mcs/class/System.Web/System.Web.UI.WebControls/ListControl.cs

   1 //
   2 // System.Web.UI.WebControls.ListControl.cs
   3 //
   4 // Authors:
   5 //   Gaurav Vaish (gvaish@iitk.ac.in)
   6 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   7 //
   8 // (C) Gaurav Vaish (2002)
   9 // (C) 2003 Andreas Nahr
  10 //
  11 \r
  12 using System;\r
  13 using System.Collections;\r
  14 using System.ComponentModel;
  15 using System.ComponentModel.Design;\r
  16 using System.Web;\r
  17 using System.Web.UI;\r
  18 using System.Web.Util;\r
  19 \r
  20 namespace System.Web.UI.WebControls\r
  21 {\r
  22         [DefaultEvent("SelectedIndexChanged")]\r
  23         #if !NET_2_0
  24         [DefaultProperty("DataSource")]
  25         #endif\r
  26         [Designer ("System.Web.UI.Design.WebControls.ListControlDesigner, " + Consts.AssemblySystem_Design, typeof (IDesigner))]\r
  27         [DataBindingHandler("System.Web.UI.Design.ListControlDataBindingHandler, " + Consts.AssemblySystem_Design)]\r
  28         [ParseChildren(true, "Items")]\r
  29         public abstract class ListControl :
  30                 #if NET_2_0
  31                         DataBoundControl
  32                 #else
  33                         WebControl
  34                 #endif\r
  35         {\r
  36                 private static readonly object SelectedIndexChangedEvent = new object();\r
  37
  38                 #if !NET_2_0\r
  39                 private object             dataSource;
  40                 #endif
  41                 \r
  42                 private ListItemCollection items;\r
  43 \r
  44                 private int cachedSelectedIndex = -1;\r
  45                 private string cachedSelectedValue;
  46
  47                 #if !NET_2_0\r
  48                 public ListControl(): base(HtmlTextWriterTag.Select)\r
  49                 {\r
  50                 }
  51                 #else
  52                 protected override HtmlTextWriterTag TagKey {
  53                         get { return HtmlTextWriterTag.Select; }
  54                 }
  55                 #endif\r
  56
  57                 [WebCategory ("Action")]
  58                 [WebSysDescription ("Raised when the selected index entry has changed.")]\r
  59                 public event EventHandler SelectedIndexChanged\r
  60                 {\r
  61                         add\r
  62                         {\r
  63                                 Events.AddHandler(SelectedIndexChangedEvent, value);\r
  64                         }\r
  65                         remove\r
  66                         {\r
  67                                 Events.RemoveHandler(SelectedIndexChangedEvent, value);\r
  68                         }\r
  69                 }\r
  70
  71                 [DefaultValue (false), WebCategory ("Behavior")]
  72                 [WebSysDescription ("The control automatically posts back after changing the text.")]\r
  73                 public virtual bool AutoPostBack\r
  74                 {\r
  75                         get\r
  76                         {\r
  77                                 object o = ViewState["AutoPostBack"];\r
  78                                 if(o!=null)\r
  79                                         return (bool)o;\r
  80                                 return false;\r
  81                         }\r
  82                         set\r
  83                         {\r
  84                                 ViewState["AutoPostBack"] = value;\r
  85                         }\r
  86                 }\r
  87
  88                 #if !NET_2_0
  89                 [DefaultValue (""), WebCategory ("Data")]
  90                 [WebSysDescription ("The name of the table that is used for binding when a DataSource is specified.")]\r
  91                 public virtual string DataMember\r
  92                 {\r
  93                         get\r
  94                         {\r
  95                                 object o = ViewState["DataMember"];\r
  96                                 if(o!=null)\r
  97                                         return (string)o;\r
  98                                 return String.Empty;\r
  99                         }\r
 100                         set\r
 101                         {\r
 102                                 ViewState["DataMember"] = value;\r
 103                         }\r
 104                 }\r
 105
 106
 107                 [DefaultValue (null), Bindable (true), WebCategory ("Data")]
 108                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 109                 [WebSysDescription ("The DataSource that is used for data-binding.")]\r
 110                 public virtual object DataSource\r
 111                 {\r
 112                         get\r
 113                         {\r
 114                                 return dataSource;\r
 115                         }\r
 116                         set\r
 117                         {\r
 118                                 if(value == null || value is IListSource || value is IEnumerable) {
 119                                         dataSource = value;
 120                                         return;
 121                                 }
 122                                 throw new ArgumentException(HttpRuntime.FormatResourceString(ID, "Invalid DataSource Type"));\r
