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)
  43                 {
  44                         if (data_source is IListSource) {
  45                                 list = ((IListSource) data_source).GetList ();
  46                         } else if (data_source is IList) {
  47                                 list = (IList) data_source;
  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                         if (table != null) {
  68                                 table.Columns.CollectionChanged  += new CollectionChangeEventHandler (MetaDataChangedHandler);
  69                                 table.ChildRelations.CollectionChanged  += new CollectionChangeEventHandler (MetaDataChangedHandler);
  70                                 table.ParentRelations.CollectionChanged  += new CollectionChangeEventHandler (MetaDataChangedHandler);
  71                                 table.Constraints.CollectionChanged += new CollectionChangeEventHandler (MetaDataChangedHandler);
  72                         }
  73                 }
  74
  75                 public IList List {
  76                         get { return list; }
  77                 }
  78
  79                 public override object Current {
  80                         get {
  81                                 return list [listposition];
  82                         }
  83                 }
  84
  85                 public override int Count {
  86                         get { return list.Count; }
  87                 }
  88
  89                 public override int Position {
  90                         get {
  91                                 return listposition;
  92                         }
  93                         set {
  94                                 if (value < 0)
  95                                         value = 0;
  96                                 if (value == list.Count)
  97                                         value = list.Count - 1;
  98                                 if (listposition == value)
  99                                         return;
 100                                 listposition = value;
 101                                 OnCurrentChanged (EventArgs.Empty);
 102                                 OnPositionChanged (EventArgs.Empty);
 103                         }
 104                 }
 105
 106                 internal string ListName {
 107                         get {
 108                                 ITypedList typed = list as ITypedList;
 109
 110                                 if (typed == null) {
 111                                         return finalType.Name;
 112                                 } else {
 113                                         return typed.GetListName (null);
 114                                 }
 115                         }
 116                 }
 117
 118                 public override PropertyDescriptorCollection GetItemProperties ()
 119                 {
 120                         ITypedList typed = list as ITypedList;
 121
 122                         if (list is Array) {
 123                                 Type element = list.GetType ().GetElementType ();
 124                                 return TypeDescriptor.GetProperties (element);
 125                         }
 126
 127                         if (typed != null) {
 128                                 return typed.GetItemProperties (null);
 129                         }
 130
 131                         PropertyInfo [] props = finalType.GetProperties ();
 132                         for (int i = 0; i < props.Length; i++) {
 133                                 if (props [i].Name == "Item") {
 134                                         Type t = props [i].PropertyType;
 135                                         if (t == typeof (object))
 136                                                 continue;
 137                                         return GetBrowsableProperties (t);
 138                                 }
 139                         }
 140
 141                         if (list.Count > 0) {
 142                                 return GetBrowsableProperties (list [0].GetType ());
 143                         }
 144
 145                         return new PropertyDescriptorCollection (null);
 146                 }
 147
 148                 public override void RemoveAt (int index)
 149                 {
 150                         list.RemoveAt (index);
 151                 }
 152
 153                 public override void SuspendBinding ()
 154                 {
 155                         binding_suspended = true;
 156                 }
 157
 158                 public override void ResumeBinding ()
 159                 {
 160                         binding_suspended = false;
 161                 }
 162
 163                 internal override bool IsSuspended {
 164                         get { return binding_suspended; }
 165                 }
 166
 167                 internal bool CanAddRows {
 168                         get {
 169                                 if (list as IBindingList == null) {
 170                                         return false;
 171                                 }
 172
 173                                 return true;
 174                         }
 175                 }
 176
 177                 public override void AddNew ()
 178                 {
 179                         if (list as IBindingList == null)
 180                                 throw new NotSupportedException ();
 181
 182                         (list as IBindingList).AddNew ();
 183                 }
 184
 185                 public override void CancelCurrentEdit ()
 186                 {
 187                         IEditableObject editable = Current as IEditableObject;
 188
 189                         if (editable == null)
 190                                 return;
 191                         editable.CancelEdit ();
 192                         OnItemChanged (new ItemChangedEventArgs (Position));
 193                 }
 194
 195                 public override void EndCurrentEdit ()
 196                 {
 197                         IEditableObject editable = Current as IEditableObject;
 198
 199                         if (editable == null)
 200                                 return;
 201                         editable.EndEdit ();
 202                 }
 203
 204                 public void Refresh ()
 205                 {
 206                         PullData ();
 207                 }
 208
 209                 [MonoTODO ("This is just a guess, as I can't figure out how to test this method")]
 210                 protected void CheckEmpty ()
 211                 {
 212                         if (list == null || list.Count < 1)
 213                                 throw new Exception ("List is empty.");
 214
 215                 }
 216
 217                 protected internal override void OnCurrentChanged (EventArgs e)
 218                 {
 219                         PullData ();
 220
 221                         if (onCurrentChangedHandler != null) {
 222                                 onCurrentChangedHandler (this, e);
 223                         }
 224                 }
 225
 226                 protected virtual void OnItemChanged (ItemChangedEventArgs e)
 227                 {
 228                         PushData ();
 229
 230                         if (ItemChanged != null)
 231                                 ItemChanged (this, e);
 232                 }
 233
 234                 protected virtual void OnPositionChanged (EventArgs e)
 235                 {
 236                         if (onPositionChangedHandler == null)
 237                                 return;
 238                         onPositionChangedHandler (this, e);
 239                 }
 240
 241                 protected internal override string GetListName (ArrayList accessors)
 242                 {
 243                         if (list is ITypedList) {
 244                                 PropertyDescriptor [] pds;
 245                                 pds = new PropertyDescriptor [accessors.Count];
 246                                 accessors.CopyTo (pds, 0);
 247                                 return ((ITypedList) list).GetListName (pds);
 248                         }
 249                         return String.Empty;
 250                 }
 251
 252                 [MonoTODO ("Not totally sure how this works, its doesn't seemt to do a pull/push like i originally assumed")]
 253                 protected override void UpdateIsBinding ()
 254                 {
 255                         UpdateItem ();
 256
 257                         foreach (Binding binding in Bindings)
 258                                 binding.UpdateIsBinding ();
 259                 }
 260
 261                 private void UpdateItem ()
 262                 {
 263                         // Probably should be validating or something here
 264                         EndCurrentEdit ();
 265                 }
 266
 267                 internal object GetItem (int index)
 268                 {
 269                         return list [index];
 270                 }
 271
 272                 private PropertyDescriptorCollection GetBrowsableProperties (Type t)
 273                 {
 274                         Attribute [] att = new System.Attribute [1];
 275                         att [0] = new BrowsableAttribute (true);
 276                         return TypeDescriptor.GetProperties (t, att);
 277                 }
 278
 279                 private void MetaDataChangedHandler (object sender, CollectionChangeEventArgs e)
 280                 {
 281                         if (MetaDataChanged != null)
 282                                 MetaDataChanged (this, EventArgs.Empty);
 283                 }
 284
 285                 public event ItemChangedEventHandler ItemChanged;
 286                 public event EventHandler MetaDataChanged;
 287         }
 288 }
 289