mcs/class/System/System.ComponentModel/BaseNumberConverter.cs

   1 //
   2 // System.ComponentModel.BaseNumberConverter.cs
   3 //
   4 // Authors:
   5 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   6 //
   7 // (C) 2002/2003 Ximian, Inc (http://www.ximian.com)
   8 // (C) 2003 Andreas Nahr
   9 //
  10
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System;
  33 using System.Globalization;
  34
  35 namespace System.ComponentModel
  36 {
  37         public abstract class BaseNumberConverter : TypeConverter
  38         {
  39                 internal Type InnerType;
  40
  41                 protected BaseNumberConverter()
  42                 {
  43                 }
  44
  45                 internal abstract bool SupportHex {
  46                         get;
  47                 }
  48
  49                 public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
  50                 {
  51                         if (sourceType == typeof (string))
  52                                 return true;
  53                         return base.CanConvertFrom (context, sourceType);
  54                 }
  55
  56                 public override bool CanConvertTo(ITypeDescriptorContext context, Type t)
  57                 {
  58                         if (t == typeof (string))
  59                                 return true;
  60
  61                         return base.CanConvertTo (context, t);
  62                 }
  63
  64                 public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
  65                 {
  66                         if (culture == null)
  67                                 culture = CultureInfo.CurrentCulture;
  68
  69                         string text = value as string;
  70                         if (text != null) {
  71                                 try {
  72                                         if (SupportHex) {
  73                                                 if (text.Length >= 1 && text[0] == '#') {
  74                                                         return ConvertFromString (text.Substring (1), 16);
  75                                                 }
  76
  77                                                 if (text.StartsWith ("0x") || text.StartsWith ("0X")) {
  78                                                         return ConvertFromString (text, 16);
  79                                                 }
  80                                         }
  81
  82                                         return ConvertFromString (text, culture.NumberFormat);
  83                                 } catch (Exception e) {
  84                                         // LAMESPEC MS wraps the actual exception in an Exception
  85                                         throw new Exception (value.ToString() + " is not a valid "
  86                                                 + "value for " + InnerType.Name + ".", e);
  87                                 }
  88                         }
  89
  90                         return base.ConvertFrom (context, culture, value);
  91                 }
  92
  93                 public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture,
  94                                                  object value, Type destinationType)
  95                 {
  96                         if (value == null)
  97                                 throw new ArgumentNullException ("value");
  98
  99                         if (culture == null)
 100                                 culture = CultureInfo.CurrentCulture;
 101
 102                         if (destinationType == typeof (string) && value.GetType() == InnerType)
 103                                 return Convert.ChangeType (value, typeof (string), culture.NumberFormat);
 104
 105                         return base.ConvertTo (context, culture, value, destinationType);
 106                 }
 107
 108                 internal abstract object ConvertFromString (string value, NumberFormatInfo format);
 109
 110                 internal virtual object ConvertFromString (string value, int fromBase)
 111                 {
 112                         if (SupportHex) {
 113                                 throw new NotImplementedException ();
 114                         } else {
 115                                 throw new InvalidOperationException ();
 116                         }
 117                 }
 118         }
 119 }