Adding a Callback

To provide a function for the push button so that when it is pressed a message appears in the terminal window and the script terminates, you have to add a callback. Also, you must tell the push button about the existence of this callback. The following is the script with the new code added:

#!/usr/dt/bin/dtksh  
activateCB() {    echo "Pushbutton activated; normal termination."

   exit 0  }   XtInitialize TOPLEVEL dttest2 Dtksh $0  XtSetValues $TOPLEVEL

title:"dttest2"  XtCreateManagedWidget BBOARD bboard

XmBulletinBoard $TOPLEVEL \
     resizePolicy:RESIZE_NONE \    

background:SkyBlue \
     height:150 width:250  XtCreateManagedWidget BUTTON

pushbutton XmPushButton $BBOARD \
     background:goldenrod \    

foreground:MidnightBlue \
     labelString:"Push Here"\    

height:30 width:100 x:75 y:60 shadowThickness:3   XtAddCallback $BUTTON

activateCallback activateCB  XtRealizeWidget $TOPLEVEL 

XtMainLoop

The callback is the function activateCB(). You typically add the callback to the push button after it (the push button) has been created:

XtAddCallback $BUTTON
activateCallback activateCB

Now the pushbutton knows about the callback. When you click the push button, the function activateCB() is executed, and the message "Pushbutton activated; normal termination." appears in the terminal window from which you executed the script. The script is terminated by the call to the function exit 0().