org.aspectj/docs/teaching/exercises/answers/Answer4c.java

/* *******************************************************************
 * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
 * All rights reserved. 
 * This program and the accompanying materials are made available 
 * under the terms of the Common Public License v1.0 
 * which accompanies this distribution and is available at 
 * http://www.eclipse.org/legal/cpl-v10.html 
 *  
 * Contributors: 
 *     PARC     initial implementation 
 * ******************************************************************/

package answers;

import figures.FigureElement;
import figures.Group;
import java.awt.Rectangle;

aspect Answer4c {
    private Rectangle Group.cache = null;

    Rectangle around(Group g):
            execution(Rectangle Group.getBounds()) && this(g) {
	if (g.cache == null) {
	    g.cache = proceed(g);
	}
	return g.cache;
    }

    before(Group g): call(void move(int, int)) && target(g) {
	g.cache = null;
    }
}