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

   1 //
   2 // System.Web.UI.WebControls.TreeNode.cs
   3 //
   4 // Authors:
   5 //      Lluis Sanchez Gual (lluis@novell.com)
   6 //
   7 // (C) 2004 Novell, Inc (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  29 //
  30
  31 #if NET_2_0
  32
  33 using System;
  34 using System.Collections;
  35 using System.Text;
  36 using System.ComponentModel;
  37 using System.Web.UI;
  38
  39 namespace System.Web.UI.WebControls
  40 {
  41         [ParseChildrenAttribute (true, "ChildNodes")]
  42         public class TreeNode: IStateManager, ICloneable
  43         {
  44                 StateBag ViewState = new StateBag ();
  45                 TreeNodeCollection nodes;
  46                 bool marked;
  47                 TreeView tree;
  48                 TreeNode parent;
  49                 int index;
  50                 string path;
  51                 int depth = -1;
  52
  53                 object dataItem;
  54                 IHierarchyData hierarchyData;
  55
  56                 bool gotBinding;
  57                 TreeNodeBinding binding;
  58                 PropertyDescriptorCollection boundProperties;
  59
  60                 internal TreeNode (TreeView tree)
  61                 {
  62                         Tree = tree;
  63                 }
  64
  65                 public TreeNode ()
  66                 {
  67                 }
  68
  69                 public TreeNode (string text)
  70                 {
  71                         Text = text;
  72                 }
  73
  74                 public TreeNode (string text, string value)
  75                 {
  76                         Text = text;
  77                         Value = value;
  78                 }
  79
  80                 public TreeNode (string text, string value, string imageUrl)
  81                 {
  82                         Text = text;
  83                         Value = value;
  84                         ImageUrl = imageUrl;
  85                 }
  86
  87                 public TreeNode (string text, string value, string imageUrl, string navigateUrl, string target)
  88                 {
  89                         Text = text;
  90                         Value = value;
  91                         ImageUrl = imageUrl;
  92                         NavigateUrl = navigateUrl;
  93                         Target = target;
  94                 }
  95
  96                 [MonoTODO ("Not implemented")]
  97                 protected TreeNode (TreeView owner, bool isRoot)
  98                 {
  99                         throw new NotImplementedException ();
 100                 }
 101
 102                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 103                 [Browsable (false)]
 104                 public int Depth {
 105                         get {
 106                                 if (depth != -1) return depth;
 107                                 depth = 0;
 108                                 TreeNode nod = parent;
 109                                 while (nod != null) {
 110                                         depth++;
 111                                         nod = nod.parent;
 112                                 }
 113                                 return depth;
 114                         }
 115                 }
 116
 117                 void ResetPathData ()
 118                 {
 119                         path = null;
 120                         depth = -1;
 121                         gotBinding = false;
 122                 }
 123
 124                 internal TreeView Tree {
 125                         get { return tree; }
 126                         set {
 127                                 if (SelectedFlag) {
 128                                         if (value != null)
 129                                                 value.SetSelectedNode (this, false);
 130                                         if (tree != null)
 131                                                 tree.SetSelectedNode (null, false);
 132                                 }
 133                                 tree = value;
 134                                 if (nodes != null)
 135                                         nodes.SetTree (tree);
 136                                 ResetPathData ();
 137                                 if (PopulateOnDemand && !Populated && Expanded.HasValue && Expanded.Value)
 138                                         Populate ();
 139                         }
 140                 }
 141
 142                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 143                 [DefaultValue (false)]
 144                 [Browsable (false)]
 145                 public bool DataBound {
 146                         get { return ViewState ["DataBound"] == null ? false : (bool) ViewState ["DataBound"]; }
 147                         private set { ViewState ["DataBound"] = value; }
 148                 }
 149
 150                 [DefaultValue (null)]
 151                 [Browsable (false)]
 152                 public object DataItem {
 153                         get {
 154                                 return dataItem;
 155                         }
 156                 }
 157
 158                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 159                 [DefaultValue ("")]
 160                 [Browsable (false)]
 161                 public string DataPath {
 162                         get { return ViewState ["DataPath"] == null ? String.Empty : (String) ViewState ["DataPath"]; }
 163                         private set { ViewState ["DataPath"] = value; }
 164                 }
 165
 166                 [DefaultValue (false)]
 167                 public bool Checked {
 168                         get {
 169                                 object o = ViewState ["Checked"];
 170                                 if (o != null) return (bool)o;
 171                                 return false;
 172                         }
 173                         set {
 174                                 ViewState ["Checked"] = value;
 175                                 if (tree != null)
 176                                         tree.NotifyCheckChanged (this);
 177                         }
 178                 }
 179
 180                 [DefaultValue (null)]
 181                 [MergableProperty (false)]
 182                 [Browsable (false)]
