/**
 *
 */
package example10;

import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JApplet;

/**
 * @author pajensen
 *
 */
public class BouncingBall extends JApplet implements Runnable
{
    // Object variables
    double x, y;
    double xVelocity, yVelocity;

    public void init ()
    {
        x = 50;
        y = 0;
        xVelocity = 1;
        yVelocity = 0;

        // Begin a new thread of execution.

        Thread otherExecutionThread;
        otherExecutionThread = new Thread (this);
        otherExecutionThread.start();

        // At this point, the old thread is still running,
        //   but a new thread has started.

        System.out.println ("The old thread is still running.");
    }

    public void paint(Graphics g)
    {
        // Clear background

        g.setColor(Color.BLUE.darker());
        g.fillRect(0, 0, getWidth(), getHeight());

        // Draw a ball.

        g.setColor(Color.YELLOW);
        g.fillOval((int)x, (int)y, 40, 40);
        g.setColor(Color.GREEN);
        g.fillArc((int)x+20, (int)y+10, 10, 10, 45, 45);
    }

    public void run ()
    {
        System.out.println ("The other thread has started.");

        while(true)
        {
            try
            {
                Thread.sleep(20);  // Fifty times a second.
            }
            catch(Exception e) {}
            y = y + yVelocity;
            x = x + xVelocity;

            if (y > this.getHeight()-40)
                yVelocity = -(Math.abs(yVelocity));
            else
                yVelocity += 0.1;  // Fixed after class, used to be before the if statement

            if (x > this.getWidth()-40)
                xVelocity = -(Math.abs(xVelocity));

            if (x < 0)
                xVelocity = +(Math.abs(xVelocity));

            repaint();
        }


    }

}