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 bool binding_suspended;
  40
  41                 internal CurrencyManager (object data_source)
  42                 {
  43                         if (data_source is IListSource) {
  44                                 list = ((IListSource) data_source).GetList ();
  45                         } else if (data_source is IList) {
  46                                 list = (IList) data_source;
  47                         } else {
  48                                 throw new Exception ("Attempted to create currency manager " +
  49                                         "from invalid type: " + data_source.GetType ());
  50                         }
  51
  52                         if (data_source as ArrayList != null) {
  53                                 finalType = ((ArrayList)data_source).GetType ();
  54                         } else {
  55                                 if (data_source as Array != null) {
  56                                         finalType = ((Array) data_source).GetType ();
  57                                 } else {
  58                                         finalType = null;
  59                                 }
  60                         }
  61                 }
  62
  63                 public IList List {
  64                         get { return list; }
  65                 }
  66
  67                 public override object Current {
  68                         get {
  69                                 return list [listposition];
  70                         }
  71                 }
  72
  73                 public override int Count {
  74                         get { return list.Count; }
  75                 }
  76
  77                 public override int Position {
  78                         get {
  79                                 return listposition;
  80                         }
  81                         set {
  82                                 if (value < 0)
  83                                         value = 0;
  84                                 if (value == list.Count)
  85                                         value = list.Count - 1;
  86                                 if (listposition == value)
  87                                         return;
  88                                 listposition = value;
  89                                 OnCurrentChanged (EventArgs.Empty);
  90                                 OnPositionChanged (EventArgs.Empty);
  91                         }
  92                 }
  93
  94                 internal string ListName {
  95                         get {
  96                                 ITypedList typed = list as ITypedList;
  97
  98                                 if (typed == null) {
  99                                         return finalType.Name;
 100                                 } else {
 101                                         return typed.GetListName (null);
 102                                 }
 103                         }
 104                 }
 105
 106                 public override PropertyDescriptorCollection GetItemProperties ()
 107                 {
 108                         ITypedList typed = list as ITypedList;
 109
 110                         if (list is Array) {
 111                                 Type element = list.GetType ().GetElementType ();
 112                                 return TypeDescriptor.GetProperties (element);
 113                         }
 114
 115                         if (typed != null) {
 116                                 return typed.GetItemProperties (null);
 117                         }
 118
 119                         PropertyInfo [] props = finalType.GetProperties ();
 120                         for (int i = 0; i < props.Length; i++) {
 121                                 if (props [i].Name == "Item") {
 122                                         Type t = props [i].PropertyType;
 123                                         if (t == typeof (object))
 124                                                 continue;
 125                                         return GetBrowsableProperties (t);
 126                                 }
 127                         }
 128
 129                         if (list.Count > 0) {
 130                                 return GetBrowsableProperties (list [0].GetType ());
 131                         }
 132
 133                         return new PropertyDescriptorCollection (null);
 134                 }
 135
 136                 public override void RemoveAt (int index)
 137                 {
 138                         list.RemoveAt (index);
 139                 }
 140
 141                 public override void SuspendBinding ()
 142                 {
 143                         binding_suspended = true;
 144                 }
 145
 146                 public override void ResumeBinding ()
 147                 {
 148                         binding_suspended = false;
 149                 }
 150
 151                 internal override bool IsSuspended {
 152                         get { return binding_suspended; }
 153                 }
 154
 155                 internal bool CanAddRows {
 156                         get {
 157                                 if (list as IBindingList == null) {
 158                                         return false;
 159                                 }
 160
 161                                 return true;
 162                         }
 163                 }
 164
 165                 public override void AddNew ()
 166                 {
 167                         if (list as IBindingList == null)
 168                                 throw new NotSupportedException ();
 169
 170                         (list as IBindingList).AddNew ();
 171                 }
 172
 173                 public override void CancelCurrentEdit ()
 174                 {
 175                         IEditableObject editable = Current as IEditableObject;
 176
 177                         if (editable == null)
 178                                 return;
 179                         editable.CancelEdit ();
 180                         OnItemChanged (new ItemChangedEventArgs (Position));
 181                 }
 182
 183                 public override void EndCurrentEdit ()
 184                 {
 185                         IEditableObject editable = Current as IEditableObject;
 186
 187                         if (editable == null)
 188                                 return;
 189                         editable.EndEdit ();
 190                 }
 191
 192                 protected internal override void OnCurrentChanged (EventArgs e)
 193                 {
 194                         PullData ();
 195
 196                         if (onCurrentChangedHandler != null) {
 197                                 onCurrentChangedHandler (this, e);
 198                         }
 199                 }
 200
 201                 protected virtual void OnItemChanged (ItemChangedEventArgs e)
 202                 {
 203                         PushData ();
 204
 205                         if (ItemChanged != null)
 206                                 ItemChanged (this, e);
 207                 }
 208
 209                 protected virtual void OnPositionChanged (EventArgs e)
 210                 {
 211                         if (onPositionChangedHandler == null)
 212                                 return;
 213                         onPositionChangedHandler (this, e);
 214                 }
 215
 216                 protected internal override string GetListName (ArrayList accessors)
 217                 {
 218                         if (list is ITypedList) {
 219                                 PropertyDescriptor [] pds;
 220                                 pds = new PropertyDescriptor [accessors.Count];
 221                                 accessors.CopyTo (pds, 0);
 222                                 return ((ITypedList) list).GetListName (pds);
 223                         }
 224                         return String.Empty;
 225                 }
 226
 227                 [MonoTODO ("Not totally sure how this works, its doesn't seemt to do a pull/push like i originally assumed")]
 228                 protected override void UpdateIsBinding ()
 229                 {
 230                         UpdateItem ();
 231
 232                         foreach (Binding binding in Bindings)
 233                                 binding.UpdateIsBinding ();
 234                 }
 235
 236                 private void UpdateItem ()
 237                 {
 238                         // Probably should be validating or something here
 239                         EndCurrentEdit ();
 240                 }
 241
 242                 internal object GetItem (int index)
 243                 {
 244                         return list [index];
 245                 }
 246
 247                 private PropertyDescriptorCollection GetBrowsableProperties (Type t)
 248                 {
 249                         Attribute [] att = new System.Attribute [1];
 250                         att [0] = new BrowsableAttribute (true);
 251                         return TypeDescriptor.GetProperties (t, att);
 252                 }
 253
 254                 public event ItemChangedEventHandler ItemChanged;
 255         }
 256 }
 257