Source/WebCore/css/StyleColor.h

/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
 * Copyright (C) 2016 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
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 * notice, this list of conditions and the following disclaimer.
 *     * 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.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 */

#pragma once

#include "CSSValueKeywords.h"
#include "Color.h"
#include <wtf/OptionSet.h>

namespace WebCore {

class StyleColor {
public:
    StyleColor()
        : m_currentColor(true) { }
    StyleColor(Color color)
        : m_color(color)
        , m_currentColor(false) { }
    static StyleColor currentColor() { return StyleColor(); }

    bool isCurrentColor() const { return m_currentColor; }
    const Color& getColor() const { ASSERT(!isCurrentColor()); return m_color; }

    const Color& resolve(const Color& currentColor) const { return m_currentColor ? currentColor : m_color; }

    enum class Options : uint8_t {
        ForVisitedLink = 1 << 0,
        UseSystemAppearance = 1 << 1,
        UseDarkAppearance = 1 << 2,
        UseElevatedUserInterfaceLevel = 1 << 3
    };

    static Color colorFromKeyword(CSSValueID, OptionSet<Options>);
    static bool isColorKeyword(CSSValueID);
    static bool isSystemColor(CSSValueID);

private:
    Color m_color;
    bool m_currentColor;
};

inline bool operator==(const StyleColor& a, const StyleColor& b)
{
    if (a.isCurrentColor() || b.isCurrentColor())
        return a.isCurrentColor() && b.isCurrentColor();
    return a.getColor() == b.getColor();
}

inline bool operator!=(const StyleColor& a, const StyleColor& b)
{
    return !(a == b);
}


} // namespace WebCore