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
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System;
  34 using System.Collections;
  35 using System.ComponentModel;
  36 using System.ComponentModel.Design;
  37 using System.Web;
  38 using System.Web.UI;
  39 using System.Web.Util;
  40
  41 namespace System.Web.UI.WebControls
  42 {
  43         [DefaultEvent("SelectedIndexChanged")]
  44         #if !NET_2_0
  45         [DefaultProperty("DataSource")]
  46         #endif
  47         [Designer ("System.Web.UI.Design.WebControls.ListControlDesigner, " + Consts.AssemblySystem_Design, typeof (IDesigner))]
  48         [DataBindingHandler("System.Web.UI.Design.ListControlDataBindingHandler, " + Consts.AssemblySystem_Design)]
  49         [ParseChildren(true, "Items")]
  50         public abstract class ListControl :
  51                 #if NET_2_0
  52                         DataBoundControl
  53                 #else
  54                         WebControl
  55                 #endif
  56         {
  57                 private static readonly object SelectedIndexChangedEvent = new object();
  58
  59                 #if !NET_2_0
  60                 private object             dataSource;
  61                 #endif
  62
  63                 private ListItemCollection items;
  64
  65                 private int cachedSelectedIndex = -1;
  66                 private string cachedSelectedValue;
  67
  68                 #if !NET_2_0
  69                 public ListControl(): base(HtmlTextWriterTag.Select)
  70                 {
  71                 }
  72                 #else
  73                 protected override HtmlTextWriterTag TagKey {
  74                         get { return HtmlTextWriterTag.Select; }
  75                 }
  76                 #endif
  77
  78                 [WebCategory ("Action")]
  79                 [WebSysDescription ("Raised when the selected index entry has changed.")]
  80                 public event EventHandler SelectedIndexChanged
  81                 {
  82                         add
  83                         {
  84                                 Events.AddHandler(SelectedIndexChangedEvent, value);
  85                         }
  86                         remove
  87                         {
  88                                 Events.RemoveHandler(SelectedIndexChangedEvent, value);
  89                         }
  90                 }
  91
  92                 [DefaultValue (false), WebCategory ("Behavior")]
  93                 [WebSysDescription ("The control automatically posts back after changing the text.")]
  94                 public virtual bool AutoPostBack
  95                 {
  96                         get
  97                         {
  98                                 object o = ViewState["AutoPostBack"];
  99                                 if(o!=null)
 100                                         return (bool)o;
 101                                 return false;
 102                         }
 103                         set
 104                         {
 105                                 ViewState["AutoPostBack"] = value;
 106                         }
 107                 }
 108
 109                 #if !NET_2_0
 110                 [DefaultValue (""), WebCategory ("Data")]
 111                 [WebSysDescription ("The name of the table that is used for binding when a DataSource is specified.")]
 112                 public virtual string DataMember
 113                 {
 114                         get
 115                         {
 116                                 object o = ViewState["DataMember"];
 117                                 if(o!=null)
 118                                         return (string)o;
 119                                 return String.Empty;
 120                         }
 121                         set
 122                         {
 123                                 ViewState["DataMember"] = value;
 124                         }
 125                 }
 126
 127
 128                 [DefaultValue (null), Bindable (true), WebCategory ("Data")]
 129                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 130                 [WebSysDescription ("The DataSource that is used for data-binding.")]
 131                 public virtual object DataSource
 132                 {
 133                         get
 134                         {
 135                                 return dataSource;
 136                         }
 137                         set
 138                         {
 139                                 if(value == null || value is IListSource || value is IEnumerable) {
 140                                         dataSource = value;
 141                                         return;
 142                                 }
 143                                 throw new ArgumentException(HttpRuntime.FormatResourceString(ID, "Invalid DataSource Type"));
 144                         }
 145                 }
 146                 #endif
 147
 148                 [DefaultValue (""), WebCategory ("Data")]
 149                 [WebSysDescription ("The field in the datatable that provides the text entry.")]
 150                 public virtual string DataTextField
 151                 {
 152                         get
 153                         {
 154                                 object o = ViewState["DataTextField"];
 155                                 if(o!=null)
 156                                         return (string)o;
 157                                 return String.Empty;
 158                         }
 159                         set
 160                         {
 161                                 ViewState["DataTextField"] = value;
 162                         }
 163                 }
 164
 165                 [DefaultValue (""), WebCategory ("Data")]
 166                 [WebSysDescription ("Specifies a formatting rule for the texts that are returned.")]
 167                 public virtual string DataTextFormatString
 168                 {
 169                         get
 170                         {
 171                                 object o = ViewState["DataTextFormatString"];
 172                                 if(o!=null)
 173                                         return (string)o;
 174                                 return String.Empty;
 175                         }
 176                         set
 177                         {
 178                                 ViewState["DataTextFormatString"] = value;
 179                         }
 180                 }
 181
 182                 [DefaultValue (""), WebCategory ("Data")]
 183                 [WebSysDescription ("The field in the datatable that provides the entry value.")]
