mcs/class/System/System.ComponentModel/TypeConverter.cs

   1 //
   2 // System.ComponentModel.TypeConverter.cs
   3 //
   4 // Authors:
   5 //   Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   7 //
   8 // (C) 2002/2003 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
  33 using System;
  34 using System.Collections;
  35 using System.ComponentModel.Design.Serialization;
  36 using System.Globalization;
  37 using System.Runtime.InteropServices;
  38
  39 namespace System.ComponentModel
  40 {
  41         [ComVisible (true)]
  42         public class TypeConverter
  43         {
  44                 public bool CanConvertFrom (Type sourceType)
  45                 {
  46                         return CanConvertFrom (null, sourceType);
  47                 }
  48
  49                 public virtual bool CanConvertFrom (ITypeDescriptorContext context, Type sourceType)
  50                 {
  51                         if (sourceType == typeof (InstanceDescriptor)) {
  52                                 return true;
  53                         }
  54
  55                         return false;
  56                 }
  57
  58                 public bool CanConvertTo (Type destinationType)
  59                 {
  60                         return CanConvertTo (null, destinationType);
  61                 }
  62
  63                 public virtual bool CanConvertTo (ITypeDescriptorContext context, Type destinationType)
  64                 {
  65                         return (destinationType == typeof (string));
  66                 }
  67
  68                 public object ConvertFrom (object o)
  69                 {
  70                         return ConvertFrom (null, CultureInfo.CurrentCulture, o);
  71                 }
  72
  73                 public virtual object ConvertFrom (ITypeDescriptorContext context, CultureInfo culture, object value)
  74                 {
  75                         if (value is InstanceDescriptor) {
  76                                 return ((InstanceDescriptor) value).Invoke ();
  77                         }
  78                         if (value == null)
  79                                 throw new NotSupportedException ("Cannot convert from null");
  80                         throw new NotSupportedException (this.ToString() + " cannot be created from '" +
  81                                                          value.GetType().ToString() + "'");
  82                 }
  83
  84                 public object ConvertFromInvariantString (string text)
  85                 {
  86                         return ConvertFromInvariantString (null, text);
  87                 }
  88
  89                 public object ConvertFromInvariantString (ITypeDescriptorContext context, string text)
  90                 {
  91                         return ConvertFromString (context, CultureInfo.InvariantCulture, text);
  92                 }
  93
  94                 public object ConvertFromString (string text)
  95                 {
  96                         return ConvertFrom (text);
  97                 }
  98
  99                 public object ConvertFromString (ITypeDescriptorContext context, string text)
 100                 {
 101                         return ConvertFromString (context, CultureInfo.CurrentCulture, text);
 102                 }
 103
 104                 public object ConvertFromString (ITypeDescriptorContext context, CultureInfo culture, string text)
 105                 {
 106                         return ConvertFrom (context, culture, text);
 107                 }
 108
 109                 public object ConvertTo (object value, Type destinationType)
 110                 {
 111                         return ConvertTo (null, null, value, destinationType);
 112                 }
 113
 114                 public virtual object ConvertTo (ITypeDescriptorContext context, CultureInfo culture, object value,
 115                                                  Type destinationType)
 116                 {
 117                         // context? culture?
 118                         if (destinationType == null)
 119                                 throw new ArgumentNullException ("destinationType");
 120
 121                         if (destinationType == typeof (string)) {
 122                                 if (value != null)
 123                                         return value.ToString();
 124                                 return String.Empty;
 125                         }
 126
 127                         throw new NotSupportedException ("Conversion not supported");
 128                 }
 129
 130                 public string ConvertToInvariantString (object value)
 131                 {
 132                         return ConvertToInvariantString (null, value);
 133                 }
 134
 135                 public string ConvertToInvariantString (ITypeDescriptorContext context, object value)
 136                 {
 137                         return (string) ConvertTo (context, CultureInfo.InvariantCulture, value, typeof (string));
 138                 }
 139
 140                 public string ConvertToString (object value)
 141                 {
 142                         return (string) ConvertTo (null, CultureInfo.CurrentCulture, value, typeof (string));
 143                 }
 144
 145                 public string ConvertToString (ITypeDescriptorContext context, object value)
 146                 {
 147                         return (string) ConvertTo (context, CultureInfo.CurrentCulture, value, typeof (string));
 148                 }
 149
 150                 public string ConvertToString (ITypeDescriptorContext context, CultureInfo culture, object value)
 151                 {
 152                         return (string) ConvertTo (context, culture, value, typeof (string));
 153                 }
 154
 155                 protected Exception GetConvertFromException (object value)
 156                 {
 157                         throw new NotSupportedException (this.ToString() + " cannot convert from '" +
 158                                                         value.GetType().ToString() + "'");
 159                 }
 160
 161                 protected Exception GetConvertToException (object value, Type destinationType)
 162                 {
 163                         throw new NotSupportedException (this.ToString() + " cannot convert from '" +
 164                                                         value.GetType().ToString() + "' to '" + destinationType.ToString() + "'");
 165                 }
 166
 167                 public object CreateInstance (IDictionary propertyValues)
 168                 {
 169                         return CreateInstance (null, propertyValues);
 170                 }
 171
 172                 public virtual object CreateInstance (ITypeDescriptorContext context, IDictionary propertyValues)
 173                 {
 174                         return null;
 175                 }
 176
 177                 public bool GetCreateInstanceSupported ()
 178                 {
 179                         return GetCreateInstanceSupported (null);
 180                 }
 181
 182                 public virtual bool GetCreateInstanceSupported (ITypeDescriptorContext context)
 183                 {
 184                         return false;
 185                 }
 186
 187                 public PropertyDescriptorCollection GetProperties (object value)
 188                 {
 189                         return GetProperties (null, value);
 190                 }
 191
