mcs/class/Managed.Windows.Forms/System.Windows.Forms/ListBindingHelper.cs

   1 // Permission is hereby granted, free of charge, to any person obtaining
   2 // a copy of this software and associated documentation files (the
   3 // "Software"), to deal in the Software without restriction, including
   4 // without limitation the rights to use, copy, modify, merge, publish,
   5 // distribute, sublicense, and/or sell copies of the Software, and to
   6 // permit persons to whom the Software is furnished to do so, subject to
   7 // the following conditions:
   8 //
   9 // The above copyright notice and this permission notice shall be
  10 // included in all copies or substantial portions of the Software.
  11 //
  12 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  13 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  14 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  15 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  16 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  17 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  18 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19 //
  20 // Copyright (c) 2007 Novell, Inc.
  21 //
  22 // Author:
  23 //      Carlos Alberto Cortez <calberto.cortez@gmail.com>
  24 //      Ivan Zlatev <contact@i-nz.net>
  25 //
  26
  27 using System;
  28 using System.Collections;
  29 using System.ComponentModel;
  30 using System.Reflection;
  31
  32 #if NET_2_0
  33 using System.Collections.Generic;
  34 #endif
  35
  36 namespace System.Windows.Forms
  37 {
  38
  39 #if NET_2_0
  40         public
  41 #else
  42         internal
  43 #endif
  44         static class ListBindingHelper
  45         {
  46                 public static object GetList (object list)
  47                 {
  48                         if (list is IListSource)
  49                                 return ((IListSource) list).GetList ();
  50                         return list;
  51                 }
  52
  53                 public static object GetList (object dataSource, string dataMember)
  54                 {
  55                         dataSource = GetList (dataSource);
  56                         if (dataSource == null || dataMember == null || dataMember.Length == 0)
  57                                 return dataSource;
  58
  59                         PropertyDescriptor property = GetListItemProperties (dataSource).Find (dataMember, true);
  60                         if (property == null)
  61                                 throw new ArgumentException ("dataMember");
  62
  63                         object item = null;
  64 #if NET_2_0
  65                         ICurrencyManagerProvider currencyManagerProvider = dataSource as ICurrencyManagerProvider;
  66                         if (currencyManagerProvider != null && currencyManagerProvider.CurrencyManager != null) {
  67                                 CurrencyManager currencyManager = currencyManagerProvider.CurrencyManager;
  68                                 if (currencyManager != null && currencyManager.Count > 0 && currencyManager.Current != null)
  69                                         item = currencyManager.Current;
  70                         }
  71 #endif
  72
  73                         if (item == null) {
  74                                 if (dataSource is IEnumerable) {
  75                                         if (dataSource is IList) {
  76                                                 IList list = (IList) dataSource;
  77                                                 item = list.Count > 0 ? list[0] : null;
  78                                         } else {
  79                                                 IEnumerator e = ((IEnumerable) dataSource).GetEnumerator ();
  80                                                 if (e != null && e.MoveNext ())
  81                                                         item = e.Current;
  82                                         }
  83                                 } else {
  84                                         item = dataSource;
  85                                 }
  86                         }
  87
  88                         if (item != null)
  89                                 return property.GetValue (item);
  90                         return null;
  91                 }
  92
  93                 public static Type GetListItemType (object list)
  94                 {
  95                         return GetListItemType (list, String.Empty);
  96                 }
  97
  98                 public static Type GetListItemType (object dataSource, string dataMember)
  99                 {
 100                         if (dataSource == null)
 101                                 return null;
 102
 103                         if (dataMember != null && dataMember.Length > 0) {
 104                                 PropertyDescriptor property = GetProperty (dataSource, dataMember);
 105                                 if (property == null)
 106                                         return typeof (object);
 107
 108                                 return property.PropertyType;
 109                         }
 110
 111                         if (dataSource is Array)
 112                                 return dataSource.GetType ().GetElementType ();
 113
 114                         // IEnumerable seems to have higher precedence over IList
 115                         if (dataSource is IEnumerable) {
 116                                 IEnumerator enumerator = ((IEnumerable) dataSource).GetEnumerator ();
 117                                 if (enumerator.MoveNext () && enumerator.Current != null)
 118                                         return enumerator.Current.GetType ();
 119
 120                                 if (dataSource is IList
 121 #if NET_2_0
 122                                         || dataSource.GetType () == typeof (IList<>)
 123 #endif
 124                                         ) {
 125                                         PropertyInfo property = GetPropertyByReflection (dataSource.GetType (), "Item");
 126                                         if (property != null) // `Item' could be interface-explicit, and thus private
 127                                                 return property.PropertyType;
 128                                 }
 129
 130                                 // fallback to object
 131                                 return typeof (object);
 132                         }
 133
 134                         return dataSource.GetType ();
 135                 }
 136
 137                 public static PropertyDescriptorCollection GetListItemProperties (object list)
 138                 {
 139                         return GetListItemProperties (list, null);
 140                 }
 141
 142                 public static PropertyDescriptorCollection GetListItemProperties (object list, PropertyDescriptor [] listAccessors)
 143                 {
 144                         list = GetList (list);
 145
 146                         if (list == null)
 147                                 return new PropertyDescriptorCollection (null);
 148
 149                         if (list is ITypedList)
 150                                 return ((ITypedList)list).GetItemProperties (listAccessors);
 151
 152                         if (listAccessors == null || listAccessors.Length == 0) {
 153                                 Type item_type = GetListItemType (list);
 154                                 return TypeDescriptor.GetProperties (item_type,
 155                                         new Attribute [] { new BrowsableAttribute (true) });
 156                         }
 157
 158                         // Take into account only the first property
 159                         Type property_type = listAccessors [0].PropertyType;
 160                         if (typeof (IList).IsAssignableFrom (property_type)
 161 #if NET_2_0
 162                                 || typeof (IList<>).IsAssignableFrom (property_type)
 163 #endif
 164                                 ) {
 165
 166                                 PropertyInfo property = GetPropertyByReflection (property_type, "Item");
 167                                 return TypeDescriptor.GetProperties (property.PropertyType);
 168                         }
 169
 170                         return new PropertyDescriptorCollection (new PropertyDescriptor [0]);
 171                 }
 172
 173                 public static PropertyDescriptorCollection GetListItemProperties (object dataSource, string dataMember,
 174                         PropertyDescriptor [] listAccessors)
 175                 {
 176                         throw new NotImplementedException ();
 177                 }
 178
 179                 public static string GetListName (object list, PropertyDescriptor [] listAccessors)
 180                 {
 181                         if (list == null)
 182                                 return String.Empty;
 183
 184                         Type item_type = GetListItemType (list);
 185                         return item_type.Name;
 186                 }
 187
 188                 static PropertyDescriptor GetProperty (object obj, string property_name)
 189                 {
 190                         return TypeDescriptor.GetProperties (obj,
 191                                                              new Attribute [] { new BrowsableAttribute (true) })[property_name];
 192                 }
 193
 194                 //
 195                 // Need to use reflection as we need to bypass the TypeDescriptor.GetProperties () limitations
 196                 //
 197                 static PropertyInfo GetPropertyByReflection (Type type, string property_name)
 198                 {
 199                         foreach (PropertyInfo prop in type.GetProperties (BindingFlags.Public | BindingFlags.Instance))
 200                                 if (prop.Name == property_name)
 201                                         return prop;
 202
 203                         return null;
 204                 }
 205         }
 206 }