In many instances the application will need to use functions from the
Xlib layer for graphics or pure flexibility. Most of the the Xlib
procedures take as arguments the display, screen, window, or gc
structures. Therefore proxt provides the predicates
xtWindowToWidget to facilitate the mapping between Xt and Xlib.
Also, the predicate
xLoadQueryFont is provided to supply the font
structure needed by Motif font predicates such as