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

public class Phone extends Applet {
  Button lookup;
  TextField entryField;
  Choice bookChoice;
  Hashtable phonebook = new Hashtable();
  Hashtable reversePhonebook = new Hashtable();


  final class LookupHandler implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      Object o = reversePhonebook.get(entryField.getText());
      if (o == null) {
        getToolkit().beep();
      } else {
        bookChoice.select(o.toString());
      }
    }
  }

  final class PhoneInputHandler extends KeyAdapter {
    public void keyTyped(KeyEvent e) {
      char c = e.getKeyChar();
       if ((c == KeyEvent.VK_BACK_SPACE) ||
           (c == KeyEvent.VK_DELETE)     ||
           (c == KeyEvent.VK_ENTER)      ||
           (c == KeyEvent.VK_TAB))
         return;
       if (!Character.isDigit(c) && (c != '-'))
         e.consume();
    }
  }

  final class ChoiceHandler implements ItemListener {
    public void itemStateChanged(ItemEvent e) {
      Object o = phonebook.get(e.getItem());
      if (o == null) {
        getToolkit().beep();
        entryField.setText("");
      } else {
        entryField.setText(o.toString());
      }
    }
  }

  public void init() {
    ActionListener al = new LookupHandler();
    setLayout(new BorderLayout(10, 10));

    Panel p = new Panel(new GridLayout(0, 1));
    p.add(new Label("Enter number to lookup name", Label.CENTER));
    p.add(new Label("Or pick name to show number", Label.CENTER));
    entryField = new TextField(10);
    entryField.addActionListener(al);
    entryField.addKeyListener(new PhoneInputHandler());
    p.add(entryField);
    add(p, BorderLayout.CENTER);

    bookChoice = new Choice();
    bookChoice.addItemListener(new ChoiceHandler());
    initializePhoneBook(bookChoice);
    add(bookChoice, BorderLayout.NORTH);

    lookup = new Button("Lookup");
    lookup.addActionListener(al);
    add(lookup, BorderLayout.SOUTH);
  }

  private void initializePhoneBook(Choice list) {
    String s[][] = {{"Mom",    "555-1111"},
                    {"Dad",    "555-2222"},
                    {"Hon",    "555-3333"},
                    {"Boss",   "555-4444"},
                    {"Broker", "555-5555"},
                    {"Jenny",  "867-5309"}};
    for (int i = 0; i < s.length; i++) {
      list.add(s[i][0]);
      phonebook.put(s[i][0], s[i][1]);
      reversePhonebook.put(s[i][1], s[i][0]);
    }
  }
}