import  java.awt.*;
 import  java.awt.event.*;
 import  java.util.*;
 import  java.io.*;
 import  javagently.*;

 class  ConverterGUI  extends  Frame {

  /* The Converter Program     by J M Bishop  Dec 1998
   * ---------------------     Display version July 1999
   *                           GUI version July 1999
   *                           updated August 2000
   * Keeps the exchange rates from one currency into
   * many others and enables currency exchanges to be
   * estimated.
   *
   * Illustrates the use of a customised GUI
   * and managed sequences of events
   */

   ConverterGUI ()  throws  IOException {
      DataHandler data =  new  DataHandler ();
      data.initialize();
      data.readIn();
  }

   class  DataHandler  extends  Frame
                implements  ActionListener, ItemListener {
    Hashtable table =  new  Hashtable();

    // read in each line of data and store in
    // the hash table with country as key

    Choice    fromChoice, toChoice;
     boolean    fromSelected, toSelected;
    TextField amountField;
    TextArea  resultField;
    String    toCountry, fromCountry;
    Button    goButton;

     void  initialize () {
      Panel p =  new  Panel ( new  BorderLayout());

        // left hand side panel
        Panel q =  new  Panel();
          q.add ("North", new  Label ("From"));
          fromChoice =  new  Choice();
            fromChoice.addItemListener ( this );
            q.add("Center",fromChoice);
          p.add ("West", q);
        // right hand side panel
        q =  new  Panel();
          q.add ("North", new  Label ("To"));
          toChoice =  new  Choice();
            toChoice.addItemListener ( this );
            q.add("Center",toChoice);
          p.add ("East",q);
        // Centre panel
        q =  new  Panel( new  BorderLayout());
          Panel r =  new  Panel();
            r.add( new  Label("Amount"));
            amountField =  new  TextField("1000  ");
              amountField.addActionListener( this );
              r.add(amountField);
              q.add("North",r);
            resultField =  new  TextArea( 8 , 20 );
              q.add ("Center",resultField);
              resultField.append("First select the countries\n");
            goButton =  new  Button ("Convert");
              goButton.addActionListener( this );
              q.add("South",goButton);
          p.add("Center",q);
      add(p);
      setTitle("Currency Converter");
      setSize( 610 , 300 );
      addWindowListener( new  WindowAdapter() {
         public   void  windowClosing(WindowEvent e) {
          System.exit( 0 );
        }
      });
    }

     public   void  actionPerformed (ActionEvent e) {
       int  amount =  1000 ;
       if  (e.getSource() == amountField)
        amount = ( int ) Integer.parseInt(amountField.getText());
       else 
       if  (e.getSource() == goButton) {
         if  (fromSelected && toSelected)
          transaction(amount);
         else 
          resultField.append("First select the countries\n");
      }
    }

     public   void  itemStateChanged(ItemEvent e) {
      String s = (String) e.getItem();
       if  (e.getItemSelectable() == fromChoice) {
        fromSelected = true;
        fromCountry = s;
      }
       else  {
        toSelected = true;
        toCountry = s;
      }
    }

     void  transaction ( int  amount) {
      Rates fromRate = (Rates) table.get(fromCountry);
      Rates toRate = (Rates) table.get(toCountry);
      resultField.append(amount+" "+fromRate.country+" "+
          fromRate.currency+
          "\n in "+toRate.country+" "+toRate.currency+"\n was "+
          Stream.format(amount/fromRate.conversion*
                      toRate.conversion, 10 , 3 )+"\n\n");
      fromSelected = false;
      toSelected = false;
    }

   void  readIn()  throws  IOException {
    Stream fin =  new  Stream("Rates.dat", Stream.READ);
    Rates rate;
     try  {
       for  ( int  i =  0 ; ; i++) {
        rate =  new  Rates();
        rate.setRate(fin);
        table.put(rate.country, rate);
        toChoice.addItem(rate.country);
        fromChoice.addItem(rate.country);
      }
     }
      catch  (EOFException e) {}
     fromSelected = false;
     toSelected = false;
     setVisible(true);
   }
  }

    public   static   void  main(String[] args)  throws  IOException {
     new  ConverterGUI();
  }


}