 123                         }\r
 124                 }
 125                 #endif\r
 126
 127                 [DefaultValue (""), WebCategory ("Data")]
 128                 [WebSysDescription ("The field in the datatable that provides the text entry.")]\r
 129                 public virtual string DataTextField\r
 130                 {\r
 131                         get\r
 132                         {\r
 133                                 object o = ViewState["DataTextField"];\r
 134                                 if(o!=null)\r
 135                                         return (string)o;\r
 136                                 return String.Empty;\r
 137                         }\r
 138                         set\r
 139                         {\r
 140                                 ViewState["DataTextField"] = value;\r
 141                         }\r
 142                 }\r
 143
 144                 [DefaultValue (""), WebCategory ("Data")]
 145                 [WebSysDescription ("Specifies a formatting rule for the texts that are returned.")]\r
 146                 public virtual string DataTextFormatString\r
 147                 {\r
 148                         get\r
 149                         {\r
 150                                 object o = ViewState["DataTextFormatString"];\r
 151                                 if(o!=null)\r
 152                                         return (string)o;\r
 153                                 return String.Empty;\r
 154                         }\r
 155                         set\r
 156                         {\r
 157                                 ViewState["DataTextFormatString"] = value;\r
 158                         }\r
 159                 }\r
 160
 161                 [DefaultValue (""), WebCategory ("Data")]
 162                 [WebSysDescription ("The field in the datatable that provides the entry value.")]\r
 163                 public virtual string DataValueField\r
 164                 {\r
 165                         get\r
 166                         {\r
 167                                 object o = ViewState["DataValueField"];\r
 168                                 if(o!=null)\r
 169                                         return (string)o;\r
 170                                 return String.Empty;\r
 171                         }\r
 172                         set\r
 173                         {\r
 174                                 ViewState["DataValueField"] = value;\r
 175                         }\r
 176                 }\r
 177
 178                 [DefaultValue (null), MergableProperty (false), WebCategory ("Misc")]
 179                 [PersistenceMode (PersistenceMode.InnerDefaultProperty)]
 180                 [WebSysDescription ("A collection of all items contained in this list.")]\r
 181                 public virtual ListItemCollection Items\r
 182                 {\r
 183                         get\r
 184                         {\r
 185                                 if(items==null)\r
 186                                 {\r
 187                                         items = new ListItemCollection();\r
 188                                         if(IsTrackingViewState)\r
 189                                         {\r
 190                                                 items.TrackViewState();\r
 191                                         }\r
 192                                 }\r
 193                                 return items;\r
 194                         }\r
 195                 }\r
 196
 197                 [DefaultValue (0), Bindable (true), WebCategory ("Misc")]
 198                 [Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 199                 [WebSysDescription ("The index number of the currently selected ListItem.")]\r
 200                 public virtual int SelectedIndex\r
 201                 {\r
 202                         get {\r
 203                                 ListItemCollection items = Items;\r
 204                                 int last = items.Count;\r
 205                                 for (int i = 0; i < last; i++) {\r
 206                                         if (items [i].Selected)\r
 207                                                 return i;\r
 208                                 }\r
 209                                 return -1;\r
 210                         }\r
 211                         set {\r
 212                                 if (Items.Count == 0)\r
 213                                 {\r
 214                                         cachedSelectedIndex = value;\r
 215                                         return;\r
 216                                 }\r
 217                                 if ((value < -1) || (value >= Items.Count))\r
 218                                         throw new ArgumentOutOfRangeException ();\r
 219 \r
 220                                 ClearSelection ();\r
 221                                 if (value != -1)\r
 222                                         Items [value].Selected = true;\r
 223                         }\r
 224                 }\r
 225
 226                 [DefaultValue (null), WebCategory ("Misc")]
 227                 [Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 228                 [WebSysDescription ("The currently selected ListItem.")]\r
