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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 PassRefPtrWillBeRawPtr<MediaQueryList> MediaQueryList::create(PassRefPtrWillBeRawPtr<MediaQueryMatcher> vector, PassRefPtrWillBeRawPtr<MediaQuerySet> media, bool matches)
     31 {
     32     return adoptRefWillBeNoop(new MediaQueryList(vector, media, matches));
     33 }
     34 
     35 MediaQueryList::MediaQueryList(PassRefPtrWillBeRawPtr<MediaQueryMatcher> vector, PassRefPtrWillBeRawPtr<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 DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(MediaQueryList)
     45 
     46 String MediaQueryList::media() const
     47 {
     48     return m_media->mediaText();
     49 }
     50 
     51 void MediaQueryList::addListener(PassRefPtrWillBeRawPtr<MediaQueryListListener> listener)
     52 {
     53     if (!listener)
     54         return;
     55 
     56     m_matcher->addListener(listener, this);
     57 }
     58 
     59 void MediaQueryList::removeListener(PassRefPtrWillBeRawPtr<MediaQueryListListener> listener)
     60 {
     61     if (!listener)
     62         return;
     63 
     64     m_matcher->removeListener(listener.get(), this);
     65 }
     66 
     67 bool MediaQueryList::evaluate(MediaQueryEvaluator* evaluator)
     68 {
     69     if (m_evaluationRound != m_matcher->evaluationRound() && evaluator)
     70         setMatches(evaluator->eval(m_media.get()));
     71     return m_changeRound == m_matcher->evaluationRound();
     72 }
     73 
     74 void MediaQueryList::setMatches(bool newValue)
     75 {
     76     m_evaluationRound = m_matcher->evaluationRound();
     77 
     78     if (newValue == m_matches)
     79         return;
     80 
     81     m_matches = newValue;
     82     m_changeRound = m_evaluationRound;
     83 }
     84 
     85 bool MediaQueryList::matches()
     86 {
     87     if (m_evaluationRound != m_matcher->evaluationRound())
     88         setMatches(m_matcher->evaluate(m_media.get()));
     89     return m_matches;
     90 }
     91 
     92 void MediaQueryList::trace(Visitor* visitor)
     93 {
     94     visitor->trace(m_matcher);
     95     visitor->trace(m_media);
     96 }
     97 
     98 }
     99