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;;; linum.el --- display line numbers in the left margin
;; Copyright (C) 2008, 2009 Free Software Foundation, Inc.
;; Author: Markus Triska <>
;; Maintainer: FSF
;; 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:
;; Display line numbers for the current buffer.
;; Toggle display of line numbers with M-x linum-mode. To enable
;; line numbering in all buffers, use M-x global-linum-mode.
;;; Code:
(defconst linum-version "0.9x")
(defvar linum-overlays nil "Overlays used in this buffer.")
(defvar linum-available nil "Overlays available for reuse.")
(defvar linum-before-numbering-hook nil
"Functions run in each buffer before line numbering starts.")
(mapc #'make-variable-buffer-local '(linum-overlays linum-available))
(defgroup linum nil
"Show line numbers in the left margin."
:group 'convenience)
(defcustom linum-format 'dynamic
"Format used to display line numbers.
Either a format string like \"%7d\", `dynamic' to adapt the width
as needed, or a function that is called with a line number as its
argument and should evaluate to a string to be shown on that line.
See also `linum-before-numbering-hook'."
:group 'linum
:type 'sexp)
(defface linum
'((t :inherit (shadow default)))
"Face for displaying line numbers in the display margin."
:group 'linum)
(defcustom linum-eager t
"Whether line numbers should be updated after each command.
The conservative setting `nil' might miss some buffer changes,
and you have to scroll or press \\[recenter-top-bottom] to update the numbers."
:group 'linum
:type 'boolean)
(defcustom linum-delay nil
"Delay updates to give Emacs a chance for other changes."
:group 'linum
:type 'boolean)
(define-minor-mode linum-mode
"Toggle display of line numbers in the left margin."
:lighter "" ; for desktop.el
(if linum-mode
(if linum-eager
(add-hook 'post-command-hook (if linum-delay
'linum-update-current) nil t)
(add-hook 'after-change-functions 'linum-after-change nil t))
(add-hook 'window-scroll-functions 'linum-after-scroll nil t)
;; Using both window-size-change-functions and
;; window-configuration-change-hook seems redundant. --Stef
;; (add-hook 'window-size-change-functions 'linum-after-size nil t)
(add-hook 'change-major-mode-hook 'linum-delete-overlays nil t)
(add-hook 'window-configuration-change-hook
;; FIXME: If the buffer is shown in N windows, this
;; will be called N times rather than once. We should use
;; something like linum-update-window instead.
'linum-update-current nil t)
(remove-hook 'post-command-hook 'linum-update-current t)
(remove-hook 'post-command-hook 'linum-schedule t)
;; (remove-hook 'window-size-change-functions 'linum-after-size t)
(remove-hook 'window-scroll-functions 'linum-after-scroll t)
(remove-hook 'after-change-functions 'linum-after-change t)
(remove-hook 'window-configuration-change-hook 'linum-update-current t)
(remove-hook 'change-major-mode-hook 'linum-delete-overlays t)
(define-globalized-minor-mode global-linum-mode linum-mode linum-on)
(defun linum-on ()
(unless (minibufferp)
(linum-mode 1)))
(defun linum-delete-overlays ()
"Delete all overlays displaying line numbers for this buffer."
(mapc #'delete-overlay linum-overlays)
(setq linum-overlays nil)
(dolist (w (get-buffer-window-list (current-buffer) nil t))
(set-window-margins w 0 (cdr (window-margins w)))))
(defun linum-update-current ()
"Update line numbers for the current buffer."
(linum-update (current-buffer)))
(defun linum-update (buffer)
"Update line numbers for all windows displaying BUFFER."
(with-current-buffer buffer
(when linum-mode
(setq linum-available linum-overlays)
(setq linum-overlays nil)
(mapc #'linum-update-window
(get-buffer-window-list buffer nil 'visible)))
(mapc #'delete-overlay linum-available)
(setq linum-available nil))))
(defun linum-update-window (win)
"Update line numbers for the portion visible in window WIN."
(goto-char (window-start win))
(let ((line (line-number-at-pos))
(limit (window-end win t))
(fmt (cond ((stringp linum-format) linum-format)
((eq linum-format 'dynamic)
(let ((w (length (number-to-string
(count-lines (point-min) (point-max))))))
(concat "%" (number-to-string w) "d")))))
(width 0))
(run-hooks 'linum-before-numbering-hook)
;; Create an overlay (or reuse an existing one) for each
;; line visible in this window, if necessary.
(while (and (not (eobp)) (<= (point) limit))
(let* ((str (if fmt
(propertize (format fmt line) 'face 'linum)
(funcall linum-format line)))
(visited (catch 'visited
(dolist (o (overlays-in (point) (point)))
(when (equal-including-properties
(overlay-get o 'linum-str) str)
(unless (memq o linum-overlays)
(push o linum-overlays))
(setq linum-available (delq o linum-available))
(throw 'visited t))))))
(setq width (max width (length str)))
(unless visited
(let ((ov (if (null linum-available)
(make-overlay (point) (point))
(move-overlay (pop linum-available) (point) (point)))))
(push ov linum-overlays)
(overlay-put ov 'before-string
(propertize " " 'display `((margin left-margin) ,str)))
(overlay-put ov 'linum-str str))))
;; Text may contain those nasty intangible properties, but that
;; shouldn't prevent us from counting those lines.
(let ((inhibit-point-motion-hooks t))
(setq line (1+ line)))
(set-window-margins win width (cdr (window-margins win)))))
(defun linum-after-change (beg end len)
;; update overlays on deletions, and after newlines are inserted
(when (or (= beg end)
(= end (point-max))
(string-match-p "\n" (buffer-substring-no-properties beg end)))
(defun linum-after-scroll (win start)
(linum-update (window-buffer win)))
;; (defun linum-after-size (frame)
;; (linum-after-config))
(defun linum-schedule ()
;; schedule an update; the delay gives Emacs a chance for display changes
(run-with-idle-timer 0 nil #'linum-update-current))
;; (defun linum-after-config ()
;; (walk-windows (lambda (w) (linum-update (window-buffer w))) nil 'visible))
(defun linum-unload-function ()
"Unload the Linum library."
(global-linum-mode -1)
;; continue standard unloading
(provide 'linum)
;; arch-tag: dea45631-ed3c-4867-8b49-1c41c80aec6a
;;; linum.el ends here