code.delx.au - gnu-emacs-elpa/blob - packages/nlinum/nlinum.el

   1 ;;; nlinum.el --- Show line numbers in the margin  -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 2012  Free Software Foundation, Inc.
   4
   5 ;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
   6 ;; Keywords: convenience
   7 ;; Version: 1.1
   8
   9 ;; This program is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; This program is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Commentary:
  23
  24 ;; This is like linum-mode, but uses jit-lock to be (hopefully)
  25 ;; more efficient.
  26
  27 ;;; Code:
  28
  29 (require 'linum)                        ;For its face.
  30
  31 (defvar nlinum--width 2)
  32 (make-variable-buffer-local 'nlinum--width)
  33
  34 ;; (defvar nlinum--desc "")
  35
  36 ;;;###autoload
  37 (define-minor-mode nlinum-mode
  38   "Toggle display of line numbers in the left margin (Linum mode).
  39 With a prefix argument ARG, enable Linum mode if ARG is positive,
  40 and disable it otherwise.  If called from Lisp, enable the mode
  41 if ARG is omitted or nil.
  42
  43 Linum mode is a buffer-local minor mode."
  44   :lighter nil ;; (" NLinum" nlinum--desc)
  45   (jit-lock-unregister #'nlinum--region)
  46   (remove-hook 'window-configuration-change-hook #'nlinum--setup-window t)
  47   (remove-hook 'after-change-functions #'nlinum--after-change)
  48   (kill-local-variable 'nlinum--line-number-cache)
  49   (remove-overlays (point-min) (point-max) 'nlinum t)
  50   ;; (kill-local-variable 'nlinum--ol-counter)
  51   (kill-local-variable 'nlinum--width)
  52   (when nlinum-mode
  53     (add-hook 'window-configuration-change-hook #'nlinum--setup-window nil t)
  54     (add-hook 'after-change-functions #'nlinum--after-change nil t)
  55     (jit-lock-register #'nlinum--region t))
  56   (nlinum--setup-windows))
  57
  58 (defun nlinum--setup-window ()
  59   (set-window-margins nil (if nlinum-mode nlinum--width)
  60                       (cdr (window-margins))))
  61
  62 (defun nlinum--setup-windows ()
  63   (dolist (win (get-buffer-window-list nil nil t))
  64     (with-selected-window win (nlinum--setup-window))))
  65
  66 (defun nlinum--new-width ()
  67   (nlinum--setup-windows)
  68   ;; (kill-local-variable 'nlinum--ol-counter)
  69   (remove-overlays (point-min) (point-max) 'nlinum t)
  70   (run-with-timer 0 nil
  71                   (lambda (buf)
  72                     (with-current-buffer buf
  73                       (with-silent-modifications
  74                         (remove-text-properties
  75                          (point-min) (point-max) '(fontified)))))
  76                   (current-buffer)))
  77
  78 ;; (defun nlinum--ol-count ()
  79 ;;   (let ((i 0))
  80 ;;     (dolist (ol (overlays-in (point-min) (point-max)))
  81 ;;       (when (overlay-get ol 'nlinum) (incf i)))
  82 ;;     i))
  83
  84 ;; (defvar nlinum--ol-counter 100)
  85 ;; (make-variable-buffer-local 'nlinum--ol-counter)
  86
  87 ;; (defun nlinum--flush-overlays (buffer)
  88 ;;   (with-current-buffer buffer
  89 ;;     (kill-local-variable 'nlinum--ol-counter)
  90 ;;     ;; We've created many overlays in this buffer, which can slow
  91 ;;     ;; down operations significantly.  Let's flush them.
  92 ;;     ;; An easy way to flush them is
  93 ;;     ;;   (remove-overlays min max 'nlinum t)
  94 ;;     ;;   (put-text-property min max 'fontified nil)
  95 ;;     ;; but if the visible part of the buffer requires more than
  96 ;;     ;; nlinum-overlay-threshold overlays, then we'll inf-loop.
  97 ;;     ;; So let's be more careful about removing overlays.
