/* Text from RGC */
/* Coverted to Java 1.1 October 199 by SBJ */

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

public class Calc extends Applet 
		  implements ActionListener {

  private Button[] bdigit = new Button[10];
  private int number = 0, total = 0;
  private Button cl = new Button("Clear");
  private Button plus = new Button("+");
  
  public void init() {
    // Each button named by a digit
    for (int i = 0; i < 10; i++) {
      bdigit[i] = new Button(Integer.toString(i));
      bdigit[i].addActionListener(this);
      add(bdigit[i]);
    }
    add(cl); add(plus);
    cl.addActionListener(this);
    plus.addActionListener(this);
  }
  
  public void paint( Graphics g ) {
    g.drawString( "Total = " + total, 30, 100 );
    g.drawString( "Number = " + number, 30, 120 );
  }
  
  public void actionPerformed(ActionEvent ev) {
    if (ev.getSource() == cl) {
      total = 0; number = 0;
    }
    else if (ev.getSource() == plus) {
      total += number;
      number = 0;
    }
    else
      // convert button label to digit
      number = 10 * number + Integer.parseInt(((Button)ev.getSource()).getLabel());
    repaint();
  }
}