import java.applet.*;
import java.awt.*;

public class BounceGIF extends Applet implements Runnable {
  int x = 100, y = 0, dx = 10, dy = 10, maxx, maxy, sizex, sizey;
  int interval;
  String imagefile;
  Image img;
  Thread th;
  int Nbounce;
  double accele = 0.8;
  double speed  = 0;
  double refrec = 0.8;

  public void init() {
    String param;

    param = getParameter("interval");
    interval = (param != null) ? new Integer(param).intValue() : 50;

    param = getParameter("image");
    imagefile = (param != null) ? param : "asakawa.gif";

    param = getParameter("dx");
    dx = (param != null) ? new Integer(param).intValue() : 3;

    param = getParameter("dy");
    dy = (param != null) ? new Integer(param).intValue() : 10;

    param = getParameter("accele");
    accele = (param != null) ? Float.valueOf(param).floatValue() : 0.8;

    param = getParameter("refrec");
    refrec = (param != null) ? Float.valueOf(param).floatValue() : 0.8;

    img = getImage(getCodeBase(), imagefile);

    maxx = size().width;
    maxy = size().height;

    setBackground(Color.black);
  }

  public void start() {
    if (th == null) {
      resize(maxx, maxy);
      th = new Thread(this);
      th.start();
    }
  }

  public void stop() {
    if (th != null) {
      th.stop();
      th = null;
    }
  }

  public void paint(Graphics g) {
    sizex = img.getWidth(this);
    sizey = img.getHeight(this);
    g.drawImage(img, x, y, this);
  }

  /*
  public void update(Graphics g) {
    paint(g);
  }
  */

  public void run() {
    while (th != null) {
      //      if (Nbounce > 10) {
      if (Nbounce > 2) {
	//	th.stop();
	//	th = null;
	try {
	  Thread.sleep(3000);
	} catch(InterruptedException e) {
	  break;
	}
	speed = -15.0;
      }
      try {
	Thread.sleep(interval);  // sleep for interval msec
      } catch (InterruptedException e) {
	break;
      }

      speed += accele;
      y += (int)speed;
      if ( y > (maxy - sizey)) {
	y = (maxy - sizey);
	speed = speed * -refrec;
      }
      if ( y == (maxy - sizey)) {
	++Nbounce;
      } else {
	Nbounce = 0;
      }
      if (x <= 0 || x >= (maxx - sizex) ) dx = -dx;
      if ( y <= 0 ) y = 0;
      x += dx;  
      repaint();
    }
  }
}