(compilation-directory): New defvar.
[bpt/emacs.git] / lisp / autorevert.el
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e8af40ee 1;;; autorevert.el --- revert buffers when files on disk change
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bf2150fa 3;; Copyright (C) 1997, 1998, 1999, 2001 Free Software Foundation, Inc.
4a35aff3 4
a468671a 5;; Author: Anders Lindgren <andersl@andersl.com>
f5f727f8 6;; Keywords: convenience
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7;; Created: 1997-06-01
8;; Date: 1999-11-30
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9
10;; This file is part of GNU Emacs.
11
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 2, or (at your option)
15;; any later version.
16
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.
21
22;; You should have received a copy of the GNU General Public License
23;; along with GNU Emacs; see the file COPYING. If not, write to the
24;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
25;; Boston, MA 02111-1307, USA.
26
27;;; Commentary:
28
29;; Introduction:
30;;
31;; Whenever a file that Emacs is editing has been changed by another
48764ae2 32;; program the user normally has to execute the command `revert-buffer'
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33;; to load the new content of the file into Emacs.
34;;
35;; This package contains two minor modes: Global Auto-Revert Mode and
48764ae2 36;; Auto-Revert Mode. Both modes automatically revert buffers
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37;; whenever the corresponding files have been changed on disk.
38;;
39;; Auto-Revert Mode can be activated for individual buffers.
40;; Global Auto-Revert Mode applies to all file buffers.
41;;
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42;; Both modes operate by checking the time stamp of all files at
43;; intervals of `auto-revert-interval'. The default is every five
44;; seconds. The check is aborted whenever the user actually uses
45;; Emacs. You should never even notice that this package is active
46;; (except that your buffers will be reverted, of course).
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47
48;; Usage:
49;;
50;; Go to the appropriate buffer and press:
51;; M-x auto-revert-mode RET
52;;
53;; To activate Global Auto-Revert Mode, press:
54;; M-x global-auto-revert-mode RET
55;;
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56;; To activate Global Auto-Revert Mode every time Emacs is started
57;; customise the option `global-auto-revert-mode' or the following
58;; line could be added to your ~/.emacs:
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59;; (global-auto-revert-mode 1)
60;;
61;; The function `turn-on-auto-revert-mode' could be added to any major
62;; mode hook to activate Auto-Revert Mode for all buffers in that
63;; mode. For example, the following line will activate Auto-Revert
64;; Mode in all C mode buffers:
65;;
66;; (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)
67
68;;; Code:
69
70;; Dependencies:
71
72(require 'timer)
73(eval-when-compile (require 'cl))
74
75
76;; Custom Group:
77;;
78;; The two modes will be placed next to Auto Save Mode under the
79;; Files group under Emacs.
80
81(defgroup auto-revert nil
48764ae2 82 "Revert individual buffers when files on disk change.
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83
84Auto-Revert Mode can be activated for individual buffer.
85Global Auto-Revert Mode applies to all buffers."
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86 :group 'files
87 :group 'convenience)
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88
89
90;; Variables:
91
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92;; Autoload for the benefit of `make-mode-line-mouse-sensitive'.
93;;;###autoload
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94(defvar auto-revert-mode nil
95 "*Non-nil when Auto-Revert Mode is active.
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96Never set this variable directly, use the command `auto-revert-mode' instead.")
97(put 'auto-revert-mode 'permanent-local t)
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98
99(defcustom auto-revert-interval 5
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100 "Time, in seconds, between Auto-Revert Mode file checks.
101Setting this variable has no effect on buffers that are already in
102auto-revert-mode; it only affects buffers that are put into
103auto-revert-mode afterwards."
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104 :group 'auto-revert
105 :type 'integer)
106
107(defcustom auto-revert-stop-on-user-input t
108 "When non-nil Auto-Revert Mode stops checking files on user input."
109 :group 'auto-revert
110 :type 'boolean)
111
112(defcustom auto-revert-verbose t
113 "When nil, Auto-Revert Mode will not generate any messages.
114
115Currently, messages are generated when the mode is activated or
116deactivated, and whenever a file is reverted."
117 :group 'auto-revert
118 :type 'boolean)
119
120(defcustom auto-revert-mode-text " ARev"
121 "String to display in the mode line when Auto-Revert Mode is active.
122
123\(When the string is not empty, make sure that it has a leading space.)"
