Figure 6-1: Motif GUI

; The QUITIT procedure is a callback routine that is executed

; when the "Hello World" button is selected.

PRO QUITIT, wid, data, npars, reason, event, count

COMMON widgets, warr, pushed

; If button selected, replace button label with "Good Bye!!!".

; Next time button selected, close top-level window to quit

; the application.

IF pushed EQ 0 THEN BEGIN

; args is defined as an unnamed structure.

args={,labelString:'Good Bye!!!!'}

status=WtSet(wid,args)

pushed=1

ENDIF ELSE BEGIN

PRINT, 'Quitting...'

status=WtClose(warr(0))

ENDELSE

END

; This procedure creates pushbutton with QUITIT routine as

; callback.

PRO EXAMPLE

@wtxmclasses

@wtxmconsts

COMMON widgets, warr, pushed

warr = LONARR(4)

pushed=0

; Initialize the application.

warr(0)=WtInit('example','Examples')

; Create a "container" widget.

warr(1) = WtCreate('form',xmFormWidgetClass, warr(0))

args={,x:10,y:10}

; Create a label.

warr(2)=WtCreate('Push Me, Please!', xmLabelWidgetClass, $
warr(1),args)

args={,y:40,width:140,height:25,recomputeSize:FALSE}

; Create the "Hello World" push button.

warr(3)=WtCreate('Hello,World!', xmPushButtonWidgetClass, $
warr(1),args)

; Add the button callback.

status=WtAddCallback(warr(3), 'activateCallback', 'quitit')

; Display the top-level shell.

status=WtSet(warr(0), /Realize)

; Process events. Call callbacks.

WtLoop

END