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 "NodeRenderStyle.h"
32#include "StyleResolver.h"
33
34namespace WebCore {
35
36MediaQueryMatcher::Listener::Listener(PassRefPtr<MediaQueryListListener> listener, PassRefPtr<MediaQueryList> query)
37    : m_listener(listener)
38    , m_query(query)
39{
40}
41
42MediaQueryMatcher::Listener::~Listener()
43{
44}
45
46void MediaQueryMatcher::Listener::evaluate(MediaQueryEvaluator* evaluator)
47{
48    bool notify;
49    m_query->evaluate(evaluator, notify);
50    if (notify)
51        m_listener->queryChanged(m_query.get());
52}
53
54MediaQueryMatcher::MediaQueryMatcher(Document* document)
55    : m_document(document)
56    , m_evaluationRound(1)
57{
58    ASSERT(m_document);
59}
60
61MediaQueryMatcher::~MediaQueryMatcher()
62{
63}
64
65void MediaQueryMatcher::documentDestroyed()
66{
67    m_listeners.clear();
68    m_document = 0;
69}
70
71String MediaQueryMatcher::mediaType() const
72{
73    if (!m_document || !m_document->frame() || !m_document->frame()->view())
74        return String();
75
76    return m_document->frame()->view()->mediaType();
77}
78
79std::unique_ptr<MediaQueryEvaluator> MediaQueryMatcher::prepareEvaluator() const
80{
81    if (!m_document || !m_document->frame())
82        return nullptr;
83
84    Element* documentElement = m_document->documentElement();
85    if (!documentElement)
86        return nullptr;
87
88    RefPtr<RenderStyle> rootStyle = m_document->ensureStyleResolver().styleForElement(documentElement, m_document->renderStyle(), DisallowStyleSharing, MatchOnlyUserAgentRules);
89
90    return std::make_unique<MediaQueryEvaluator>(mediaType(), m_document->frame(), rootStyle.get());
91}
92
93bool MediaQueryMatcher::evaluate(const MediaQuerySet* media)
94{
95    if (!media)
96        return false;
97
98    std::unique_ptr<MediaQueryEvaluator> evaluator = prepareEvaluator();
99    return evaluator && evaluator->eval(media);
100}
101
102PassRefPtr<MediaQueryList> MediaQueryMatcher::matchMedia(const String& query)
103{
104    if (!m_document)
105        return 0;
106
107    RefPtr<MediaQuerySet> media = MediaQuerySet::create(query);
108#if ENABLE(RESOLUTION_MEDIA_QUERY)
109    // Add warning message to inspector whenever dpi/dpcm values are used for "screen" media.
110    reportMediaQueryWarningIfNeeded(m_document, media.get());
111#endif
112    return MediaQueryList::create(this, media, evaluate(media.get()));
113}
114
115void MediaQueryMatcher::addListener(PassRefPtr<MediaQueryListListener> listener, PassRefPtr<MediaQueryList> query)
116{
117    if (!m_document)
118        return;
119
120    for (size_t i = 0; i < m_listeners.size(); ++i) {
121        if (*m_listeners[i]->listener() == *listener && m_listeners[i]->query() == query)
122            return;
123    }
124
125    m_listeners.append(std::make_unique<Listener>(listener, query));
126}
127
128void MediaQueryMatcher::removeListener(MediaQueryListListener* listener, MediaQueryList* query)
129{
130    if (!m_document)
131        return;
132
133    for (size_t i = 0; i < m_listeners.size(); ++i) {
134        if (*m_listeners[i]->listener() == *listener && m_listeners[i]->query() == query) {
135            m_listeners.remove(i);
136            return;
137        }
138    }
139}
140
141void MediaQueryMatcher::styleResolverChanged()
142{
143    ASSERT(m_document);
144
145    ++m_evaluationRound;
146    std::unique_ptr<MediaQueryEvaluator> evaluator = prepareEvaluator();
147    if (!evaluator)
148        return;
149
150    for (size_t i = 0; i < m_listeners.size(); ++i)
151        m_listeners[i]->evaluate(evaluator.get());
152}
153
154} // namespace WebCore
155