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

public class HelloWorld8 extends Applet implements Runnable {
  private int Width;
  private int Height;
  private String Str;
  private int StrLen;

  private Font f = new Font("Helvetica", Font.BOLD, 20);
  private FontMetrics fm;
  private Thread th;

  private int stp = 0;
  private double freq = 1.0;

  private boolean stpflg = false;

  public void init(){
    String param;

    param = getParameter("strings");
    Str = (param != null) ? param : new String("Hey! this is a test of .......");

    param = getParameter("freq");
    freq = (param != null) ? Double.valueOf(param).doubleValue() : 1.0;

    setBackground(new Color(255, 255, 255));
    setForeground(new Color(255, 0, 0));

    Width = size().width;
    Height = size().height;
    resize(Width, Height);
  }

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

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

  public void run() {
    while (true) {
      if (++stp > Str.length()) stp = 0;
      repaint();
      try {
	Thread.sleep(66);
      } catch (InterruptedException e){
      }
    }
  }

  public void paint(Graphics g){
    g.setFont(f);
    FontMetrics fm = g.getFontMetrics();
    int x = (Width - fm.stringWidth(Str))/2;
    int yo = Height/2;
    double tmp;
    int y;

    for (int i = 0; i < Str.length(); i++) {
      tmp = Math.sin( freq * (double)(i + stp) / (double)Str.length() * Math.PI * 2.0);
      y = yo + (int)(tmp * yo * 0.5);
      g.drawChars(Str.toCharArray(), i, 1, x, y);
      x += fm.charWidth(Str.toCharArray()[i]);
    }
  }

  public boolean mouseDown ( Event e, int x, int y ) {
    if ( stpflg ) {
      th.resume();
      stpflg = false;
    } else {
      th.suspend();
      stpflg = true;
    }
    return true;
  }
}