2 // System.MultiCastDelegate.cs
5 // Miguel de Icaza (miguel@ximian.com)
6 // Daniel Stodden (stodden@in.tum.de)
8 // (C) Ximian, Inc. http://www.ximian.com
12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
14 // Permission is hereby granted, free of charge, to any person obtaining
15 // a copy of this software and associated documentation files (the
16 // "Software"), to deal in the Software without restriction, including
17 // without limitation the rights to use, copy, modify, merge, publish,
18 // distribute, sublicense, and/or sell copies of the Software, and to
19 // permit persons to whom the Software is furnished to do so, subject to
20 // the following conditions:
22 // The above copyright notice and this permission notice shall be
23 // included in all copies or substantial portions of the Software.
25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
34 using System.Collections;
35 using System.Runtime.Serialization;
39 [System.Runtime.InteropServices.ComVisible (true)]
41 public abstract class MulticastDelegate : Delegate
43 private MulticastDelegate prev;
44 private MulticastDelegate kpm_next;
46 protected MulticastDelegate (object target, string method)
47 : base (target, method)
52 protected MulticastDelegate (Type target, string method)
53 : base (target, method)
58 public override void GetObjectData (SerializationInfo info, StreamingContext context)
60 base.GetObjectData (info, context);
64 protected sealed override object DynamicInvokeImpl (object[] args)
67 prev.DynamicInvokeImpl (args);
69 return base.DynamicInvokeImpl (args);
72 internal bool HasSingleTarget {
73 get { return prev == null; }
76 // Equals: two multicast delegates are equal if their base is equal
77 // and their invocations list is equal.
79 public sealed override bool Equals (object obj)
81 if (!base.Equals (obj))
84 MulticastDelegate d = obj as MulticastDelegate;
88 if (this.prev == null) {
95 return this.prev.Equals (d.prev);
99 // FIXME: This could use some improvements.
101 public sealed override int GetHashCode ()
103 return base.GetHashCode ();
107 // Return, in order of invocation, the invocation list
108 // of a MulticastDelegate
110 public sealed override Delegate[] GetInvocationList ()
113 d = (MulticastDelegate) this.Clone ();
114 for (d.kpm_next = null; d.prev != null; d = d.prev)
117 if (d.kpm_next == null) {
118 MulticastDelegate other = (MulticastDelegate) d.Clone ();
120 other.kpm_next = null;
121 return new Delegate [1] { other };
124 ArrayList list = new ArrayList ();
125 for (; d != null; d = d.kpm_next) {
126 MulticastDelegate other = (MulticastDelegate) d.Clone ();
128 other.kpm_next = null;
132 return (Delegate []) list.ToArray (typeof (Delegate));
136 // Combines this MulticastDelegate with the (Multicast)Delegate `follow'.
137 // This does _not_ combine with Delegates. ECMA states the whole delegate
138 // thing should have better been a simple System.Delegate class.
139 // Compiler generated delegates are always MulticastDelegates.
141 protected sealed override Delegate CombineImpl (Delegate follow)
143 MulticastDelegate combined, orig, clone;
145 if (this.GetType() != follow.GetType ())
146 throw new ArgumentException (Locale.GetText ("Incompatible Delegate Types."));
148 combined = (MulticastDelegate)follow.Clone ();
149 combined.SetMulticastInvoke ();
151 for (clone = combined, orig = ((MulticastDelegate)follow).prev; orig != null; orig = orig.prev) {
153 clone.prev = (MulticastDelegate)orig.Clone ();
157 clone.prev = (MulticastDelegate)this.Clone ();
159 for (clone = clone.prev, orig = this.prev; orig != null; orig = orig.prev) {
161 clone.prev = (MulticastDelegate)orig.Clone ();
168 private bool BaseEquals (MulticastDelegate value)
170 return base.Equals (value);
174 * Perform a slightly crippled version of
175 * Knuth-Pratt-Morris over MulticastDelegate chains.
176 * Border values are set as pointers in kpm_next;
177 * Generally, KPM border arrays are length n+1 for
178 * strings of n. This one works with length n at the
179 * expense of a few additional comparisions.
181 private static MulticastDelegate KPM (MulticastDelegate needle, MulticastDelegate haystack,
182 out MulticastDelegate tail)
184 MulticastDelegate nx, hx;
188 nx = needle.kpm_next = null;
190 while ((nx != null) && (!nx.BaseEquals (hx)))
197 nx = nx == null ? needle : nx.prev;
198 if (hx.BaseEquals (nx))
199 hx.kpm_next = nx.kpm_next;
206 MulticastDelegate match = haystack;
210 while (nx != null && !nx.BaseEquals (hx)) {
215 nx = nx == null ? needle : nx.prev;
223 } while (hx != null);
229 protected sealed override Delegate RemoveImpl (Delegate value)
234 // match this with value
235 MulticastDelegate head, tail;
236 head = KPM ((MulticastDelegate)value, this, out tail);
240 // duplicate chain without head..tail
241 MulticastDelegate prev = null, retval = null, orig;
242 for (orig = this; (object)orig != (object)head; orig = orig.prev) {
243 MulticastDelegate clone = (MulticastDelegate)orig.Clone ();
250 for (orig = tail; (object)orig != null; orig = orig.prev) {
251 MulticastDelegate clone = (MulticastDelegate)orig.Clone ();
264 public static bool operator == (MulticastDelegate d1, MulticastDelegate d2)
269 return d1.Equals (d2);
272 public static bool operator != (MulticastDelegate d1, MulticastDelegate d2)
277 return !d1.Equals (d2);