  98 ;;     (let ((windows (get-buffer-window-list nil nil t))
  99 ;;           (start (point-min))
 100 ;;           (debug-count (nlinum--ol-count)))
 101 ;;       (with-silent-modifications
 102 ;;         (while (< start (point-max))
 103 ;;           (let ((end (point-max)))
 104 ;;             (dolist (window windows)
 105 ;;               (cond
 106 ;;                ((< start (1- (window-start window)))
 107 ;;                 (setq end (min (1- (window-start window)) end)))
 108 ;;                ((< start (1+ (window-end window)))
 109 ;;                 (setq start (1+ (window-end window))))))
 110 ;;             (when (< start end)
 111 ;;               (remove-overlays start end 'nlinum t)
 112 ;;               ;; Warn jit-lock that this part of the buffer is not done any
 113 ;;               ;; more.  This has the downside that font-lock will be re-applied
 114 ;;               ;; as well.  But jit-lock doesn't know how to (and doesn't want
 115 ;;               ;; to) keep track of the status of its various
 116 ;;               ;; clients independently.
 117 ;;               (put-text-property start end 'fontified nil)
 118 ;;               (setq start (+ end 1))))))
 119 ;;       (let ((debug-new-count (nlinum--ol-count)))
 120 ;;         (message "Flushed %d overlays, %d remaining"
 121 ;;                  (- debug-count debug-new-count) debug-new-count)))))
 122
 123
 124 (defvar nlinum--line-number-cache nil)
 125 (make-variable-buffer-local 'nlinum--line-number-cache)
 126
 127 (defun nlinum--after-change (&rest _args)
 128   (setq nlinum--line-number-cache nil))
 129
 130 (defun nlinum--line-number-at-pos ()
 131   "Like `line-number-at-pos' but sped up with a cache."
 132   ;; (assert (bolp))
 133   (let ((pos
 134          (if (and nlinum--line-number-cache
 135                   (> (- (point) (point-min))
 136                      (abs (- (point) (car nlinum--line-number-cache)))))
 137              (funcall (if (> (point) (car nlinum--line-number-cache))
 138                           #'+ #'-)
 139                       (cdr nlinum--line-number-cache)
 140                       (count-lines (point) (car nlinum--line-number-cache)))
 141            (line-number-at-pos))))
 142     ;;(assert (= pos (line-number-at-pos)))
 143     (setq nlinum--line-number-cache (cons (point) pos))
 144     pos))
 145
 146 (defun nlinum--region (start limit)
 147   (save-excursion
 148     ;; Text may contain those nasty intangible properties, but
 149     ;; that shouldn't prevent us from counting those lines.
 150     (let ((inhibit-point-motion-hooks t))
 151       (goto-char start)
 152       (unless (bolp) (forward-line 1))
 153       (remove-overlays (point) limit 'nlinum t)
 154       (let ((line (nlinum--line-number-at-pos))
 155             (fmt (format "%%%dd" nlinum--width)))
 156         (while
 157             (and (not (eobp)) (< (point) limit)
 158                  (let* ((ol (make-overlay (point) (1+ (point))))
 159                         (str (format fmt line))
 160                         (width (string-width str)))
 161                    (when (< nlinum--width width)
 162                      (setq nlinum--width width)
 163                      (nlinum--new-width))
 164                    (overlay-put ol 'nlinum t)
 165                    (overlay-put ol 'evaporate t)
 166                    (overlay-put ol 'before-string
 167                                 (propertize " " 'display
 168                                             `((margin left-margin)
 169                                               ,(propertize str
 170                                                            'face 'linum))))
 171                    ;; (setq nlinum--ol-counter (1- nlinum--ol-counter))
 172                    ;; (when (= nlinum--ol-counter 0)
 173                    ;;   (run-with-idle-timer 0.5 nil #'nlinum--flush-overlays
 174                    ;;                        (current-buffer)))
 175                    (setq line (1+ line))
 176                    (zerop (forward-line 1))))))))
 177   ;; (setq nlinum--desc (format "-%d" (nlinum--ol-count)))
 178   nil)
 179
 180
 181 (provide 'nlinum)
 182 ;;; nlinum.el ends here