class/System/System.ComponentModel.Design.Serialization/ContextStack.cs

   1 //
   2 // System.ComponentModel.Design.Serialization.ContextStack.cs
   3 //
   4 // Author:
   5 //   Alejandro Sánchez Acosta (raciel@gnome.org)
   6 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   7 //   Ivan N. Zlatev (contact@i-nz.net)
   8 //
   9 // (C) Alejandro Sánchez Acosta
  10 // (C) 2003 Andreas Nahr
  11 // (C) 2007 Ivan N. Zlatev
  12 //
  13
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34
  35 using System;
  36 using System.Collections;
  37
  38 namespace System.ComponentModel.Design.Serialization
  39 {
  40         public sealed class ContextStack
  41         {
  42                 private ArrayList _contextList;
  43
  44                 public ContextStack ()
  45                 {
  46                         _contextList = new ArrayList ();
  47                 }
  48
  49                 public object Current {
  50                         get {
  51                                 int context_count = _contextList.Count;
  52                                 if (context_count > 0)
  53                                         return _contextList [context_count - 1];
  54                                 return null;
  55                         }
  56                 }
  57
  58                 public object this[Type type] {
  59                         get {
  60                                 if (type == null)
  61                                         throw new ArgumentNullException ("type");
  62                                 for (int i = _contextList.Count - 1; i >= 0; i--) {
  63                                         object context = _contextList [i];
  64                                         if (type.IsInstanceOfType (context))
  65                                                 return context;
  66                                 }
  67                                 return null;
  68                         }
  69                 }
  70
  71                 public object this[int level] {
  72                         get {
  73                                 if (level < 0)
  74                                         throw new ArgumentOutOfRangeException ("level");
  75                                 int context_count = _contextList.Count;
  76                                 if (context_count > 0 && context_count > level)
  77                                         return _contextList [context_count - 1 - level];
  78                                 return null;
  79                         }
  80                 }
  81
  82                 public object Pop ()
  83                 {
  84                         object o = null;
  85                         int context_count = _contextList.Count;
  86                         if (context_count > 0) {
  87                                 int lastItem = context_count - 1;
  88                                 o = _contextList [lastItem];
  89                                 _contextList.RemoveAt (lastItem);
  90                         }
  91                         return o;
  92                 }
  93
  94                 public void Push (object context)
  95                 {
  96                         if (context == null)
  97                                 throw new ArgumentNullException ("context");
  98                         _contextList.Add (context);
  99                 }
 100
 101 #if NET_2_0
 102                 public void Append (object context)
 103                 {
 104                         if (context == null)
 105                                 throw new ArgumentNullException ("context");
 106                         _contextList.Insert (0, context);
 107                 }
 108 #endif
 109         }
 110 }
 111