2 // System.Reflection/EventInfo.cs
5 // Paolo Molaro (lupus@ximian.com)
7 // (C) 2001 Ximian, Inc. http://www.ximian.com
8 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
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15 // permit persons to whom the Software is furnished to do so, subject to
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30 using System.Diagnostics;
31 using System.Runtime.InteropServices;
33 namespace System.Reflection {
36 [ComDefaultInterfaceAttribute (typeof (_EventInfo))]
38 [ClassInterface(ClassInterfaceType.None)]
39 [StructLayout (LayoutKind.Sequential)]
41 public abstract class EventInfo : MemberInfo {
43 public abstract class EventInfo : MemberInfo, _EventInfo {
45 AddEventAdapter cached_add_event;
47 public abstract EventAttributes Attributes {get;}
53 Type EventHandlerType {
56 MethodInfo add = GetAddMethod (true);
57 p = add.GetParametersInternal ();
59 Type t = p [0].ParameterType;
60 /* is it alwasys the first arg?
61 if (!t.IsSubclassOf (typeof (System.Delegate)))
62 throw new Exception ("no delegate in event");*/
74 bool IsMulticast {get {return true;}}
75 public bool IsSpecialName {get {return (Attributes & EventAttributes.SpecialName ) != 0;}}
76 public override MemberTypes MemberType {
77 get {return MemberTypes.Event;}
80 protected EventInfo() {
90 void AddEventHandler (object target, Delegate handler)
92 // this optimization cause problems with full AOT
93 // see bug https://bugzilla.xamarin.com/show_bug.cgi?id=3682
95 MethodInfo add = GetAddMethod ();
97 throw new InvalidOperationException ("Cannot add a handler to an event that doesn't have a visible add method");
98 if (target == null && !add.IsStatic)
99 throw new TargetException ("Cannot add a handler to a non static event with a null target");
100 add.Invoke (target, new object [] {handler});
102 if (cached_add_event == null) {
103 MethodInfo add = GetAddMethod ();
105 throw new InvalidOperationException ("Cannot add a handler to an event that doesn't have a visible add method");
106 if (add.DeclaringType.IsValueType) {
107 if (target == null && !add.IsStatic)
108 throw new TargetException ("Cannot add a handler to a non static event with a null target");
109 add.Invoke (target, new object [] {handler});
112 cached_add_event = CreateAddEventDelegate (add);
114 //if (target == null && is_instance)
115 // throw new TargetException ("Cannot add a handler to a non static event with a null target");
116 cached_add_event (target, handler);
120 public MethodInfo GetAddMethod() {
121 return GetAddMethod (false);
123 public abstract MethodInfo GetAddMethod(bool nonPublic);
124 public MethodInfo GetRaiseMethod() {
125 return GetRaiseMethod (false);
127 public abstract MethodInfo GetRaiseMethod( bool nonPublic);
128 public MethodInfo GetRemoveMethod() {
129 return GetRemoveMethod (false);
131 public abstract MethodInfo GetRemoveMethod( bool nonPublic);
133 public virtual MethodInfo[] GetOtherMethods (bool nonPublic) {
134 // implemented by the derived class
135 return EmptyArray<MethodInfo>.Value;
138 public MethodInfo[] GetOtherMethods () {
139 return GetOtherMethods (false);
143 [DebuggerStepThrough]
148 void RemoveEventHandler (object target, Delegate handler)
150 MethodInfo remove = GetRemoveMethod ();
152 throw new InvalidOperationException ("Cannot remove a handler to an event that doesn't have a visible remove method");
154 remove.Invoke (target, new object [] {handler});
158 public override bool Equals (object obj)
160 return obj == (object) this;
163 public override int GetHashCode ()
165 return base.GetHashCode ();
168 public static bool operator == (EventInfo left, EventInfo right)
170 if ((object)left == (object)right)
172 if ((object)left == null ^ (object)right == null)