 183                 [PersistenceMode (PersistenceMode.InnerDefaultProperty)]
 184                 public TreeNodeCollection ChildNodes {
 185                         get {
 186                                 if (nodes == null) {
 187                                         nodes = new TreeNodeCollection (this);
 188
 189                                         if (IsTrackingViewState)
 190                                                 ((IStateManager)nodes).TrackViewState();
 191                                 }
 192                                 return nodes;
 193                         }
 194                 }
 195
 196                 [DefaultValue (null)]
 197                 public bool? Expanded {
 198                         get {
 199                                 object o = ViewState ["Expanded"];
 200                                 return (bool?)o;
 201                         }
 202                         set {
 203                                 bool? current = (bool?) ViewState ["Expanded"];
 204                                 if (current == value)
 205                                         return;
 206                                 ViewState ["Expanded"] = value;
 207                                 if (tree != null)
 208                                         tree.NotifyExpandedChanged (this);
 209                                 if (PopulateOnDemand && !Populated && value.HasValue && value.Value)
 210                                         Populate ();
 211                         }
 212                 }
 213
 214                 [Localizable (true)]
 215                 [DefaultValue ("")]
 216                 public string ImageToolTip {
 217                         get {
 218                                 object o = ViewState ["ImageToolTip"];
 219                                 if (o != null) return (string)o;
 220                                 return "";
 221                         }
 222                         set {
 223                                 ViewState ["ImageToolTip"] = value;
 224                         }
 225                 }
 226
 227                 [DefaultValue ("")]
 228                 [UrlProperty]
 229                 [Editor ("System.Web.UI.Design.ImageUrlEditor, " + Consts.AssemblySystem_Design, typeof (System.Drawing.Design.UITypeEditor))]
 230                 public string ImageUrl {
 231                         get {
 232                                 object o = ViewState ["ImageUrl"];
 233                                 if (o != null) return (string)o;
 234                                 return "";
 235                         }
 236                         set {
 237                                 ViewState ["ImageUrl"] = value;
 238                         }
 239                 }
 240
 241                 [DefaultValue ("")]
 242                 [UrlProperty]
 243                 [Editor ("System.Web.UI.Design.UrlEditor, " + Consts.AssemblySystem_Design, typeof (System.Drawing.Design.UITypeEditor))]
 244                 public string NavigateUrl {
 245                         get {
 246                                 object o = ViewState ["NavigateUrl"];
 247                                 if (o != null) return (string)o;
 248                                 return "";
 249                         }
 250                         set {
 251                                 ViewState ["NavigateUrl"] = value;
 252                         }
 253                 }
 254
 255                 [DefaultValue (false)]
 256                 public bool PopulateOnDemand {
 257                         get {
 258                                 object o = ViewState ["PopulateOnDemand"];
 259                                 if (o != null) return (bool)o;
 260                                 return false;
 261                         }
 262                         set {
 263                                 ViewState ["PopulateOnDemand"] = value;
 264                         }
 265                 }
 266
 267                 [DefaultValue (TreeNodeSelectAction.Select)]
 268                 public TreeNodeSelectAction SelectAction {
 269                         get {
 270                                 object o = ViewState ["SelectAction"];
 271                                 if (o != null) return (TreeNodeSelectAction)o;
 272                                 return TreeNodeSelectAction.Select;
 273                         }
 274                         set {
 275                                 ViewState ["SelectAction"] = value;
 276                         }
 277                 }
 278
 279                 [DefaultValue (null)]
 280                 public bool? ShowCheckBox {
 281                         get {
 282                                 object o = ViewState ["ShowCheckBox"];
 283                                 return (bool?)o;
 284                         }
 285                         set {
 286                                 ViewState ["ShowCheckBox"] = value;
 287                         }
 288                 }
 289
 290                 internal bool ShowCheckBoxInternal {
 291                         get {
 292                                 if (ShowCheckBox.HasValue)
 293                                         return ShowCheckBox.Value;
 294                                 else
 295                                         return (Tree.ShowCheckBoxes == TreeNodeTypes.All) ||
 296                                                  ((Tree.ShowCheckBoxes & TreeNodeTypes.Leaf) > 0 && IsLeafNode) ||
 297                                                  ((Tree.ShowCheckBoxes & TreeNodeTypes.Parent) > 0 && IsParentNode && Parent != null) ||
 298                                                  ((Tree.ShowCheckBoxes & TreeNodeTypes.Root) > 0 && Parent == null && ChildNodes.Count > 0);
 299                         }
 300                 }
 301
 302                 [DefaultValue ("")]
 303                 public string Target {
 304                         get {
 305                                 object o = ViewState ["Target"];
 306                                 if(o != null) return (string)o;
 307                                 return "";
 308                         }
 309                         set {
 310                                 ViewState ["Target"] = value;
 311                         }
 312                 }
 313
 314                 [Localizable (true)]
 315                 [DefaultValue ("")]
 316                 [WebSysDescription ("The display text of the tree node.")]
