public   final   class  Main {

     public   static   void  main(String[] args) {

        new  Converter().start();               }

}


 public   final   class  Converter {

     private  Model model;
  
     private  View view;

      public  Converter() {
         this .model =  new  Model();
         this .view =  new  View();

        // create controllers
        QuitController qc =  new  QuitController( this );
         this .view.getFrame().addWindowListener(qc);
        InputController ic =  new  InputController( this );
         this .view.getInputField().getDocument().addDocumentListener(ic);
         this .view.getExchangeRateField().getDocument().addDocumentListener(ic);

        // init view
         this .view.getExchangeRateField().setText(
                 Float .toString( this .model.getExchangeRate()));

    }

     public  Model getModel() {
         return   this .model;  }

     public  View getView() {
         return   this .view;  }

     public   void  start() {
         this .view.show();   }

}


 public   final   class  Model {

     private   float  exchangeRate;
     public  Model() {  this .exchangeRate =  1 ; }

     public   float  getExchangeRate() {
         return   this .exchangeRate;  }

    
     public   void  setExchangeRate( float  rate) {

         if  (rate <  0 )  throw   new  NegativeExchangeRateException(rate);
         this .exchangeRate = rate;

    }

}

 public   final   class  View {
     private  JFrame frame;
     private  JTextField inputField;
     private  JTextField exchangeRateField;
     private  JTextField outputField;
     private  JLabel statusBar;

     public  View() {

         this .frame =  new  JFrame();
         this .frame.setTitle("Currency converter");
         this .frame.setLocation( 30 ,  40 );
         this .frame.setResizable(false);
         this .frame.setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
         this .frame.getContentPane().setLayout( new  BorderLayout());

        JPanel center =  new  JPanel();
        center.setBorder(BorderFactory.createEmptyBorder(BORDER, BORDER,
                BORDER, BORDER));
        center.setLayout( new  GridLayout( 3 ,  2 , BORDER, BORDER));
         this .frame.getContentPane().add(center, CENTER);

         JLabel inputLabel =  new  JLabel("Amount to convert:");
        center.add(inputLabel);
         this .inputField =  new  JTextField("1");
         this .inputField.selectAll();
        center.add( this .inputField);

         JLabel exchangeRateLabel =  new  JLabel("Exchange rate:");
        center.add(exchangeRateLabel);
         this .exchangeRateField =  new  JTextField();
        center.add( this .exchangeRateField);

          JLabel outputLabel =  new  JLabel("Converted amount:");
        center.add(outputLabel);
         this .outputField =  new  JTextField();
         this .outputField.setEditable(false);
        center.add( this .outputField);

          this .statusBar =  new  JLabel(" ");
         this .statusBar.setBorder(BorderFactory.createEmptyBorder( 0 , BORDER,
                BORDER, BORDER));
         this .statusBar.setFont( this .statusBar.getFont().deriveFont( 10 .0f));
         this .frame.getContentPane().add( this .statusBar, SOUTH);

         this .frame.pack();

    }

   
     public  JFrame getFrame() {
         return   this .frame;   }

    
     public  JTextField getInputField() {
         return   this .inputField;        }

     public  JTextField getExchangeRateField() {
         return   this .exchangeRateField;       }

    
     public  JTextField getOutputField() {
         return   this .outputField;       }

    
     public  JLabel getStatusBar() {
         return   this .statusBar;   }

     public   void  show() {
         this .frame.setVisible(true);
    }

}