class/System/System.ComponentModel/CharConverter.cs

   1 //
   2 // System.ComponentModel.CharConverter
   3 //
   4 // Author:
   5 //  Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   6 //  Ivan N. Zlatev (contact@i-nz.net)
   7 //
   8 // (C) 2003 Andreas Nahr
   9 // (C) 2008 Novell, Inc. (http://www.novell.com)
  10 //
  11
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System.Globalization;
  34
  35 namespace System.ComponentModel
  36 {
  37         public class CharConverter : TypeConverter
  38         {
  39                 public override bool CanConvertFrom (ITypeDescriptorContext context, Type sourceType)
  40                 {
  41                         if (sourceType == typeof (string))
  42                                 return true;
  43                         return base.CanConvertFrom (context, sourceType);
  44                 }
  45
  46                 public override object ConvertFrom (ITypeDescriptorContext context, CultureInfo culture, object value)
  47                 {
  48                         string char_string = value as string;
  49                         if (char_string != null) {
  50                                 if (char_string.Length > 1)
  51                                         char_string = char_string.Trim ();
  52                                 if (char_string.Length > 1)
  53                                         throw new FormatException (string.Format (
  54                                                 "String {0} is not a valid Char: " +
  55                                                 "it has to be less than or equal to " +
  56                                                 "one char long.", char_string));
  57                                 if (char_string.Length == 0)
  58                                         return '\0';
  59                                 return char_string [0];
  60                         }
  61                         return base.ConvertFrom (context, culture, value);
  62                 }
  63
  64                 public override object ConvertTo (ITypeDescriptorContext context,
  65                                                   CultureInfo culture, object value, Type destinationType)
  66                 {
  67                         if (destinationType == typeof (string)) {
  68                                 if ((value != null) && (value is char)) {
  69                                         char c = (char) value;
  70                                         if (c == '\0')
  71                                                 return String.Empty;
  72                                         else
  73                                                 return new string (c, 1);
  74                                 }
  75                         }
  76
  77                         return base.ConvertTo (context, culture, value, destinationType);
  78                 }
  79         }
  80 }
  81