 317                 public string Text {
 318                         get {
 319                                 object o = ViewState ["Text"];
 320                                 if (o == null)
 321                                         o = ViewState ["Value"];
 322                                 if (o != null) return (string)o;
 323                                 return String.Empty;
 324                         }
 325                         set {
 326                                 ViewState ["Text"] = value;
 327                         }
 328                 }
 329
 330                 [Localizable (true)]
 331                 [DefaultValue ("")]
 332                 public string ToolTip {
 333                         get {
 334                                 object o = ViewState ["ToolTip"];
 335                                 if(o != null) return (string)o;
 336                                 return "";
 337                         }
 338                         set {
 339                                 ViewState ["ToolTip"] = value;
 340                         }
 341                 }
 342
 343                 [Localizable (true)]
 344                 [DefaultValue ("")]
 345                 public string Value {
 346                         get {
 347                                 object o = ViewState ["Value"];
 348                                 if (o == null)
 349                                         o = ViewState ["Text"];
 350                                 if(o != null) return (string)o;
 351                                 return String.Empty;
 352                         }
 353                         set {
 354                                 ViewState ["Value"] = value;
 355                         }
 356                 }
 357
 358                 [DefaultValue (false)]
 359                 public bool Selected {
 360                         get {
 361                                 return SelectedFlag;
 362                         }
 363                         set {
 364                                 SelectedFlag = value;
 365
 366                                 if (tree != null) {
 367                                         if (!value && tree.SelectedNode == this)
 368                                                 tree.SetSelectedNode (null, false);
 369                                         else if (value)
 370                                                 tree.SetSelectedNode (this, false);
 371                                 }
 372                         }
 373                 }
 374
 375                 internal virtual bool SelectedFlag {
 376                         get {
 377                                 object o = ViewState ["Selected"];
 378                                 if(o != null) return (bool)o;
 379                                 return false;
 380                         }
 381                         set {
 382                                 ViewState ["Selected"] = value;
 383                         }
 384                 }
 385
 386                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 387                 [Browsable (false)]
 388                 public TreeNode Parent {
 389                         get { return parent; }
 390                 }
 391
 392                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Hidden)]
 393                 [Browsable (false)]
 394                 public string ValuePath {
 395                         get {
 396                                 if (tree == null) return Value;
 397
 398                                 StringBuilder sb = new StringBuilder (Value);
 399                                 TreeNode node = parent;
 400                                 while (node != null) {
 401                                         sb.Insert (0, tree.PathSeparator);
 402                                         sb.Insert (0, node.Value);
 403                                         node = node.Parent;
 404                                 }
 405                                 return sb.ToString ();
 406                         }
 407                 }
 408
 409                 internal int Index {
 410                         get { return index; }
 411                         set { index = value; ResetPathData (); }
 412                 }
 413
 414                 internal void SetParent (TreeNode node) {
 415                         parent = node;
 416                         ResetPathData ();
 417                 }
 418
 419                 internal string Path {
 420                         get {
 421                                 if (path != null) return path;
 422                                 StringBuilder sb = new StringBuilder (index.ToString());
 423                                 TreeNode node = parent;
 424                                 while (node != null) {
 425                                         sb.Insert (0, '_');
 426                                         sb.Insert (0, node.Index.ToString ());
 427                                         node = node.Parent;
 428                                 }
 429                                 path = sb.ToString ();
 430                                 return path;
 431                         }
 432                 }
 433
 434                 internal bool Populated {
 435                         get {
 436                                 object o = ViewState ["Populated"];
