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