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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-16 09:50:25 +00:00
emacs/lisp/linum.el
Paul Eggert bc511a64f6 Prefer HTTPS to FTP and HTTP in documentation
Most of this change is to boilerplate commentary such as license URLs.
This change was prompted by ftp://ftp.gnu.org's going-away party,
planned for November.  Change these FTP URLs to https://ftp.gnu.org
instead.  Make similar changes for URLs to other organizations moving
away from FTP.  Also, change HTTP to HTTPS for URLs to gnu.org and
fsf.org when this works, as this will further help defend against
man-in-the-middle attacks (for this part I omitted the MS-DOS and
MS-Windows sources and the test tarballs to keep the workload down).
HTTPS is not fully working to lists.gnu.org so I left those URLs alone
for now.
2017-09-13 15:54:37 -07:00

249 lines
9.9 KiB
EmacsLisp

;;; linum.el --- display line numbers in the left margin -*- lexical-binding: t -*-
;; Copyright (C) 2008-2017 Free Software Foundation, Inc.
;; Author: Markus Triska <markus.triska@gmx.at>
;; Maintainer: emacs-devel@gnu.org
;; Keywords: convenience
;; Version: 0.9x
;; 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
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; 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 <https://www.gnu.org/licenses/>.
;;; 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 '(choice (string :tag "Format string")
(const :tag "Dynamic width" dynamic)
(function :tag "Function")))
(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)
;;;###autoload
(define-minor-mode linum-mode
"Toggle display of line numbers in the left margin (Linum mode).
With a prefix argument ARG, enable Linum mode if ARG is positive,
and disable it otherwise. If called from Lisp, enable the mode
if ARG is omitted or nil.
Linum mode is a buffer-local minor mode."
:lighter "" ; for desktop.el
(if linum-mode
(progn
(if linum-eager
(add-hook 'post-command-hook (if linum-delay
'linum-schedule
'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)
(linum-update-current))
(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)
(linum-delete-overlays)))
;;;###autoload
(define-globalized-minor-mode global-linum-mode linum-mode linum-on)
(defun linum-on ()
(unless (or (minibufferp)
;; Turning linum-mode in the daemon's initial frame
;; could significantly slow down startup, if the buffer
;; in which this is done is large, because Emacs thinks
;; the "window" spans the entire buffer then. This
;; could happen when restoring session via desktop.el,
;; if some large buffer was under linum-mode when
;; desktop was saved. So we disable linum-mode for
;; non-client frames in a daemon session.
(and (daemonp) (null (frame-parameter nil 'client))))
(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))
;; restore margins if needed FIXME: This still fails if the
;; "other" mode has incidentally set margins to exactly what linum
;; had: see bug#20674 for a similar workaround in nlinum.el
(let ((set-margins (window-parameter w 'linum--set-margins))
(current-margins (window-margins w)))
(when (and set-margins
(equal set-margins current-margins))
(set-window-margins w 0 (cdr current-margins))
(set-window-parameter w 'linum--set-margins nil)))))
(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)
(save-excursion
(mapc #'linum-update-window
(get-buffer-window-list buffer nil 'visible)))
(mapc #'delete-overlay linum-available)
(setq linum-available nil))))
;; Behind display-graphic-p test.
(declare-function font-info "font.c" (name &optional frame))
(defun linum--face-width (face)
(let ((info (font-info (face-font face)))
width)
(setq width (aref info 11))
(if (<= width 0)
(setq width (aref info 10)))
width))
(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))
(forward-line))
(setq line (1+ line)))
(when (display-graphic-p)
(setq width (ceiling
(/ (* width 1.0 (linum--face-width 'linum))
(frame-char-width)))))
;; open up space in the left margin, if needed, and record that
;; fact as the window-parameter `linum--set-margins'
(let ((existing-margins (window-margins win)))
(when (> width (or (car existing-margins) 0))
(set-window-margins win width (cdr existing-margins))
(set-window-parameter win 'linum--set-margins (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)))
(linum-update-current)))
(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
nil)
(provide 'linum)
;;; linum.el ends here