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      1 /*
      2  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
      3  *
      4  *  This library is free software; you can redistribute it and/or
      5  *  modify it under the terms of the GNU Library General Public
      6  *  License as published by the Free Software Foundation; either
      7  *  version 2 of the License, or (at your option) any later version.
      8  *
      9  *  This library is distributed in the hope that it will be useful,
     10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
     11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     12  *  Library General Public License for more details.
     13  *
     14  *  You should have received a copy of the GNU Library General Public License
     15  *  along with this library; see the file COPYING.LIB.  If not, write to
     16  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     17  *  Boston, MA 02110-1301, USA.
     18  */
     19 
     20 #include "config.h"
     21 #include "core/css/MediaQueryList.h"
     22 
     23 #include "core/css/MediaList.h"
     24 #include "core/css/MediaQueryEvaluator.h"
     25 #include "core/css/MediaQueryListListener.h"
     26 #include "core/css/MediaQueryMatcher.h"
     27 
     28 namespace WebCore {
     29 
     30 PassRefPtr<MediaQueryList> MediaQueryList::create(PassRefPtr<MediaQueryMatcher> vector, PassRefPtr<MediaQuerySet> media, bool matches)
     31 {
     32     return adoptRef(new MediaQueryList(vector, media, matches));
     33 }
     34 
     35 MediaQueryList::MediaQueryList(PassRefPtr<MediaQueryMatcher> vector, PassRefPtr<MediaQuerySet> media, bool matches)
     36     : m_matcher(vector)
     37     , m_media(media)
     38     , m_evaluationRound(m_matcher->evaluationRound())
     39     , m_changeRound(m_evaluationRound - 1) // m_evaluationRound and m_changeRound initial values must be different.
     40     , m_matches(matches)
     41 {
     42 }
     43 
     44 MediaQueryList::~MediaQueryList()
     45 {
     46 }
     47 
     48 String MediaQueryList::media() const
     49 {
     50     return m_media->mediaText();
     51 }
     52 
     53 void MediaQueryList::addListener(PassRefPtr<MediaQueryListListener> listener)
     54 {
     55     if (!listener)
     56         return;
     57 
     58     m_matcher->addListener(listener, this);
     59 }
     60 
     61 void MediaQueryList::removeListener(PassRefPtr<MediaQueryListListener> listener)
     62 {
     63     if (!listener)
     64         return;
     65 
     66     m_matcher->removeListener(listener.get(), this);
     67 }
     68 
     69 void MediaQueryList::evaluate(MediaQueryEvaluator* evaluator, bool& notificationNeeded)
     70 {
     71     if (m_evaluationRound != m_matcher->evaluationRound() && evaluator)
     72         setMatches(evaluator->eval(m_media.get()));
     73     notificationNeeded = m_changeRound == m_matcher->evaluationRound();
     74 }
     75 
     76 void MediaQueryList::setMatches(bool newValue)
     77 {
     78     m_evaluationRound = m_matcher->evaluationRound();
     79 
     80     if (newValue == m_matches)
     81         return;
     82 
     83     m_matches = newValue;
     84     m_changeRound = m_evaluationRound;
     85 }
     86 
     87 bool MediaQueryList::matches()
     88 {
     89     if (m_evaluationRound != m_matcher->evaluationRound())
     90         setMatches(m_matcher->evaluate(m_media.get()));
     91     return m_matches;
     92 }
     93 
     94 }
     95