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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;
39  import java.lang.reflect.Method;
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 {
49  
50      private String listenerMethodName;
51      private Closure closure;
52  
53      public ClosureListener(String listenerMethodName, Closure closure) {
54          this.listenerMethodName = listenerMethodName;
55          this.closure = closure;
56      }
57  
58      public Object invoke(Object object, Method method, Object[] arguments) throws Throwable {
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 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(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 that) {
92          return this == that;
93      }
94  
95  }