GNU Info

(elisp)Display Margins

---

Next: Conditional Display Prev: Other Display Specs Up: Display Property

---

Enter node , (file) or (file)node

Displaying in the Margins
-------------------------

   A buffer can have blank areas called "display margins" on the left
and on the right.  Ordinary text never appears in these areas, but you
can put things into the display margins using the `display' property.

   To put text in the left or right display margin of the window, use a
display specification of the form `(margin right-margin)' or `(margin
left-margin)' on it.  To put an image in a display margin, use that
display specification along with the display specification for the
image.

   Before the display margins can display anything, you must give them
a nonzero width.  The usual way to do that is to set these variables:

 - Variable: left-margin-width
     This variable specifies the width of the left margin.  It is
     buffer-local in all buffers.

 - Variable: right-margin-width
     This variable specifies the width of the right margin.  It is
     buffer-local in all buffers.

   Setting these variables does not immediately affect the window.
These variables are checked when a new buffer is displayed in the
window.  Thus, you can make changes take effect by calling
`set-window-buffer'.

   You can also set the margin widths immediately.

 - Function: set-window-margins window left &optional right
     This function specifies the margin widths for window WINDOW.  The
     argument LEFT controls the left margin and RIGHT controls the
     right margin (default `0').

 - Function: window-margins &optional window
     This function returns the left and right margins of WINDOW as a
     cons cell of the form `(LEFT . RIGHT)'.  If WINDOW is `nil', the
     selected window is used.