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 | #pragma once |
21 | |
22 | #include <memory> |
23 | #include <wtf/Forward.h> |
24 | #include <wtf/RefCounted.h> |
25 | #include <wtf/Vector.h> |
26 | #include <wtf/WeakPtr.h> |
27 | |
28 | namespace WebCore { |
29 | |
30 | class Document; |
31 | class MediaQueryList; |
32 | class MediaQueryListListener; |
33 | class MediaQueryEvaluator; |
34 | class MediaQuerySet; |
35 | class RenderStyle; |
36 | |
37 | // MediaQueryMatcher class is responsible for keeping a vector of pairs |
38 | // MediaQueryList x MediaQueryListListener. It is responsible for evaluating the queries |
39 | // whenever it is needed and to call the listeners if the corresponding query has changed. |
40 | // The listeners must be called in the order in which they were added. |
41 | |
42 | class MediaQueryMatcher final : public RefCounted<MediaQueryMatcher> { |
43 | public: |
44 | static Ref<MediaQueryMatcher> create(Document& document) { return adoptRef(*new MediaQueryMatcher(document)); } |
45 | ~MediaQueryMatcher(); |
46 | |
47 | void documentDestroyed(); |
48 | |
49 | void addListener(Ref<MediaQueryListListener>&&, MediaQueryList&); |
50 | void removeListener(MediaQueryListListener&, MediaQueryList&); |
51 | |
52 | RefPtr<MediaQueryList> matchMedia(const String&); |
53 | |
54 | unsigned evaluationRound() const { return m_evaluationRound; } |
55 | |
56 | void styleResolverChanged(); |
57 | |
58 | bool evaluate(const MediaQuerySet&); |
59 | |
60 | private: |
61 | struct Listener { |
62 | Ref<MediaQueryListListener> listener; |
63 | Ref<MediaQueryList> query; |
64 | }; |
65 | |
66 | explicit MediaQueryMatcher(Document&); |
67 | std::unique_ptr<RenderStyle> documentElementUserAgentStyle() const; |
68 | String mediaType() const; |
69 | |
70 | WeakPtr<Document> m_document; |
71 | Vector<Listener> m_listeners; |
72 | |
73 | // This value is incremented at style selector changes. |
74 | // It is used to avoid evaluating queries more then once and to make sure |
75 | // that a media query result change is notified exactly once. |
76 | unsigned m_evaluationRound { 1 }; |
77 | }; |
78 | |
79 | } // namespace WebCore |
80 | |