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      1 /*
      2  * CSS Media Query
      3  *
      4  * Copyright (C) 2005, 2006 Kimmo Kinnunen <kimmo.t.kinnunen (at) nokia.com>.
      5  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
     17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     20  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     23  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     24  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include "config.h"
     30 #include "MediaQuery.h"
     31 
     32 #include "MediaQueryExp.h"
     33 #include <wtf/NonCopyingSort.h>
     34 #include <wtf/text/StringBuilder.h>
     35 
     36 namespace WebCore {
     37 
     38 // http://dev.w3.org/csswg/cssom/#serialize-a-media-query
     39 String MediaQuery::serialize() const
     40 {
     41     StringBuilder result;
     42 
     43     switch (m_restrictor) {
     44     case MediaQuery::Only:
     45         result.append("only ");
     46         break;
     47     case MediaQuery::Not:
     48         result.append("not ");
     49         break;
     50     case MediaQuery::None:
     51         break;
     52     }
     53 
     54     if (m_expressions->isEmpty()) {
     55         result.append(m_mediaType);
     56         return result.toString();
     57     }
     58 
     59     if (m_mediaType != "all" || m_restrictor != None) {
     60         result.append(m_mediaType);
     61         result.append(" and ");
     62     }
     63 
     64     result.append(m_expressions->at(0)->serialize());
     65     for (size_t i = 1; i < m_expressions->size(); ++i) {
     66         result.append(" and ");
     67         result.append(m_expressions->at(i)->serialize());
     68     }
     69     return result.toString();
     70 }
     71 
     72 static bool expressionCompare(const OwnPtr<MediaQueryExp>& a, const OwnPtr<MediaQueryExp>& b)
     73 {
     74     return codePointCompare(a->serialize(), b->serialize()) < 0;
     75 }
     76 
     77 
     78 MediaQuery::MediaQuery(Restrictor r, const String& mediaType, PassOwnPtr<Vector<OwnPtr<MediaQueryExp> > > exprs)
     79     : m_restrictor(r)
     80     , m_mediaType(mediaType.lower())
     81     , m_expressions(exprs)
     82     , m_ignored(false)
     83 {
     84     if (!m_expressions) {
     85         m_expressions = adoptPtr(new Vector<OwnPtr<MediaQueryExp> >);
     86         return;
     87     }
     88 
     89     nonCopyingSort(m_expressions->begin(), m_expressions->end(), expressionCompare);
     90 
     91     // remove all duplicated expressions
     92     String key;
     93     for (int i = m_expressions->size() - 1; i >= 0; --i) {
     94 
     95         // if not all of the expressions is valid the media query must be ignored.
     96         if (!m_ignored)
     97             m_ignored = !m_expressions->at(i)->isValid();
     98 
     99         if (m_expressions->at(i)->serialize() == key)
    100             m_expressions->remove(i);
    101         else
    102             key = m_expressions->at(i)->serialize();
    103     }
    104 }
    105 
    106 MediaQuery::~MediaQuery()
    107 {
    108 }
    109 
    110 // http://dev.w3.org/csswg/cssom/#compare-media-queries
    111 bool MediaQuery::operator==(const MediaQuery& other) const
    112 {
    113     return cssText() == other.cssText();
    114 }
    115 
    116 // http://dev.w3.org/csswg/cssom/#serialize-a-list-of-media-queries
    117 String MediaQuery::cssText() const
    118 {
    119     if (m_serializationCache.isNull())
    120         const_cast<MediaQuery*>(this)->m_serializationCache = serialize();
    121 
    122     return m_serializationCache;
    123 }
    124 
    125 } //namespace
    126