mcs/class/Managed.Windows.Forms/System.Windows.Forms/OpenTreeNodeEnumerator.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) 2004 Novell, Inc.
  21 //
  22 // Authors:
  23 //      Jackson Harper (jackson@ximian.com)
  24
  25
  26 using System;
  27 using System.Collections;
  28
  29 namespace System.Windows.Forms {
  30
  31         internal class OpenTreeNodeEnumerator : IEnumerator {
  32
  33                 private TreeNode start;
  34                 private TreeNode current;
  35                 private bool started;
  36
  37                 public OpenTreeNodeEnumerator (TreeNode start)
  38                 {
  39                         this.start = start;
  40                 }
  41
  42                 public object Current {
  43                         get { return current; }
  44                 }
  45
  46                 public TreeNode CurrentNode {
  47                         get { return current; }
  48                 }
  49
  50                 public bool MoveNext ()
  51                 {
  52                         if (!started) {
  53                                 started = true;
  54                                 current = start;
  55                                 return (current != null);
  56                         }
  57
  58                         if (current.IsExpanded && current.Nodes.Count > 0) {
  59                                 current = current.Nodes [0];
  60                                 return true;
  61                         }
  62
  63                         TreeNode prev = current;
  64                         TreeNode next = current.NextNode;
  65                         while (next == null) {
  66                                 // The next node is null so we need to move back up the tree until we hit the top
  67                                 if (prev.parent == null)
  68                                         return false;
  69                                 prev = prev.parent;
  70                                 if (prev.parent != null)
  71                                         next = prev.NextNode;
  72                         }
  73                         current = next;
  74                         return true;
  75                 }
  76
  77                 public bool MovePrevious ()
  78                 {
  79                         if (!started) {
  80                                 started = true;
  81                                 current = start;
  82                                 return (current != null);
  83                         }
  84
  85                         if (current.PrevNode != null) {
  86                                 current = current.PrevNode;
  87                                 return true;
  88                         }
  89
  90                         if (current.parent == null)
  91                                 return false;
  92
  93                         current = current.parent.LastNode;
  94                         return true;
  95                 }
  96
  97                 public void Reset ()
  98                 {
  99                         started = false;
 100                 }
 101         }
 102 }
 103