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#ifndef MediaQueryList_h
21#define MediaQueryList_h
22
23#include <wtf/Forward.h>
24#include <wtf/RefCounted.h>
25#include <wtf/RefPtr.h>
26
27namespace WebCore {
28
29class MediaQueryListListener;
30class MediaQueryEvaluator;
31class MediaQueryMatcher;
32class MediaQuerySet;
33
34// MediaQueryList interface is specified at http://dev.w3.org/csswg/cssom-view/#the-mediaquerylist-interface
35// The objects of this class are returned by window.matchMedia. They may be used to
36// retrieve the current value of the given media query and to add/remove listeners that
37// will be called whenever the value of the query changes.
38
39class MediaQueryList : public RefCounted<MediaQueryList> {
40public:
41    static PassRefPtr<MediaQueryList> create(PassRefPtr<MediaQueryMatcher>, PassRefPtr<MediaQuerySet>, bool);
42    ~MediaQueryList();
43
44    String media() const;
45    bool matches();
46
47    void addListener(PassRefPtr<MediaQueryListListener>);
48    void removeListener(PassRefPtr<MediaQueryListListener>);
49
50    void evaluate(MediaQueryEvaluator*, bool& notificationNeeded);
51
52private:
53    MediaQueryList(PassRefPtr<MediaQueryMatcher>, PassRefPtr<MediaQuerySet>, bool matches);
54    void setMatches(bool);
55
56    RefPtr<MediaQueryMatcher> m_matcher;
57    RefPtr<MediaQuerySet> m_media;
58    unsigned m_evaluationRound; // Indicates if the query has been evaluated after the last style selector change.
59    unsigned m_changeRound; // Used to know if the query has changed in the last style selector change.
60    bool m_matches;
61};
62
63}
64
65#endif // MediaQueryList_h
66