A thread-safe Media Query Parser

Source/core/css/parser/MediaQueryParser.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MediaQueryParser_h
+#define MediaQueryParser_h
+
+#include "core/css/CSSParserValues.h"
+#include "core/css/MediaList.h"
+#include "core/css/MediaQuery.h"
+#include "core/css/MediaQueryExp.h"
+#include "core/css/parser/CSSToken.h"
+#include "wtf/Vector.h"
+#include "wtf/text/WTFString.h"
+
+namespace WebCore {
+
+class MediaQuerySet;
+
+class MediaQueryData {
+private:
+    RefPtr<MediaQuerySet> m_querySet;
+    MediaQuery::Restrictor m_restrictor;
+    String m_mediaType;
+    OwnPtr<ExpressionVector> m_expressions;
+    String m_mediaFeature;
+    CSSParserValueList m_valueList;
+    bool m_mediaTypeSet;
+
+public:
+    MediaQueryData();
+    void resetCurrentQuery();
+    void addCurrentMediaQuery();
+    bool addExpression();
+    void addParserValue(CSSTokenType, CSSToken*);
+    void setMediaType(const String&);
+
+    inline PassRefPtr<MediaQuerySet> querySet()
+    {
+        return m_querySet;
+    }
+
+    inline unsigned querySetSize()
+    {
+        return m_querySet->queryVector().size();
+    }
+
+    inline bool currentMediaQueryChanged()
+    {
+        return (m_restrictor != MediaQuery::None || m_mediaTypeSet || m_expressions->size() > 0);
+    }
+
+    inline void addNotAllMediaQuery()
+    {
+        m_querySet->addMediaQuery(adoptPtr(new MediaQuery(MediaQuery::Not, "all", nullptr)));
+    }
+
+    inline void setRestrictor(MediaQuery::Restrictor restrictor) { m_restrictor = restrictor; }
+
+    inline void setMediaFeature(const String& str) { m_mediaFeature = str; }
+};
+
+class MediaQueryParser {
+public:
+    static PassRefPtr<MediaQuerySet> parse(String);
+
+private:
+    MediaQueryParser(String);
+    virtual ~MediaQueryParser() { };
+
+    PassRefPtr<MediaQuerySet> parseImpl();
+
+
+    typedef Vector<CSSToken>::iterator TokenIterator;
+
+    void readRestrictor(CSSTokenType, TokenIterator&);
+    void readMediaType(CSSTokenType, TokenIterator&);
+    void readAnd(CSSTokenType, TokenIterator&);
+    void readFeatureStart(CSSTokenType, TokenIterator&);
+    void readFeature(CSSTokenType, TokenIterator&);
+    void readFeatureColon(CSSTokenType, TokenIterator&);
+    void readFeatureValue(CSSTokenType, TokenIterator&);
+    void readFeatureEnd(CSSTokenType, TokenIterator&);
+    void skipTillComma(CSSTokenType, TokenIterator&);
+    void skipTillParen(CSSTokenType, TokenIterator&);
+    void done(CSSTokenType, TokenIterator&);
+
+    typedef void (MediaQueryParser::*State)(CSSTokenType, TokenIterator&);
+
+    State m_state;
+    Vector<CSSToken> m_tokens;
+    MediaQueryData m_mediaQueryData;
+};
+
+} // namespace WebCore
+
+#endif // MediaQueryParser_h