Program 1 (due Midnight Friday, September 10th)       Your Questions Answered

Program 1 (Exercise 7-19) extends the calculator of exercise 7-18 on p 460. The class needs to implement a calculator with layout similar to the picture shown on p 460. The user has a choice of how to enter a number -either the buttons or the keyboard (your program must respond to button clicks and keyboard entry). Additional required features include

1. Colorful yet legible screen background, font combination (use either a JLabel or JTextField).
2. Colorful background to simulate the frame.
3. Colorful buttons to lend a calculator look and feel.
4. The frame's close button should exit the program.
5. The clear (c) and clear entry (ce) buttons should be functional.

You will have to decide on several design issues such as

• Whether entries are displayed as single units one at a time (operand, operand, followed by answer) or as an algebraic expression (operand operator operand, followed by the answer). The former is similar to the calculator on your computer while the latter is similar to the TI-83. 
• How to determine whether the user is entering a left operand or a right operand.
• How to handle the entering of multiple decimal points. (erroneous entries)
• When the display is 0 and the user enters 0, the display will not change. However, if the display is nonzero and the user enters 0, the 0 is appended to the number currently displayed.
• How to handle the operator precedence. For example, what will be the result if the user enters 4 + 3 * 2? Will it be 14 or 10? It is easier to treat all operators as having equal precedence and process the from left to right.

For full credit make effective use of event handling, exception handling, regular expressions, and pattern matching. At least two of these techniques should be used.

Submit your completed source code and any images in a zipped folder as an attachment to the email address for your section. Your code must compile and run. This is more important than full functionality.
Email: CSC221.001@uncw.edu / CSC221.002@uncw.edu
Note, if your program does not use images (none are required) then just the source code is sufficient. Your name must be in a remark block in your source code and in the subject line of your email.

Use the following code to your benefit, provided as an example of one way to handle getting the operands and operator if you decide to show the full expression in your screen: Calculator.java