//
//	the Ball World game
//	Described in Chapter 5 of
//	Understanding Object-Oriented Programming with Java
//	by Timothy A Budd
//	Published by Addison-Wesley
//
//	see ftp://ftp.cs.orst.edu/pub/budd/java/ReadMe.html
//	for further information
//
//      Two constructor variant (bp)
//
//        compare calling
//           
//          java TwoConsBallWorld 
//
//       to 
//
//          java TwoConsBallWorld default
//

import java.awt.*;


public class TwoConsBallWorld extends Frame {

    public static void main (String [ ] args)
    {
	TwoConsBallWorld world;
	
	if ((args.length > 0) && (args[0].equals("default")))
	    world = new TwoConsBallWorld();
	else world = new TwoConsBallWorld(Color.red);
	world.show ();
    }

    protected static final int FrameWidth = 600;
    protected static final int FrameHeight = 400;
    protected Ball aBall;
    protected int counter = 0;

    public TwoConsBallWorld (Color ballColor) {
	// constructor for new ball world
	// resize our frame
	setSize (FrameWidth, FrameHeight);
	setTitle ("Ball World");

	// initialize object data field
	aBall = new Ball (10, 15, 5);
	aBall.setColor (ballColor);
	aBall.setMotion (1.0, 2.0);
    }

    public TwoConsBallWorld () {
	// constructor for new ball world
	// resize our frame
	setSize (FrameWidth, FrameHeight);
	setTitle ("Ball World");

	// initialize object data field
	aBall = new Ball (10, 15, 5);
	aBall.setMotion (1.0, 2.0);
    }

    public void paint (Graphics g) {
	// first, draw the ball
	aBall.paint (g);
	// then move it slightly
	aBall.move();
	if ((aBall.x() < 0) || (aBall.x() > FrameWidth))
	    aBall.setMotion (-aBall.xMotion(), aBall.yMotion());
	if ((aBall.y() < 0) || (aBall.y() > FrameHeight))
	    aBall.setMotion (aBall.xMotion(), -aBall.yMotion());
				// finally, redraw the frame
	counter = counter + 1;
	if (counter < 2000) repaint(1);
	else System.exit(0);
    }
}