 437                                 if (o != null) return (bool) o;
 438                                 return false;
 439                         }
 440                         set {
 441                                 ViewState ["Populated"] = value;
 442                         }
 443                 }
 444
 445                 internal bool HasChildData {
 446                         get { return nodes != null; }
 447                 }
 448
 449                 internal void Populate ()
 450                 {
 451                         if (tree == null)
 452                                 return;
 453
 454                         Populated = true;
 455                         tree.NotifyPopulateRequired (this);
 456                 }
 457
 458                 public void Collapse ()
 459                 {
 460                         Expanded = false;
 461                 }
 462
 463                 public void CollapseAll ()
 464                 {
 465                         SetExpandedRec (false, -1);
 466                 }
 467
 468                 public void Expand ()
 469                 {
 470                         Expanded = true;
 471                 }
 472
 473                 internal void Expand (int depth)
 474                 {
 475                         SetExpandedRec (true, depth);
 476                 }
 477
 478                 public void ExpandAll ()
 479                 {
 480                         SetExpandedRec (true, -1);
 481                 }
 482
 483                 void SetExpandedRec (bool expanded, int depth)
 484                 {
 485                         Expanded = expanded;
 486                         if (depth == 0) return;
 487
 488                         foreach (TreeNode nod in ChildNodes)
 489                                 nod.SetExpandedRec (expanded, depth - 1);
 490                 }
 491
 492                 public void Select ()
 493                 {
 494                         Selected = true;
 495                 }
 496
 497                 public void ToggleExpandState ()
 498                 {
 499 #if TARGET_JVM //No support for Nullable<bool>.GetValueOrDefault() yet
 500                         bool? value = Expanded;
 501                         Expanded = value.HasValue ? !value.Value : true;
 502 #else
 503                         Expanded = !Expanded.GetValueOrDefault(false);
 504 #endif
 505                 }
 506
 507                 void IStateManager.LoadViewState (object savedState)
 508                 {
 509                         LoadViewState (savedState);
 510                 }
 511
 512                 protected virtual void LoadViewState (object savedState)
 513                 {
 514                         if (savedState == null)
 515                                 return;
 516
 517                         object[] states = (object[]) savedState;
 518                         ViewState.LoadViewState (states [0]);
 519
 520                         if (tree != null && SelectedFlag)
 521                                 tree.SetSelectedNode (this, true);
 522
 523                         if (!PopulateOnDemand || Populated)
 524                                 ((IStateManager)ChildNodes).LoadViewState (states [1]);
 525                 }
 526
 527                 object IStateManager.SaveViewState ()
 528                 {
 529                         return SaveViewState ();
 530                 }
 531
 532                 protected virtual object SaveViewState ()
 533                 {
 534                         object[] states = new object[2];
 535                         states[0] = ViewState.SaveViewState();
 536                         states[1] = (nodes == null ? null : ((IStateManager)nodes).SaveViewState());
 537
 538                         for (int i = 0; i < states.Length; i++) {
 539                                 if (states [i] != null)
 540                                         return states;
 541                         }
 542                         return null;
 543                 }
 544
 545                 void IStateManager.TrackViewState ()
 546                 {
 547                         TrackViewState ();
 548                 }
 549
 550                 protected void TrackViewState ()
 551                 {
 552                         if (marked) return;
 553                         marked = true;
 554                         ViewState.TrackViewState();
 555
 556                         if (nodes != null)
 557                                 ((IStateManager)nodes).TrackViewState ();
 558                 }
 559
 560                 bool IStateManager.IsTrackingViewState {
 561                         get { return IsTrackingViewState; }
 562                 }
 563
 564                 protected bool IsTrackingViewState
 565                 {
 566                         get { return marked; }
 567                 }
 568
 569                 internal void SetDirty ()
 570                 {
 571                         ViewState.SetDirty (true);
 572                         if (nodes != null)
 573                                 nodes.SetDirty ();
 574                 }
 575
 576                 public virtual object Clone ()
 577                 {
 578                         TreeNode nod = tree != null ? tree.CreateNode () : new TreeNode ();
 579                         foreach (DictionaryEntry e in ViewState)
