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 using System.Runtime.Remoting.Activation;
  11 using System.Collections;
  12
  13 namespace System.Runtime.Remoting.Contexts {
  14
  15         [AttributeUsage (AttributeTargets.Class)]
  16         [Serializable]
  17         public class ContextAttribute : Attribute, IContextAttribute, IContextProperty {
  18                 protected string AttributeName;
  19
  20                 public virtual string Name {
  21                         get {
  22                                 return AttributeName;
  23                         }
  24                 }
  25
  26                 public override bool Equals (object o)
  27                 {
  28                         if (o == null)
  29                                 return false;
  30
  31                         if (!(o is ContextAttribute))
  32                                 return false;
  33
  34                         ContextAttribute ca = (ContextAttribute) o;
  35
  36                         if (ca.AttributeName != AttributeName)
  37                                 return false;
  38
  39                         return true;
  40                 }
  41
  42                 public virtual void Freeze (Context ctx)
  43                 {
  44                 }
  45
  46                 public override int GetHashCode ()
  47                 {
  48                         if (AttributeName == null)
  49                                 return 0;
  50
  51                         return AttributeName.GetHashCode ();
  52                 }
  53
  54                 /// <summary>
  55                 ///    Adds the current context property to the IConstructionCallMessage
  56                 /// </summary>
  57                 public virtual void GetPropertiesForNewContext (IConstructionCallMessage msg)
  58                 {
  59                         if (msg == null)
  60                                 throw new ArgumentNullException ("IConstructionCallMessage");
  61
  62                         IList list = msg.ContextProperties;
  63
  64                         list.Add (this);
  65                 }
  66
  67                 // <summary>
  68                 //   True whether the context arguments satisfies the requirements
  69                 //   of the current context.
  70                 // </summary>
  71                 public virtual bool IsContextOK (Context ctx, IConstructionCallMessage msg)
  72                 {
  73                         if (msg == null)
  74                                 throw new ArgumentNullException ("IConstructionCallMessage");
  75                         if (ctx == null)
  76                                 throw new ArgumentNullException ("Context");
  77
  78                         if (!msg.ActivationType.IsContextful)
  79                                 return true;
  80
  81                         IContextProperty p = ctx.GetProperty (AttributeName);
  82                         if (p == null)
  83                                 return false;
  84
  85                         if (this != p)
  86                                 return false;
  87
  88                         return true;
  89                 }
  90
  91                 public virtual bool IsNewContextOK (Context ctx)
  92                 {
  93                         return true;
  94                 }
  95         }
  96 }