22.12.1.3 Menu Separators

A menu separator is a kind of menu item that doesn't display any text--instead, it divides the menu into subparts with a horizontal line. A separator looks like this in the menu keymap:

(menu-item separator-type)

where separator-type is a string starting with two or more dashes.

In the simplest case, separator-type consists of only dashes. That specifies the default kind of separator. (For compatibility, "" and - also count as separators.)

Starting in Emacs 21, certain other values of separator-type specify a different style of separator. Here is a table of them:

"--no-line"

"--space"

An extra vertical space, with no actual line.

"--single-line"

A single line in the menu's foreground color.

"--double-line"

A double line in the menu's foreground color.

"--single-dashed-line"

A single dashed line in the menu's foreground color.

"--double-dashed-line"

A double dashed line in the menu's foreground color.

"--shadow-etched-in"

A single line with a 3D sunken appearance. This is the default, used separators consisting of dashes only.

"--shadow-etched-out"

A single line with a 3D raised appearance.

"--shadow-etched-in-dash"

A single dashed line with a 3D sunken appearance.

"--shadow-etched-out-dash"

A single dashed line with a 3D raised appearance.

"--shadow-double-etched-in"

Two lines with a 3D sunken appearance.

"--shadow-double-etched-out"

Two lines with a 3D raised appearance.

"--shadow-double-etched-in-dash"

Two dashed lines with a 3D sunken appearance.

"--shadow-double-etched-out-dash"

Two dashed lines with a 3D raised appearance.

You can also give these names in another style, adding a colon after the double-dash and replacing each single dash with capitalization of the following word. Thus, "--:singleLine", is equivalent to "--single-line".

Some systems and display toolkits don't really handle all of these separator types. If you use a type that isn't supported, the menu displays a similar kind of separator that is supported.