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 MediaQueryMatcher_h 21#define MediaQueryMatcher_h 22 23#include "ScriptState.h" 24#include <wtf/Forward.h> 25#include <wtf/RefCounted.h> 26#include <wtf/Vector.h> 27 28namespace WebCore { 29 30class Document; 31class MediaQueryList; 32class MediaQueryListListener; 33class MediaQueryEvaluator; 34class MediaQuerySet; 35 36// MediaQueryMatcher class is responsible for keeping a vector of pairs 37// MediaQueryList x MediaQueryListListener. It is responsible for evaluating the queries 38// whenever it is needed and to call the listeners if the corresponding query has changed. 39// The listeners must be called in the very same order in which they have been added. 40 41class MediaQueryMatcher : public RefCounted<MediaQueryMatcher> { 42public: 43 static PassRefPtr<MediaQueryMatcher> create(Document* document) { return adoptRef(new MediaQueryMatcher(document)); } 44 ~MediaQueryMatcher(); 45 void documentDestroyed(); 46 47 void addListener(PassRefPtr<MediaQueryListListener>, PassRefPtr<MediaQueryList>); 48 void removeListener(MediaQueryListListener*, MediaQueryList*); 49 50 PassRefPtr<MediaQueryList> matchMedia(const String&); 51 52 unsigned evaluationRound() const { return m_evaluationRound; } 53 void styleResolverChanged(); 54 bool evaluate(const MediaQuerySet*); 55 56private: 57 class Listener { 58 public: 59 Listener(PassRefPtr<MediaQueryListListener>, PassRefPtr<MediaQueryList>); 60 ~Listener(); 61 62 void evaluate(ScriptState*, MediaQueryEvaluator*); 63 64 MediaQueryListListener* listener() { return m_listener.get(); } 65 MediaQueryList* query() { return m_query.get(); } 66 67 private: 68 RefPtr<MediaQueryListListener> m_listener; 69 RefPtr<MediaQueryList> m_query; 70 }; 71 72 MediaQueryMatcher(Document*); 73 PassOwnPtr<MediaQueryEvaluator> prepareEvaluator() const; 74 String mediaType() const; 75 76 Document* m_document; 77 Vector<OwnPtr<Listener> > m_listeners; 78 79 // This value is incremented at style selector changes. 80 // It is used to avoid evaluating queries more then once and to make sure 81 // that a media query result change is notified exactly once. 82 unsigned m_evaluationRound; 83}; 84 85} 86 87#endif // MediaQueryMatcher_h 88