mcs/class/System/System.ComponentModel/ReflectionEventDescriptor.cs

   1 //
   2 // System.ComponentModel.EventDescriptor.cs
   3 //
   4 // Authors:
   5 //  Lluis Sanchez Gual (lluis@ximian.com)
   6 //
   7 // (C) Novell, Inc. 2004
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System;
  32 using System.Runtime.InteropServices;
  33 using System.Collections;
  34 using System.Reflection;
  35
  36 namespace System.ComponentModel
  37 {
  38         internal class ReflectionEventDescriptor: EventDescriptor
  39         {
  40                 Hashtable handlers;
  41                 Type _eventType;
  42                 Type _componentType;
  43                 EventInfo _eventInfo;
  44
  45                 public ReflectionEventDescriptor (EventInfo eventInfo) : base (eventInfo.Name, (Attribute[]) eventInfo.GetCustomAttributes (true))
  46                 {
  47                         _eventInfo = eventInfo;
  48                         _componentType = eventInfo.DeclaringType;
  49                         _eventType = eventInfo.EventHandlerType;
  50                 }
  51
  52                 public ReflectionEventDescriptor (Type componentType, EventDescriptor oldEventDescriptor, Attribute[] attrs) : base (oldEventDescriptor, attrs)
  53                 {
  54                         _componentType = componentType;
  55                         _eventType = oldEventDescriptor.EventType;
  56                 }
  57
  58                 public ReflectionEventDescriptor (Type componentType, string name, Type type, Attribute[] attrs) : base (name, attrs)
  59                 {
  60                         _componentType = componentType;
  61                         _eventType = type;
  62                 }
  63
  64                 EventInfo GetEventInfo ()
  65                 {
  66                         if (_eventInfo == null) {
  67                                 _eventInfo = _componentType.GetEvent (Name);
  68                                 if (_eventInfo == null)
  69                                         throw new ArgumentException ("Accessor methods for the " + Name + " event are missing");
  70                         }
  71                         return _eventInfo;
  72                 }
  73
  74                 public override void AddEventHandler (object component, System.Delegate value)
  75                 {
  76                         if (handlers == null)
  77                                 handlers = new Hashtable ();
  78
  79                         ArrayList delegates = (ArrayList) handlers [component];
  80                         if (delegates == null) {
  81                                 delegates = new ArrayList ();
  82                                 handlers [component] = delegates;
  83                         }
  84
  85                         if (!delegates.Contains (value))
  86                                 delegates.Add (value);
  87                 }
  88
  89                 public override void RemoveEventHandler (object component, System.Delegate value)
  90                 {
  91                         if (handlers == null) return;
  92
  93                         ArrayList delegates = (ArrayList) handlers [component];
  94                         if (delegates == null) return;
  95
  96                         delegates.Remove (value);
  97                 }
  98
  99                 public override System.Type ComponentType
 100                 {
 101                         get { return _componentType; }
 102                 }
 103
 104                 public override System.Type EventType
 105                 {
 106                         get { return _eventType; }
 107                 }
 108
 109                 public override bool IsMulticast
 110                 {
 111                         get { return GetEventInfo().IsMulticast; }
 112                 }
 113         }
 114 }