Any toolbar object may be disabled, by setting its
enabled
slot to nil
. Disabling a toolbar or toolbar component prevents the user from interacting with any buttons contained in it.
All toolbar objects may also have an
enabled-function
specified. This is called whenever update-toolbar is called. If it returns t
, the toolbar object will be enabled; if it returns nil
, the object will be disabled.
The function enabled-function should not display a dialog or do anything that may cause the system to hang. In general this means interacting with anything outside the Lisp image, including files, databases and so on.
CAPI User Guide and Reference Manual (Macintosh version) - 3 Aug 2017