




The function interface-visible-p returns 
nil
 if 
An error is signalled if pane is not a CAPI pane (that is, it is not an instance of a subclass of element, collection or pinboard-object).
Otherwise 
interface-visible-p
 returns 
t
.
Note: On MS Windows, 
interface-visible-p
 may return 
t
 even though the interface is entirely obscured by another window.