Skip to content
Switch branches/tags
Go to file
Cannot retrieve contributors at this time
;;; display-line-numbers.el --- interface for display-line-numbers -*- lexical-binding: t -*-
;; Copyright (C) 2017-2021 Free Software Foundation, Inc.
;; Maintainer:
;; Keywords: convenience
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <>.
;;; Commentary:
;; Provides a minor mode interface for `display-line-numbers'.
;; Toggle display of line numbers with M-x display-line-numbers-mode.
;; To enable line numbering in all buffers, use M-x
;; global-display-line-numbers-mode. To change the default type of
;; line numbers displayed, customize display-line-numbers-type.
;; NOTE: Customization variables for `display-line-numbers' itself are
;; defined in cus-start.el.
;;; Code:
(defgroup display-line-numbers nil
"Display line numbers in the buffer."
:group 'convenience
:group 'display)
(defcustom display-line-numbers-type t
"The default type of line numbers to use in `display-line-numbers-mode'.
See `display-line-numbers' for value options."
:group 'display-line-numbers
:type '(choice (const :tag "Relative line numbers" relative)
(const :tag "Relative visual line numbers" visual)
(other :tag "Absolute line numbers" t))
:version "26.1")
(defcustom display-line-numbers-grow-only nil
"If non-nil, do not shrink line number width."
:group 'display-line-numbers
:type 'boolean
:version "26.1")
(defcustom display-line-numbers-width-start nil
"If non-nil, count number of lines to use for line number width.
When `display-line-numbers-mode' is turned on, if this option is
non-nil, `display-line-numbers-width' is set up front to a width
necessary to display all line numbers in the buffer. If the value
is a positive number, it is interpreted as extra lines to account
for when computing the required width; this should be set to the
number of lines in the tallest window in which you want to prevent
the line-number width from changing."
:group 'display-line-numbers
:type '(choice (boolean :tag "Minimum width for buffer's line count")
(integer :tag "Number of extra lines to account for"))
:version "28.1")
(defun display-line-numbers-update-width ()
"Prevent the line number width from shrinking."
(let ((width (line-number-display-width)))
(when (> width (or display-line-numbers-width 1))
(setq display-line-numbers-width width))))
(define-minor-mode display-line-numbers-mode
"Toggle display of line numbers in the buffer.
This uses `display-line-numbers' internally.
To change the type of line numbers displayed by default,
customize `display-line-numbers-type'. To change the type while
the mode is on, set `display-line-numbers' directly."
:lighter nil
(if display-line-numbers-mode
(when display-line-numbers-width-start
(setq display-line-numbers-width
(length (number-to-string
(+ (count-lines (point-min) (point-max))
(if (and (numberp display-line-numbers-width-start)
(> display-line-numbers-width-start 0))
(when display-line-numbers-grow-only
(add-hook 'pre-command-hook #'display-line-numbers-update-width nil t))
(setq display-line-numbers display-line-numbers-type))
(remove-hook 'pre-command-hook #'display-line-numbers-update-width t)
(setq display-line-numbers nil)))
(defun display-line-numbers--turn-on ()
"Turn on `display-line-numbers-mode'."
(unless (minibufferp)
(define-globalized-minor-mode global-display-line-numbers-mode
display-line-numbers-mode display-line-numbers--turn-on)
(provide 'display-line-numbers)
;;; display-line-numbers.el ends here