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/Frame.h"
30#include "core/frame/FrameView.h"
31
32namespace WebCore {
33
34MediaQueryMatcher::Listener::Listener(PassRefPtr<MediaQueryListListener> listener, PassRefPtr<MediaQueryList> query)
35    : m_listener(listener)
36    , m_query(query)
37{
38}
39
40MediaQueryMatcher::Listener::~Listener()
41{
42}
43
44void MediaQueryMatcher::Listener::evaluate(ScriptState* state, MediaQueryEvaluator* evaluator)
45{
46    bool notify;
47    m_query->evaluate(evaluator, notify);
48    if (notify)
49        m_listener->queryChanged(state, m_query.get());
50}
51
52MediaQueryMatcher::MediaQueryMatcher(Document* document)
53    : m_document(document)
54    , m_evaluationRound(1)
55{
56    ASSERT(m_document);
57}
58
59MediaQueryMatcher::~MediaQueryMatcher()
60{
61}
62
63void MediaQueryMatcher::documentDestroyed()
64{
65    m_listeners.clear();
66    m_document = 0;
67}
68
69AtomicString MediaQueryMatcher::mediaType() const
70{
71    if (!m_document || !m_document->frame() || !m_document->frame()->view())
72        return nullAtom;
73
74    return m_document->frame()->view()->mediaType();
75}
76
77PassOwnPtr<MediaQueryEvaluator> MediaQueryMatcher::prepareEvaluator() const
78{
79    if (!m_document || !m_document->frame())
80        return nullptr;
81
82    Element* documentElement = m_document->documentElement();
83    if (!documentElement)
84        return nullptr;
85
86    StyleResolver& styleResolver = m_document->ensureStyleResolver();
87    RefPtr<RenderStyle> rootStyle = styleResolver.styleForElement(documentElement, 0 /*defaultParent*/, DisallowStyleSharing, MatchOnlyUserAgentRules);
88
89    return adoptPtr(new MediaQueryEvaluator(mediaType(), m_document->frame(), rootStyle.get()));
90}
91
92bool MediaQueryMatcher::evaluate(const MediaQuerySet* media)
93{
94    if (!media)
95        return false;
96
97    OwnPtr<MediaQueryEvaluator> evaluator(prepareEvaluator());
98    return evaluator && evaluator->eval(media);
99}
100
101PassRefPtr<MediaQueryList> MediaQueryMatcher::matchMedia(const String& query)
102{
103    if (!m_document)
104        return 0;
105
106    RefPtr<MediaQuerySet> media = MediaQuerySet::create(query);
107    // Add warning message to inspector whenever dpi/dpcm values are used for "screen" media.
108    reportMediaQueryWarningIfNeeded(m_document, media.get());
109    return MediaQueryList::create(this, media, evaluate(media.get()));
110}
111
112void MediaQueryMatcher::addListener(PassRefPtr<MediaQueryListListener> listener, PassRefPtr<MediaQueryList> query)
113{
114    if (!m_document)
115        return;
116
117    for (size_t i = 0; i < m_listeners.size(); ++i) {
118        if (*m_listeners[i]->listener() == *listener && m_listeners[i]->query() == query)
119            return;
120    }
121
122    m_listeners.append(adoptPtr(new Listener(listener, query)));
123}
124
125void MediaQueryMatcher::removeListener(MediaQueryListListener* listener, MediaQueryList* query)
126{
127    if (!m_document)
128        return;
129
130    for (size_t i = 0; i < m_listeners.size(); ++i) {
131        if (*m_listeners[i]->listener() == *listener && m_listeners[i]->query() == query) {
132            m_listeners.remove(i);
133            return;
134        }
135    }
136}
137
138void MediaQueryMatcher::styleResolverChanged()
139{
140    if (!m_document)
141        return;
142
143    ScriptState* scriptState = m_document->frame() ? mainWorldScriptState(m_document->frame()) : 0;
144    if (!scriptState)
145        return;
146
147    ++m_evaluationRound;
148    OwnPtr<MediaQueryEvaluator> evaluator = prepareEvaluator();
149    if (!evaluator)
150        return;
151
152    for (size_t i = 0; i < m_listeners.size(); ++i)
153        m_listeners[i]->evaluate(scriptState, evaluator.get());
154}
155
156}
157