1 /*

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

     3     Copyright (C) 2006, 2008 Apple Inc. All rights reserved.

     4 

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

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

     7     License as published by the Free Software Foundation; either

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

     9 

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

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

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

    13     Library General Public License for more details.

    14 

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

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

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

    18     Boston, MA 02110-1301, USA.

    19 */

    20 

    21 #ifndef Length_h

    22 #define Length_h

    23 

    24 #include <wtf/Assertions.h>

    25 #include <wtf/FastAllocBase.h>

    26 #include <wtf/MathExtras.h>

    27 

    28 namespace WebCore {

    29 

    30 class String;

    31 

    32 const int undefinedLength = -1;

    33 const int percentScaleFactor = 128;

    34 

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

    36 

    37 struct Length : FastAllocBase {

    38     Length()

    39         : m_value(0)

    40     {

    41     }

    42 

    43     Length(LengthType t)

    44         : m_value(t)

    45     {

    46     }

    47 

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

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

    50     {

    51         ASSERT(t != Percent);

    52     }

    53 

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

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

    56     {

    57         ASSERT(t == Percent);

    58     }

    59 

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

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

    62 

    63     int value() const {

    64         ASSERT(type() != Percent);

    65         return rawValue();

    66     }

    67 

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

    69 

    70     double percent() const

    71     {

    72         ASSERT(type() == Percent);

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

    74     }

    75 

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

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

    78 

    79     void setValue(LengthType t, int value)

    80     {

    81         ASSERT(t != Percent);

    82         setRawValue(t, value);

    83     }

    84 

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

    86 

    87     void setValue(int value)

    88     {

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

    90         setRawValue(value);

    91     }

    92 

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

    94 

    95     void setValue(LengthType t, double value)

    96     {

    97         ASSERT(t == Percent);

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

    99     }

   100 

   101     void setValue(double value)

   102     {

   103         ASSERT(type() == Percent);

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

   105     }

   106 

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

   108     int calcValue(int maxValue, bool roundPercentages = false) const

   109     {

   110         switch (type()) {

   111             case Fixed:

   112                 return value();

   113             case Percent:

   114                 if (roundPercentages)

   115                     return static_cast<int>(round(maxValue * percent() / 100.0));

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

   117             case Auto:

   118                 return maxValue;

   119             default:

   120                 return undefinedLength;

   121         }

   122     }

   123 

   124     int calcMinValue(int maxValue, bool roundPercentages = false) const

   125     {

   126         switch (type()) {

   127             case Fixed:

   128                 return value();

   129             case Percent:

   130                 if (roundPercentages)

   131                     return static_cast<int>(round(maxValue * percent() / 100.0));

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

   133             case Auto:

   134             default:

   135                 return 0;

   136         }

   137     }

   138 

   139     float calcFloatValue(int maxValue) const

   140     {

   141         switch (type()) {

   142             case Fixed:

   143                 return static_cast<float>(value());

   144             case Percent:

   145                 return static_cast<float>(maxValue * percent() / 100.0);

   146             case Auto:

   147                 return static_cast<float>(maxValue);

   148             default:

   149                 return static_cast<float>(undefinedLength);

   150         }

   151     }

   152 

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

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

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

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

   157 

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

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

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

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

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

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

   164 

   165     Length blend(const Length& from, double progress) const

   166     {

   167         // Blend two lengths to produce a new length that is in between them.  Used for animation.

   168         if (!from.isZero() && !isZero() && from.type() != type())

   169             return *this;

   170 

   171         if (from.isZero() && isZero())

   172             return *this;

   173         

   174         LengthType resultType = type();

   175         if (isZero())

   176             resultType = from.type();

   177         

   178         if (resultType == Percent) {

   179             double fromPercent = from.isZero() ? 0. : from.percent();

   180             double toPercent = isZero() ? 0. : percent();

   181             return Length(fromPercent + (toPercent - fromPercent) * progress, Percent);

   182         } 

   183             

   184         int fromValue = from.isZero() ? 0 : from.value();

   185         int toValue = isZero() ? 0 : value();

   186         return Length(int(fromValue + (toValue - fromValue) * progress), resultType);

   187     }

   188 

   189 private:

   190     int m_value;

   191 };

   192 

   193 Length* newCoordsArray(const String&, int& len);

   194 Length* newLengthArray(const String&, int& len);

   195 

   196 } // namespace WebCore

   197 

   198 #endif // Length_h