mcs/class/corlib/System.Runtime.Remoting.Contexts/ContextAttribute.cs

   1 //
   2 // System.Runtime.Remoting.Contexts.ContextAttribute..cs
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) Ximian, Inc.  http://www.ximian.com
   8 //
   9
  10 //
  11 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  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.Runtime.Remoting.Activation;
  34 using System.Collections;
  35
  36 namespace System.Runtime.Remoting.Contexts {
  37
  38         [AttributeUsage (AttributeTargets.Class)]
  39         [Serializable]
  40         public class ContextAttribute : Attribute, IContextAttribute, IContextProperty {
  41                 protected string AttributeName;
  42
  43                 public ContextAttribute (string name)
  44                 {
  45                         AttributeName = name;
  46                 }
  47
  48                 public virtual string Name {
  49                         get {
  50                                 return AttributeName;
  51                         }
  52                 }
  53
  54                 public override bool Equals (object o)
  55                 {
  56                         if (o == null)
  57                                 return false;
  58
  59                         if (!(o is ContextAttribute))
  60                                 return false;
  61
  62                         ContextAttribute ca = (ContextAttribute) o;
  63
  64                         if (ca.AttributeName != AttributeName)
  65                                 return false;
  66
  67                         return true;
  68                 }
  69
  70                 public virtual void Freeze (Context ctx)
  71                 {
  72                 }
  73
  74                 public override int GetHashCode ()
  75                 {
  76                         if (AttributeName == null)
  77                                 return 0;
  78
  79                         return AttributeName.GetHashCode ();
  80                 }
  81
  82                 /// <summary>
  83                 ///    Adds the current context property to the IConstructionCallMessage
  84                 /// </summary>
  85                 public virtual void GetPropertiesForNewContext (IConstructionCallMessage msg)
  86                 {
  87                         if (msg == null)
  88                                 throw new ArgumentNullException ("IConstructionCallMessage");
  89
  90                         IList list = msg.ContextProperties;
  91
  92                         list.Add (this);
  93                 }
  94
  95                 // <summary>
  96                 //   True whether the context arguments satisfies the requirements
  97                 //   of the current context.
  98                 // </summary>
  99                 public virtual bool IsContextOK (Context ctx, IConstructionCallMessage msg)
 100                 {
 101                         if (msg == null)
 102                                 throw new ArgumentNullException ("IConstructionCallMessage");
 103                         if (ctx == null)
 104                                 throw new ArgumentNullException ("Context");
 105
 106                         if (!msg.ActivationType.IsContextful)
 107                                 return true;
 108
 109                         IContextProperty p = ctx.GetProperty (AttributeName);
 110                         if (p == null)
 111                                 return false;
 112
 113                         if (this != p)
 114                                 return false;
 115
 116                         return true;
 117                 }
 118
 119                 public virtual bool IsNewContextOK (Context ctx)
 120                 {
 121                         return true;
 122                 }
 123         }
 124 }