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
32namespace WebCore {
33
34MediaQueryMatcher::Listener::Listener(PassRefPtrWillBeRawPtr<MediaQueryListListener> listener, PassRefPtrWillBeRawPtr<MediaQueryList> query)
35    : m_listener(listener)
36    , m_query(query)
37{
38}
39
40void MediaQueryMatcher::Listener::evaluate(MediaQueryEvaluator* evaluator)
41{
42    if (m_query->evaluate(evaluator))
43        m_listener->queryChanged(m_query.get());
44}
45
46void MediaQueryMatcher::Listener::trace(Visitor* visitor)
47{
48    visitor->trace(m_listener);
49    visitor->trace(m_query);
50}
51
52MediaQueryMatcher::MediaQueryMatcher(Document* document)
53    : m_document(document)
54    , m_evaluationRound(1)
55{
56    ASSERT(m_document);
57}
58
59DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(MediaQueryMatcher)
60
61void MediaQueryMatcher::documentDestroyed()
62{
63    m_listeners.clear();
64    m_document = nullptr;
65}
66
67AtomicString 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
75PassOwnPtr<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
83bool 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
92PassRefPtrWillBeRawPtr<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
103void 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
116void 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
129void 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
143void 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