external/webkit r30707

1 files changed, 91 insertions, 0 deletions

diff --git a/WebCore/css/MediaQueryEvaluator.h b/WebCore/css/MediaQueryEvaluator.h
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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
+{
+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