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                         onCollectionChangedHandler = null;
  69                 }
  70
  71                 public bool IsReadOnly {
  72                         get { return false; }
  73                 }
  74
  75                 public BindingManagerBase this [object dataSource] {
  76                         get { return this [dataSource, String.Empty]; }
  77                 }
  78
  79                 public BindingManagerBase this [object dataSource, string dataMember] {
  80                         get {
  81                                 if (dataSource == null)
  82                                         throw new ArgumentNullException ("dataSource");
  83                                 if (dataMember == null)
  84                                         dataMember = String.Empty;
  85
  86                                 ICurrencyManagerProvider cm_provider = dataSource as ICurrencyManagerProvider;
  87                                 if (cm_provider != null) {
  88                                         if (dataMember.Length == 0)
  89                                                 return cm_provider.CurrencyManager;
  90
  91                                         return cm_provider.GetRelatedCurrencyManager (dataMember);
  92                                 }
  93
  94                                 HashKey key = new HashKey (dataSource, dataMember);
  95                                 BindingManagerBase res = managers [key] as BindingManagerBase;
  96
  97                                 if (res != null)
  98                                         return res;
  99
 100                                 res = CreateBindingManager (dataSource, dataMember);
 101                                 if (res == null)
 102                                         return null;
 103                                 managers [key] = res;
 104                                 return res;
 105                         }
 106                 }
 107
 108                 private BindingManagerBase CreateBindingManager (object data_source, string data_member)
 109                 {
 110                         if (data_member == "") {
 111                                 if (IsListType (data_source.GetType ()))
 112                                         return new CurrencyManager (data_source);
 113                                 else
 114                                         return new PropertyManager (data_source);
 115                         }
 116                         else {
 117                                 BindingMemberInfo info = new BindingMemberInfo (data_member);
 118
 119                                 BindingManagerBase parent_manager = this[data_source, info.BindingPath];
 120
 121                                 PropertyDescriptor pd = parent_manager == null ? null : parent_manager.GetItemProperties ().Find (info.BindingField, true);
 122
 123                                 if (pd == null)
 124                                         throw new ArgumentException (String.Format ("Cannot create a child list for field {0}.", info.BindingField));
 125
 126                                 if (IsListType (pd.PropertyType))
 127                                         return new RelatedCurrencyManager (parent_manager, pd);
 128                                 else
 129                                         return new RelatedPropertyManager (parent_manager, info.BindingField);
 130                         }
 131                 }
 132
 133                 bool IsListType (Type t)
 134                 {
 135                         return (typeof (IList).IsAssignableFrom (t)
 136                                 || typeof (IListSource).IsAssignableFrom (t));
 137                 }
 138
 139                 #region Public Instance Methods
 140                 public bool Contains(object dataSource)
 141                 {
 142                         return Contains (dataSource, String.Empty);
 143                 }
 144
 145                 public bool Contains (object dataSource, string dataMember)
 146                 {
 147                         if (dataSource == null)
 148                                 throw new ArgumentNullException ("dataSource");
 149                         if (dataMember == null)
 150                                 dataMember = String.Empty;
 151
 152                         HashKey key = new HashKey (dataSource, dataMember);
 153                         return managers [key] != null;
 154                 }
 155                 #endregion      // Public Instance Methods
 156
 157                 #region Protected Instance Methods
 158
 159                 protected internal void Add (object dataSource, BindingManagerBase listManager)
 160                 {
 161                         AddCore (dataSource, listManager);
 162                         OnCollectionChanged (new CollectionChangeEventArgs (CollectionChangeAction.Add, dataSource));
 163                 }
 164
 165                 protected virtual void AddCore (object dataSource, BindingManagerBase listManager)
 166                 {
 167                         if (dataSource == null)
 168                                 throw new ArgumentNullException ("dataSource");
 169                         if (listManager == null)
 170                                 throw new ArgumentNullException ("listManager");
 171
 172                         HashKey key = new HashKey (dataSource, String.Empty);
 173                         managers [key] = listManager;
 174                 }
 175
 176                 protected internal void Clear ()
 177                 {
 178                         ClearCore();
 179                         OnCollectionChanged (new CollectionChangeEventArgs (CollectionChangeAction.Refresh, null));
 180                 }
 181
 182                 protected virtual void ClearCore ()
 183                 {
 184                         managers.Clear ();
 185                 }
 186
 187                 protected virtual void OnCollectionChanged (CollectionChangeEventArgs ccevent)
 188                 {
 189                         if (onCollectionChangedHandler != null) {
 190                                 onCollectionChangedHandler (this, ccevent);
 191                         }
 192                 }
 193
 194                 protected internal void Remove (object dataSource)
 195                 {
 196                         if (dataSource == null)
 197                                 throw new ArgumentNullException ("dataSource");
 198
 199                         RemoveCore (dataSource);
 200                         OnCollectionChanged (new CollectionChangeEventArgs (CollectionChangeAction.Remove, dataSource));
 201                 }
 202
 203                 protected virtual void RemoveCore (object dataSource)
 204                 {
 205                         HashKey[] keys = new HashKey [managers.Keys.Count];
 206                         managers.Keys.CopyTo (keys, 0);
 207
 208                         for (int i = 0; i < keys.Length; i ++) {
 209                                 if (keys[i].source == dataSource)
 210                                         managers.Remove (keys[i]);
 211                         }
 212                 }
 213
 214                 [MonoTODO ("Stub, does nothing")]
 215                 public static void UpdateBinding (BindingContext newBindingContext, Binding binding)
 216                 {
 217                 }
 218
 219                 #endregion      // Protected Instance Methods
 220
 221                 #region Events
 222                 [Browsable (false)]
 223                 [EditorBrowsable (EditorBrowsableState.Never)]
 224                 public event CollectionChangeEventHandler CollectionChanged {
 225                         add { throw new NotImplementedException (); }
 226                         remove { /* nothing to do here.. */ }
 227                 }
 228                 #endregion      // Events
 229
 230                 #region ICollection Interfaces
 231                 void ICollection.CopyTo (Array ar, int index)
 232                 {
 233                         managers.CopyTo (ar, index);
 234                 }
 235
 236                 int ICollection.Count {
 237                         get { return managers.Count; }
 238                 }
 239
 240                 bool ICollection.IsSynchronized {
 241                         get { return false; }
 242                 }
 243
 244                 object ICollection.SyncRoot {
 245                         get { return null; }
 246                 }
 247
 248                 #endregion      // ICollection Interfaces
 249
 250                 #region IEnumerable Interfaces
 251                 [MonoInternalNote ("our enumerator is slightly different.  in MS's implementation the Values are WeakReferences to the managers.")]
 252                 IEnumerator IEnumerable.GetEnumerator() {
 253                         return managers.GetEnumerator ();
 254                 }
 255                 #endregion      // IEnumerable Interfaces
 256         }
 257 }