For this assignment, you will re-implement the Airline Ticket Redeemer from Assignment 1 as a Java GUI application with Swing components.
The Destination class should remain the same as in Assignment 1. This reusability is one of the advantages of encapsulation.
In addition, the MilesRedeemer class from Assignment 1 can be reused as well. Many methods of MilesRedeemer can be invoked directly, such as readDestinations() and the method that contains the redemption algorithm. Of course, the application will need to supply new code for obtaining the input and displaying the output.
Two JPanel objects are used in the application shown above (They have further nested JPanel objects for layout purposes). Each JPanel should have a background color set. Recall
the Color constructor:
Color(int r, int g, int b)
where the arguments are in the range 0...255 and higher numbers are lighter colors. Use colors that are not too intense, and be sure that the text is legible. You can learn how to add a Titled Border, etc. using the Java Tutorials here.
The left (LINE_START) panel contains a JList so that the user can go back and forth to look at the information for different tickets to different cities. The array of strings returned by the MilesRedeemer method getCityNames() can be used to populate the JList. When a city in the JList is selected, its details (i.e., the members of its corresponding Destination object) should be displayed in the corresponding JTextField objects. These JTextField objects should not be editable. To listen for this event, the applet needs to implement the interface javax.swing.event.ListSelectionListener, and provide the method
public void valueChanged(ListSelectionEvent e)
Add a method to your MilesRedeemer class to return the corresponding Destination object for a given city name, e.g.:
public Destination findDestination(String cityName)
The right (CENTER) panel takes in the accumulated miles using a JTextField and a JSpinner. After the "Redeem Tickets" button is clicked, it outputs ticket details in a JTextArea, and the remaining miles in a JTextField. The components for output are not editable.
How to Populate the Months for the JSpinner
The spinner's month Strings can be obtained using the following code. (Some logic is included to remove an extra, empty value.)
private String[] getMonthStrings() {
String[] months = new java.text.DateFormatSymbols().getMonths(); int lastIndex = months.length - 1;
if (months[lastIndex] == null || months[lastIndex].length() <= 0) { //last item empty
String[] monthStrings = new String[lastIndex]; System.arraycopy(months, 0, monthStrings, 0, lastIndex); return monthStrings;
} else {
//last item not empty
return months;
}
}
Other Hints
Any error messages or messages printed as a result of caught exceptions should be printed on the Java console.
How to Submit the Assignment
Submission of the source code files should be done via Blackboard as in Assignment1.
