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1 ;;; linum.el --- display line numbers in the left margin -*- lexical-binding: t -*-
3 ;; Copyright (C) 2008-2016 Free Software Foundation, Inc.
5 ;; Author: Markus Triska <markus.triska@gmx.at>
6 ;; Maintainer: emacs-devel@gnu.org
7 ;; Keywords: convenience
8 ;; Version: 0.9x
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software: you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation, either version 3 of the License, or
15 ;; (at your option) any later version.
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
25 ;;; Commentary:
27 ;; Display line numbers for the current buffer.
29 ;; Toggle display of line numbers with M-x linum-mode. To enable
30 ;; line numbering in all buffers, use M-x global-linum-mode.
32 ;;; Code:
34 (defconst linum-version "0.9x")
36 (defvar linum-overlays nil "Overlays used in this buffer.")
37 (defvar linum-available nil "Overlays available for reuse.")
38 (defvar linum-before-numbering-hook nil
39 "Functions run in each buffer before line numbering starts.")
41 (mapc #'make-variable-buffer-local '(linum-overlays linum-available))
43 (defgroup linum nil
44 "Show line numbers in the left margin."
45 :group 'convenience)
47 (defcustom linum-format 'dynamic
48 "Format used to display line numbers.
49 Either a format string like \"%7d\", `dynamic' to adapt the width
50 as needed, or a function that is called with a line number as its
51 argument and should evaluate to a string to be shown on that line.
52 See also `linum-before-numbering-hook'."
53 :group 'linum
54 :type '(choice (string :tag "Format string")
55 (const :tag "Dynamic width" dynamic)
56 (function :tag "Function")))
58 (defface linum
59 '((t :inherit (shadow default)))
60 "Face for displaying line numbers in the display margin."
61 :group 'linum)
63 (defcustom linum-eager t
64 "Whether line numbers should be updated after each command.
65 The conservative setting nil might miss some buffer changes,
66 and you have to scroll or press \\[recenter-top-bottom] to update the numbers."
67 :group 'linum
68 :type 'boolean)
70 (defcustom linum-delay nil
71 "Delay updates to give Emacs a chance for other changes."
72 :group 'linum
73 :type 'boolean)
75 ;;;###autoload
76 (define-minor-mode linum-mode
77 "Toggle display of line numbers in the left margin (Linum mode).
78 With a prefix argument ARG, enable Linum mode if ARG is positive,
79 and disable it otherwise. If called from Lisp, enable the mode
80 if ARG is omitted or nil.
82 Linum mode is a buffer-local minor mode."
83 :lighter "" ; for desktop.el
84 (if linum-mode
85 (progn
86 (if linum-eager
87 (add-hook 'post-command-hook (if linum-delay
88 'linum-schedule
89 'linum-update-current) nil t)
90 (add-hook 'after-change-functions 'linum-after-change nil t))
91 (add-hook 'window-scroll-functions 'linum-after-scroll nil t)
92 ;; Using both window-size-change-functions and
93 ;; window-configuration-change-hook seems redundant. --Stef
94 ;; (add-hook 'window-size-change-functions 'linum-after-size nil t)
95 (add-hook 'change-major-mode-hook 'linum-delete-overlays nil t)
96 (add-hook 'window-configuration-change-hook
97 ;; FIXME: If the buffer is shown in N windows, this
98 ;; will be called N times rather than once. We should use
99 ;; something like linum-update-window instead.
100 'linum-update-current nil t)
101 (linum-update-current))
102 (remove-hook 'post-command-hook 'linum-update-current t)
103 (remove-hook 'post-command-hook 'linum-schedule t)
104 ;; (remove-hook 'window-size-change-functions 'linum-after-size t)
105 (remove-hook 'window-scroll-functions 'linum-after-scroll t)
106 (remove-hook 'after-change-functions 'linum-after-change t)
107 (remove-hook 'window-configuration-change-hook 'linum-update-current t)
108 (remove-hook 'change-major-mode-hook 'linum-delete-overlays t)
109 (linum-delete-overlays)))
111 ;;;###autoload
112 (define-globalized-minor-mode global-linum-mode linum-mode linum-on)
114 (defun linum-on ()
115 (unless (minibufferp)
116 (linum-mode 1)))
118 (defun linum-delete-overlays ()
119 "Delete all overlays displaying line numbers for this buffer."
