* This class calculates and prints
 * Total Gallons Used, Total Fuel Cost,
 * and Travel Time from data entered by user.
*/
 
/** text files imported to aid in formatting decimals,
 *  and creating GUI interface */
[
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
 
public class RoadTripCalculationFrame extends JFrame implements ActionListener {
 
      //Variables declared to be visible to all methods
      JTextArea output;
      JTextField distanceTf;
      JTextField mpgTf;
      JTextField speedTf;
      JTextField costTf;
 
      NumberFormat formatter = new DecimalFormat("#0.00");
 
      public RoadTripCalculationFrame() {
      }
 
      //This constructor used when RoadTripCalculationFrame
     //object is created from main() method
 
      public RoadTripCalculationFrame(String title) {
            super(title);
 
            Container myContainer = getContentPane();
 
            BorderLayout layout = new BorderLayout();
            myContainer.setLayout(layout);
 
            JLabel titleL = new JLabel ("Road Trip Calculator");
            JLabel distanceL = new JLabel("Distance:");
            distanceTf = new JTextField(10);
            JLabel mpgL = new JLabel("MPG:");
            mpgTf = new JTextField(10);
            JLabel speedL = new JLabel("Speed:");
            speedTf = new JTextField(10);
            JLabel costpergallonL = new JLabel("Cost per Gallon:");
            costTf = new JTextField(10);
 
            JButton calculateB = new JButton("Calculate");
            calculateB.addActionListener(this);
            JButton clearB = new JButton("Clear");
            clearB.addActionListener(this);
 
            JPanel north = new JPanel();
            north.add(titleL);
            JPanel center = new JPanel();
            center.setLayout(new GridLayout(2,5));
            center.add(distanceL);
            center.add(distanceTf);
            center.add(mpgL);
            center.add(mpgTf);
            center.add(speedL);
            center.add(speedTf);
            center.add(costpergallonL);
            center.add(costTf);
            center.add(calculateB);
            center.add(clearB);
 
            output = new JTextArea(100, 80);
 
            myContainer.add(north, BorderLayout.NORTH);
            myContainer.add(center, BorderLayout.CENTER);
            myContainer.add(output, BorderLayout.SOUTH);
 
      }
 
      //This method is called when the buttons are pressed
 
      public void actionPerformed(ActionEvent e) {
            JButton myButton = (JButton)e.getSource();
 
            if (myButton.getText().equals("Calculate")){
                  double distance = Double.parseDouble(distanceTf.getText());
                  double mpg = Double.parseDouble(mpgTf.getText());
                  double speed = Double.parseDouble(speedTf.getText());
                  double cost = Double.parseDouble(costTf.getText());
 
                  double gallonsUsed = distance / mpg;
                  double fuelCost = gallonsUsed * cost;
                  double travel = distance / speed;
                  double hours = travel;
                  double decimalValue = distance % speed;
                  double seconds = (decimalValue / speed) * 3600;
 
                  output.setText("Total Gallons Used:" + gallonsUsed +", Total Fuel Cost: $" + fuelCost +
                        ", Travel Time:" + hours + "hrs, " + seconds + "seconds");
 
            }
            else {
                  output.setText("");
                  distanceTf.setText("");
                  mpgTf.setText("");
                  speedTf.setText("");
                  costTf.setText("");
            }
      }
 
      //Entry point (main method) for the program
 
      public static void main(String []args){
 
            RoadTripCalculationFrame frame = new RoadTripCalculationFrame("Road Trip Calculation");
 
            frame.setSize(500, 300);
            frame.setVisible(true);
      }
 
}

this.pack();
this.show();

outputArea = new JTextArea() {
            public Dimension getPreferredSize() {
                return new Dimension(100, 80);
            }
        };

output = new JTextArea(100, 80);

output = new JTextArea() {
            public Dimension getPreferredSize() {
                return new Dimension(100, 80);
            }
        };