124 :tag "Auto Revert Mode Text" ; To separate it from `global-...'
125 :group 'auto-revert
126 :type 'string)
127
128(defcustom auto-revert-mode-hook nil
129 "Functions to run when Auto-Revert Mode is activated."
130 :tag "Auto Revert Mode Hook" ; To separate it from `global-...'
131 :group 'auto-revert
132 :type 'hook)
133
134(defcustom global-auto-revert-mode-text ""
135 "String to display when Global Auto-Revert Mode is active.
136
137The default is nothing since when this mode is active this text doesn't
48764ae2 138vary over time, or between buffers. Hence mode line text
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139would only waste precious space."
140 :group 'auto-revert
141 :type 'string)
142
143(defcustom global-auto-revert-mode-hook nil
144 "Hook called when Global Auto-Revert Mode is activated."
145 :group 'auto-revert
146 :type 'hook)
147
148(defcustom global-auto-revert-non-file-buffers nil
0e4f9468 149 "When nil only file buffers are reverted by Global Auto-Revert Mode.
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150
151When non-nil, both file buffers and buffers with a custom
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152`revert-buffer-function' are reverted by Global Auto-Revert Mode.
153
154Use this option with care since it could lead to excessive reverts."
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155 :group 'auto-revert
156 :type 'boolean)
157
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158(defcustom global-auto-revert-ignore-modes '()
159 "List of major modes Global Auto-Revert Mode should not check."
160 :group 'auto-revert
161 :type '(repeat sexp))
162
163(defcustom auto-revert-load-hook nil
164 "Functions to run when Auto-Revert Mode is first loaded."
165 :tag "Load Hook"
166 :group 'auto-revert
167 :type 'hook)
168
169(defvar global-auto-revert-ignore-buffer nil
f1e3ff80 170 "*When non-nil, Global Auto-Revert Mode will not revert this buffer.
4a35aff3 171
48764ae2 172This variable becomes buffer local when set in any fashion.")
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173(make-variable-buffer-local 'global-auto-revert-ignore-buffer)
174
175
176;; Internal variables:
177
178(defvar auto-revert-buffer-list '()
179 "List of buffers in Auto-Revert Mode.
180
181Note that only Auto-Revert Mode, never Global Auto-Revert Mode, adds
182buffers to this list.
183
184The timer function `auto-revert-buffers' is responsible for purging
185the list of old buffers.")
186
187(defvar auto-revert-timer nil
188 "Timer used by Auto-Revert Mode.")
189
190(defvar auto-revert-remaining-buffers '()
191 "Buffers not checked when user input stopped execution.")
192
193
194;; Functions:
195
196;;;###autoload
0e4f9468 197(define-minor-mode auto-revert-mode
48764ae2 198 "Toggle reverting buffer when file on disk changes.
4a35aff3 199
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200With arg, turn Auto Revert mode on if and only if arg is positive.
201This is a minor mode that affects only the current buffer.
4a35aff3 202Use `global-auto-revert-mode' to automatically revert all buffers."
0e4f9468 203 nil auto-revert-mode-text nil
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204 (if auto-revert-mode
205 (if (not (memq (current-buffer) auto-revert-buffer-list))
206 (push (current-buffer) auto-revert-buffer-list))
207 (setq auto-revert-buffer-list
208 (delq (current-buffer) auto-revert-buffer-list)))
209 (auto-revert-set-timer)
210 (when auto-revert-mode
0e4f9468 211 (auto-revert-buffers)))
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212
213
214;;;###autoload
215(defun turn-on-auto-revert-mode ()
216 "Turn on Auto-Revert Mode.
217
218This function is designed to be added to hooks, for example:
219 (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)"
220 (auto-revert-mode 1))
221
222
223;;;###autoload
0e4f9468 224(define-minor-mode global-auto-revert-mode
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225 "Revert any buffer when file on disk change.
226
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227With arg, turn Auto Revert mode on globally if and only if arg is positive.
228This is a minor mode that affects all buffers.
4a35aff3 229Use `auto-revert-mode' to revert a particular buffer."
0e4f9468 230 :global t :group 'auto-revert :lighter global-auto-revert-mode-text
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231 (auto-revert-set-timer)
232 (when global-auto-revert-mode
0e4f9468 233 (auto-revert-buffers)))
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234
235
236(defun auto-revert-set-timer ()
237 "Restart or cancel the timer."
