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.Collections;
  28 using System.ComponentModel;
  29
  30 namespace System.Windows.Forms {
  31
  32         public class CurrencyManager : BindingManagerBase {
  33
  34                 protected Type finalType;
  35                 protected int listposition;
  36
  37                 private IList list;
  38                 private IBindingList binding_list;
  39
  40                 private bool binding_suspended;
  41
  42                 internal CurrencyManager (object data_source)
  43                 {
  44                         binding_list = data_source as IBindingList;
  45                         if (data_source is IListSource) {
  46                                 list = ((IListSource) data_source).GetList ();
  47                         } else if (data_source is IList) {
  48                                 list = (IList) data_source;
  49                         } else {
  50                                 throw new Exception ("Attempted to create currency manager " +
  51                                         "from invalid type: " + data_source.GetType ());
  52                         }
  53                 }
  54
  55                 public IList List {
  56                         get { return list; }
  57                 }
  58
  59                 public override object Current {
  60                         get {
  61                                 return list [listposition];
  62                         }
  63                 }
  64
  65                 public override int Count {
  66                         get { return list.Count; }
  67                 }
  68
  69                 public override int Position {
  70                         get {
  71                                 return listposition;
  72                         }
  73                         set {
  74                                 if (value < 0)
  75                                         value = 0;
  76                                 if (value == list.Count)
  77                                         value = list.Count - 1;
  78                                 if (listposition == value)
  79                                         return;
  80                                 listposition = value;
  81                                 OnCurrentChanged (EventArgs.Empty);
  82                                 OnPositionChanged (EventArgs.Empty);
  83                         }
  84                 }
  85
  86                 public override PropertyDescriptorCollection GetItemProperties ()
  87                 {
  88                         ITypedList typed = list as ITypedList;
  89
  90                         if (typed == null)
  91                                 return null;
  92                         return typed.GetItemProperties (null);
  93                 }
  94
  95                 public override void RemoveAt (int index)
  96                 {
  97                         list.RemoveAt (index);
  98                 }
  99
 100                 public override void SuspendBinding ()
 101                 {
 102                         binding_suspended = true;
 103                 }
 104
 105                 public override void ResumeBinding ()
 106                 {
 107                         binding_suspended = false;
 108                 }
 109
 110                 public override void AddNew ()
 111                 {
 112                         if (binding_list == null)
 113                                 throw new NotSupportedException ();
 114                         binding_list.AddNew ();
 115                 }
 116
 117                 public override void CancelCurrentEdit ()
 118                 {
 119                         IEditableObject editable = Current as IEditableObject;
 120
 121                         if (editable == null)
 122                                 return;
 123                         editable.CancelEdit ();
 124                         OnItemChanged (new ItemChangedEventArgs (Position));
 125                 }
 126
 127                 public override void EndCurrentEdit ()
 128                 {
 129                         IEditableObject editable = Current as IEditableObject;
 130
 131                         if (editable == null)
 132                                 return;
 133                         editable.EndEdit ();
 134                 }
 135
 136                 protected internal override void OnCurrentChanged (EventArgs e)
 137                 {
 138                         PullData ();
 139
 140                         if (onCurrentChangedHandler != null) {
 141                                 onCurrentChangedHandler (this, e);
 142                         }
 143                 }
 144
 145                 protected virtual void OnItemChanged (ItemChangedEventArgs e)
 146                 {
 147                         PushData ();
 148
 149                         if (ItemChanged != null)
 150                                 ItemChanged (this, e);
 151                 }
 152
 153                 protected virtual void OnPositionChanged (EventArgs e)
 154                 {
 155                         if (onPositionChangedHandler == null)
 156                                 return;
 157                         onPositionChangedHandler (this, e);
 158                 }
 159
 160                 protected internal override string GetListName (ArrayList accessors)
 161                 {
 162                         if (list is ITypedList) {
 163                                 PropertyDescriptor [] pds;
 164                                 pds = new PropertyDescriptor [accessors.Count];
 165                                 accessors.CopyTo (pds, 0);
 166                                 return ((ITypedList) list).GetListName (pds);
 167                         }
 168                         return String.Empty;
 169                 }
 170
 171                 [MonoTODO ("Not totally sure how this works, its doesn't seemt to do a pull/push like i originally assumed")]
 172                 protected override void UpdateIsBinding ()
 173                 {
 174                         UpdateItem ();
 175
 176                         foreach (Binding binding in Bindings)
 177                                 binding.UpdateIsBinding ();
 178                 }
 179
 180                 private void UpdateItem ()
 181                 {
 182                         // Probably should be validating or something here
 183                         EndCurrentEdit ();
 184                 }
 185
 186                 public event ItemChangedEventHandler ItemChanged;
 187         }
 188 }
 189