 184                 public virtual string DataValueField
 185                 {
 186                         get
 187                         {
 188                                 object o = ViewState["DataValueField"];
 189                                 if(o!=null)
 190                                         return (string)o;
 191                                 return String.Empty;
 192                         }
 193                         set
 194                         {
 195                                 ViewState["DataValueField"] = value;
 196                         }
 197                 }
 198
 199                 [DefaultValue (null), MergableProperty (false), WebCategory ("Misc")]
 200                 [PersistenceMode (PersistenceMode.InnerDefaultProperty)]
 201                 [WebSysDescription ("A collection of all items contained in this list.")]
 202                 public virtual ListItemCollection Items
 203                 {
 204                         get
 205                         {
 206                                 if(items==null)
 207                                 {
 208                                         items = new ListItemCollection();
 209                                         if(IsTrackingViewState)
 210                                         {
 211                                                 items.TrackViewState();
 212                                         }
 213                                 }
 214                                 return items;
 215                         }
 216                 }
 217
 218                 [DefaultValue (0), Bindable (true), WebCategory ("Misc")]
 219                 [Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 220                 [WebSysDescription ("The index number of the currently selected ListItem.")]
 221                 public virtual int SelectedIndex
 222                 {
 223                         get {
 224                                 ListItemCollection items = Items;
 225                                 int last = items.Count;
 226                                 for (int i = 0; i < last; i++) {
 227                                         if (items [i].Selected)
 228                                                 return i;
 229                                 }
 230                                 return -1;
 231                         }
 232                         set {
 233                                 if (Items.Count == 0)
 234                                 {
 235                                         cachedSelectedIndex = value;
 236                                         return;
 237                                 }
 238                                 if ((value < -1) || (value >= Items.Count))
 239                                         throw new ArgumentOutOfRangeException ();
 240
 241                                 ClearSelection ();
 242                                 if (value != -1)
 243                                         Items [value].Selected = true;
 244                         }
 245                 }
 246
 247                 [DefaultValue (null), WebCategory ("Misc")]
 248                 [Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 249                 [WebSysDescription ("The currently selected ListItem.")]
 250                 public virtual ListItem SelectedItem
 251                 {
 252                         get
 253                         {
 254                                 int idx = SelectedIndex;
 255                                 if (idx < 0)
 256                                         return null;
 257
 258                                 return Items [idx];
 259                         }
 260                 }
 261
 262 #if NET_1_1
 263                 [DefaultValue (""), Bindable (true), WebCategory ("Misc")]
 264                 [Browsable (false), DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 265                 [WebSysDescription ("The value of the currently selected ListItem.")]
 266                 public virtual string SelectedValue {
 267                         get {
 268                                 int idx = SelectedIndex;
 269                                 if (idx == -1)
 270                                         return "";
 271
 272                                 return Items [idx].Value;
 273                         }
 274
 275                         set {
 276                                 ListItem item = null;
 277
 278                                 if (value != null) {
 279                                         if (Items.Count > 0) {
 280                                                 item = Items.FindByValue (value);
 281                                                 if (item == null)
 282                                                         throw new ArgumentOutOfRangeException ("value");
 283                                         } else {
 284                                                 cachedSelectedValue = value;
 285                                                 return;
 286                                         }
 287                                 }
 288
 289                                 ClearSelection ();
 290                                 if (item != null)
 291                                         item.Selected = true;
 292                         }
 293                 }
 294 #endif
 295
 296                 internal virtual ArrayList SelectedIndices
 297                 {
 298                         get
 299                         {
 300                                 ArrayList si = new ArrayList();
 301                                 for(int i=0; i < Items.Count; i++)
 302                                 {
 303                                         if(Items[i].Selected)
 304                                                 si.Add(i);
 305                                 }
 306                                 return si;
 307                         }
 308                 }
 309
 310                 internal void Select(ArrayList indices)
 311                 {
 312                         ClearSelection();
 313                         foreach(object intObj in indices)
 314                         {
 315                                 int index = (int)intObj;
 316                                 if(index >= 0 && index < Items.Count)
 317                                         Items[index].Selected = true;
 318                         }
 319                 }
 320
 321                 public virtual void ClearSelection()
 322                 {
 323                         for(int i=0; i < Items.Count; i++)
 324                         {
 325                                 Items[i].Selected = false;
 326                         }
 327                 }
 328
