of source code must retain the above copyright

    10  *    notice, this list of conditions and the following disclaimer.

    11  * 2. Redistributions in binary form must reproduce the above copyright

    12  *    notice, this list of conditions and the following disclaimer in the

    13  *    documentation and/or other materials provided with the distribution.

    14  *

    15  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

    16  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

    18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

    19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

    20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

    21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

    22  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

    23  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

    25  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

    26  */

    27 

    28 #include "config.h"

    29 #include "CSSPreloadScanner.h"

    30 

    31 #include "CSSHelper.h"

    32 #include "CachedCSSStyleSheet.h"

    33 #include "DocLoader.h"

    34 #include "Document.h"

    35 #include "HTMLToken.h"

    36 

    37 namespace WebCore {

    38 

    39 static inline bool isWhitespace(UChar c)

    40 {

    41     return c == ' ' || c == '\n' || c == '\r' || c == '\t';

    42 }

    43 

    44 CSSPreloadScanner::CSSPreloadScanner(Document* document)

    45     : m_document(document)

    46 {

    47     reset();

    48 }

    49 

    50 void CSSPreloadScanner::reset()

    51 {

    52     m_state = Initial;

    53     m_rule.clear();

    54     m_ruleValue.clear();

    55 }

    56 

    57 void CSSPreloadScanner::scan(const HTMLToken& token, bool scanningBody)

    58 {

    59     m_scanningBody = scanningBody;

    60 

    61     const HTMLToken::DataVector& characters = token.characters();

    62     for (HTMLToken::DataVector::const_iterator iter = characters.begin();

    63          iter != characters.end(); ++iter) {

    64         tokenize(*iter);

    65     }

    66 }

    67 

    68 inline void CSSPreloadScanner::tokenize(UChar c)

    69 {

    70     // We are just interested in @import rules, no need for real tokenization here

    71     // Searching for other types of resources is probably low payoff.

    72     switch (m_state) {

    73     case Initial:

    74         if (c == '@')

    75             m_state = RuleStart;

    76         else if (c == '/')

    77             m_state = MaybeComment;

    78         break;

    79     case MaybeComment:

    80         if (c == '*')

    81             m_state = Comment;

    82         else

    83             m_state = Initial;

    84         break;

    85     case Comment:

    86         if (c == '*')

    87             m_state = MaybeCommentEnd;

    88         break;

    89     case MaybeCommentEnd:

    90         if (c == '/')

    91             m_state = Initial;

    92         else if (c == '*')

    93             ;

    94         else

    95             m_state = Comment;

    96         break;

    97     case RuleStart:

    98         if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')) {

    99             m_rule.clear();

   100             m_ruleValue.clear();

   101             m_rule.append(c);

   102             m_state = Rule;

   103         } else

   104             m_state = Initial;

   105         break;

   106     case Rule:

   107         if (isWhitespace(c))

   108             m_state = AfterRule;

   109         else if (c == ';')

   110             m_state = Initial;

   111         else

   112             m_rule.append(c);

   113         break;

   114     case AfterRule:

   115         if (isWhitespace(c))

   116             ;

   117         else if (c == ';')

   118             m_state = Initial;

   119         else {

   120             m_state = RuleValue;

   121             m_ruleValue.append(c);

   122         }

   123         break;

   124     case RuleValue:

   125         if (isWhitespace(c))

   126             m_state = AfterRuleValue;

   127         else if (c == ';') {

   128             emitRule();

   129             m_state = Initial;

   130         } else 

   131             m_ruleValue.append(c);

   132         break;

   133     case AfterRuleValue:

   134         if (isWhitespace(c))

   135             ;

   136         else if (c == ';') {

   137             emitRule();

   138             m_state = Initial;

   139         } else {

   140             // FIXME: media rules

   141             m_state = Initial;

   142         }

   143         break;

   144     }

   145 }

   146 

   147 void CSSPreloadScanner::emitRule()

   148 {

   149     String rule(m_rule.data(), m_rule.size());

   150     if (equalIgnoringCase(rule, "import") && !m_ruleValue.isEmpty()) {

   151         String value(m_ruleValue.data(), m_ruleValue.size());

   152         String url = deprecatedParseURL(value);

   153         if (!url.isEmpty())

   154             m_document->docLoader()->preload(CachedResource::CSSStyleSheet, url, String(), m_scanningBody);

   155     }

   156     m_rule.clear();

   157     m_ruleValue.clear();

   158 }

   159 

   160 }