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    1   /*
    2    * $Id: ClosureListener.java,v 1.2 2005/04/12 16:38:42 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: 1.2 $
    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  }