//CS5-HMC-Sp.,00-Lab 10
//A. Khakpour, Apr., 00

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

//==================================================================
// Converts US Dollars to other currency.
//==================================================================
public class Currency3 extends Applet
{
   private CurrencyGUI gui;

   public void init ()
   {
      gui = new CurrencyGUI (this);
   } 
} 

//==================================================================
// Creates the graphical interface for the applet.
//==================================================================
class CurrencyGUI
{
   private static Label titleLabel;
   private static Choice countryChoice;
   private static Label resultLabel;
   private static Label resultLabel1;
   private static TextField quote; 
   private static Label enter;
   private static Button button;

   private ConversionActionListener listener;

   public CurrencyGUI (Applet app)
   {
      FlowLayout tempLayout = (FlowLayout) app.getLayout();
      tempLayout.setHgap (10);

      app.setBackground (Color.yellow);

      titleLabel = new Label ("US Dollars Converter");
      resultLabel = new Label ("Result of Conversion");
      resultLabel1 = new Label ("Result: ");
      quote = new TextField(10);
      button = new Button("Convert");

      listener = new ConversionActionListener ();
      quote.addActionListener (listener);
      button.addActionListener (listener);

      enter = new Label ("Enter US Dollars: $");
      countryChoice = new Choice();
      countryChoice.add ("English pound");
      countryChoice.add ("Japanese yen");
      countryChoice.add ("French franc");

      // add the components to the applet
      app.add (titleLabel);
      resultLabel.setAlignment(Label.LEFT);
      app.add (resultLabel1);
      app.add (enter);
      app.add (quote);
      app.add (resultLabel);
      app.add (countryChoice);
      app.add (button);
   //   app.setSize (250, 250);
   } 

   public static void setResultLabel (String str)
   {
      resultLabel.setText(str);
   }                             

   public static int getCurrencyChoice()
   {
      return countryChoice.getSelectedIndex();
   } 

   public static String getUSDollars()
   {
      return quote.getText();
   }
} 

//==================================================================
// Contains the code to perform the conversion.
//==================================================================
class CurrencyConverter
{
   final static double POUNDSTOUSD = 0.61203;
   final static double YENSTOUSD = 138.509;
   final static double FRANCSTOUSD = 5.97415;

   final static int POUND = 0;
   final static int YEN = 1;
   final static int FRANC = 2;

   public static double convert (double dollars)
   {
      double conversionFactor = 0.0;
      int convertTo = CurrencyGUI.getCurrencyChoice();

      switch(convertTo)
      {
         case POUND:
            conversionFactor = POUNDSTOUSD;
            break;
         case YEN:
            conversionFactor = YENSTOUSD;
            break;
         case FRANC:
            conversionFactor = FRANCSTOUSD;
      }
      return dollars * conversionFactor;
   } 
}

class ConversionActionListener implements ActionListener
{
   public void actionPerformed (ActionEvent e)
   {
      CurrencyGUI.setResultLabel ("ERROR");
      String text =  CurrencyGUI.getUSDollars();
      Double x = new Double(text);
      double val = x.doubleValue();
      double value = CurrencyConverter.convert(val);
      CurrencyGUI.setResultLabel(Double.toString(value));
   }
}