 329                 protected override void LoadViewState(object savedState)
 330                 {
 331                         //Order: BaseClass, Items (Collection), Indices
 332                         if(savedState != null && savedState is Triplet)
 333                         {
 334                                 Triplet state = (Triplet)savedState;
 335                                 base.LoadViewState(state.First);
 336                                 Items.LoadViewState(state.Second);
 337                                 object indices = state.Third;
 338                                 if(indices != null)
 339                                 {
 340                                         Select((ArrayList)indices);
 341                                 }
 342                         }
 343                 }
 344
 345                 #if NET_2_0
 346                 protected override void PerformDataBinding ()
 347                 {
 348                         base.PerformDataBinding ();
 349                         IEnumerable ds = GetResolvedDataSource ();
 350                 #else
 351                 protected override void OnDataBinding(EventArgs e)
 352                 {
 353                         base.OnDataBinding(e);
 354                         IEnumerable ds = DataSourceHelper.GetResolvedDataSource (DataSource, DataMember);
 355                 #endif
 356                         if(ds != null) {
 357                                 string dtf = DataTextField;
 358                                 string dvf = DataValueField;
 359                                 string dtfs = DataTextFormatString;
 360                                 if (dtfs.Length == 0)
 361                                         dtfs = "{0}";
 362
 363                                 Items.Clear();
 364
 365                                 bool dontUseProperties = (dtf.Length == 0 && dvf.Length == 0);
 366
 367                                 foreach (object current in ds) {
 368                                         ListItem li = new ListItem();
 369                                         if (dontUseProperties){
 370                                                 li.Text  = String.Format (dtfs, current);
 371                                                 li.Value = current.ToString ();
 372                                                 Items.Add (li);
 373                                                 continue;
 374                                         }
 375
 376                                         object o;
 377                                         if (dtf.Length > 0) {
 378                                                 o = DataBinder.GetPropertyValue (current, dtf, dtfs);
 379                                                 li.Text = o.ToString ();
 380                                         }
 381
 382                                         if (dvf.Length > 0) {
 383                                                 o = DataBinder.GetPropertyValue (current, dvf, null);
 384                                                 li.Value = o.ToString ();
 385                                         }
 386
 387                                         Items.Add(li);
 388                                 }
 389                         }
 390
 391                         if (cachedSelectedValue != null) {
 392                                 int index = Items.FindByValueInternal (cachedSelectedValue);
 393                                 if (index == -1)
 394                                         throw new ArgumentOutOfRangeException("value");
 395
 396                                 if (cachedSelectedIndex != -1 && cachedSelectedIndex != index)
 397                                         throw new ArgumentException(HttpRuntime.FormatResourceString(
 398                                                 "Attributes_mutually_exclusive", "Selected Index", "Selected Value"));
 399
 400                                 SelectedIndex = index;
 401                                 cachedSelectedIndex = -1;
 402                                 cachedSelectedValue = null;
 403                                 return;
 404                         }
 405
 406                         if (cachedSelectedIndex != -1) {
 407                                 SelectedIndex = cachedSelectedIndex;
 408                                 cachedSelectedIndex = -1;
 409                         }
 410                 }
 411
 412                 protected virtual void OnSelectedIndexChanged(EventArgs e)
 413                 {
 414                         if(Events!=null)
 415                                 {
 416                                         EventHandler eh = (EventHandler)(Events[SelectedIndexChangedEvent]);
 417                                         if(eh!=null)
 418                                                 eh(this, e);
 419                                 }
 420                 }
 421
 422                 protected override void OnPreRender (EventArgs e)
 423                 {
 424                         base.OnPreRender(e);
 425                 }
 426
 427                 protected override object SaveViewState()
 428                 {
 429                         //Order: BaseClass, Items (Collection), Indices
 430                         object vs = base.SaveViewState();
 431                         object itemSvs = Items.SaveViewState();
 432                         object indices = null;
 433                         if (SaveSelectedIndicesViewState)
 434                                 indices = SelectedIndices;
 435
 436                         if (vs != null || itemSvs != null || indices != null)
 437                                 return new Triplet(vs, itemSvs, indices);
 438
 439                         return null;
 440                 }
 441
 442                 protected override void TrackViewState()
 443                 {
 444                         base.TrackViewState();
 445                         Items.TrackViewState();
 446                 }
 447
 448                 private bool SaveSelectedIndicesViewState {
 449                         get {
 450                                 if (Events[SelectedIndexChangedEvent] == null && Enabled && Visible) {
 451                                         Type t = GetType();
 452                                         // If I am a derivative, let it take of storing the selected indices.
 453                                         if (t == typeof(DropDownList) || t == typeof(ListBox) ||
 454                                             t == typeof(CheckBoxList) || t == typeof(RadioButtonList))
 455                                                 return false;
 456                                 }
 457                                 return true;
 458                         }
 459                 }
 460         }
 461 }