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 public abstract class MulticastDelegate : Delegate
41 private MulticastDelegate prev;
42 private MulticastDelegate kpm_next;
44 protected MulticastDelegate (object target, string method)
45 : base (target, method)
50 protected MulticastDelegate (Type target_type, string method)
51 : base (target_type, method)
56 public override void GetObjectData (SerializationInfo info, StreamingContext context)
58 base.GetObjectData (info, context);
62 protected sealed override object DynamicInvokeImpl (object[] args)
65 prev.DynamicInvokeImpl (args);
67 return base.DynamicInvokeImpl (args);
71 // Equals: two multicast delegates are equal if their base is equal
72 // and their invocations list is equal.
74 public sealed override bool Equals (object o)
79 MulticastDelegate d = (MulticastDelegate) o;
81 if (this.prev == null) {
88 return this.prev.Equals (d.prev);
92 // FIXME: This could use some improvements.
94 public sealed override int GetHashCode ()
96 return base.GetHashCode ();
100 // Return, in order of invocation, the invocation list
101 // of a MulticastDelegate
103 public sealed override Delegate[] GetInvocationList ()
106 d = (MulticastDelegate) this.Clone ();
107 for (d.kpm_next = null; d.prev != null; d = d.prev)
110 if (d.kpm_next == null) {
111 MulticastDelegate other = (MulticastDelegate) d.Clone ();
113 other.kpm_next = null;
114 return new Delegate [1] { other };
117 ArrayList list = new ArrayList ();
118 for (; d != null; d = d.kpm_next) {
119 MulticastDelegate other = (MulticastDelegate) d.Clone ();
121 other.kpm_next = null;
125 return (Delegate []) list.ToArray (typeof (Delegate));
129 // Combines this MulticastDelegate with the (Multicast)Delegate `follow'.
130 // This does _not_ combine with Delegates. ECMA states the whole delegate
131 // thing should have better been a simple System.Delegate class.
132 // Compiler generated delegates are always MulticastDelegates.
134 protected sealed override Delegate CombineImpl (Delegate follow)
136 MulticastDelegate combined, orig, clone;
138 if (this.GetType() != follow.GetType ())
139 throw new ArgumentException (Locale.GetText ("Incompatible Delegate Types."));
141 combined = (MulticastDelegate)follow.Clone ();
143 for (clone = combined, orig = ((MulticastDelegate)follow).prev; orig != null; orig = orig.prev) {
145 clone.prev = (MulticastDelegate)orig.Clone ();
149 clone.prev = (MulticastDelegate)this.Clone ();
151 for (clone = clone.prev, orig = this.prev; orig != null; orig = orig.prev) {
153 clone.prev = (MulticastDelegate)orig.Clone ();
160 private bool BaseEquals (MulticastDelegate value)
162 return base.Equals (value);
166 * Perform a slightly crippled version of
167 * Knuth-Pratt-Morris over MulticastDelegate chains.
168 * Border values are set as pointers in kpm_next;
169 * Generally, KPM border arrays are length n+1 for
170 * strings of n. This one works with length n at the
171 * expense of a few additional comparisions.
173 private static MulticastDelegate KPM (MulticastDelegate needle, MulticastDelegate haystack,
174 out MulticastDelegate tail)
176 MulticastDelegate nx, hx;
180 nx = needle.kpm_next = null;
182 while ((nx != null) && (!nx.BaseEquals (hx)))
189 nx = nx == null ? needle : nx.prev;
190 if (hx.BaseEquals (nx))
191 hx.kpm_next = nx.kpm_next;
198 MulticastDelegate match = haystack;
202 while (nx != null && !nx.BaseEquals (hx)) {
207 nx = nx == null ? needle : nx.prev;
215 } while (hx != null);
221 protected sealed override Delegate RemoveImpl (Delegate value)
226 // match this with value
227 MulticastDelegate head, tail;
228 head = KPM ((MulticastDelegate)value, this, out tail);
232 // duplicate chain without head..tail
233 MulticastDelegate prev = null, retval = null, orig;
234 for (orig = this; (object)orig != (object)head; orig = orig.prev) {
235 MulticastDelegate clone = (MulticastDelegate)orig.Clone ();
242 for (orig = tail; (object)orig != null; orig = orig.prev) {
243 MulticastDelegate clone = (MulticastDelegate)orig.Clone ();
256 public static bool operator == (MulticastDelegate a, MulticastDelegate b)
258 if ((object)a == null) {
259 if ((object)b == null)
266 public static bool operator != (MulticastDelegate a, MulticastDelegate b)