1 /* 2 * CSS Media Query Evaluator 3 * 4 * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen (at) nokia.com>. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY 16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef MediaQueryEvaluator_h 29 #define MediaQueryEvaluator_h 30 31 #include "wtf/text/WTFString.h" 32 33 namespace WebCore { 34 class Frame; 35 class MediaQueryExp; 36 class MediaQueryResult; 37 class MediaQuerySet; 38 class RenderStyle; 39 40 typedef Vector<RefPtr<MediaQueryResult> > MediaQueryResultList; 41 42 /** 43 * Class that evaluates css media queries as defined in 44 * CSS3 Module "Media Queries" (http://www.w3.org/TR/css3-mediaqueries/) 45 * Special constructors are needed, if simple media queries are to be 46 * evaluated without knowledge of the medium features. This can happen 47 * for example when parsing UA stylesheets, if evaluation is done 48 * right after parsing. 49 * 50 * the boolean parameter is used to approximate results of evaluation, if 51 * the device characteristics are not known. This can be used to prune the loading 52 * of stylesheets to only those which are probable to match. 53 */ 54 class MediaQueryEvaluator { 55 WTF_MAKE_NONCOPYABLE(MediaQueryEvaluator); WTF_MAKE_FAST_ALLOCATED; 56 public: 57 /** Creates evaluator which evaluates only simple media queries 58 * Evaluator returns true for "all", and returns value of \mediaFeatureResult 59 * for any media features 60 */ 61 explicit MediaQueryEvaluator(bool mediaFeatureResult = false); 62 63 /** Creates evaluator which evaluates only simple media queries 64 * Evaluator returns true for acceptedMediaType and returns value of \mediafeatureResult 65 * for any media features 66 */ 67 MediaQueryEvaluator(const AtomicString& acceptedMediaType, bool mediaFeatureResult = false); 68 MediaQueryEvaluator(const char* acceptedMediaType, bool mediaFeatureResult = false); 69 70 /** Creates evaluator which evaluates full media queries */ 71 MediaQueryEvaluator(const AtomicString& acceptedMediaType, Frame*, RenderStyle*); 72 73 ~MediaQueryEvaluator(); 74 75 bool mediaTypeMatch(const AtomicString& mediaTypeToMatch) const; 76 bool mediaTypeMatchSpecific(const char* mediaTypeToMatch) const; 77 78 /** Evaluates a list of media queries */ 79 bool eval(const MediaQuerySet*, MediaQueryResultList* = 0) const; 80 81 /** Evaluates media query subexpression, ie "and (media-feature: value)" part */ 82 bool eval(const MediaQueryExp*) const; 83 84 private: 85 AtomicString m_mediaType; 86 Frame* m_frame; // Not owned. 87 RefPtr<RenderStyle> m_style; 88 bool m_expResult; 89 }; 90 91 } // namespace 92 #endif 93
