import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

/* <applet code="UpDownButton.class" width="200" height="70"> </applet> */

public class UpDownButton extends JApplet implements ActionListener {
  int x = 20;
  JButton lBtn, rBtn;

  @Override
  public void init() {
    lBtn = new JButton("Left");
    rBtn = new JButton("Right");
    lBtn.addActionListener(this);
    rBtn.addActionListener(this);
    setLayout(new FlowLayout());
    add(lBtn); add(rBtn);
  }

  @Override
  public void paint(Graphics g) {
    super.paint(g);
    g.drawString("HELLO WORLD!", x, 55);
  }

  public void actionPerformed(ActionEvent e) {
    Object source = e.getSource();
    if (source == lBtn) {      // lBtnが押された
      x -= 10;
    }
    else if (source == rBtn) { // rBtnが押された
      x += 10;
    }
    repaint();
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame("");
    JApplet applet = new UpDownButton();
    applet.setPreferredSize(new Dimension(200, 70));
    frame.add(applet);
    frame.pack();
    frame.setVisible(true);
    applet.start();
    applet.init();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }
}