| /* |
| * 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 THIRD_PARTY_BLINK_RENDERER_CORE_CSS_MEDIA_QUERY_EVALUATOR_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_CORE_CSS_MEDIA_QUERY_EVALUATOR_H_ |
| |
| #include "third_party/blink/renderer/core/core_export.h" |
| #include "third_party/blink/renderer/platform/heap/handle.h" |
| #include "third_party/blink/renderer/platform/wtf/text/wtf_string.h" |
| |
| namespace blink { |
| |
| class LocalFrame; |
| class MediaQuery; |
| class MediaQueryExp; |
| class MediaQueryResult; |
| class MediaQuerySet; |
| class MediaQuerySetResult; |
| class MediaValues; |
| |
| using MediaQueryResultList = Vector<MediaQueryResult>; |
| |
| // 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 CORE_EXPORT MediaQueryEvaluator final |
| : public GarbageCollected<MediaQueryEvaluator> { |
| public: |
| static void Init(); |
| |
| MediaQueryEvaluator() = delete; |
| |
| // Creates evaluator to evaluate media types only. Evaluator returns true for |
| // accepted_media_type and triggers a NOTREACHED returning false for any media |
| // features. Should only be used for UA stylesheets. |
| explicit MediaQueryEvaluator(const char* accepted_media_type); |
| |
| // Creates evaluator which evaluates full media queries. |
| explicit MediaQueryEvaluator(LocalFrame*); |
| |
| // Creates evaluator which evaluates in a thread-safe manner a subset of media |
| // values. |
| explicit MediaQueryEvaluator(const MediaValues&); |
| |
| MediaQueryEvaluator(const MediaQueryEvaluator&) = delete; |
| MediaQueryEvaluator& operator=(const MediaQueryEvaluator&) = delete; |
| |
| ~MediaQueryEvaluator(); |
| |
| bool MediaTypeMatch(const String& media_type_to_match) const; |
| |
| // Evaluates a list of media queries. |
| bool Eval(const MediaQuerySet&, |
| MediaQueryResultList* viewport_dependent = nullptr, |
| MediaQueryResultList* device_dependent = nullptr) const; |
| |
| // Evaluates media query. |
| bool Eval(const MediaQuery&, |
| MediaQueryResultList* viewport_dependent = nullptr, |
| MediaQueryResultList* device_dependent = nullptr) const; |
| |
| // Evaluates media query subexpression, ie "and (media-feature: value)" part. |
| bool Eval(const MediaQueryExp&) const; |
| |
| // Returns true if any of the expressions in the results lists changed its |
| // evaluation. |
| bool DidResultsChange(const MediaQueryResultList& results) const; |
| |
| // Returns true if any of the media queries in the results lists changed its |
| // evaluation. |
| bool DidResultsChange(const Vector<MediaQuerySetResult>& results) const; |
| |
| void Trace(Visitor*) const; |
| |
| private: |
| const String MediaType() const; |
| |
| String media_type_; |
| Member<MediaValues> media_values_; |
| |
| // Even if UKM reporting is enabled, do not report any media query evaluation |
| // results if this is set to true. |
| mutable bool skip_ukm_reporting_{false}; |
| }; |
| |
| } // namespace blink |
| #endif |