The class displaying the message when a pane is created with the :message
initarg.
capi
The class message-pane
is used to implement the message decoration on subclasses of titled-object.
A message-pane
with text "Message" is created automatically when a titled-object is created with message "Message".
message-pane
does not add functionality to title-pane, and it is used only to allow different resources in GTK+ and Motif.
CAPI User Guide and Reference Manual (Macintosh version) - 01 Dec 2021 19:31:27