1 /*

     2     This file is part of the KDE libraries

     3 

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

     5     Copyright (C) 2006 Apple Computer, Inc.

     6 

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

     8     modify it under the terms of the GNU Library General Public

     9     License as published by the Free Software Foundation; either

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

    11 

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

    13     but WITHOUT ANY WARRANTY; without even the implied warranty of

    14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    15     Library General Public License for more details.

    16 

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

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

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

    20     Boston, MA 02110-1301, USA.

    21 */

    22 

    23 #ifndef Length_h

    24 #define Length_h

    25 

    26 #include <wtf/Assertions.h>

    27 

    28 namespace WebCore {

    29 

    30     const int undefinedLength = -1;

    31     const int percentScaleFactor = 128;

    32 

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

    34 

    35     struct Length {

    36         Length()

    37             : m_value(0)

    38         {

    39         }

    40 

    41         Length(LengthType t)

    42             : m_value(t)

    43         {

    44         }

    45 

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

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

    48         {

    49             ASSERT(t != Percent);

    50         }

    51 

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

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

    54         {

    55             ASSERT(t == Percent);

    56         }

    57 

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

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

    60 

    61         int value() const {

    62             ASSERT(type() != Percent);

    63             return rawValue();

    64         }

    65 

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

    67 

    68         double percent() const

    69         {

    70             ASSERT(type() == Percent);

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

    72         }

    73 

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

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

    76 

    77         void setValue(LengthType t, int value)

    78         {

    79             ASSERT(t != Percent);

    80             setRawValue(t, value);

    81         }

    82 

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

    84 

    85         void setValue(int value)

    86         {

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

    88             setRawValue(value);

    89         }

    90 

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

    92 

    93         void setValue(LengthType t, double value)

    94         {

    95             ASSERT(t == Percent);

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

    97         }

    98 

    99         void setValue(double value)

   100         {

   101             ASSERT(type() == Percent);

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

   103         }

   104 

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

   106         int calcValue(int maxValue) const

   107         {

   108             switch (type()) {

   109                 case Fixed:

   110                     return value();

   111                 case Percent:

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

   113                 case Auto:

   114                     return maxValue;

   115                 default:

   116                     return undefinedLength;

   117             }

   118         }

   119 

   120         int calcMinValue(int maxValue) const

   121         {

   122             switch (type()) {

   123                 case Fixed:

   124                     return value();

   125                 case Percent:

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

   127                 case Auto:

   128                 default:

   129                     return 0;

   130             }

   131         }

   132 

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

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

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

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

   137 

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

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

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

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

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

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

   144 

   145     private:

   146         int m_value;

   147     };

   148 

   149 } // namespace WebCore

   150 

   151 #endif // Length_h