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

public class M extends Applet implements ActionListener {

  int raskus_a=0, raskus_b=0, vahe, vana_vahe, vahe_vahe, i;
  TextField tf_a = new TextField(10);
  TextField tf_b = new TextField(10);

  public void init() {
    setLayout(new BorderLayout());

    Panel p = new Panel(new BorderLayout());
      p.add(tf_a, BorderLayout.WEST);
      p.add(tf_b, BorderLayout.EAST);
    add(p, BorderLayout.SOUTH);

    tf_a.addActionListener(this);
    tf_b.addActionListener(this);
  }

  public void paint(Graphics g) {

    g.setColor(Color.white);
    g.fillRect(0,0,getSize().width,getSize().height);

    g.setColor(Color.black);
    joonistaSkaala(g, 10, 10, true);
    joonistaSkaala(g, 180, 10, false);
    g.drawLine(52,80+vahe,198,80-vahe);

    g.drawString(""+raskus_a, 50,150+vahe);
    g.drawString(""+raskus_b, 185,150-vahe);

    g.drawLine(55,  77+vahe, 55,  135+vahe);
    g.drawLine(195, 77-vahe, 195, 135-vahe);
  }

  public void joonistaSkaala(Graphics o, int a, int b, boolean ab) {

    int t;
    if(ab == true) { t = 0; } else { t = 55; }
    o.drawLine  (a+30,  b+0,   a+30,   b+120);
    o.drawLine  (a+20,  b+20,  a+40,   b+20);  // 50
    o.drawString("-50",        t+a-10, b+20);
    o.drawLine  (a+20,  b+45,  a+40,   b+45);  // 25
    o.drawString("-25",        t+a-10, b+45);
    o.drawLine  (a+20,  b+70,  a+40,   b+70);  // 0
    o.drawString("0",          t+a-10, b+70);
    o.drawLine  (a+20,  b+95,  a+40,   b+95);  // -25
    o.drawString("25",         t+a-10, b+95);
    o.drawLine  (a+20,  b+120, a+40,   b+120);  // -50
    o.drawString("50",         t+a-10, b+120);
  }

  public void arvutaKalle() {
    vana_vahe = vahe;
    vahe = raskus_a - raskus_b;
    if(vahe > 50) {
      vahe=50;
    }

    if(vahe < -50) {
      vahe=-50;
    }
  }

  public void actionPerformed(ActionEvent e) {

    raskus_a = Integer.parseInt(tf_a.getText().trim());
    raskus_b = Integer.parseInt(tf_b.getText().trim());

    arvutaKalle();
    Graphics g = getGraphics();

    vahe_vahe = vahe;

    i=0;

    if(vahe != vana_vahe) {
      while((i > vahe_vahe-vana_vahe) || (i < vahe_vahe-vana_vahe)) {

        try { Thread.sleep(50); } catch(Exception ex) {}
        vahe = vana_vahe+i;

        paint(g);

        if((vahe_vahe-vana_vahe) > 0) {
          i++;
        } else {
          i--;
        }
      }
    }
  }
}