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 //   Ivan N. Zlatev (contact@i-nz.net)
   8 //
   9 // (C) 2002 Ximian, Inc (http://www.ximian.com)
  10 // (C) 2003 Andreas Nahr
  11 // (C) 2007 Ivan N. Zlatev
  12 //
  13
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34 using System;
  35 using System.Collections;
  36 using System.Globalization;
  37 using System.Reflection;
  38 using System.ComponentModel.Design.Serialization;
  39
  40 namespace System.ComponentModel
  41 {
  42         public class EnumConverter : TypeConverter
  43         {
  44                 private Type type;
  45                 private StandardValuesCollection stdValues;
  46
  47                 public EnumConverter (Type type)
  48                 {
  49                         this.type = type;
  50                 }
  51
  52                 public override bool CanConvertTo (ITypeDescriptorContext context, Type destinationType)
  53                 {
  54                         if (destinationType == typeof (InstanceDescriptor))
  55                                 return true;
  56
  57                         if (destinationType == typeof (Enum[]))
  58                                 return true;
  59
  60                         return base.CanConvertTo (context, destinationType);
  61                 }
  62
  63                 public override object ConvertTo (ITypeDescriptorContext context,
  64                                                   CultureInfo culture,
  65                                                   object value,
  66                                                   Type destinationType)
  67                 {
  68                         if (destinationType == typeof (string) && value != null) {
  69                                 // we need to be able to convert enum names,
  70                                 // integral values and other enum fields
  71                                 if (value is IConvertible) {
  72                                         Type underlyingType = Enum.GetUnderlyingType (type);
  73                                         if (underlyingType != value.GetType ()) {
  74                                                 value = ((IConvertible) value).ToType (
  75                                                         underlyingType, culture);
  76                                         }
  77                                 }
  78
  79                                 if (!IsFlags && !IsValid (context, value))
  80                                         throw CreateValueNotValidException (value);
  81
  82                                 return Enum.Format (type, value, "G");
  83                         } else if (destinationType == typeof (InstanceDescriptor) && value != null) {
  84                                 string enumString = ConvertToString (context, culture, value);
  85                                 if (IsFlags && enumString.IndexOf (",") != -1) {
  86                                         if (value is IConvertible) {
  87                                                 Type underlyingType = Enum.GetUnderlyingType (type);
  88                                                 object enumValue = ((IConvertible)value).ToType (underlyingType, culture);
  89                                                 MethodInfo toObjectMethod = typeof (Enum).GetMethod ("ToObject", new Type[] { typeof (Type),
  90                                                                                                                                                           underlyingType });
  91                                                 return new InstanceDescriptor (toObjectMethod, new object[] { type, enumValue });
  92                                         }
  93                                 } else {
  94                                         FieldInfo f = type.GetField (enumString);
  95                                         if (f != null)
  96                                                 return new InstanceDescriptor (f, null);
  97                                 }
  98                         } else if (destinationType == typeof (Enum[]) && value != null) {
  99                                 if (!IsFlags) {
 100                                         return new Enum[] { (Enum) Enum.ToObject (type, value) };
 101                                 } else {
 102                                         long valueLong = Convert.ToInt64 (
 103                                                 (Enum) value, culture);
 104                                         Array enumValArray = Enum.GetValues (type);
 105                                         long[] enumValues = new long[enumValArray.Length];
 106                                         for (int i=0; i < enumValArray.Length; i++)
 107                                                 enumValues[i] = Convert.ToInt64 (enumValArray.GetValue (i));
 108
 109                                         ArrayList enums = new ArrayList ();
 110                                         bool interrupt = false;
 111                                         while (!interrupt) {
 112                                                 // interrupt the loop unless we find a match to avoid
 113                                                 // looping indefinitely
 114                                                 interrupt = true;
 115                                                 foreach (long val in enumValues) {
 116                                                         if ((val != 0 && ((val & valueLong) == val)) || val == valueLong) {
 117                                                                 enums.Add (Enum.ToObject (type, val));
 118                                                                 valueLong &= (~val);
 119                                                                 interrupt = false;
 120                                                         }
 121                                                 }
 122                                                 if (valueLong == 0) // nothing left to do
