mcs/class/System/System.Collections.Generic/LinkedListNode.cs

   1 //
   2 // System.Collections.Generic.LinkedListNode
   3 //
   4 // Author:
   5 //    David Waite
   6 //
   7 // (C) 2005 David Waite (mass@akuma.org)
   8 //
   9
  10 //
  11 // Copyright (C) 2005 David Waite
  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 #if NET_2_0
  34 using System;
  35 using System.Runtime.InteropServices;
  36
  37 namespace System.Collections.Generic
  38 {
  39         [ComVisible (false)]
  40         public sealed class LinkedListNode <T>
  41         {
  42                 T item;
  43                 LinkedList <T> container;
  44
  45                 internal LinkedListNode <T> forward, back;
  46
  47                 public LinkedListNode (T value)
  48                 {
  49                         item = value;
  50                 }
  51
  52                 internal LinkedListNode (LinkedList <T> list, T value)
  53                 {
  54                         container = list;
  55                         item = value;
  56                         this.back = this.forward = this;
  57                 }
  58
  59                 internal LinkedListNode (LinkedList <T> list, T value, LinkedListNode <T> previousNode, LinkedListNode <T> nextNode)
  60                 {
  61                         container = list;
  62                         item = value;
  63                         this.back = previousNode;
  64                         this.forward = nextNode;
  65                         previousNode.forward = this;
  66                         nextNode.back = this;
  67                 }
  68
  69                 internal void Detach ()
  70                 {
  71                         back.forward = forward;
  72                         forward.back = back;
  73
  74                         forward = back = null;
  75                         container = null;
  76                 }
  77
  78                 internal void SelfReference (LinkedList <T> list)
  79                 {
  80                         forward = this;
  81                         back = this;
  82                         container = list;
  83                 }
  84
  85                 internal void InsertBetween (LinkedListNode <T> previousNode, LinkedListNode <T> nextNode, LinkedList <T> list)
  86                 {
  87                         previousNode.forward = this;
  88                         nextNode.back = this;
  89                         this.forward = nextNode;
  90                         this.back = previousNode;
  91                         this.container = list;
  92                 }
  93
  94                 public LinkedList <T> List {
  95                         get { return container; }
  96                 }
  97
  98                 public LinkedListNode <T> Next {
  99                         get { return (container != null && forward != container.first) ? forward : null; }
 100                 }
 101
 102                 public LinkedListNode <T> Previous {
 103                         get { return (container != null && this != container.first) ? back : null ; }
 104                 }
 105
 106                 public T Value {
 107                         get { return item; }
 108                         set { item = value; }
 109                 }
 110         }
 111 }
 112 #endif