Next sample: a multiplying calculator

This sample shows a simple calculator that multiplies two numbers. It updates with every keystroke due to the EDIT_MODIFY event that is registered for the two BBjInputN.

Create a new program in your IDE and copy this program into your editor. Examine and run it, and play with it. Try to understand how the events work.

wnd! = BBjAPI().openSysGui("X0").addWindow(50,50,400,200,"Multiply")

label1! = wnd!.addStaticText(100,10,12,20,25,"X:")
field_x! = wnd!.addInputN(101,30,10,50,25,"")

label2! = wnd!.addStaticText(103,10,42,20,25,"Y:")
field_y! = wnd!.addInputN(104,30,40,50,25,"")

result! = wnd!.addStaticText(105,10,72,200,25,"")

rem register the callback to close the program
wnd!.setCallback(BBjAPI.ON_CLOSE,"byebye")

rem register the callbacks for ON_EDIT_MODIFY
field_x!.setCallback(BBjAPI.ON_EDIT_MODIFY,"updateResult")
field_y!.setCallback(BBjAPI.ON_EDIT_MODIFY,"updateResult")

rem set the focus in the X-Input
field_x!.focus()

process_events

byebye:
    bye

updateResult:
    x = field_x!.getValue()
    y = field_y!.getValue()
    r = x*y
    result!.setText("X * Y = "+str(r))
return

Exercise: Can you enhance it? Add a button to clear the input in both fields. Hint: the setValue() - Method for BBjInputN can be used to sets their value to "0." Find it in the documentation.