mcs/class/Managed.Windows.Forms/System.Windows.Forms/CurrencyManager.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) 2005 Novell, Inc.
  21 //
  22 // Authors:
  23 //      Jackson Harper (jackson@ximian.com)
  24 //
  25
  26 using System;
  27 using System.Data;
  28 using System.Reflection;
  29 using System.Collections;
  30 using System.ComponentModel;
  31
  32 namespace System.Windows.Forms {
  33         [DefaultMember("Item")]
  34         public class CurrencyManager : BindingManagerBase {
  35
  36                 protected Type finalType;
  37                 protected int listposition;
  38
  39                 private IList list;
  40                 private bool binding_suspended;
  41
  42                 internal CurrencyManager (object data_source, string data_member)
  43                 {
  44                         if (data_source is IList) {
  45                                 list = (IList) data_source;
  46                         } else if (data_source is IListSource) {
  47                                 list = ((IListSource) data_source).GetList ();
  48                         } else {
  49                                 throw new Exception ("Attempted to create currency manager " +
  50                                         "from invalid type: " + data_source.GetType ());
  51                         }
  52
  53                         if (data_source as ArrayList != null) {
  54                                 finalType = ((ArrayList)data_source).GetType ();
  55                         } else {
  56                                 if (data_source as Array != null) {
  57                                         finalType = ((Array) data_source).GetType ();
  58                                 } else {
  59                                         finalType = null;
  60                                 }
  61                         }
  62
  63                         DataTable table = data_source as DataTable;
  64                         if (table == null && data_source is DataView)
  65                                 table = ((DataView) data_source).Table;
  66
  67
  68                         if (table == null) {
  69                                 DataSet dataset = data_source as DataSet;
  70                                 int sp = data_member.IndexOf ('.');
  71                                 if (sp != -1) {
  72                                         data_member = data_member.Substring (0, sp);
  73                                 }
  74                                 if (dataset != null) {
  75                                         table = dataset.Tables [data_member];
  76                                 }
  77                         }
  78
  79                         if (table != null) {
  80                                 list = new DataView (table);
  81                                 ((DataView) list).ListChanged += new ListChangedEventHandler (ListChangedHandler);
  82                                 table.Columns.CollectionChanged  += new CollectionChangeEventHandler (MetaDataChangedHandler);
  83                                 table.ChildRelations.CollectionChanged  += new CollectionChangeEventHandler (MetaDataChangedHandler);
  84                                 table.ParentRelations.CollectionChanged  += new CollectionChangeEventHandler (MetaDataChangedHandler);
  85                                 table.Constraints.CollectionChanged += new CollectionChangeEventHandler (MetaDataChangedHandler);
  86                         }
  87                 }
  88
  89                 public IList List {
  90                         get { return list; }
  91                 }
  92
  93                 public override object Current {
  94                         get {
  95                                 if (list.Count == 0)
  96                                         return null;
  97                                 return list [listposition];
  98                         }
  99                 }
 100
 101                 public override int Count {
 102                         get { return list.Count; }
 103                 }
 104
 105                 public override int Position {
 106                         get {
 107                                 return listposition;
 108                         }
 109                         set {
 110                                 if (value < 0)
 111                                         value = 0;
 112                                 if (value == list.Count)
 113                                         value = list.Count - 1;
 114                                 if (listposition == value)
 115                                         return;
 116                                 listposition = value;
 117                                 OnCurrentChanged (EventArgs.Empty);
 118                                 OnPositionChanged (EventArgs.Empty);
 119                         }
 120                 }
 121
 122                 internal string ListName {
 123                         get {
 124                                 ITypedList typed = list as ITypedList;
 125
 126                                 if (typed == null) {
 127                                         return finalType.Name;
 128                                 } else {
 129                                         return typed.GetListName (null);
 130                                 }
 131                         }
 132                 }
 133
 134                 public override PropertyDescriptorCollection GetItemProperties ()
 135                 {
 136                         ITypedList typed = list as ITypedList;
 137
 138                         if (list is Array) {
 139                                 Type element = list.GetType ().GetElementType ();
 140                                 return TypeDescriptor.GetProperties (element);
 141                         }
 142
 143                         if (typed != null) {
 144                                 return typed.GetItemProperties (null);
 145                         }
 146
 147                         PropertyInfo [] props = finalType.GetProperties ();
 148                         for (int i = 0; i < props.Length; i++) {
 149                                 if (props [i].Name == "Item") {