174 return left.Equals (right);
177 public static bool operator != (EventInfo left, EventInfo right)
179 if ((object)left == (object)right)
181 if ((object)left == null ^ (object)right == null)
183 return !left.Equals (right);
188 void _EventInfo.GetIDsOfNames ([In] ref Guid riid, IntPtr rgszNames, uint cNames, uint lcid, IntPtr rgDispId)
190 throw new NotImplementedException ();
193 Type _EventInfo.GetType ()
195 // Required or object::GetType becomes virtual final
196 return base.GetType ();
199 void _EventInfo.GetTypeInfo (uint iTInfo, uint lcid, IntPtr ppTInfo)
201 throw new NotImplementedException ();
204 void _EventInfo.GetTypeInfoCount (out uint pcTInfo)
206 throw new NotImplementedException ();
209 void _EventInfo.Invoke (uint dispIdMember, [In] ref Guid riid, uint lcid, short wFlags, IntPtr pDispParams, IntPtr pVarResult, IntPtr pExcepInfo, IntPtr puArgErr)
211 throw new NotImplementedException ();
215 delegate void AddEventAdapter (object _this, Delegate dele);
217 // this optimization cause problems with full AOT
218 // see bug https://bugzilla.xamarin.com/show_bug.cgi?id=3682
219 // do not revove the above delegate or it's field since it's required by the runtime!
220 #if !FULL_AOT_RUNTIME
221 delegate void AddEvent<T, D> (T _this, D dele);
222 delegate void StaticAddEvent<D> (D dele);
224 #pragma warning disable 169
225 // Used via reflection
226 static void AddEventFrame<T,D> (AddEvent<T,D> addEvent, object obj, object dele)
229 throw new TargetException ("Cannot add a handler to a non static event with a null target");
231 throw new TargetException ("Object doesn't match target");
232 addEvent ((T)obj, (D)dele);
235 static void StaticAddEventAdapterFrame<D> (StaticAddEvent<D> addEvent, object obj, object dele)
239 #pragma warning restore 169
242 * The idea behing this optimization is to use a pair of delegates to simulate the same effect of doing a reflection call.
243 * The first delegate performs casting and boxing, the second dispatch to the add_... method.
245 static AddEventAdapter CreateAddEventDelegate (MethodInfo method)
249 object addHandlerDelegate;
250 MethodInfo adapterFrame;
251 Type addHandlerDelegateType;
254 if (method.IsStatic) {
255 typeVector = new Type[] { method.GetParametersInternal () [0].ParameterType };
256 addHandlerDelegateType = typeof (StaticAddEvent<>);
257 frameName = "StaticAddEventAdapterFrame";
259 typeVector = new Type[] { method.DeclaringType, method.GetParametersInternal () [0].ParameterType };
260 addHandlerDelegateType = typeof (AddEvent<,>);
261 frameName = "AddEventFrame";
264 addHandlerType = addHandlerDelegateType.MakeGenericType (typeVector);
266 // with Silverlight a coreclr failure (e.g. Transparent caller creating a delegate on a Critical method)
267 // would normally throw an ArgumentException, so we set throwOnBindFailure to false and check for a null
268 // delegate that we can transform into a MethodAccessException
269 addHandlerDelegate = Delegate.CreateDelegate (addHandlerType, method, false);
270 if (addHandlerDelegate == null)
271 throw new MethodAccessException ();
273 addHandlerDelegate = Delegate.CreateDelegate (addHandlerType, method);
275 adapterFrame = typeof (EventInfo).GetMethod (frameName, BindingFlags.Static | BindingFlags.NonPublic);
276 adapterFrame = adapterFrame.MakeGenericMethod (typeVector);
277 return (AddEventAdapter)Delegate.CreateDelegate (typeof (AddEventAdapter), addHandlerDelegate, adapterFrame, true);
282 public virtual MethodInfo AddMethod {
283 get { return GetAddMethod (true); }
285 public virtual MethodInfo RaiseMethod {
286 get { return GetRaiseMethod (true); }
288 public virtual MethodInfo RemoveMethod {
289 get { return GetRemoveMethod (true); }