 229                 public virtual ListItem SelectedItem\r
 230                 {\r
 231                         get\r
 232                         {\r
 233                                 int idx = SelectedIndex;\r
 234                                 if (idx < 0)\r
 235                                         return null;\r
 236 \r
 237                                 return Items [idx];\r
 238                         }\r
 239                 }\r
 240 \r
 241 #if NET_1_1
 242                 [DefaultValue (""), Bindable (true), WebCategory ("Misc")]
 243                 [Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 244                 [WebSysDescription ("The value of the currently selected ListItem.")]\r
 245                 public virtual string SelectedValue {\r
 246                         get {\r
 247                                 int idx = SelectedIndex;\r
 248                                 if (idx == -1)\r
 249                                         return "";\r
 250 \r
 251                                 return Items [idx].Value;\r
 252                         }\r
 253 \r
 254                         set {\r
 255                                 ListItem item = null;\r
 256 \r
 257                                 if (value != null) {\r
 258                                         if (Items.Count > 0) {
 259                                                 item = Items.FindByValue (value);
 260                                                 if (item == null)
 261                                                         throw new ArgumentOutOfRangeException ("value");
 262                                         } else {
 263                                                 cachedSelectedValue = value;
 264                                                 return;
 265                                         }
 266                                 }\r
 267 \r
 268                                 ClearSelection ();\r
 269                                 if (item != null)\r
 270                                         item.Selected = true;\r
 271                         }\r
 272                 }\r
 273 #endif\r
 274                 \r
 275                 internal virtual ArrayList SelectedIndices\r
 276                 {\r
 277                         get\r
 278                         {\r
 279                                 ArrayList si = new ArrayList();\r
 280                                 for(int i=0; i < Items.Count; i++)\r
 281                                 {\r
 282                                         if(Items[i].Selected)\r
 283                                                 si.Add(i);\r
 284                                 }\r
 285                                 return si;\r
 286                         }\r
 287                 }\r
 288 \r
 289                 internal void Select(ArrayList indices)\r
 290                 {\r
 291                         ClearSelection();\r
 292                         foreach(object intObj in indices)\r
 293                         {\r
 294                                 int index = (int)intObj;\r
 295                                 if(index >= 0 && index < Items.Count)\r
 296                                         Items[index].Selected = true;\r
 297                         }\r
 298                 }\r
 299 \r
 300                 public virtual void ClearSelection()\r
 301                 {\r
 302                         for(int i=0; i < Items.Count; i++)\r
 303                         {\r
 304                                 Items[i].Selected = false;\r
 305                         }\r
 306                 }\r
 307 \r
 308                 protected override void LoadViewState(object savedState)\r
 309                 {\r
 310                         //Order: BaseClass, Items (Collection), Indices\r
 311                         if(savedState != null && savedState is Triplet)\r
 312                         {\r
 313                                 Triplet state = (Triplet)savedState;\r
 314                                 base.LoadViewState(state.First);\r
 315                                 Items.LoadViewState(state.Second);\r
 316                                 object indices = state.Third;\r
 317                                 if(indices != null)\r
 318                                 {\r
 319                                         Select((ArrayList)indices);\r
 320                                 }\r
 321                         }\r
 322                 }\r
 323
 324                 #if NET_2_0
 325                 protected override void PerformDataBinding ()
 326                 {
 327                         base.PerformDataBinding ();
 328                         IEnumerable ds = GetResolvedDataSource ();
 329                 #else\r
 330                 protected override void OnDataBinding(EventArgs e)\r
 331                 {\r
 332                         base.OnDataBinding(e);\r
 333                         IEnumerable ds = DataSourceHelper.GetResolvedDataSource (DataSource, DataMember);
 334                 #endif\r
 335                         if(ds != null) {\r
 336                                 string dtf = DataTextField;\r
 337                                 string dvf = DataValueField;\r
 338                                 string dtfs = DataTextFormatString;\r
 339                                 if (dtfs.Length == 0)\r
