SimpleMouseInteraction

import acm.program.*;
import acm.graphics.*;
import java.awt.event.*;
 
public class SimpleMouseInteraction extends GraphicsProgram {
 
    private GRect rect = new GRect(72,72);
    // this is an instance variable
 
    public void run() {
        add(rect,144,144);
        addMouseListeners();
    }
 
    public void mouseClicked(MouseEvent e) {
        rect.move(15,15);
    }
 
    public static void main(String[] args) {
        String[] newArgs = new String[args.length + 1];
        System.arraycopy(args, 0, newArgs, 0, args.length);
        newArgs[args.length] = "code=" + new SecurityManager(){
            public String className() {
                return this.getClassContext()[1].getCanonicalName();
            }
        }.className();
        GraphicsProgram.main(newArgs);
    }
}