Program Structure

Programs written using the X Toolkit typically have the following structure:

Header files

to include the declarations and definitions for the Xt intrinsics and widget set.

Initialize the Xt intrinsics

handles connection to a display, sets the application's class name and deals with command line options.

Create the application's main widgets

specifying their class, parent widget, etc. and configure their resources.

Register callbacks

for those widgets that are to interact with the application programmer's code.

Realize widgets

causing the widgets to set window attributes and windows to be drawn on to the screen.

Enter the event loop

passing control of the application to Xt.

Callback routines

(the application programmer's code) are usually defined afterwards.