mcs/class/System.Xaml/System.Xaml/TypeExtensionMethods.cs

   1 //
   2 // Copyright (C) 2010 Novell Inc. http://novell.com
   3 //
   4 // Permission is hereby granted, free of charge, to any person obtaining
   5 // a copy of this software and associated documentation files (the
   6 // "Software"), to deal in the Software without restriction, including
   7 // without limitation the rights to use, copy, modify, merge, publish,
   8 // distribute, sublicense, and/or sell copies of the Software, and to
   9 // permit persons to whom the Software is furnished to do so, subject to
  10 // the following conditions:
  11 //
  12 // The above copyright notice and this permission notice shall be
  13 // included in all copies or substantial portions of the Software.
  14 //
  15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  19 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  20 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  21 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22 //
  23 using System;
  24 using System.Collections;
  25 using System.Collections.Generic;
  26 using System.ComponentModel;
  27 using System.Linq;
  28 using System.Reflection;
  29 using System.Windows.Markup;
  30 using System.Xaml.Schema;
  31
  32 namespace System.Xaml
  33 {
  34         static class TypeExtensionMethods
  35         {
  36                 // FIXME: this likely needs to be replaced with XamlTypeName
  37                 public static string GetXamlName (this Type type)
  38                 {
  39                         if (!type.IsNested)
  40                                 return type.Name;
  41                         return type.DeclaringType.GetXamlName () + "+" + type.Name;
  42                 }
  43
  44                 #region inheritance search and custom attribute provision
  45
  46                 public static T GetCustomAttribute<T> (this ICustomAttributeProvider type, bool inherit) where T : Attribute
  47                 {
  48                         foreach (var a in type.GetCustomAttributes (typeof (T), inherit))
  49                                 return (T) (object) a;
  50                         return null;
  51                 }
  52
  53                 public static T GetCustomAttribute<T> (this XamlType type) where T : Attribute
  54                 {
  55                         if (type.UnderlyingType == null)
  56                                 return null;
  57
  58                         T ret = type.CustomAttributeProvider.GetCustomAttribute<T> (true);
  59                         if (ret != null)
  60                                 return ret;
  61                         if (type.BaseType != null)
  62                                 return type.BaseType.GetCustomAttribute<T> ();
  63                         return null;
  64                 }
  65
  66                 public static bool ImplementsAnyInterfacesOf (this Type type, params Type [] definitions)
  67                 {
  68                         return definitions.Any (t => ImplementsInterface (type, t));
  69                 }
  70
  71                 public static bool ImplementsInterface (this Type type, Type definition)
  72                 {
  73                         if (type == null)
  74                                 throw new ArgumentNullException ("type");
  75                         if (definition == null)
  76                                 throw new ArgumentNullException ("definition");
  77
  78                         foreach (var iface in type.GetInterfaces ())
  79                                 if (iface == definition || (iface.IsGenericType && iface.GetGenericTypeDefinition () == definition))
  80                                         return true;
  81                         return false;
  82                 }
  83
  84                 #endregion
  85
  86                 #region type conversion and member value retrieval
  87
  88                 public static string GetStringValue (this XamlType xt, object obj)
  89                 {
  90                         if (obj == null)
  91                                 return String.Empty;
  92                         if (obj is DateTime)
  93                                 // FIXME: DateTimeValueSerializer should apply
  94                                 return (string) TypeDescriptor.GetConverter (typeof (DateTime)).ConvertToInvariantString (obj);
  95                         else
  96                                 return (string) xt.ConvertObject (obj, typeof (string));
  97                 }
  98
  99                 public static object ConvertObject (this XamlType xt, object target, Type explicitTargetType)
 100                 {
 101                         return DoConvert (xt.TypeConverter, target, explicitTargetType ?? xt.UnderlyingType);
 102                 }
 103
 104                 public static object GetMemberValue (this XamlMember xm, XamlType xt, object target)
 105                 {
 106                         object native = GetPropertyOrFieldValue (xm, xt, target);
 107                         var memberRType = xm.Type == null ? null : xm.Type.UnderlyingType;
 108                         return DoConvert (xm.TypeConverter, native, memberRType);
 109                 }
 110
 111                 static object DoConvert (XamlValueConverter<TypeConverter> converter, object value, Type targetType)
 112                 {
 113                         // First get member value, then convert it to appropriate target type.
 114                         var tc = converter != null ? converter.ConverterInstance : null;
 115                         if (tc != null && targetType != null && tc.CanConvertTo (targetType))
 116                                 return tc.ConvertTo (value, targetType);
 117                         return value;
 118                 }
 119
 120                 static object GetPropertyOrFieldValue (this XamlMember xm, XamlType xt, object target)
 121                 {
 122                         // FIXME: should this be done here??
 123                         if (xm == XamlLanguage.Initialization)
 124                                 return target;
 125                         if (xm == XamlLanguage.PositionalParameters) {
 126                                 var argdefs = xt.GetConstructorArguments ().ToArray ();
 127                                 string [] args = new string [argdefs.Length];
 128                                 for (int i = 0; i < args.Length; i++) {
 129                                         var am = argdefs [i];
 130                                         args [i] = GetStringValue (am.Type, GetMemberValue (am, xt, target));
 131                                 }
 132                                 return String.Join (", ", args);
 133                         }
 134
 135                         var mi = xm.UnderlyingMember;
 136                         var fi = mi as FieldInfo;
 137                         if (fi != null)
 138                                 return fi.GetValue (target);
 139                         var pi = mi as PropertyInfo;
 140                         if (pi != null)
 141                                 return pi.GetValue (target, null);
 142
 143                         throw new NotImplementedException (String.Format ("Cannot get value for {0}", xm));
 144                 }
 145
 146                 #endregion
 147
 148                 public static bool IsContentValue (this XamlMember member)
 149                 {
 150                         if (member == XamlLanguage.Initialization)
 151                                 return true;
 152                         if (member == XamlLanguage.PositionalParameters)
 153                                 return true;
 154                         return IsContentValue (member.Type);
 155                 }
 156
 157                 public static bool IsContentValue (this XamlType type)
 158                 {
 159                         var t = type.UnderlyingType;
 160                         if (Type.GetTypeCode (t) != TypeCode.Object)
 161                                 return true;
 162                         else if (t == typeof (TimeSpan) || t == typeof (Uri)) // special predefined types
 163                                 return true;
 164                         return false;
 165                 }
 166
 167                 public static IEnumerable<XamlMember> GetAllReadWriteMembers (this XamlType type)
 168                 {
 169                         // FIXME: find out why only TypeExtension yields this directive. Seealso XamlObjectReaderTest
 170                         if (type == XamlLanguage.Type) {
 171                                 yield return XamlLanguage.PositionalParameters;
 172                                 yield break;
 173                         }
 174
 175                         if (type.IsContentValue ())
 176                                 yield return XamlLanguage.Initialization;
 177
 178                         foreach (var m in type.GetAllMembers ())
 179                                 yield return m;
 180                 }
 181
 182                 public static bool ListEquals (this IList<XamlType> a1, IList<XamlType> a2)
 183                 {
 184                         if (a1 == null || a1.Count == 0)
 185                                 return a2 == null || a2.Count == 0;
 186                         if (a2 == null || a2.Count == 0)
 187                                 return false;
 188                         if (a1.Count != a2.Count)
 189                                 return false;
 190                         for (int i = 0; i < a1.Count; i++)
 191                                 if (a1 [i] != a2 [i])
 192                                         return false;
 193                         return true;
 194                 }
 195         }
 196 }