Animacija

import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Color;

public class Animacija extends Applet {
  int xsize, ysize, iy = 0;

  class Ritam extends Thread {
    long pauza, kraj;

    Ritam(double frekv, double trajanje) {
      pauza = Math.round(1000.0 / frekv);
      kraj = Math.round(trajanje * frekv);
    } // Ritam

    public void run() {
      long brojac = 0;
      int korak = 1;

      while(brojac++ < kraj) {
        try {
          sleep(pauza); // pauza u milisekundama
        } catch (InterruptedException e) { }
        if(iy >= ysize) korak = -2;
        if(iy < 0) korak = 2;
        iy += korak;
        repaint();
      }
    } // run
  } // class Ritam

  public void init() {
    setBackground(Color.yellow);
    (new Ritam(50.0, 30.0)).start();
  } // init

  public void paint(Graphics g) {
    xsize = getWidth();
    ysize = getHeight();

    g.setColor(Color.red);
    g.drawLine(0, iy, xsize, ysize - iy);
    g.setColor(Color.blue);
    g.drawLine(0, ysize - iy, xsize, iy);
  } // paint

} // class Animacija