 192                 public PropertyDescriptorCollection GetProperties (ITypeDescriptorContext context, object value)
 193                 {
 194                         return GetProperties (context, value, new Attribute[1] { BrowsableAttribute.Yes });
 195                 }
 196
 197                 public virtual PropertyDescriptorCollection GetProperties (ITypeDescriptorContext context,
 198                                                                            object value, Attribute[] attributes)
 199                 {
 200                         return null;
 201                 }
 202
 203                 public bool GetPropertiesSupported ()
 204                 {
 205                         return GetPropertiesSupported (null);
 206                 }
 207
 208                 public virtual bool GetPropertiesSupported (ITypeDescriptorContext context)
 209                 {
 210                         return false;
 211                 }
 212
 213                 public ICollection GetStandardValues ()
 214                 {
 215                         return GetStandardValues (null);
 216                 }
 217
 218                 public virtual StandardValuesCollection GetStandardValues (ITypeDescriptorContext context)
 219                 {
 220                         return null;
 221                 }
 222
 223                 public bool GetStandardValuesExclusive ()
 224                 {
 225                         return GetStandardValuesExclusive (null);
 226                 }
 227
 228                 public virtual bool GetStandardValuesExclusive (ITypeDescriptorContext context)
 229                 {
 230                         return false;
 231                 }
 232
 233                 public bool GetStandardValuesSupported ()
 234                 {
 235                         return GetStandardValuesSupported (null);
 236                 }
 237
 238                 public virtual bool GetStandardValuesSupported (ITypeDescriptorContext context)
 239                 {
 240                         return false;
 241                 }
 242
 243                 public bool IsValid (object value)
 244                 {
 245                         return IsValid (null, value);
 246                 }
 247
 248                 public virtual bool IsValid (ITypeDescriptorContext context, object value)
 249                 {
 250                         return true;
 251                 }
 252
 253                 protected PropertyDescriptorCollection SortProperties (PropertyDescriptorCollection props, string[] names)
 254                 {
 255                         props.Sort (names);
 256                         return props;
 257                 }
 258
 259                 public class StandardValuesCollection : ICollection, IEnumerable
 260                 {
 261                         private ICollection values;
 262
 263                         public StandardValuesCollection (ICollection values)
 264                         {
 265                                 this.values = values;
 266                         }
 267
 268                         void ICollection.CopyTo (Array array, int index) {
 269                                 CopyTo (array, index);
 270                         }
 271
 272                         public void CopyTo (Array array, int index)
 273                         {
 274                                 values.CopyTo (array, index);
 275                         }
 276
 277                         IEnumerator IEnumerable.GetEnumerator () {
 278                                 return GetEnumerator ();
 279                         }
 280
 281                         public IEnumerator GetEnumerator ()
 282                         {
 283                                 return values.GetEnumerator ();
 284                         }
 285
 286                         bool ICollection.IsSynchronized {
 287                                 get { return false; }
 288                         }
 289
 290                         object ICollection.SyncRoot {
 291                                 get { return null; }
 292                         }
 293
 294                         int ICollection.Count {
 295                                 get { return this.Count; }
 296                         }
 297
 298                         public int Count {
 299                                 get { return values.Count; }
 300                         }
 301
 302                         public object this [int index] {
 303                                 get { return ((IList) values) [index]; }
 304                         }
 305                 }
 306
 307                 protected abstract class SimplePropertyDescriptor : PropertyDescriptor
 308                 {
 309                         private Type componentType;
 310                         private Type propertyType;
 311
 312                         public SimplePropertyDescriptor (Type componentType,
 313                                                          string name,
 314                                                          Type propertyType) :
 315                                 this (componentType, name, propertyType, null)
 316                         {
 317                         }
 318
 319                         public SimplePropertyDescriptor (Type componentType,
 320                                                          string name,
 321                                                          Type propertyType,
 322                                                          Attribute [] attributes) : base (name, attributes)
 323                         {
 324                                 this.componentType = componentType;
 325                                 this.propertyType = propertyType;
 326                         }
 327
 328                         public override Type ComponentType {
 329                                 get { return componentType; }
 330                         }
 331
 332                         public override Type PropertyType {
 333                                 get { return propertyType; }
 334                         }
 335
 336                         public override bool IsReadOnly {
 337                                 get { return Attributes.Contains (ReadOnlyAttribute.Yes); }
 338                         }
 339
 340                         public override bool ShouldSerializeValue (object component)
 341                         {
 342                                         return false;
 343                         }
 344
 345                         public override bool CanResetValue (object component)
 346                         {
 347                                 DefaultValueAttribute Attrib = ((DefaultValueAttribute) Attributes[typeof (DefaultValueAttribute)]);
 348                                 if (Attrib == null) {
 349                                         return false;
 350                                 }
 351                                 return (Attrib.Value == GetValue (component));
 352                         }
 353
 354                         public override void ResetValue (object component)
 355                         {
 356                                 DefaultValueAttribute Attrib = ((DefaultValueAttribute) Attributes[typeof (DefaultValueAttribute)]);
 357                                 if (Attrib != null) {
 358                                         SetValue (component, Attrib.Value);
 359                                 }
 360
 361                         }
 362                 }
 363         }
 364 }
 365