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/*
* CSS Media Query Evaluator
*
* Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef MediaQueryEvaluator_h
#define MediaQueryEvaluator_h
#include "PlatformString.h"
namespace WebCore {
class CSSStyleSelector;
class Frame;
class RenderStyle;
class MediaList;
class MediaQueryExp;
/**
* Class that evaluates css media queries as defined in
* CSS3 Module "Media Queries" (http://www.w3.org/TR/css3-mediaqueries/)
* Special constructors are needed, if simple media queries are to be
* evaluated without knowledge of the medium features. This can happen
* for example when parsing UA stylesheets, if evaluation is done
* right after parsing.
*
* the boolean parameter is used to approximate results of evaluation, if
* the device characteristics are not known. This can be used to prune the loading
* of stylesheets to only those which are probable to match.
*/
class MediaQueryEvaluator {
WTF_MAKE_NONCOPYABLE(MediaQueryEvaluator); WTF_MAKE_FAST_ALLOCATED;
public:
/** Creates evaluator which evaluates only simple media queries
* Evaluator returns true for "all", and returns value of \mediaFeatureResult
* for any media features
*/
MediaQueryEvaluator(bool mediaFeatureResult = false);
/** Creates evaluator which evaluates only simple media queries
* Evaluator returns true for acceptedMediaType and returns value of \mediafeatureResult
* for any media features
*/
MediaQueryEvaluator(const String& acceptedMediaType, bool mediaFeatureResult = false);
MediaQueryEvaluator(const char* acceptedMediaType, bool mediaFeatureResult = false);
/** Creates evaluator which evaluates full media queries
*/
MediaQueryEvaluator(const String& acceptedMediaType, Frame*, RenderStyle*);
~MediaQueryEvaluator();
bool mediaTypeMatch(const String& mediaTypeToMatch) const;
bool mediaTypeMatchSpecific(const char* mediaTypeToMatch) const;
/** Evaluates a list of media queries */
bool eval(const MediaList*, CSSStyleSelector* = 0) const;
/** Evaluates media query subexpression, ie "and (media-feature: value)" part */
bool eval(const MediaQueryExp*) const;
private:
String m_mediaType;
Frame* m_frame; // not owned
RenderStyle* m_style; // not owned
bool m_expResult;
};
} // namespace
#endif
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