mcs/class/System.Web/System.Web.UI/StateManagedCollection.cs

   1 //
   2 // System.Web.UI.StateManagedCollection
   3 //
   4 // Authors:
   5 //      Ben Maurer (bmaurer@users.sourceforge.net)
   6 //
   7 // (C) 2003 Ben Maurer
   8 //
   9
  10 #if NET_2_0
  11 using System.Collections;
  12 using System.Collections.Specialized;
  13 using System.Text;
  14
  15 namespace System.Web.UI {
  16         public abstract class StateManagedCollection : IList, IStateManager {
  17
  18                 protected abstract object CreateKnownType (int index);
  19                 protected abstract void SetDirtyObject (object o);
  20                 protected virtual Type [] GetKnownTypes ()
  21                 {
  22                         return null;
  23                 }
  24
  25                 #region OnXXX
  26                 protected virtual void OnClear ()
  27                 {
  28                 }
  29
  30                 protected virtual void OnClearComplete ()
  31                 {
  32                 }
  33
  34                 protected virtual void OnInsert (int index, object value)
  35                 {
  36                 }
  37
  38                 protected virtual void OnInsertComplete (int index, object value)
  39                 {
  40                 }
  41
  42                 protected virtual void OnRemove (int index, object value)
  43                 {
  44                 }
  45
  46                 protected virtual void OnRemoveComplete (int index, object value)
  47                 {
  48                 }
  49
  50                 protected virtual void OnValidate (object value)
  51                 {
  52                         if (value == null)
  53                                 throw new ArgumentNullException ("value");
  54                 }
  55                 #endregion
  56
  57                 #region IStateManager
  58                 void IStateManager.LoadViewState (object savedState)
  59                 {
  60                         int pos = -1;
  61                         foreach (Pair p in (ArrayList)savedState) {
  62                                 pos ++;
  63
  64                                 if (p == null)
  65                                         continue;
  66                                 IStateManager itm;
  67
  68                                 if (p.Second is Type)
  69                                         itm = (IStateManager) Activator.CreateInstance ((Type) p.Second);
  70                                 else
  71                                         itm = (IStateManager) CreateKnownType ((int) p.Second);
  72
  73                                 itm.LoadViewState (p.First);
  74
  75                                 if (pos >= Count)
  76                                         items.Add (itm);
  77                                 else
  78                                         items [pos] = itm;
  79
  80                         }
  81                 }
  82
  83                 object IStateManager.SaveViewState ()
  84                 {
  85                         ArrayList saved = new ArrayList ();
  86                         Type [] knownTypes = GetKnownTypes ();
  87
  88                         foreach (IStateManager itm in items) {
  89                                 object state = itm.SaveViewState ();
  90                                 if (state == null && !saveEverything) {
  91                                         saved.Add (null);
  92                                         continue;
  93                                 }
  94
  95                                 Pair p = new Pair ();
  96                                 p.First = state;
  97
  98                                 Type t = itm.GetType ();
  99                                 int idx = -1;
 100                                 if (knownTypes != null)
 101                                         idx = Array.IndexOf (knownTypes, t);
 102
 103                                 if (idx != -1)
 104                                         p.Second = idx;
 105                                 else
 106                                         p.Second = t;
 107
 108                                 saved.Add (p);
 109                         }
 110
 111                         return saved;
 112                 }
 113
 114                 void IStateManager.TrackViewState ()
 115                 {
 116                         isTrackingViewState = true;
 117
 118                         foreach (IStateManager i in items)
 119                                 i.TrackViewState ();
 120                 }
 121
 122                 bool isTrackingViewState;
 123                 bool IStateManager.IsTrackingViewState {
 124                         get { return isTrackingViewState; }
 125                 }
 126                 #endregion
 127
 128                 #region ICollection, IList, IEnumerable
 129
 130                 public void Clear ()
 131                 {
 132                         this.OnClear ();
 133                         items.Clear ();
 134                         this.OnClearComplete ();
 135
 136                         SetSaveEverything ();
 137                 }
 138
 139                 public int IndexOf (object o)
 140                 {
 141                         if (o == null)
