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
  40                 internal Type InnerType;
  41
  42                 protected BaseNumberConverter()
  43                 {
  44                 }
  45
  46                 public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
  47                 {
  48                         if (sourceType == typeof (string))
  49                         return true;
  50                         return base.CanConvertFrom (context, sourceType);
  51                 }
  52
  53                 public override bool CanConvertTo(ITypeDescriptorContext context, Type t)
  54                 {
  55                         if (t == typeof (string))
  56                                 return true;
  57
  58                         return base.CanConvertTo (context, t);
  59                 }
  60
  61                 public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
  62                 {
  63                         if (value.GetType() == typeof (string)) {
  64                                 try {
  65                                         return Convert.ChangeType (value, InnerType, culture.NumberFormat);
  66                                 } catch (Exception e) {
  67                                         // LAMESPEC MS just seems to pass the internal Exception on to the user
  68                                         // so it throws a pure Exception here. We should probably throw a
  69                                         // ArgumentException or something like that
  70                                         throw e;
  71                                 }
  72                         }
  73
  74                         return base.ConvertFrom (context, culture, value);
  75                 }
  76
  77                 public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture,
  78                                                  object value, Type destinationType)
  79                 {
  80                         if (value == null)
  81                                 throw new ArgumentNullException ("value");
  82
  83                         if (destinationType == typeof (string) && value.GetType() == InnerType)
  84                                 return Convert.ChangeType (value, typeof (string), culture.NumberFormat);
  85
  86                         return base.ConvertTo (context, culture, value, destinationType);
  87                 }
  88         }
  89 }
  90