 150                                         Type t = props [i].PropertyType;
 151                                         if (t == typeof (object))
 152                                                 continue;
 153                                         return GetBrowsableProperties (t);
 154                                 }
 155                         }
 156
 157                         if (list.Count > 0) {
 158                                 return GetBrowsableProperties (list [0].GetType ());
 159                         }
 160
 161                         return new PropertyDescriptorCollection (null);
 162                 }
 163
 164                 public override void RemoveAt (int index)
 165                 {
 166                         list.RemoveAt (index);
 167                 }
 168
 169                 public override void SuspendBinding ()
 170                 {
 171                         binding_suspended = true;
 172                 }
 173
 174                 public override void ResumeBinding ()
 175                 {
 176                         binding_suspended = false;
 177                 }
 178
 179                 internal override bool IsSuspended {
 180                         get { return binding_suspended; }
 181                 }
 182
 183                 internal bool CanAddRows {
 184                         get {
 185                                 if (list as IBindingList == null) {
 186                                         return false;
 187                                 }
 188
 189                                 return true;
 190                         }
 191                 }
 192
 193                 public override void AddNew ()
 194                 {
 195                         if (list as IBindingList == null)
 196                                 throw new NotSupportedException ();
 197
 198                         (list as IBindingList).AddNew ();
 199                 }
 200
 201                 public override void CancelCurrentEdit ()
 202                 {
 203                         IEditableObject editable = Current as IEditableObject;
 204
 205                         if (editable == null)
 206                                 return;
 207                         editable.CancelEdit ();
 208                         OnItemChanged (new ItemChangedEventArgs (Position));
 209                 }
 210
 211                 public override void EndCurrentEdit ()
 212                 {
 213                         IEditableObject editable = Current as IEditableObject;
 214
 215                         if (editable == null)
 216                                 return;
 217                         editable.EndEdit ();
 218                 }
 219
 220                 public void Refresh ()
 221                 {
 222                         PullData ();
 223                 }
 224
 225                 protected void CheckEmpty ()
 226                 {
 227                         if (list == null || list.Count < 1)
 228                                 throw new Exception ("List is empty.");
 229
 230                 }
 231
 232                 protected internal override void OnCurrentChanged (EventArgs e)
 233                 {
 234                         PullData ();
 235
 236                         if (onCurrentChangedHandler != null) {
 237                                 onCurrentChangedHandler (this, e);
 238                         }
 239                 }
 240
 241                 protected virtual void OnItemChanged (ItemChangedEventArgs e)
 242                 {
 243                         PushData ();
 244
 245                         if (ItemChanged != null)
 246                                 ItemChanged (this, e);
 247                 }
 248
 249                 protected virtual void OnPositionChanged (EventArgs e)
 250                 {
 251                         if (onPositionChangedHandler == null)
 252                                 return;
 253                         onPositionChangedHandler (this, e);
 254                 }
 255
 256                 protected internal override string GetListName (ArrayList accessors)
 257                 {
 258                         if (list is ITypedList) {
 259                                 PropertyDescriptor [] pds;
 260                                 pds = new PropertyDescriptor [accessors.Count];
 261                                 accessors.CopyTo (pds, 0);
 262                                 return ((ITypedList) list).GetListName (pds);
 263                         }
 264                         return String.Empty;
 265                 }
 266
 267                 protected override void UpdateIsBinding ()
 268                 {
 269                         UpdateItem ();
 270
 271                         foreach (Binding binding in Bindings)
 272                                 binding.UpdateIsBinding ();
 273                 }
 274
 275                 private void UpdateItem ()
 276                 {
 277                         // Probably should be validating or something here
 278                         EndCurrentEdit ();
 279                 }
 280
 281                 internal object GetItem (int index)
 282                 {
 283                         return list [index];
 284                 }
 285
 286                 private PropertyDescriptorCollection GetBrowsableProperties (Type t)
 287                 {
 288                         Attribute [] att = new System.Attribute [1];
 289                         att [0] = new BrowsableAttribute (true);
 290                         return TypeDescriptor.GetProperties (t, att);
 291                 }
 292
 293                 private void MetaDataChangedHandler (object sender, CollectionChangeEventArgs e)
 294                 {
 295                         if (MetaDataChanged != null)
 296                                 MetaDataChanged (this, EventArgs.Empty);
 297                 }
 298
 299                 private void ListChangedHandler (object sender, ListChangedEventArgs e)
 300                 {
 301                         UpdateIsBinding ();
 302                 }
 303
 304                 public event ItemChangedEventHandler ItemChanged;
 305                 public event EventHandler MetaDataChanged;
 306         }
 307 }
 308