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emacs/lisp/obsolete/linum.el
2024-01-02 09:47:10 +08:00

254 lines
10 KiB
EmacsLisp

;;; linum.el --- display line numbers in the left margin -*- lexical-binding: t -*-
;; Copyright (C) 2008-2024 Free Software Foundation, Inc.
;; Author: Markus Triska <markus.triska@gmx.at>
;; Maintainer: emacs-devel@gnu.org
;; Keywords: convenience
;; Old-Version: 0.9x
;; Obsolete-since: 29.1
;; 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:
;; NOTE: This library was made obsolete in Emacs 29.1. We recommend
;; using either the built-in `display-line-numbers-mode', or the
;; `nlinum' package from GNU ELPA instead. The former has better
;; performance, but the latter is closer to a drop-in replacement.
;;
;; --------------------
;;
;; 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.
;;
;; Consider using native line numbers instead:
;; M-x display-line-numbers-mode
;;; Code:
(defvar-local linum-overlays nil "Overlays used in this buffer.")
(defvar-local linum-available nil "Overlays available for reuse.")
(defvar linum-before-numbering-hook nil
"Functions run in each buffer before line numbering starts.")
(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).
This mode has been largely replaced by `display-line-numbers-mode'
(which is much faster and has fewer interaction problems with other
modes).
Linum mode is a buffer-local minor mode."
:lighter "" ; for desktop.el
:append-arg-docstring t
(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)
(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-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.
;; Note that nowadays, this actually doesn't show line
;; numbers in client frames at all, because we visit the
;; file before creating the client frame. See bug#35726.
(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))))
(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-search "\n" (buffer-substring-no-properties beg end)))
(linum-update-current)))
(defun linum-after-scroll (win _start)
(linum-update (window-buffer win)))
(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-unload-function ()
"Unload the Linum library."
(global-linum-mode -1)
;; continue standard unloading
nil)
(defconst linum-version "0.9x")
(make-obsolete-variable 'linum-version 'emacs-version "28.1")
(make-obsolete 'linum-mode #'display-line-numbers-mode "29.1")
(make-obsolete 'global-linum-mode #'global-display-line-numbers-mode "29.1")
(provide 'linum)
;;; linum.el ends here