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 "MediaQueryMatcher.h"
22
23#include "Document.h"
24#include "Element.h"
25#include "Frame.h"
26#include "FrameView.h"
27#include "MediaList.h"
28#include "MediaQueryEvaluator.h"
29#include "MediaQueryList.h"
30#include "MediaQueryListListener.h"
31#include "StyleResolver.h"
32
33namespace WebCore {
34
35MediaQueryMatcher::Listener::Listener(PassRefPtr<MediaQueryListListener> listener, PassRefPtr<MediaQueryList> query)
36    : m_listener(listener)
37    , m_query(query)
38{
39}
40
41MediaQueryMatcher::Listener::~Listener()
42{
43}
44
45void MediaQueryMatcher::Listener::evaluate(ScriptState* state, MediaQueryEvaluator* evaluator)
46{
47    bool notify;
48    m_query->evaluate(evaluator, notify);
49    if (notify)
50        m_listener->queryChanged(state, m_query.get());
51}
52
53MediaQueryMatcher::MediaQueryMatcher(Document* document)
54    : m_document(document)
55    , m_evaluationRound(1)
56{
57    ASSERT(m_document);
58}
59
60MediaQueryMatcher::~MediaQueryMatcher()
61{
62}
63
64void MediaQueryMatcher::documentDestroyed()
65{
66    m_listeners.clear();
67    m_document = 0;
68}
69
70String MediaQueryMatcher::mediaType() const
71{
72    if (!m_document || !m_document->frame() || !m_document->frame()->view())
73        return String();
74
75    return m_document->frame()->view()->mediaType();
76}
77
78PassOwnPtr<MediaQueryEvaluator> MediaQueryMatcher::prepareEvaluator() const
79{
80    if (!m_document || !m_document->frame())
81        return nullptr;
82
83    Element* documentElement = m_document->documentElement();
84    if (!documentElement)
85        return nullptr;
86
87    StyleResolver* styleResolver = m_document->ensureStyleResolver();
88
89    RefPtr<RenderStyle> rootStyle = styleResolver->styleForElement(documentElement, 0 /*defaultParent*/, DisallowStyleSharing, MatchOnlyUserAgentRules);
90
91    return adoptPtr(new MediaQueryEvaluator(mediaType(), m_document->frame(), rootStyle.get()));
92}
93
94bool MediaQueryMatcher::evaluate(const MediaQuerySet* media)
95{
96    if (!media)
97        return false;
98
99    OwnPtr<MediaQueryEvaluator> evaluator(prepareEvaluator());
100    return evaluator && evaluator->eval(media);
101}
102
103PassRefPtr<MediaQueryList> MediaQueryMatcher::matchMedia(const String& query)
104{
105    if (!m_document)
106        return 0;
107
108    RefPtr<MediaQuerySet> media = MediaQuerySet::create(query);
109#if ENABLE(RESOLUTION_MEDIA_QUERY)
110    // Add warning message to inspector whenever dpi/dpcm values are used for "screen" media.
111    reportMediaQueryWarningIfNeeded(m_document, media.get());
112#endif
113    return MediaQueryList::create(this, media, evaluate(media.get()));
114}
115
116void MediaQueryMatcher::addListener(PassRefPtr<MediaQueryListListener> listener, PassRefPtr<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            return;
124    }
125
126    m_listeners.append(adoptPtr(new Listener(listener, query)));
127}
128
129void MediaQueryMatcher::removeListener(MediaQueryListListener* listener, MediaQueryList* query)
130{
131    if (!m_document)
132        return;
133
134    for (size_t i = 0; i < m_listeners.size(); ++i) {
135        if (*m_listeners[i]->listener() == *listener && m_listeners[i]->query() == query) {
136            m_listeners.remove(i);
137            return;
138        }
139    }
140}
141
142void MediaQueryMatcher::styleResolverChanged()
143{
144    ASSERT(m_document);
145
146    ScriptState* scriptState = mainWorldScriptState(m_document->frame());
147    if (!scriptState)
148        return;
149
150    ++m_evaluationRound;
151    OwnPtr<MediaQueryEvaluator> evaluator = prepareEvaluator();
152    if (!evaluator)
153        return;
154
155    for (size_t i = 0; i < m_listeners.size(); ++i)
156        m_listeners[i]->evaluate(scriptState, evaluator.get());
157}
158
159}
160