carfield.com.hk

Button.java

2004-03-24T16:00:00Z

Label.java

2004-03-24T16:00:00Z

Main.java

2004-03-24T16:00:00Z

package examples.mediator.aspectj;

/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This file is part of the design patterns project at UBC
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * either http://www.mozilla.org/MPL/ or http://aspectj.org/MPL/.
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is ca.ubc.cs.spl.patterns.
 *
 * Contributor(s): 
 */
 
import javax.swing.*;
import java.awt.event.*;

/**
 * Implements the driver for the mediator design pattern example. 
 *
 * Intent: Define an object that encapsulates how a set of objects
 * interact. Mediator promotes loose coupling by keeping objects from 
 * referring to each other explicitly, and it lets you vary their interaction
 * independently.
 *
 * Participatng objects are <code>Button</code>s as Colleagues,
 * and a <code>Label</code> as Mediator.
 *
 * Every time an event of interest (a button click) occurs, the mediating
 * <code>Label</code> is updated and it updates the calling button.
 *
 * This is the AspectJ version.
 *
 * @author Jan Hannemann
 * @author Gregor Kiczales
 * @version 1.0, 05/13/02
 * 
 * @see Button
 * @see Label
 */
 
public class Main {

 
 static JFrame frame = new JFrame("Mediator Demo"); 
 static Button button1 = new Button("Button1");
 static Button button2 = new Button("Button2");
 static Label label = new Label ("Click a button!");

 /**
 * Implements the driver for the mediator example. It creates a small
 * GUI with a label and two buttons. The buttons are Colleagues,
 * the label is the Mediator. 
 *
 * Each button click causes the mediator to update itself and the
 * calling button.
 */ 
 
	public static void main(String[] args) {;

	 
		frame.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {System.exit(0);}
		});
		 
		JPanel panel = new JPanel();
	
		panel.add(label);
		panel.add(button1);
		panel.add(button2); 
		
		frame.getContentPane().add(panel);
		frame.pack();
		frame.setVisible(true); 
		
	 MediatorImplementation.aspectOf().setMediator(button1, label); 
	 MediatorImplementation.aspectOf().setMediator(button2, label); 
	}
}

MediatorImplementation.java

2004-03-24T16:00:00Z

package examples.mediator.aspectj;


/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This file is part of the design patterns project at UBC
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * either http://www.mozilla.org/MPL/ or http://aspectj.org/MPL/.
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is ca.ubc.cs.spl.patterns.
 *
 * Contributor(s): 
 */ 
 
import ca.ubc.cs.spl.pattern.library.MediatorProtocol;

/**
 * Concretizes the mediation relationship for <code>Button</code> (colleague) 
 * and <code>Label</code> (mediator). button clicks trigger updates. 
 *
 * @author Jan Hannemann
 * @author Gregor Kiczales
 * @version 1.0, 05/13/02
 */

public aspect MediatorImplementation extends MediatorProtocol {

 /**
 * Assings the <code>Colleague</code> role to the <code>Button</code> 
 * class. Roles are modeled as (empty) interfaces.
 */
 
	declare parents: Button implements Colleague;

 /**
 * Assings the <code>Colleague</code> role to the <code>Label</code> 
 * class. Roles are modeled as (empty) interfaces.
 */

	declare parents: Label	implements Mediator;

 /**
 * Defines what changes on Colleagues cause their mediator to be notified
 * (here: Button clicks)
 *
 * @param cs the colleague on which the change occured
 */

	protected pointcut change(Colleague c): 
	 (call(void Button.clicked()) && target(c));

 /**
 * Defines how the <code>Mediator</code> is to be updated when a change
 * to a <code>Colleague</code> occurs. Here, the label's text is set 
 * depending on which button was clicked. The appropriate button's label 
 * is also updated.
 *
 * @param c the colleague on which a change of interest occured
 * @param m the mediator to be notifed of the change 
 */

	protected void notifyMediator(Colleague c, Mediator m) {
		Button button = (Button) c;
		Label label = (Label) m; 
		if (button == Main.button1) {
			label.setText("Button1 clicked"); 
		} else if (button == Main.button2) {
			label.setText("Button2 clicked");
		}
		button.setText("(Done)");
	}

}

files.lst

2004-03-24T16:00:00Z