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                                 table.Columns.CollectionChanged  += new CollectionChangeEventHandler (MetaDataChangedHandler);
  82                                 table.ChildRelations.CollectionChanged  += new CollectionChangeEventHandler (MetaDataChangedHandler);
  83                                 table.ParentRelations.CollectionChanged  += new CollectionChangeEventHandler (MetaDataChangedHandler);
  84                                 table.Constraints.CollectionChanged += new CollectionChangeEventHandler (MetaDataChangedHandler);
  85                         }
  86                 }
  87
  88                 public IList List {
  89                         get { return list; }
  90                 }
  91
  92                 public override object Current {
  93                         get {
  94                                 return list [listposition];
  95                         }
  96                 }
  97
  98                 public override int Count {
  99                         get { return list.Count; }
 100                 }
 101
 102                 public override int Position {
 103                         get {
 104                                 return listposition;
 105                         }
 106                         set {
 107                                 if (value < 0)
 108                                         value = 0;
 109                                 if (value == list.Count)
 110                                         value = list.Count - 1;
 111                                 if (listposition == value)
 112                                         return;
 113                                 listposition = value;
 114                                 OnCurrentChanged (EventArgs.Empty);
 115                                 OnPositionChanged (EventArgs.Empty);
 116                         }
 117                 }
 118
 119                 internal string ListName {
 120                         get {
 121                                 ITypedList typed = list as ITypedList;
 122
 123                                 if (typed == null) {
 124                                         return finalType.Name;
 125                                 } else {
 126                                         return typed.GetListName (null);
 127                                 }
 128                         }
 129                 }
 130
 131                 public override PropertyDescriptorCollection GetItemProperties ()
 132                 {
 133                         ITypedList typed = list as ITypedList;
 134
 135                         if (list is Array) {
 136                                 Type element = list.GetType ().GetElementType ();
 137                                 return TypeDescriptor.GetProperties (element);
 138                         }
 139
 140                         if (typed != null) {
 141                                 return typed.GetItemProperties (null);
 142                         }
 143
 144                         PropertyInfo [] props = finalType.GetProperties ();
 145                         for (int i = 0; i < props.Length; i++) {
 146                                 if (props [i].Name == "Item") {
 147                                         Type t = props [i].PropertyType;
 148                                         if (t == typeof (object))
 149                                                 continue;
 150                                         return GetBrowsableProperties (t);
 151                                 }
 152                         }
 153
 154                         if (list.Count > 0) {
 155                                 return GetBrowsableProperties (list [0].GetType ());
 156                         }
 157
 158                         return new PropertyDescriptorCollection (null);
 159                 }
 160
 161                 public override void RemoveAt (int index)
 162                 {
 163                         list.RemoveAt (index);
 164                 }
 165
 166                 public override void SuspendBinding ()
 167                 {
 168                         binding_suspended = true;
 169                 }
 170
 171                 public override void ResumeBinding ()
 172                 {
 173                         binding_suspended = false;
 174                 }
 175
 176                 internal override bool IsSuspended {
 177                         get { return binding_suspended; }
 178                 }
 179
 180                 internal bool CanAddRows {
 181                         get {
 182                                 if (list as IBindingList == null) {
 183                                         return false;
 184                                 }
 185
 186                                 return true;
 187                         }
 188                 }
 189
 190                 public override void AddNew ()
 191                 {
 192                         if (list as IBindingList == null)
 193                                 throw new NotSupportedException ();
 194
 195                         (list as IBindingList).AddNew ();
 196                 }
 197
 198                 public override void CancelCurrentEdit ()
 199                 {
 200                         IEditableObject editable = Current as IEditableObject;
 201
 202                         if (editable == null)
 203                                 return;
 204                         editable.CancelEdit ();
 205                         OnItemChanged (new ItemChangedEventArgs (Position));
 206                 }
 207
 208                 public override void EndCurrentEdit ()
 209                 {
 210                         IEditableObject editable = Current as IEditableObject;
 211
 212                         if (editable == null)
 213                                 return;
 214                         editable.EndEdit ();
 215                 }
 216
 217                 public void Refresh ()
 218                 {
 219                         PullData ();
 220                 }
 221
 222                 [MonoTODO ("This is just a guess, as I can't figure out how to test this method")]
 223                 protected void CheckEmpty ()
 224                 {
 225                         if (list == null || list.Count < 1)
 226                                 throw new Exception ("List is empty.");
 227
 228                 }
 229
 230                 protected internal override void OnCurrentChanged (EventArgs e)
 231                 {
 232                         PullData ();
 233
 234                         if (onCurrentChangedHandler != null) {
 235                                 onCurrentChangedHandler (this, e);
 236                         }
 237                 }
 238
 239                 protected virtual void OnItemChanged (ItemChangedEventArgs e)
 240                 {
 241                         PushData ();
 242
 243                         if (ItemChanged != null)
 244                                 ItemChanged (this, e);
 245                 }
 246
 247                 protected virtual void OnPositionChanged (EventArgs e)
 248                 {
 249                         if (onPositionChangedHandler == null)
 250                                 return;
 251                         onPositionChangedHandler (this, e);
 252                 }
 253
 254                 protected internal override string GetListName (ArrayList accessors)
 255                 {
 256                         if (list is ITypedList) {
 257                                 PropertyDescriptor [] pds;
 258                                 pds = new PropertyDescriptor [accessors.Count];
 259                                 accessors.CopyTo (pds, 0);
 260                                 return ((ITypedList) list).GetListName (pds);
 261                         }
 262                         return String.Empty;
 263                 }
 264
 265                 [MonoTODO ("Not totally sure how this works, its doesn't seemt to do a pull/push like i originally assumed")]
 266                 protected override void UpdateIsBinding ()
 267                 {
 268                         UpdateItem ();
 269
 270                         foreach (Binding binding in Bindings)
 271                                 binding.UpdateIsBinding ();
 272                 }
 273
 274                 private void UpdateItem ()
 275                 {
 276                         // Probably should be validating or something here
 277                         EndCurrentEdit ();
 278                 }
 279
 280                 internal object GetItem (int index)
 281                 {
 282                         return list [index];
 283                 }
 284
 285                 private PropertyDescriptorCollection GetBrowsableProperties (Type t)
 286                 {
 287                         Attribute [] att = new System.Attribute [1];
 288                         att [0] = new BrowsableAttribute (true);
 289                         return TypeDescriptor.GetProperties (t, att);
 290                 }
 291
 292                 private void MetaDataChangedHandler (object sender, CollectionChangeEventArgs e)
 293                 {
 294                         if (MetaDataChanged != null)
 295                                 MetaDataChanged (this, EventArgs.Empty);
 296                 }
 297
 298                 public event ItemChangedEventHandler ItemChanged;
 299                 public event EventHandler MetaDataChanged;
 300         }
 301 }
 302