A predicate for whether any CAPI window is currently displayed.
any-capi-window-displayed-p => result
any-capi-window-displayed-p is a predicate for whether any CAPI window (other than dialogs) is currently displayed.
CAPI User Guide and Reference Manual
for a description of the CAPI toolkit which allows you to write graphical user interfaces in Lisp.
Tools in the LispWorks IDE are all CAPI windows.
LispWorks User Guide and Reference Manual - 20 Sep 2017