 580                                 nod.ViewState [(string)e.Key] = ((StateItem)e.Value).Value;
 581
 582                         foreach (TreeNode c in ChildNodes)
 583                                 nod.ChildNodes.Add ((TreeNode)c.Clone ());
 584
 585                         return nod;
 586                 }
 587
 588                 object ICloneable.Clone () {
 589                         return Clone ();
 590                 }
 591
 592                 internal void Bind (IHierarchyData hierarchyData)
 593                 {
 594                         this.hierarchyData = hierarchyData;
 595                         DataBound = true;
 596                         DataPath = hierarchyData.Path;
 597                         dataItem = hierarchyData.Item;
 598
 599                         TreeNodeBinding bin = GetBinding ();
 600                         if (bin != null) {
 601
 602                                 // Bind ImageToolTip property
 603
 604                                 if (bin.ImageToolTipField.Length > 0) {
 605                                         ImageToolTip = Convert.ToString (GetBoundPropertyValue (bin.ImageToolTipField));
 606                                         if (ImageToolTip.Length == 0)
 607                                                 ImageToolTip = bin.ImageToolTip;
 608                                 }
 609                                 else if (bin.ImageToolTip.Length > 0)
 610                                         ImageToolTip = bin.ImageToolTip;
 611
 612                                 // Bind ImageUrl property
 613
 614                                 if (bin.ImageUrlField.Length > 0) {
 615                                         ImageUrl = Convert.ToString (GetBoundPropertyValue (bin.ImageUrlField));
 616                                         if (ImageUrl.Length == 0)
 617                                                 ImageUrl = bin.ImageUrl;
 618                                 }
 619                                 else if (bin.ImageUrl.Length > 0)
 620                                         ImageUrl = bin.ImageUrl;
 621
 622                                 // Bind NavigateUrl property
 623
 624                                 if (bin.NavigateUrlField.Length > 0) {
 625                                         NavigateUrl = Convert.ToString (GetBoundPropertyValue (bin.NavigateUrlField));
 626                                         if (NavigateUrl.Length == 0)
 627                                                 NavigateUrl = bin.NavigateUrl;
 628                                 }
 629                                 else if (bin.NavigateUrl.Length > 0)
 630                                         NavigateUrl = bin.NavigateUrl;
 631
 632                                 // Bind PopulateOnDemand property
 633
 634                                 if (bin.HasPropertyValue ("PopulateOnDemand"))
 635                                         PopulateOnDemand = bin.PopulateOnDemand;
 636
 637                                 // Bind SelectAction property
 638
 639                                 if (bin.HasPropertyValue ("SelectAction"))
 640                                         SelectAction = bin.SelectAction;
 641
 642                                 // Bind ShowCheckBox property
 643
 644                                 if (bin.HasPropertyValue ("ShowCheckBox"))
 645                                         ShowCheckBox = bin.ShowCheckBox;
 646
 647                                 // Bind Target property
 648
 649                                 if (bin.TargetField.Length > 0) {
 650                                         Target = Convert.ToString (GetBoundPropertyValue (bin.TargetField));
 651                                         if (Target.Length == 0)
 652                                                 Target = bin.Target;
 653                                 }
 654                                 else if (bin.Target.Length > 0)
 655                                         Target = bin.Target;
 656
 657                                 // Bind Text property
 658                                 string text = null;
 659                                 if (bin.TextField.Length > 0) {
 660                                         text = Convert.ToString (GetBoundPropertyValue (bin.TextField));
 661                                         if (bin.FormatString.Length > 0)
 662                                                 text = string.Format (bin.FormatString, text);
 663                                 }
 664                                 if (String.IsNullOrEmpty (text)) {
 665                                         if (bin.Text.Length > 0)
 666                                                 text = bin.Text;
 667                                         else if (bin.Value.Length > 0)
 668                                                 text = bin.Value;
 669                                 }
 670                                 if (!String.IsNullOrEmpty (text))
 671                                         Text = text;
 672
 673                                 // Bind ToolTip property
 674
 675                                 if (bin.ToolTipField.Length > 0) {
 676                                         ToolTip = Convert.ToString (GetBoundPropertyValue (bin.ToolTipField));
 677                                         if (ToolTip.Length == 0)
 678                                                 ToolTip = bin.ToolTip;