 340                                         dtfs = "{0}";\r
 341 \r
 342                                 Items.Clear();\r
 343 \r
 344                                 bool dontUseProperties = (dtf.Length == 0 && dvf.Length == 0);\r
 345 \r
 346                                 foreach (object current in ds) {\r
 347                                         ListItem li = new ListItem();\r
 348                                         if (dontUseProperties){\r
 349                                                 li.Text  = String.Format (dtfs, current);\r
 350                                                 li.Value = current.ToString ();\r
 351                                                 Items.Add (li);\r
 352                                                 continue;\r
 353                                         }\r
 354 \r
 355                                         object o;\r
 356                                         if (dtf.Length > 0) {\r
 357                                                 o = DataBinder.GetPropertyValue (current, dtf, dtfs);\r
 358                                                 li.Text = o.ToString ();\r
 359                                         }\r
 360 \r
 361                                         if (dvf.Length > 0) {\r
 362                                                 o = DataBinder.GetPropertyValue (current, dvf, null);\r
 363                                                 li.Value = o.ToString ();\r
 364                                         }\r
 365 \r
 366                                         Items.Add(li);\r
 367                                 }\r
 368                         }\r
 369
 370                         if (cachedSelectedValue != null) {
 371                                 int index = Items.FindByValueInternal (cachedSelectedValue);
 372                                 if (index == -1)
 373                                         throw new ArgumentOutOfRangeException("value");
 374
 375                                 if (cachedSelectedIndex != -1 && cachedSelectedIndex != index)
 376                                         throw new ArgumentException(HttpRuntime.FormatResourceString(
 377                                                 "Attributes_mutually_exclusive", "Selected Index", "Selected Value"));
 378
 379                                 SelectedIndex = index;
 380                                 cachedSelectedIndex = -1;
 381                                 cachedSelectedValue = null;
 382                                 return;
 383                         }
 384
 385                         if (cachedSelectedIndex != -1) {\r
 386                                 SelectedIndex = cachedSelectedIndex;\r
 387                                 cachedSelectedIndex = -1;\r
 388                         }\r
 389                 }\r
 390 \r
 391                 protected virtual void OnSelectedIndexChanged(EventArgs e)\r
 392                 {\r
 393                         if(Events!=null)\r
 394                                 {\r
 395                                         EventHandler eh = (EventHandler)(Events[SelectedIndexChangedEvent]);\r
 396                                         if(eh!=null)\r
 397                                                 eh(this, e);\r
 398                                 }\r
 399                 }\r
 400 \r
 401                 protected override void OnPreRender (EventArgs e)\r
 402                 {\r
 403                         base.OnPreRender(e);\r
 404                 }\r
 405 \r
 406                 protected override object SaveViewState()\r
 407                 {\r
 408                         //Order: BaseClass, Items (Collection), Indices\r
 409                         object vs = base.SaveViewState();\r
 410                         object itemSvs = Items.SaveViewState();\r
 411                         object indices = null;\r
 412                         if (SaveSelectedIndicesViewState)\r
 413                                 indices = SelectedIndices;\r
 414 \r
 415                         if (vs != null || itemSvs != null || indices != null)\r
 416                                 return new Triplet(vs, itemSvs, indices);\r
 417 \r
 418                         return null;\r
 419                 }\r
 420 \r
 421                 protected override void TrackViewState()\r
 422                 {\r
 423                         base.TrackViewState();\r
 424                         Items.TrackViewState();\r
 425                 }\r
 426 \r
 427                 private bool SaveSelectedIndicesViewState {\r
 428                         get {\r
 429                                 if (Events[SelectedIndexChangedEvent] == null && Enabled && Visible) {\r
 430                                         Type t = GetType();\r
 431                                         // If I am a derivative, let it take of storing the selected indices.\r
 432                                         if (t == typeof(DropDownList) || t == typeof(ListBox) ||\r
 433                                             t == typeof(CheckBoxList) || t == typeof(RadioButtonList))\r
 434                                                 return false;\r
 435                                 }\r
 436                                 return true;\r
 437                         }\r
 438                 }\r
 439         }\r
 440 }\r