That specifies the default kind of separator. (For compatibility,
@code{""} and @code{-} also count as separators.)
- Starting in Emacs 21, certain other values of @var{separator-type}
-specify a different style of separator. Here is a table of them:
+ Certain other values of @var{separator-type} specify a different
+style of separator. Here is a table of them:
@table @code
@item "--no-line"
@end defvar
@defvar menu-bar-update-hook
-This normal hook is run whenever the user clicks on the menu bar, before
-displaying a submenu. You can use it to update submenus whose contents
-should vary.
+This normal hook is run by redisplay to update the menu bar contents,
+before redisplaying the menu bar. You can use it to update submenus
+whose contents should vary. Since this hook is run frequently, we
+advise you to ensure that the functions it calls do not take much time
+in the usual case.
@end defvar
@node Tool Bar
A @dfn{tool bar} is a row of icons at the top of a frame, that execute
commands when you click on them---in effect, a kind of graphical menu
-bar. Emacs supports tool bars starting with version 21.
+bar.
The frame parameter @code{tool-bar-lines} (X resource @samp{toolBar})
controls how many lines' worth of height to reserve for the tool bar. A