 142                                 return -1;
 143                         return items.IndexOf (o);
 144                 }
 145
 146                 public bool Contains (object o)
 147                 {
 148                         return o != null && items.Contains (o);
 149                 }
 150
 151                 public IEnumerator GetEnumerator ()
 152                 {
 153                         return items.GetEnumerator ();
 154                 }
 155
 156                 void System.Collections.ICollection.CopyTo (Array array, int index)
 157                 {
 158                         items.CopyTo (array, index);
 159                 }
 160
 161                 IEnumerator IEnumerable.GetEnumerator ()
 162                 {
 163                         return GetEnumerator ();
 164                 }
 165
 166                 int IList.Add (object value)
 167                 {
 168                         OnValidate(value);
 169                         if (isTrackingViewState) {
 170                                 ((IStateManager) value).TrackViewState ();
 171                                 SetDirtyObject (value);
 172                         }
 173
 174                         OnInsert (-1, value);
 175                         items.Add (value);
 176                         OnInsertComplete (-1, value);
 177
 178                         return Count - 1;
 179                 }
 180
 181                 void IList.Insert (int index, object value)
 182                 {
 183                         OnValidate(value);
 184                         if (isTrackingViewState) {
 185                                 ((IStateManager) value).TrackViewState ();
 186                                 SetDirtyObject (value);
 187                         }
 188
 189                         OnInsert (index, value);
 190                         items.Insert (index, value);
 191                         OnInsertComplete(index, value);
 192
 193                         SetSaveEverything ();
 194                 }
 195
 196                 void IList.Remove (object value)
 197                 {
 198                         if (value == null)
 199                                 return;
 200                         OnValidate (value);
 201                         ((IList)this).RemoveAt (IndexOf (value));
 202                 }
 203                 void IList.RemoveAt (int index)
 204                 {
 205                         object o = items [index];
 206
 207                         OnRemove (index, o);
 208                         items.RemoveAt (index);
 209                         OnRemoveComplete(index, o);
 210
 211                         SetSaveEverything ();
 212                 }
 213
 214                 void IList.Clear ()
 215                 {
 216                         this.Clear ();
 217                 }
 218
 219                 bool IList.Contains (object value)
 220                 {
 221                         if (value == null)
 222                                 return false;
 223
 224                         OnValidate (value);
 225                         return Contains (value);
 226                 }
 227
 228                 int IList.IndexOf (object value)
 229                 {
 230                         if (value == null)
 231                                 return -1;
 232
 233                         OnValidate (value);
 234                         return IndexOf (value);
 235                 }
 236
 237                 public int Count {
 238                         get { return items.Count; }
 239                 }
 240
 241                 int ICollection.Count {
 242                         get { return items.Count; }
 243                 }
 244
 245                 bool ICollection.IsSynchronized {
 246                         get { return false; }
 247                 }
 248
 249                 object ICollection.SyncRoot {
 250                         get { return this; }
 251                 }
 252
 253                 bool IList.IsFixedSize {
 254                         get { return false; }
 255                 }
 256
 257                 bool IList.IsReadOnly {
 258                         get { return false; }
 259                 }
 260
 261                 object IList.this [int index] {
 262                         get { return items [index]; }
 263                         set {
 264                                 if (index < 0 || index >= Count)
 265                                         throw new ArgumentOutOfRangeException ("index");
 266
 267                                 OnValidate (value);
 268                                 if (isTrackingViewState) {
 269                                         ((IStateManager) value).TrackViewState ();
 270                                         SetDirtyObject (value);
 271                                 }
 272
 273                                 items [index] = value;
 274                         }
 275                 }
 276                 #endregion
 277
 278                 ArrayList items = new ArrayList ();
 279
 280                 bool saveEverything = false;
 281                 void SetSaveEverything ()
 282                 {
 283                         if (isTrackingViewState)
 284                                 saveEverything = true;
 285                 }
 286         }
 287 }
 288 #endif
 289