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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/MediaQueryMatcher.h"
     22 
     23 #include "core/css/MediaList.h"
     24 #include "core/css/MediaQueryEvaluator.h"
     25 #include "core/css/MediaQueryList.h"
     26 #include "core/css/MediaQueryListListener.h"
     27 #include "core/css/resolver/StyleResolver.h"
     28 #include "core/dom/Document.h"
     29 #include "core/frame/FrameView.h"
     30 #include "core/frame/LocalFrame.h"
     31 
     32 namespace WebCore {
     33 
     34 MediaQueryMatcher::Listener::Listener(PassRefPtrWillBeRawPtr<MediaQueryListListener> listener, PassRefPtrWillBeRawPtr<MediaQueryList> query)
     35     : m_listener(listener)
     36     , m_query(query)
     37 {
     38 }
     39 
     40 void MediaQueryMatcher::Listener::evaluate(MediaQueryEvaluator* evaluator)
     41 {
     42     if (m_query->evaluate(evaluator))
     43         m_listener->queryChanged(m_query.get());
     44 }
     45 
     46 void MediaQueryMatcher::Listener::trace(Visitor* visitor)
     47 {
     48     visitor->trace(m_listener);
     49     visitor->trace(m_query);
     50 }
     51 
     52 MediaQueryMatcher::MediaQueryMatcher(Document* document)
     53     : m_document(document)
     54     , m_evaluationRound(1)
     55 {
     56     ASSERT(m_document);
     57 }
     58 
     59 DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(MediaQueryMatcher)
     60 
     61 void MediaQueryMatcher::documentDestroyed()
     62 {
     63     m_listeners.clear();
     64     m_document = nullptr;
     65 }
     66 
     67 AtomicString MediaQueryMatcher::mediaType() const
     68 {
     69     if (!m_document || !m_document->frame() || !m_document->frame()->view())
     70         return nullAtom;
     71 
     72     return m_document->frame()->view()->mediaType();
     73 }
     74 
     75 PassOwnPtr<MediaQueryEvaluator> MediaQueryMatcher::prepareEvaluator() const
     76 {
     77     if (!m_document || !m_document->frame())
     78         return nullptr;
     79 
     80     return adoptPtr(new MediaQueryEvaluator(mediaType(), m_document->frame()));
     81 }
     82 
     83 bool MediaQueryMatcher::evaluate(const MediaQuerySet* media)
     84 {
     85     if (!media)
     86         return false;
     87 
     88     OwnPtr<MediaQueryEvaluator> evaluator(prepareEvaluator());
     89     return evaluator && evaluator->eval(media);
     90 }
     91 
     92 PassRefPtrWillBeRawPtr<MediaQueryList> MediaQueryMatcher::matchMedia(const String& query)
     93 {
     94     if (!m_document)
     95         return nullptr;
     96 
     97     RefPtrWillBeRawPtr<MediaQuerySet> media = MediaQuerySet::create(query);
     98     // Add warning message to inspector whenever dpi/dpcm values are used for "screen" media.
     99     reportMediaQueryWarningIfNeeded(m_document, media.get());
    100     return MediaQueryList::create(this, media, evaluate(media.get()));
    101 }
    102 
    103 void MediaQueryMatcher::addListener(PassRefPtrWillBeRawPtr<MediaQueryListListener> listener, PassRefPtrWillBeRawPtr<MediaQueryList> query)
    104 {
    105     if (!m_document)
    106         return;
    107 
    108     for (size_t i = 0; i < m_listeners.size(); ++i) {
    109         if (*m_listeners[i]->listener() == *listener && m_listeners[i]->query() == query)
    110             return;
    111     }
    112 
    113     m_listeners.append(adoptPtrWillBeNoop(new Listener(listener, query)));
    114 }
    115 
    116 void MediaQueryMatcher::removeListener(MediaQueryListListener* listener, MediaQueryList* query)
    117 {
    118     if (!m_document)
    119         return;
    120 
    121     for (size_t i = 0; i < m_listeners.size(); ++i) {
    122         if (*m_listeners[i]->listener() == *listener && m_listeners[i]->query() == query) {
    123             m_listeners.remove(i);
    124             return;
    125         }
    126     }
    127 }
    128 
    129 void MediaQueryMatcher::styleResolverChanged()
    130 {
    131     if (!m_document)
    132         return;
    133 
    134     ++m_evaluationRound;
    135     OwnPtr<MediaQueryEvaluator> evaluator = prepareEvaluator();
    136     if (!evaluator)
    137         return;
    138 
    139     for (size_t i = 0; i < m_listeners.size(); ++i)
    140         m_listeners[i]->evaluate(evaluator.get());
    141 }
    142 
    143 void MediaQueryMatcher::trace(Visitor* visitor)
    144 {
    145     visitor->trace(m_document);
    146     // We don't support tracing of vectors of OwnPtrs (ie. Vector<OwnPtr<Listener> >).
    147     // Since this is a transitional object we are just ifdef'ing it out when oilpan is not enabled.
    148 #if ENABLE(OILPAN)
    149     visitor->trace(m_listeners);
    150 #endif
    151 }
    152 
    153 }
    154