wrapping program in gui

[Kirstie Fran]

Hello,
I have simple digital root calculator program that i would like to add a GUI to; rather than create a whole new program, someone suggested that i simply wrap the old one in a GUI. any suggestions on how to do this?
Here is the original program:

System.out.println("Enter an integer");
        //scanner class
        Scanner console = new Scanner(System.in);
        int n = console.nextInt();

        int dr = 0;//declared digital root variable
        int m = 0; // declared m
        //check A non-negative integer
        if (n <= 0) {
            System.out.println("Only positive numbers please!");
        } else {
            //manual summing of digits
            if (m >= 9 && m <= 1) {
                dr = n;
            } else {
                m = (1 + (n - 1) % 9);
                dr=m;
            }
            System.out.println("The digital root of " + n + " is " + dr);
            //

        }

[Bear Bibeault]

What kind of GUI? Swing? Web?

Regardless, it's not going to be that simple. Depending upon which type of GUI you choose, the method of accepting input will change drastically from reading in from the console.

[Campbell Ritchie]

If you have a calculator with a proper public interface, it is not that difficult really. It might take a long time to learn all the Swing components, however.
Do you have methods like add() subtract() divide() multiply()?
Do you have methods like takeParameter(), takeOperator()?
When you have such methods and you can do this sort of thing, you have a chance of wrapping it in a GUI:-

myCalculator.add(123);
System.out.println(myCalculator.getResult());

OR

myCalculator.takeParameter(123);
myCalculator.takeOperator(Operators.PLUS);
System.out.println(myCalculator.getResult());

You don’t need to do both; either will work (but differently).
In your case, it would appear that you might only have one operator (Operators.SQUARE_ROOT) or one method (squareRoot()).

Actually what you are doing is working out the transverse sum of the digits modulo 9. I mistook it for square root.

[Winston Gutkowski]

Kirstie Fran wrote:any suggestions on how to do this?

Yes, but it's going to be difficult to achieve with your program as it is: You need to keep your calculator and your input/display (be it GUI, console or browser-based) completely separate.

And that means, as Campbell said, coming up with a public API for your calculator.

Right now, they're all mixed up together, so your first cut should be to remove all those Scanner.get... and System.out.println() statements from your calculator and put them in another class (CalculatorDialog?). Once you have that, you'll probably find it a lot simpler to re-write to use GUI components.

Winston

[Kirstie Fran]

Bear Bibeault wrote:What kind of GUI? Swing? Web?

Regardless, it's not going to be that simple. Depending upon which type of GUI you choose, the method of accepting input will change drastically from reading in from the console.

it would be a swing gui. I'm using a jframe.