51.5 Margin Primitives

The margin widths are controllable on a buffer-local, window-local, frame-local, device-local, or device-type-local basis through the use of specifiers. See Specifiers.

Specifier: left-margin-width

This is a specifier variable controlling the width of the left outside margin, in characters. Use set-specifier to change its value.

Specifier: right-margin-width

This is a specifier variable controlling the width of the right outside margin, in characters. Use set-specifier to change its value.

Specifier: use-left-overflow

If non-nil, use the left outside margin as extra whitespace when displaying whitespace and inside-margin annotations. Defaults to nil. This is a specifier variable; use set-specifier to change its value.

Specifier: use-right-overflow

If non-nil, use the right outside margin as extra whitespace when displaying whitespace and inside-margin annotations. Defaults to nil. This is a specifier variable; use set-specifier to change its value.

Function: window-left-margin-pixel-width &optional window

This function returns the width in pixels of the left outside margin of window. If window is nil, the selected window is assumed.

Function: window-right-margin-pixel-width &optional window

This function returns the width in pixels of the right outside margin of window. If window is nil, the selected window is assumed.

The margin colors are controlled by the faces left-margin and right-margin. These can be set using the X resources Emacs.left-margin.background and Emacs.left-margin.foreground; likewise for the right margin.