 679                                 }
 680                                 else if (bin.ToolTip.Length > 0)
 681                                         ToolTip = bin.ToolTip;
 682
 683                                 // Bind Value property
 684                                 string value = null;
 685                                 if (bin.ValueField.Length > 0) {
 686                                         value = Convert.ToString (GetBoundPropertyValue (bin.ValueField));
 687                                 }
 688                                 if (String.IsNullOrEmpty (value)) {
 689                                         if (bin.Value.Length > 0)
 690                                                 value = bin.Value;
 691                                         else if (bin.Text.Length > 0)
 692                                                 value = bin.Text;
 693                                 }
 694                                 if (!String.IsNullOrEmpty (value))
 695                                         Value = value;
 696                         }
 697                         else {
 698                                 Text = Value = GetDefaultBoundText ();
 699                         }
 700
 701                         INavigateUIData navigateUIData = hierarchyData as INavigateUIData;
 702                         if (navigateUIData != null) {
 703                                 SelectAction = TreeNodeSelectAction.None;
 704                                 Text = navigateUIData.ToString ();
 705                                 NavigateUrl = navigateUIData.NavigateUrl;
 706                                 ToolTip = navigateUIData.Description;
 707                         }
 708                 }
 709
 710                 internal void SetDataItem (object item)
 711                 {
 712                         dataItem = item;
 713                 }
 714
 715                 internal void SetDataPath (string path)
 716                 {
 717                         DataPath = path;
 718                 }
 719
 720                 internal void SetDataBound (bool bound)
 721                 {
 722                         DataBound = bound;
 723                 }
 724
 725                 string GetDefaultBoundText ()
 726                 {
 727                         if (hierarchyData != null) return hierarchyData.ToString ();
 728                         else if (dataItem != null) return dataItem.ToString ();
 729                         else return string.Empty;
 730                 }
 731
 732                 string GetDataItemType ()
 733                 {
 734                         if (hierarchyData != null) return hierarchyData.Type;
 735                         else if (dataItem != null) return dataItem.GetType().ToString ();
 736                         else return string.Empty;
 737                 }
 738
 739                 internal bool IsParentNode {
 740                         get { return ChildNodes.Count > 0 || (PopulateOnDemand && !Populated); }
 741                 }
 742
 743                 internal bool IsLeafNode {
 744                         get { return !IsParentNode; }
 745                 }
 746
 747                 internal bool IsRootNode {
 748                         get { return Depth == 0; }
 749                 }
 750
 751                 TreeNodeBinding GetBinding ()
 752                 {
 753                         if (tree == null) return null;
 754                         if (gotBinding) return binding;
 755                         binding = tree.FindBindingForNode (GetDataItemType (), Depth);
 756                         gotBinding = true;
 757                         return binding;
 758                 }
 759
 760                 object GetBoundPropertyValue (string name)
 761                 {
 762                         if (boundProperties == null) {
 763                                 if (hierarchyData != null)
 764                                         boundProperties = TypeDescriptor.GetProperties (hierarchyData);
 765                                 else
 766                                         boundProperties = TypeDescriptor.GetProperties (dataItem);
 767                         }
 768
 769                         PropertyDescriptor prop = boundProperties.Find (name, true);
 770                         if (prop == null)
 771                                 throw new InvalidOperationException ("Property '" + name + "' not found in data bound item");
 772
 773                         if (hierarchyData != null)
 774                                 return prop.GetValue (hierarchyData);
 775                         else
 776                                 return prop.GetValue (dataItem);
 777                 }
 778
 779                 internal void BeginRenderText (HtmlTextWriter writer)
 780                 {
 781                         RenderPreText (writer);
 782                 }
 783
 784                 internal void EndRenderText (HtmlTextWriter writer)
 785                 {
 786                         RenderPostText (writer);
 787                 }
 788
 789                 protected virtual void RenderPreText (HtmlTextWriter writer)
 790                 {
 791                 }
 792
 793                 protected virtual void RenderPostText (HtmlTextWriter writer)
 794                 {
 795                 }
 796         }
 797 }
 798
 799 #endif