mcs/class/Managed.Windows.Forms/System.Windows.Forms/BindingContext.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) 2004-2005 Novell, Inc.
  21 //
  22 // Authors:
  23 //      Peter Bartok    pbartok@novell.com
  24 //      Jackson Harper  jackson@ximian.com
  25
  26
  27 using System.Data;
  28 using System.Collections;
  29 using System.Globalization;
  30 using System.ComponentModel;
  31
  32
  33 namespace System.Windows.Forms {
  34
  35         [DefaultEvent("CollectionChanged")]
  36         public class BindingContext : ICollection, IEnumerable {
  37
  38                 private Hashtable managers;
  39                 private EventHandler onCollectionChangedHandler;
  40
  41                 private class HashKey {
  42                         public object source;
  43                         public string member;
  44
  45                         public HashKey (object source, string member)
  46                         {
  47                                 this.source = source;
  48                                 this.member = member;
  49                         }
  50
  51                         public override int GetHashCode ()
  52                         {
  53                                 return source.GetHashCode() + member.GetHashCode ();
  54                         }
  55
  56                         public override bool Equals (object o)
  57                         {
  58                                 HashKey hk = o as HashKey;
  59                                 if (hk == null)
  60                                         return false;
  61                                 return hk.source == source && hk.member == member;
  62                         }
  63                 }
  64
  65                 public BindingContext ()
  66                 {
  67                         managers = new Hashtable ();
  68                 }
  69
  70                 public bool IsReadOnly {
  71                         get { return false; }
  72                 }
  73
  74                 public BindingManagerBase this [object dataSource] {
  75                         get { return this [dataSource, String.Empty]; }
  76                 }
  77
  78                 public BindingManagerBase this [object data_source, string data_member] {
  79                         get {
  80                                 if (data_source == null)
  81                                         throw new ArgumentNullException ("data_source");
  82                                 if (data_member == null)
  83                                         data_member = String.Empty;
  84
  85                                 HashKey key = new HashKey (data_source, data_member);
  86                                 BindingManagerBase res = managers [key] as BindingManagerBase;
  87
  88                                 if (res != null)
  89                                         return res;
  90
  91                                 res = CreateBindingManager (data_source, data_member);
  92                                 if (res == null)
  93                                         return null;
  94                                 managers [key] = res;
  95                                 return res;
  96                         }
  97                 }
  98
  99                 private BindingManagerBase CreateBindingManager (object data_source, string data_member)
 100                 {
 101                         if (data_member == "") {
 102                                 if (IsListType (data_source.GetType ()))
 103                                         return new CurrencyManager (data_source);
 104                                 else
 105                                         return new PropertyManager (data_source);
 106                         }
 107                         else {
 108                                 BindingMemberInfo info = new BindingMemberInfo (data_member);
 109
 110                                 BindingManagerBase parent_manager = this[data_source, info.BindingPath];
 111
 112                                 PropertyDescriptor pd = parent_manager == null ? null : parent_manager.GetItemProperties ().Find (info.BindingField, true);
 113
 114                                 if (pd == null)
 115                                         throw new ArgumentException (String.Format ("Cannot create a child list for field {0}.", info.BindingField));
 116
 117                                 if (IsListType (pd.PropertyType))
 118                                         return new RelatedCurrencyManager (parent_manager, pd);
 119                                 else
 120                                         return new RelatedPropertyManager (parent_manager, info.BindingField);
 121                         }
 122                 }
 123
 124                 bool IsListType (Type t)
 125                 {
 126                         return (typeof (IList).IsAssignableFrom (t)
 127                                 || typeof (IListSource).IsAssignableFrom (t));
 128                 }
 129
 130                 #region Public Instance Methods
 131                 public bool Contains(object dataSource)
 132                 {
 133                         return Contains (dataSource, String.Empty);
 134                 }
 135
 136                 public bool Contains (object dataSource, string dataMember)
 137                 {
 138                         if (dataSource == null)
 139                                 throw new ArgumentNullException ("dataSource");
 140                         if (dataMember == null)
 141                                 dataMember = String.Empty;
 142
 143                         HashKey key = new HashKey (dataSource, dataMember);
 144                         return managers [key] != null;
 145                 }
 146                 #endregion      // Public Instance Methods
 147
 148                 #region Protected Instance Methods
 149
 150                 protected internal void Add (object dataSource, BindingManagerBase listManager)
 151                 {
 152                         AddCore (dataSource, listManager);
 153                         OnCollectionChanged (new CollectionChangeEventArgs (CollectionChangeAction.Add, dataSource));
 154                 }
 155
 156                 protected virtual void AddCore (object dataSource, BindingManagerBase listManager)
 157                 {
 158                         if (dataSource == null)
 159                                 throw new ArgumentNullException ("dataSource");
 160                         if (listManager == null)
 161                                 throw new ArgumentNullException ("listManager");
 162
 163                         HashKey key = new HashKey (dataSource, String.Empty);
 164                         managers [key] = listManager;
 165                 }
 166
 167                 protected internal void Clear ()
 168                 {
 169                         ClearCore();
 170                         OnCollectionChanged (new CollectionChangeEventArgs (CollectionChangeAction.Refresh, null));
 171                 }
 172
 173                 protected virtual void ClearCore ()
 174                 {
 175                         managers.Clear ();
 176                 }
 177
 178                 protected virtual void OnCollectionChanged (CollectionChangeEventArgs ccevent)
 179                 {
 180                         if (onCollectionChangedHandler != null) {
 181                                 onCollectionChangedHandler (this, ccevent);
 182                         }
 183                 }
 184
 185                 protected internal void Remove (object dataSource)
 186                 {
 187                         if (dataSource == null)
 188                                 throw new ArgumentNullException ("dataSource");
 189
 190                         RemoveCore (dataSource);
 191                         OnCollectionChanged (new CollectionChangeEventArgs (CollectionChangeAction.Remove, dataSource));
 192                 }
 193
 194                 protected virtual void RemoveCore (object dataSource)
 195                 {
 196                         HashKey[] keys = new HashKey [managers.Keys.Count];
 197                         managers.Keys.CopyTo (keys, 0);
 198
 199                         for (int i = 0; i < keys.Length; i ++) {
 200                                 if (keys[i].source == dataSource)
 201                                         managers.Remove (keys[i]);
 202                         }
 203                 }
 204                 #endregion      // Protected Instance Methods
 205
 206                 #region Events
 207                 public event CollectionChangeEventHandler CollectionChanged {
 208                         add { throw new NotImplementedException (); }
 209                         remove { /* nothing to do here.. */ }
 210                 }
 211                 #endregion      // Events
 212
 213                 #region ICollection Interfaces
 214                 void ICollection.CopyTo (Array array, int index)
 215                 {
 216                         managers.CopyTo (array, index);
 217                 }
 218
 219                 int ICollection.Count {
 220                         get { return managers.Count; }
 221                 }
 222
 223                 bool ICollection.IsSynchronized {
 224                         get { return false; }
 225                 }
 226
 227                 object ICollection.SyncRoot {
 228                         get { return null; }
 229                 }
 230
 231                 #endregion      // ICollection Interfaces
 232
 233                 #region IEnumerable Interfaces
 234                 [MonoTODO ("our enumerator is slightly different.  in MS's implementation the Values are WeakReferences to the managers.")]
 235                 IEnumerator IEnumerable.GetEnumerator() {
 236                         return managers.GetEnumerator ();
 237                 }
 238                 #endregion      // IEnumerable Interfaces
 239         }
 240 }