For Exercises 15 through 28, use the incremental development methodology to implement th...

For Exercises 15 through 28, use the incremental development methodology to implement the program. Design a visually appealing GUI with Swing components and layout managers. For each exercise, identify the program tasks, create a design document with class descriptions, and draw the program diagram. Map out the development steps at the start. Present any design alternatives and justify your selection. Be sure to perform adequate testing at the end of each development step.

Redo Exercise 17 with a new user interface. The left side of a frame is used to enter the loan amount, interest rate, and loan period. The right side of a frame displays the mortgage table for given input values. The following layout is merely a suggestion. Feel free to use other GUI components as you see fit. For example, consider using JComboBox for entering interest rates and loan periods.

Reference Exercise 17.

Modify the mortgage table program of Exercise 30 in Chapter 6. Add this menu

to the program. When the user selects the menu choice New Table, the program opens another frame in which the user can enter three input values. The input frame should look something like this:

If the user clicks on the Compute button and the three input values are valid, generate a mortgage table. Use the OutputBox class from Exercise 5 to display the mortgage table. If the input values are invalid, then print out an appropriate error message. Decide on the range of valid values for the loan amount, interest rate, and loan period. When the user selects the menu choice About . . . , describe the purpose of the program by using another frame. You should create only one input frame, but may decide to use more than one OutputBox frame so you can see multiple loan tables at once.

Reference Exercise 5.

Define an OutputBox class as a subclass of JFrame. The OutputBox class provides the functionality of System.out (PrintStream) by supporting these methods:

public void println(String line)

public void print(String text)

The OutputBox class contains one JTextArea object. Do not use absolute positioning. Use the default layout and add a JScrollPane that wraps the JTextArea object to the content pane.