120 (mapc #'delete-overlay linum-overlays)
121 (setq linum-overlays nil)
122 (dolist (w (get-buffer-window-list (current-buffer) nil t))
123 ;; restore margins if needed FIXME: This still fails if the
124 ;; "other" mode has incidentally set margins to exactly what linum
125 ;; had: see bug#20674 for a similar workaround in nlinum.el
126 (let ((set-margins (window-parameter w 'linum--set-margins))
127 (current-margins (window-margins w)))
128 (when (and set-margins
129 (equal set-margins current-margins))
130 (set-window-margins w 0 (cdr current-margins))
131 (set-window-parameter w 'linum--set-margins nil)))))
133 (defun linum-update-current ()
134 "Update line numbers for the current buffer."
135 (linum-update (current-buffer)))
137 (defun linum-update (buffer)
138 "Update line numbers for all windows displaying BUFFER."
139 (with-current-buffer buffer
140 (when linum-mode
141 (setq linum-available linum-overlays)
142 (setq linum-overlays nil)
143 (save-excursion
144 (mapc #'linum-update-window
145 (get-buffer-window-list buffer nil 'visible)))
146 (mapc #'delete-overlay linum-available)
147 (setq linum-available nil))))
149 ;; Behind display-graphic-p test.
150 (declare-function font-info "font.c" (name &optional frame))
152 (defun linum--face-width (face)
153 (let ((info (font-info (face-font face)))
154 width)
155 (setq width (aref info 11))
156 (if (<= width 0)
157 (setq width (aref info 10)))
158 width))
160 (defun linum-update-window (win)
161 "Update line numbers for the portion visible in window WIN."
162 (goto-char (window-start win))
163 (let ((line (line-number-at-pos))
164 (limit (window-end win t))
165 (fmt (cond ((stringp linum-format) linum-format)
166 ((eq linum-format 'dynamic)
167 (let ((w (length (number-to-string
168 (count-lines (point-min) (point-max))))))
169 (concat "%" (number-to-string w) "d")))))
170 (width 0))
171 (run-hooks 'linum-before-numbering-hook)
172 ;; Create an overlay (or reuse an existing one) for each
173 ;; line visible in this window, if necessary.
174 (while (and (not (eobp)) (< (point) limit))
175 (let* ((str (if fmt
176 (propertize (format fmt line) 'face 'linum)
177 (funcall linum-format line)))
178 (visited (catch 'visited
179 (dolist (o (overlays-in (point) (point)))
180 (when (equal-including-properties
181 (overlay-get o 'linum-str) str)
182 (unless (memq o linum-overlays)
183 (push o linum-overlays))
184 (setq linum-available (delq o linum-available))
185 (throw 'visited t))))))
186 (setq width (max width (length str)))
187 (unless visited
188 (let ((ov (if (null linum-available)
189 (make-overlay (point) (point))
190 (move-overlay (pop linum-available) (point) (point)))))
191 (push ov linum-overlays)
192 (overlay-put ov 'before-string
193 (propertize " " 'display `((margin left-margin) ,str)))
194 (overlay-put ov 'linum-str str))))
195 ;; Text may contain those nasty intangible properties, but that
196 ;; shouldn't prevent us from counting those lines.
197 (let ((inhibit-point-motion-hooks t))
198 (forward-line))
199 (setq line (1+ line)))
200 (when (display-graphic-p)
201 (setq width (ceiling
202 (/ (* width 1.0 (linum--face-width 'linum))
203 (frame-char-width)))))
204 ;; open up space in the left margin, if needed, and record that
205 ;; fact as the window-parameter `linum--set-margins'
206 (let ((existing-margins (window-margins win)))
207 (when (> width (or (car existing-margins) 0))
208 (set-window-margins win width (cdr existing-margins))
209 (set-window-parameter win 'linum--set-margins (window-margins win))))))
211 (defun linum-after-change (beg end _len)
212 ;; update overlays on deletions, and after newlines are inserted
213 (when (or (= beg end)
214 (= end (point-max))
215 (string-match-p "\n" (buffer-substring-no-properties beg end)))
216 (linum-update-current)))
218 (defun linum-after-scroll (win _start)
219 (linum-update (window-buffer win)))
221 ;; (defun linum-after-size (frame)
222 ;; (linum-after-config))
224 (defun linum-schedule ()
225 ;; schedule an update; the delay gives Emacs a chance for display changes
226 (run-with-idle-timer 0 nil #'linum-update-current))
228 ;; (defun linum-after-config ()
229 ;; (walk-windows (lambda (w) (linum-update (window-buffer w))) nil 'visible))
231 (defun linum-unload-function ()
232 "Unload the Linum library."
233 (global-linum-mode -1)
234 ;; continue standard unloading
235 nil)
237 (provide 'linum)
239 ;;; linum.el ends here