mcs/class/System/System.ComponentModel/EnumConverter.cs

   1 //
   2 // System.ComponentModel.EnumConverter.cs
   3 //
   4 // Authors:
   5 //   Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   7 //
   8 // (C) 2002 Ximian, Inc (http://www.ximian.com)
   9 // (C) 2003 Andreas Nahr
  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 using System;
  33 using System.Collections;
  34 using System.Globalization;
  35 using System.Reflection;
  36 using System.ComponentModel.Design.Serialization;
  37
  38 namespace System.ComponentModel
  39 {
  40         public class EnumConverter : TypeConverter
  41         {
  42                 private Type type;
  43                 private StandardValuesCollection stdValues;
  44
  45                 public EnumConverter (Type type)
  46                 {
  47                         this.type = type;
  48                 }
  49
  50                 public override bool CanConvertTo (ITypeDescriptorContext context, Type destinationType)
  51                 {
  52                         if (destinationType == typeof (InstanceDescriptor))
  53                                 return true;
  54
  55                         return base.CanConvertTo (context, destinationType);
  56                 }
  57
  58                 public override object ConvertTo (ITypeDescriptorContext context,
  59                                                   CultureInfo culture,
  60                                                   object value,
  61                                                   Type destinationType)
  62                 {
  63                         if (destinationType == typeof (string))
  64                                 if (value != null)
  65                                         return Enum.Format (type, value, "G");
  66
  67                         if (destinationType == typeof (InstanceDescriptor) && type.IsInstanceOfType (value)) {
  68                                 FieldInfo f = type.GetField (value.ToString ());
  69                                 if (f == null) throw new ArgumentException (string.Format ("The value '{0}' is not a valid value for the enum '{1}'", value, type));
  70                                 return new InstanceDescriptor (f, null);
  71                         }
  72
  73                         return base.ConvertTo (context, culture, value, destinationType);
  74                 }
  75
  76                 public override bool CanConvertFrom (ITypeDescriptorContext context, Type sourceType)
  77                 {
  78                         if (sourceType == typeof (string))
  79                                 return true;
  80                         return base.CanConvertFrom (context, sourceType);
  81                 }
  82
  83                 public override object ConvertFrom (ITypeDescriptorContext context,
  84                                                     CultureInfo culture,
  85                                                     object value)
  86                 {
  87                         string val = value as string;
  88                         if (val == null)
  89                                 return base.ConvertFrom(context, culture, value);
  90
  91                         return Enum.Parse (type, val, true);
  92                 }
  93
  94                 public override bool IsValid (ITypeDescriptorContext context, object value)
  95                 {
  96                         return Enum.IsDefined (type, value);
  97                 }
  98
  99                 public override bool GetStandardValuesSupported (ITypeDescriptorContext context)
 100                 {
 101                         return true;
 102                 }
 103
 104                 public override bool GetStandardValuesExclusive (ITypeDescriptorContext context)
 105                 {
 106                         return !(type.IsDefined (typeof (FlagsAttribute), false));
 107                 }
 108
 109                 public override StandardValuesCollection GetStandardValues (ITypeDescriptorContext context)
 110                 {
 111                         if (stdValues == null) {
 112                                 Array values = Enum.GetValues (type);
 113                                 Array.Sort (values);
 114                                 stdValues = new StandardValuesCollection (values);
 115                         }
 116                         return stdValues;
 117                 }
 118
 119                 protected virtual IComparer Comparer {
 120                         get { return new EnumConverter.EnumComparer (); }
 121                 }
 122
 123                 protected Type EnumType {
 124                         get { return type; }
 125                 }
 126
 127                 protected TypeConverter.StandardValuesCollection Values {
 128                         get { return stdValues;  }
 129                         set { stdValues = value; }
 130                 }
 131
 132                 private class EnumComparer : IComparer
 133                 {
 134                         int IComparer.Compare (object compareObject1, object compareObject2)
 135                         {
 136                                 string CompareString1 = (compareObject1 as string);
 137                                 string CompareString2 = (compareObject2 as string);
 138                                 if ((CompareString1 == null) || (CompareString2 == null))
 139                                         return Collections.Comparer.Default.Compare (compareObject1, compareObject2);
 140                                 return CultureInfo.InvariantCulture.CompareInfo.Compare (CompareString1, CompareString2);
 141                         }
 142                 }
 143         }
 144
 145 }
 146