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.Reflection;
  28 using System.Collections;
  29 using System.ComponentModel;
  30
  31 namespace System.Windows.Forms {
  32         [DefaultMember("Item")]
  33         public class CurrencyManager : BindingManagerBase {
  34
  35                 protected Type finalType;
  36                 protected int listposition;
  37
  38                 private IList list;
  39                 private IBindingList binding_list;
  40
  41                 private bool binding_suspended;
  42
  43                 internal CurrencyManager (object data_source)
  44                 {
  45                         binding_list = data_source as IBindingList;
  46                         if (data_source is IListSource) {
  47                                 list = ((IListSource) data_source).GetList ();
  48                         } else if (data_source is IList) {
  49                                 list = (IList) data_source;
  50                         } else {
  51                                 throw new Exception ("Attempted to create currency manager " +
  52                                         "from invalid type: " + data_source.GetType ());
  53                         }
  54
  55                         if (data_source as ArrayList != null) {
  56                                 finalType = ((ArrayList)data_source).GetType ();
  57                         } else {
  58                                 if (data_source as Array != null) {
  59                                         finalType = ((Array) data_source).GetType ();
  60                                 } else {
  61                                         finalType = null;
  62                                 }
  63                         }
  64                 }
  65
  66                 public IList List {
  67                         get { return list; }
  68                 }
  69
  70                 public override object Current {
  71                         get {
  72                                 return list [listposition];
  73                         }
  74                 }
  75
  76                 public override int Count {
  77                         get { return list.Count; }
  78                 }
  79
  80                 public override int Position {
  81                         get {
  82                                 return listposition;
  83                         }
  84                         set {
  85                                 if (value < 0)
  86                                         value = 0;
  87                                 if (value == list.Count)
  88                                         value = list.Count - 1;
  89                                 if (listposition == value)
  90                                         return;
  91                                 listposition = value;
  92                                 OnCurrentChanged (EventArgs.Empty);
  93                                 OnPositionChanged (EventArgs.Empty);
  94                         }
  95                 }
  96
  97                 public override PropertyDescriptorCollection GetItemProperties ()
  98                 {
  99                         ITypedList typed = list as ITypedList;
 100
 101                         if (list is Array) {
 102                                 Type element = list.GetType ().GetElementType ();
 103                                 return TypeDescriptor.GetProperties (element);
 104                         }
 105
 106                         if (typed != null) {
 107                                 return typed.GetItemProperties (null);
 108                         }
 109
 110                         PropertyInfo [] props = finalType.GetProperties ();
 111                         for (int i = 0; i < props.Length; i++) {
 112                                 if (props [i].Name == "Item") {
 113                                         Type t = props [i].PropertyType;
 114                                         if (t == typeof (object))
 115                                                 continue;
 116                                         return GetBrowsableProperties (t);
 117                                 }
 118                         }
 119
 120                         if (list.Count > 0) {
 121                                 return GetBrowsableProperties (list [0].GetType ());
 122                         }
 123
 124                         return new PropertyDescriptorCollection (null);
 125                 }
 126
 127                 public override void RemoveAt (int index)
 128                 {
 129                         list.RemoveAt (index);
 130                 }
 131
 132                 public override void SuspendBinding ()
 133                 {
 134                         binding_suspended = true;
 135                 }
 136
 137                 public override void ResumeBinding ()
 138                 {
 139                         binding_suspended = false;
 140                 }
 141
 142                 internal override bool IsSuspended {
 143                         get { return binding_suspended; }
 144                 }
 145
 146                 public override void AddNew ()
 147                 {
 148                         if (binding_list == null)
 149                                 throw new NotSupportedException ();
 150                         binding_list.AddNew ();
 151                 }
 152
 153                 public override void CancelCurrentEdit ()
 154                 {
 155                         IEditableObject editable = Current as IEditableObject;
 156
 157                         if (editable == null)
 158                                 return;
 159                         editable.CancelEdit ();
 160                         OnItemChanged (new ItemChangedEventArgs (Position));
 161                 }
 162
 163                 public override void EndCurrentEdit ()
 164                 {
 165                         IEditableObject editable = Current as IEditableObject;
 166
 167                         if (editable == null)
 168                                 return;
 169                         editable.EndEdit ();
 170                 }
 171
 172                 protected internal override void OnCurrentChanged (EventArgs e)
 173                 {
 174                         PullData ();
 175
 176                         if (onCurrentChangedHandler != null) {
 177                                 onCurrentChangedHandler (this, e);
 178                         }
 179                 }
 180
 181                 protected virtual void OnItemChanged (ItemChangedEventArgs e)
 182                 {
 183                         PushData ();
 184
 185                         if (ItemChanged != null)
 186                                 ItemChanged (this, e);
 187                 }
 188
 189                 protected virtual void OnPositionChanged (EventArgs e)
 190                 {
 191                         if (onPositionChangedHandler == null)
 192                                 return;
 193                         onPositionChangedHandler (this, e);
 194                 }
 195
 196                 protected internal override string GetListName (ArrayList accessors)
 197                 {
 198                         if (list is ITypedList) {
 199                                 PropertyDescriptor [] pds;
 200                                 pds = new PropertyDescriptor [accessors.Count];
 201                                 accessors.CopyTo (pds, 0);
 202                                 return ((ITypedList) list).GetListName (pds);
 203                         }
 204                         return String.Empty;
 205                 }
 206
 207                 [MonoTODO ("Not totally sure how this works, its doesn't seemt to do a pull/push like i originally assumed")]
 208                 protected override void UpdateIsBinding ()
 209                 {
 210                         UpdateItem ();
 211
 212                         foreach (Binding binding in Bindings)
 213                                 binding.UpdateIsBinding ();
 214                 }
 215
 216                 private void UpdateItem ()
 217                 {
 218                         // Probably should be validating or something here
 219                         EndCurrentEdit ();
 220                 }
 221
 222                 internal object GetItem (int index)
 223                 {
 224                         return list [index];
 225                 }
 226
 227                 private PropertyDescriptorCollection GetBrowsableProperties (Type t)
 228                 {
 229                         Attribute [] att = new System.Attribute [1];
 230                         att [0] = new BrowsableAttribute (true);
 231                         return TypeDescriptor.GetProperties (t, att);
 232                 }
 233
 234                 public event ItemChangedEventHandler ItemChanged;
 235         }
 236 }
 237