Source/WebCore/css/CSSVariableData.h

// Copyright 2015 The Chromium Authors. All rights reserved.
// Copyright (C) 2016 Apple Inc. All rights reserved.
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#pragma once

#include "CSSParserToken.h"
#include "CSSParserTokenRange.h"
#include <wtf/HashSet.h>
#include <wtf/text/WTFString.h>

namespace WebCore {

class CSSParserTokenRange;

class CSSVariableData : public RefCounted<CSSVariableData> {
    WTF_MAKE_NONCOPYABLE(CSSVariableData);
    WTF_MAKE_FAST_ALLOCATED;
public:
    static Ref<CSSVariableData> create(const CSSParserTokenRange& range, bool needsVariableResolution = true)
    {
        return adoptRef(*new CSSVariableData(range, needsVariableResolution));
    }

    static Ref<CSSVariableData> createResolved(const Vector<CSSParserToken>& resolvedTokens, const CSSVariableData& unresolvedData)
    {
        return adoptRef(*new CSSVariableData(resolvedTokens, unresolvedData.m_backingString));
    }

    CSSParserTokenRange tokenRange() { return m_tokens; }

    const Vector<CSSParserToken>& tokens() const { return m_tokens; }

    bool operator==(const CSSVariableData& other) const;

    bool needsVariableResolution() const { return m_needsVariableResolution; }

    bool checkVariablesForCycles(const AtomicString& name, CustomPropertyValueMap&, HashSet<AtomicString>& seenProperties, HashSet<AtomicString>& invalidProperties) const;

    RefPtr<CSSVariableData> resolveVariableReferences(const CustomPropertyValueMap& customProperties) const;
    bool resolveTokenRange(const CustomPropertyValueMap&, CSSParserTokenRange, Vector<CSSParserToken>&) const;

private:
    CSSVariableData(const CSSParserTokenRange&, bool needsVariableResolution);

    // We can safely copy the tokens (which have raw pointers to substrings) because
    // StylePropertySets contain references to CSSCustomPropertyValues, which
    // point to the unresolved CSSVariableData values that own the backing strings
    // this will potentially reference.
    CSSVariableData(const Vector<CSSParserToken>& resolvedTokens, String backingString)
        : m_backingString(backingString)
        , m_tokens(resolvedTokens)
        , m_needsVariableResolution(false)
    { }

    void consumeAndUpdateTokens(const CSSParserTokenRange&);
    template<typename CharacterType> void updateTokens(const CSSParserTokenRange&);
    
    bool checkVariablesForCyclesWithRange(CSSParserTokenRange, CustomPropertyValueMap&, HashSet<AtomicString>& seenProperties, HashSet<AtomicString>& invalidProperties) const;
    bool resolveVariableReference(const CustomPropertyValueMap&, CSSParserTokenRange, Vector<CSSParserToken>&) const;
    bool resolveVariableFallback(const CustomPropertyValueMap&, CSSParserTokenRange, Vector<CSSParserToken>&) const;

    String m_backingString;
    Vector<CSSParserToken> m_tokens;
    const bool m_needsVariableResolution;

    // FIXME-NEWPARSER: We want to cache StyleProperties once we support @apply.
};

} // namespace WebCore