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Java > Open Source Codes > org > codehaus > groovy > runtime > ClosureListener


1 /*
2  * $Id: ClosureListener.java,v 1.1 2004/01/05 07:13:07 jstrachan Exp $
3  *
4  * Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
5  *
6  * Redistribution and use of this software and associated documentation
7  * ("Software"), with or without modification, are permitted provided that the
8  * following conditions are met: 1. Redistributions of source code must retain
9  * copyright statements and notices. Redistributions must also contain a copy
10  * of this document. 2. Redistributions in binary form must reproduce the above
11  * copyright notice, this list of conditions and the following disclaimer in
12  * the documentation and/or other materials provided with the distribution. 3.
13  * The name "groovy" must not be used to endorse or promote products derived
14  * from this Software without prior written permission of The Codehaus. For
15  * written permission, please contact info@codehaus.org. 4. Products derived
16  * from this Software may not be called "groovy" nor may "groovy" appear in
17  * their names without prior written permission of The Codehaus. "groovy" is a
18  * registered trademark of The Codehaus. 5. Due credit should be given to The
19  * Codehaus - http://groovy.codehaus.org/
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
22  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24  * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
25  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
27  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
28  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
31  * DAMAGE.
32  *
33  */
34 package org.codehaus.groovy.runtime;
35
36 import groovy.lang.Closure;
37
38 import java.lang.reflect.InvocationHandler JavaDoc;
39 import java.lang.reflect.Method JavaDoc;
40
41 /**
42  * Represents a method on an object using a closure which can be invoked at any
43  * time
44  *
45  * @author <a HREF="mailto:james@coredevelopers.net">James Strachan</a>
46  * @version $Revision: 1.1 $
47  */
48 public class ClosureListener implements InvocationHandler JavaDoc {
49
50     private String JavaDoc listenerMethodName;
51     private Closure closure;
52
53     public ClosureListener(String JavaDoc listenerMethodName, Closure closure) {
54         this.listenerMethodName = listenerMethodName;
55         this.closure = closure;
56     }
57
58     public Object JavaDoc invoke(Object JavaDoc object, Method JavaDoc method, Object JavaDoc[] arguments) throws Throwable JavaDoc {
59         if (listenerMethodName.equals(method.getName())) {
60             /** @todo hack! */
61             closure.call(arguments[0]);
62             return null;
63         }
64
65         // lets try call this object
66 String JavaDoc name = method.getName();
67         if (name.equals("equals")) {
68             return object == arguments[0] ? Boolean.TRUE : Boolean.FALSE;
69         }
70         else if (name.equals("hashCode")) {
71             return new Integer JavaDoc(hashCode());
72         }
73         else if (name.equals("toString")) {
74             return super.toString() + "[listener:" + listenerMethodName + "]";
75         }
76
77         /*
78          * int paramCount = method.getParameterTypes().length;
79          *
80          * System.out.println("Now calling method: " + method);
81          *
82          * Method[] methods = Object.class.getMethods(); for (int i = 0; i
83          * < methods.length; i++ ) { Method aMethod = methods[i]; if
84          * (name.equals(aMethod.getName()) &&
85          * aMethod.getParameterTypes().length == paramCount) { return
86          * aMethod.invoke(object, arguments); } }
87          */
88         return null;
89     }
90
91     public boolean equals(Object JavaDoc that) {
92         return this == that;
93     }
94
95 }
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