 123                                                         interrupt = true;
 124                                         }
 125
 126                                         // add item for remainder
 127                                         if (valueLong != 0)
 128                                                 enums.Add (Enum.ToObject (type, valueLong));
 129
 130                                         return enums.ToArray (typeof(Enum));
 131                                 }
 132                         }
 133
 134                         return base.ConvertTo (context, culture, value, destinationType);
 135                 }
 136
 137                 public override bool CanConvertFrom (ITypeDescriptorContext context, Type sourceType)
 138                 {
 139                         if (sourceType == typeof (string))
 140                                 return true;
 141
 142                         if (sourceType == typeof (Enum[]))
 143                                 return true;
 144
 145                         return base.CanConvertFrom (context, sourceType);
 146                 }
 147
 148                 public override object ConvertFrom (ITypeDescriptorContext context,
 149                                                     CultureInfo culture,
 150                                                     object value)
 151                 {
 152                         if (value is string) {
 153                                 string name = value as string;
 154                                 try {
 155                                         if (name.IndexOf (',') == -1)
 156                                                 return Enum.Parse (type, name, true);
 157
 158                                         long val = 0;
 159                                         string [] names = name.Split (',');
 160                                         foreach (string n in names) {
 161                                                 Enum e = (Enum) Enum.Parse (type, n, true);
 162                                                 val |= Convert.ToInt64 (e, culture);
 163                                         }
 164                                         return Enum.ToObject (type, val);
 165                                 } catch (Exception ex) {
 166                                         throw new FormatException (name + " is " +
 167                                                 "not a valid value for " +
 168                                                 type.Name, ex);
 169                                 }
 170                         } else if (value is Enum[]) {
 171                                 long val = 0;
 172                                 foreach (Enum e in (Enum[])value)
 173                                         val |= Convert.ToInt64 (e, culture);
 174                                 return Enum.ToObject (type, val);
 175                         }
 176
 177                         return base.ConvertFrom (context, culture, value);
 178                 }
 179
 180                 public override bool IsValid (ITypeDescriptorContext context, object value)
 181                 {
 182                         return Enum.IsDefined (type, value);
 183                 }
 184
 185                 public override bool GetStandardValuesSupported (ITypeDescriptorContext context)
 186                 {
 187                         return true;
 188                 }
 189
 190                 public override bool GetStandardValuesExclusive (ITypeDescriptorContext context)
 191                 {
 192                         return !IsFlags;
 193                 }
 194
 195                 public override StandardValuesCollection GetStandardValues (ITypeDescriptorContext context)
 196                 {
 197                         if (stdValues == null) {
 198                                 Array values = Enum.GetValues (type);
 199                                 Array.Sort (values);
 200                                 stdValues = new StandardValuesCollection (values);
 201                         }
 202                         return stdValues;
 203                 }
 204
 205                 protected virtual IComparer Comparer {
 206                         get { return new EnumConverter.EnumComparer (); }
 207                 }
 208
 209                 protected Type EnumType {
 210                         get { return type; }
 211                 }
 212
 213                 protected TypeConverter.StandardValuesCollection Values {
 214                         get { return stdValues;  }
 215                         set { stdValues = value; }
 216                 }
 217
 218                 ArgumentException CreateValueNotValidException (object value)
 219                 {
 220                         string msg = string.Format (CultureInfo.InvariantCulture,
 221                                 "The value '{0}' is not a valid value for the " +
 222                                 "enum '{1}'", value, type.Name);
 223                         return new ArgumentException (msg);
 224                 }
 225
 226                 bool IsFlags {
 227                         get {
 228                                 return (type.IsDefined (typeof (FlagsAttribute),
 229                                         false));
 230                         }
 231                 }
 232
 233                 private class EnumComparer : IComparer
 234                 {
 235                         int IComparer.Compare (object compareObject1, object compareObject2)
 236                         {
 237                                 string CompareString1 = (compareObject1 as string);
 238                                 string CompareString2 = (compareObject2 as string);
 239                                 if ((CompareString1 == null) || (CompareString2 == null))
 240                                         return Collections.Comparer.Default.Compare (compareObject1, compareObject2);
 241                                 return CultureInfo.InvariantCulture.CompareInfo.Compare (CompareString1, CompareString2);
 242                         }
 243                 }
 244         }
 245 }