//
//	general purpose reusable bouncing ball abstraction
//	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
//

import java.awt.*;

public class Ball {
    private Rectangle location;
    private double dx;
    private double dy;
    private Color color;
	
    public Ball (int x, int y, int r)
    {
	location = new Rectangle(x-r, y-r, 2*r, 2*r);
	dx = 0;
	dy = 0;
	color = Color.blue;
    }

    public Ball ()
    {
	location = new Rectangle(0, 0, 0, 0);
	dx = 0;
	dy = 0;
	color = Color.blue;
    }
	
    // functions that set attributes
    public void setColor (Color newColor)
    { color = newColor;	}


    public Color getColor () {
	return color;
    }

    public void setMotion (double ndx, double ndy)
    { dx = ndx; dy = ndy; }
	
    // functions that access attributes of ball
    public int radius ()
    { return location.width / 2; }
	
    public int x ()
    { return location.x + radius(); }
	
    public int y ()
    { return location.y + radius(); }
	
    public double xMotion ()
    { return dx; }

    public double yMotion ()
    { return dy; }

    public Rectangle region () { return location; }

    // functions that change attributes of ball
    public void moveTo (int x, int y)
    { location.setLocation(x, y); }

    public void move ()
    { location.translate ((int) dx, (int) dy); }
	
    public void paint (Graphics g)
    {
	g.setColor (color);
	g.fillOval (location.x, location.y, location.width, location.height);
    }
}