238 (if (timerp auto-revert-timer)
239 (cancel-timer auto-revert-timer))
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240 (setq auto-revert-timer
241 (if (or global-auto-revert-mode auto-revert-buffer-list)
242 (run-with-timer auto-revert-interval
243 auto-revert-interval
244 'auto-revert-buffers)
245 nil)))
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246
247(defun auto-revert-buffers ()
248 "Revert buffers as specified by Auto-Revert and Global Auto-Revert Mode.
249
250Should `global-auto-revert-mode' be active all file buffers are checked.
251
252Should `auto-revert-mode' be active in some buffers, those buffers
253are checked.
254
255Non-file buffers that have a custom `revert-buffer-function' are
256reverted either when Auto-Revert Mode is active in that buffer, or
257when the variable `global-auto-revert-non-file-buffers' is non-nil
258and Global Auto-Revert Mode is active.
259
48764ae2 260This function stops whenever there is user input. The buffers not
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261checked are stored in the variable `auto-revert-remaining-buffers'.
262
263To avoid starvation, the buffers in `auto-revert-remaining-buffers'
264are checked first the next time this function is called.
265
48764ae2 266This function is also responsible for removing buffers no longer in
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267Auto-Revert mode from `auto-revert-buffer-list', and for canceling
268the timer when no buffers need to be checked."
269 (let ((bufs (if global-auto-revert-mode
270 (buffer-list)
271 auto-revert-buffer-list))
272 (remaining '())
273 (new '()))
274 ;; Partition `bufs' into two halves depending on whether or not
275 ;; the buffers are in `auto-revert-remaining-buffers'. The two
276 ;; halves are then re-joined with the "remaining" buffers at the
277 ;; head of the list.
278 (dolist (buf auto-revert-remaining-buffers)
279 (if (memq buf bufs)
280 (push buf remaining)))
281 (dolist (buf bufs)
282 (if (not (memq buf remaining))
283 (push buf new)))
284 (setq bufs (nreverse (nconc new remaining)))
285 (while (and bufs
286 (not (and auto-revert-stop-on-user-input
287 (input-pending-p))))
288 (let ((buf (car bufs)))
289 (if (buffer-name buf) ; Buffer still alive?
0e4f9468 290 (with-current-buffer buf
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291 ;; Test if someone has turned off Auto-Revert Mode in a
292 ;; non-standard way, for example by changing major mode.
293 (if (and (not auto-revert-mode)
294 (memq buf auto-revert-buffer-list))
295 (setq auto-revert-buffer-list
296 (delq buf auto-revert-buffer-list)))
297 (when (and
298 (or auto-revert-mode
299 (and
300 global-auto-revert-mode
301 (not global-auto-revert-ignore-buffer)
302 (not (memq major-mode
303 global-auto-revert-ignore-modes))))
304 (not (buffer-modified-p))
305 (if (buffer-file-name)
306 (and (file-readable-p (buffer-file-name))
307 (not (verify-visited-file-modtime buf)))
308 (and revert-buffer-function
309 (or (and global-auto-revert-mode
310 global-auto-revert-non-file-buffers)
311 auto-revert-mode))))
312 (if auto-revert-verbose
313 (message "Reverting buffer `%s'." buf))
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314 (revert-buffer 'ignore-auto 'dont-ask 'preserve-modes)
315 ;; `preserve-modes' avoids changing the (minor) modes. But we
316 ;; do want to reset the mode for VC, so we do it explicitly.
317 (vc-find-file-hook)))
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318 ;; Remove dead buffer from `auto-revert-buffer-list'.
319 (setq auto-revert-buffer-list
320 (delq buf auto-revert-buffer-list))))
321 (setq bufs (cdr bufs)))
322 (setq auto-revert-remaining-buffers bufs)
323 ;; Check if we should cancel the timer.
324 (when (and (not global-auto-revert-mode)
325 (null auto-revert-buffer-list))
326 (cancel-timer auto-revert-timer)
327 (setq auto-revert-timer nil))))
328
329
330;; The end:
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331(provide 'autorevert)
332
333(run-hooks 'auto-revert-load-hook)
334
ab5796a9 335;;; arch-tag: f6bcb07b-4841-477e-9e44-b18678e58876
e8af40ee 336;;; autorevert.el ends here