2 * CSS Media Query Evaluator
4 * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
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12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
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18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
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28 #ifndef MediaQueryEvaluator_h
29 #define MediaQueryEvaluator_h
31 #include "platform/heap/Handle.h"
32 #include "wtf/text/WTFString.h"
38 class MediaQueryResult;
42 typedef WillBeHeapVector<RefPtrWillBeMember<MediaQueryResult> > MediaQueryResultList;
44 // Class that evaluates css media queries as defined in
45 // CSS3 Module "Media Queries" (http://www.w3.org/TR/css3-mediaqueries/)
46 // Special constructors are needed, if simple media queries are to be
47 // evaluated without knowledge of the medium features. This can happen
48 // for example when parsing UA stylesheets, if evaluation is done
49 // right after parsing.
51 // the boolean parameter is used to approximate results of evaluation, if
52 // the device characteristics are not known. This can be used to prune the loading
53 // of stylesheets to only those which are probable to match.
55 class MediaQueryEvaluator {
56 WTF_MAKE_NONCOPYABLE(MediaQueryEvaluator); WTF_MAKE_FAST_ALLOCATED;
58 // Creates evaluator which evaluates only simple media queries
59 // Evaluator returns true for "all", and returns value of \mediaFeatureResult
60 // for any media features.
62 explicit MediaQueryEvaluator(bool mediaFeatureResult = false);
64 // Creates evaluator which evaluates only simple media queries
65 // Evaluator returns true for acceptedMediaType and returns value of \mediafeatureResult
66 // for any media features.
68 MediaQueryEvaluator(const char* acceptedMediaType, bool mediaFeatureResult = false);
70 // Creates evaluator which evaluates full media queries.
71 explicit MediaQueryEvaluator(LocalFrame*);
73 // Creates evaluator which evaluates in a thread-safe manner a subset of media values.
74 explicit MediaQueryEvaluator(const MediaValues&);
76 ~MediaQueryEvaluator();
78 bool mediaTypeMatch(const String& mediaTypeToMatch) const;
80 // Evaluates a list of media queries.
81 bool eval(const MediaQuerySet*, MediaQueryResultList* = 0) const;
83 // Evaluates media query.
84 bool eval(const MediaQuery*, MediaQueryResultList*) const;
86 // Evaluates media query subexpression, ie "and (media-feature: value)" part.
87 bool eval(const MediaQueryExp*) const;
90 const String mediaType() const;
93 bool m_expectedResult;
94 RefPtr<MediaValues> m_mediaValues;