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 "platform/heap/Handle.h" 24 #include "wtf/Forward.h" 25 #include "wtf/RefCounted.h" 26 #include "wtf/RefPtr.h" 27 28 namespace WebCore { 29 30 class MediaQueryListListener; 31 class MediaQueryEvaluator; 32 class MediaQueryMatcher; 33 class MediaQuerySet; 34 35 // MediaQueryList interface is specified at http://dev.w3.org/csswg/cssom-view/#the-mediaquerylist-interface 36 // The objects of this class are returned by window.matchMedia. They may be used to 37 // retrieve the current value of the given media query and to add/remove listeners that 38 // will be called whenever the value of the query changes. 39 40 class MediaQueryList FINAL : public RefCountedWillBeGarbageCollected<MediaQueryList> { 41 DECLARE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(MediaQueryList); 42 public: 43 static PassRefPtrWillBeRawPtr<MediaQueryList> create(PassRefPtrWillBeRawPtr<MediaQueryMatcher>, PassRefPtrWillBeRawPtr<MediaQuerySet>, bool); 44 String media() const; 45 bool matches(); 46 47 void addListener(PassRefPtrWillBeRawPtr<MediaQueryListListener>); 48 void removeListener(PassRefPtrWillBeRawPtr<MediaQueryListListener>); 49 50 bool evaluate(MediaQueryEvaluator*); 51 52 void trace(Visitor*); 53 54 private: 55 MediaQueryList(PassRefPtrWillBeRawPtr<MediaQueryMatcher>, PassRefPtrWillBeRawPtr<MediaQuerySet>, bool matches); 56 void setMatches(bool); 57 58 RefPtrWillBeMember<MediaQueryMatcher> m_matcher; 59 RefPtrWillBeMember<MediaQuerySet> m_media; 60 unsigned m_evaluationRound; // Indicates if the query has been evaluated after the last style selector change. 61 unsigned m_changeRound; // Used to know if the query has changed in the last style selector change. 62 bool m_matches; 63 }; 64 65 } 66 67 #endif // MediaQueryList_h 68