/*

    This file is part of the KDE libraries

    Copyright (C) 1999 Lars Knoll (knoll@kde.org)

    Copyright (C) 2006 Apple Computer, Inc.

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Library General Public

    License as published by the Free Software Foundation; either

    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License

    along with this library; see the file COPYING.LIB.  If not, write to

    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

    Boston, MA 02110-1301, USA.

*/

#ifndef Length_h

#define Length_h

#include <wtf/Assertions.h>

namespace WebCore {

    const int undefinedLength = -1;

    const int percentScaleFactor = 128;

    enum LengthType { Auto, Relative, Percent, Fixed, Static, Intrinsic, MinIntrinsic };

    struct Length {

        Length()

            : m_value(0)

        {

        }

        Length(LengthType t)

            : m_value(t)

        {

        }

        Length(int v, LengthType t, bool q = false)

            : m_value((v * 16) | (q << 3) | t) // FIXME: Doesn't work if the passed-in value is very large!

        {

            ASSERT(t != Percent);

        }

        Length(double v, LengthType t, bool q = false)

            : m_value(static_cast<int>(v * percentScaleFactor) * 16 | (q << 3) | t)

        {

            ASSERT(t == Percent);

        }

        bool operator==(const Length& o) const { return m_value == o.m_value; }

        bool operator!=(const Length& o) const { return m_value != o.m_value; }

        int value() const {

            ASSERT(type() != Percent);

            return rawValue();

        }

        int rawValue() const { return (m_value & ~0xF) / 16; }

        double percent() const

        {

            ASSERT(type() == Percent);

            return static_cast<double>(rawValue()) / percentScaleFactor;

        }

        LengthType type() const { return static_cast<LengthType>(m_value & 7); }

        bool quirk() const { return (m_value >> 3) & 1; }

        void setValue(LengthType t, int value)

        {

            ASSERT(t != Percent);

            setRawValue(t, value);

        }

        void setRawValue(LengthType t, int value) { m_value = value * 16 | (m_value & 0x8) | t; }

        void setValue(int value)

        {

            ASSERT(!value || type() != Percent);

            setRawValue(value);

        }

        void setRawValue(int value) { m_value = value * 16 | (m_value & 0xF); }

        void setValue(LengthType t, double value)

        {

            ASSERT(t == Percent);

            m_value = static_cast<int>(value * percentScaleFactor) * 16 | (m_value & 0x8) | t;

        }

        void setValue(double value)

        {

            ASSERT(type() == Percent);

            m_value = static_cast<int>(value * percentScaleFactor) * 16 | (m_value & 0xF);

        }

        // note: works only for certain types, returns undefinedLength otherwise

        int calcValue(int maxValue) const

        {

            switch (type()) {

                case Fixed:

                    return value();

                case Percent:

                    return maxValue * rawValue() / (100 * percentScaleFactor);

                case Auto:

                    return maxValue;

                default:

                    return undefinedLength;

            }

        }

        int calcMinValue(int maxValue) const

        {

            switch (type()) {

                case Fixed:

                    return value();

                case Percent:

                    return maxValue * rawValue() / (100 * percentScaleFactor);

                case Auto:

                default:

                    return 0;

            }

        }

        bool isUndefined() const { return rawValue() == undefinedLength; }

        bool isZero() const { return !(m_value & ~0xF); }

        bool isPositive() const { return rawValue() > 0; }

        bool isNegative() const { return rawValue() < 0; }

        bool isAuto() const { return type() == Auto; }

        bool isRelative() const { return type() == Relative; }

        bool isPercent() const { return type() == Percent; }

        bool isFixed() const { return type() == Fixed; }

        bool isStatic() const { return type() == Static; }

        bool isIntrinsicOrAuto() const { return type() == Auto || type() == MinIntrinsic || type() == Intrinsic; }

    private:

        int m_value;

    };

} // namespace WebCore

#endif // Length_h