import java.awt.Container;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.text.NumberFormat;

import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

@SuppressWarnings("serial")
// You must create a JFrame class that extends JFrame
public class Main extends JFrame {

 final static double PARKING_FEE = 20;

 // This is the constructor for your JFrame class
 Main( ) {

   // Calling "super" calls the constructor on JFrame and takes a string for
   // the title as it's argument

   super( "Tickets" );
   setBounds( 100, 100, 300, 100 );
   setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
   Container con = this.getContentPane( );
   JPanel jPanel = new JPanel( );
   con.add( jPanel );

   // This is a combo box that holds all the categories
   final JComboBox jComboBoxCategory = new JComboBox( );
   jComboBoxCategory.setToolTipText( "Category" );
   jComboBoxCategory.addItem( "Student" );
   jComboBoxCategory.addItem( "Alumni" );
   jComboBoxCategory.addItem( "Faculty & Staff" );
   jComboBoxCategory.addItem( "Military" );
   jComboBoxCategory.addItem( "General Public" );
   jPanel.add( jComboBoxCategory );

   // This is a checkbox
   final JCheckBox jCheckBoxParking = new JCheckBox( "Parking" );
   jPanel.add( jCheckBoxParking );

   // This is a label that is used to display the price
   final JLabel jLablePrice = new JLabel( "Total: $0.00 " );
   jPanel.add( jLablePrice );

   // This adds a listener to jComboBoxCategory. The function,
   // itemStateChanged() is triggered if the user changes the selection in the
   // combobox. After that we call the recalculate function and set the text in
   // the label to the return value

   jComboBoxCategory.addItemListener( new ItemListener( ) {
     @Override
     public void itemStateChanged( ItemEvent itemEvent ) {
       jLablePrice.setText( "Total: "
           + NumberFormat.getCurrencyInstance( ).format(
               recalculate( jComboBoxCategory.getSelectedIndex( ),
                   jCheckBoxParking.isSelected( ) ) ) );
     }
   } );

   // This is the same as the jComboBoxCategory listener
   jCheckBoxParking.addItemListener( new ItemListener( ) {
     @Override
     public void itemStateChanged( ItemEvent itemEvent ) {
       jLablePrice.setText( "Total: "
           + NumberFormat.getCurrencyInstance( ).format(
               recalculate( jComboBoxCategory.getSelectedIndex( ),
                   jCheckBoxParking.isSelected( ) ) ) );
     }
   } );

   setVisible( true );
 }

 // This function recalculates the price. We pass it the itemIndex from
 // jComboBoxCategory and isSelected from jCheckBoxParking. The index starts at
 // 0, so 0 = "Student" and 4 = "General Public"

 public static double recalculate( int category, boolean parking ) {

   int result = 60;

   switch ( category ) {
     case 0 :
       result *= 0.5;
       break;
     case 1 :
       result *= 0.9;
       break;
     case 2 :
       result *= 0.85;
       break;
     case 3 :
       result *= 0.8;
       break;
     default :
       break;
   }

   if ( parking ) {
     result += PARKING_FEE;
   }

   return result;

 }

 public static void main( String args[] ) {
   new Main( );
 }
}