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 "CSSStyleSelector.h"
24#include "Document.h"
25#include "Element.h"
26#include "FrameView.h"
27#include "MediaList.h"
28#include "MediaQueryEvaluator.h"
29#include "MediaQueryList.h"
30#include "MediaQueryListListener.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
69String MediaQueryMatcher::mediaType() const
70{
71    if (!m_document || !m_document->frame() || !m_document->frame()->view())
72        return String();
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 0;
81
82    Element* documentElement = m_document->documentElement();
83    if (!documentElement)
84        return 0;
85
86    CSSStyleSelector* styleSelector = m_document->styleSelector();
87    if (!styleSelector)
88        return 0;
89
90    RefPtr<RenderStyle> rootStyle = styleSelector->styleForElement(documentElement, 0 /*defaultParent*/, false /*allowSharing*/, true /*resolveForRootDefault*/);
91
92    return adoptPtr(new MediaQueryEvaluator(mediaType(), m_document->frame(), rootStyle.get()));
93}
94
95bool MediaQueryMatcher::evaluate(MediaList* media)
96{
97    if (!media)
98        return false;
99
100    OwnPtr<MediaQueryEvaluator> evaluator(prepareEvaluator());
101    return evaluator && evaluator->eval(media);
102}
103
104PassRefPtr<MediaQueryList> MediaQueryMatcher::matchMedia(const String& query)
105{
106    if (!m_document)
107        return 0;
108
109    RefPtr<MediaList> media = MediaList::create(query, false);
110    return MediaQueryList::create(this, media, evaluate(media.get()));
111}
112
113void MediaQueryMatcher::addListener(PassRefPtr<MediaQueryListListener> listener, PassRefPtr<MediaQueryList> query)
114{
115    if (!m_document)
116        return;
117
118    for (size_t i = 0; i < m_listeners.size(); ++i) {
119        if (*m_listeners[i]->listener() == *listener && m_listeners[i]->query() == query)
120            return;
121    }
122
123    m_listeners.append(new Listener(listener, query));
124}
125
126void MediaQueryMatcher::removeListener(MediaQueryListListener* listener, MediaQueryList* query)
127{
128    if (!m_document)
129        return;
130
131    for (size_t i = 0; i < m_listeners.size(); ++i) {
132        if (*m_listeners[i]->listener() == *listener && m_listeners[i]->query() == query) {
133            m_listeners.remove(i);
134            return;
135        }
136    }
137}
138
139void MediaQueryMatcher::styleSelectorChanged()
140{
141    ASSERT(m_document);
142
143    ScriptState* scriptState = mainWorldScriptState(m_document->frame());
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