[bpt/emacs.git] / lisp / autorevert.el

;;; autorevert.el --- revert buffers when files on disk change

;; Copyright (C) 1997, 1998, 1999, 2001 Free Software Foundation, Inc.

;; Author: Anders Lindgren <andersl@andersl.com>
;; Keywords: convenience
;; Created: 1997-06-01
;; Date: 1999-11-30

;; 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 2, 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; Introduction:
;;
;; Whenever a file that Emacs is editing has been changed by another
;; program the user normally has to execute the command `revert-buffer'
;; to load the new content of the file into Emacs.
;;
;; This package contains two minor modes: Global Auto-Revert Mode and
;; Auto-Revert Mode.  Both modes automatically revert buffers
;; whenever the corresponding files have been changed on disk.
;;
;; Auto-Revert Mode can be activated for individual buffers.
;; Global Auto-Revert Mode applies to all file buffers.
;;
;; Both modes operate by checking the time stamp of all files at
;; intervals of `auto-revert-interval'.  The default is every five
;; seconds.  The check is aborted whenever the user actually uses
;; Emacs.  You should never even notice that this package is active
;; (except that your buffers will be reverted, of course).

;; Usage:
;;
;; Go to the appropriate buffer and press:
;;   M-x auto-revert-mode RET
;;
;; To activate Global Auto-Revert Mode, press:
;;   M-x global-auto-revert-mode RET
;;
;; To activate Global Auto-Revert Mode every time Emacs is started
;; customise the option `global-auto-revert-mode' or the following
;; line could be added to your ~/.emacs:
;;   (global-auto-revert-mode 1)
;;
;; The function `turn-on-auto-revert-mode' could be added to any major
;; mode hook to activate Auto-Revert Mode for all buffers in that
;; mode.  For example, the following line will activate Auto-Revert
;; Mode in all C mode buffers:
;;
;; (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)

;;; Code:

;; Dependencies:

(require 'timer)
(eval-when-compile (require 'cl))


;; Custom Group:
;;
;; The two modes will be placed next to Auto Save Mode under the
;; Files group under Emacs.

(defgroup auto-revert nil
  "Revert individual buffers when files on disk change.

Auto-Revert Mode can be activated for individual buffer.
Global Auto-Revert Mode applies to all buffers."
  :group 'files
  :group 'convenience)


;; Variables:

;; Autoload for the benefit of `make-mode-line-mouse-sensitive'.
;;;###autoload
(defvar auto-revert-mode nil
  "*Non-nil when Auto-Revert Mode is active.

Never set this variable directly, use the command `auto-revert-mode'
instead.")

;;;###autoload
(defcustom global-auto-revert-mode nil
  "When on, buffers are automatically reverted when files on disk change.

Set this variable using \\[customize] only.  Otherwise, use the
command `global-auto-revert-mode'."
  :group 'auto-revert
  :initialize 'custom-initialize-default
  :set '(lambda (symbol value)
	  (global-auto-revert-mode (or value 0)))
  :type 'boolean
  :require 'autorevert)

(defcustom auto-revert-interval 5
  "Time, in seconds, between Auto-Revert Mode file checks."
  :group 'auto-revert
  :type 'integer)

(defcustom auto-revert-stop-on-user-input t
  "When non-nil Auto-Revert Mode stops checking files on user input."
  :group 'auto-revert
  :type 'boolean)

(defcustom auto-revert-verbose t
  "When nil, Auto-Revert Mode will not generate any messages.

Currently, messages are generated when the mode is activated or
deactivated, and whenever a file is reverted."
  :group 'auto-revert
  :type 'boolean)

(defcustom auto-revert-mode-text " ARev"
  "String to display in the mode line when Auto-Revert Mode is active.

\(When the string is not empty, make sure that it has a leading space.)"
  :tag "Auto Revert Mode Text"		; To separate it from `global-...'
  :group 'auto-revert
  :type 'string)

(defcustom auto-revert-mode-hook nil
  "Functions to run when Auto-Revert Mode is activated."
  :tag "Auto Revert Mode Hook"		; To separate it from `global-...'
  :group 'auto-revert
  :type 'hook)

(defcustom global-auto-revert-mode-text ""
  "String to display when Global Auto-Revert Mode is active.

The default is nothing since when this mode is active this text doesn't
vary over time, or between buffers.  Hence mode line text
would only waste precious space."
  :group 'auto-revert
  :type 'string)

(defcustom global-auto-revert-mode-hook nil
  "Hook called when Global Auto-Revert Mode is activated."
  :group 'auto-revert
  :type 'hook)

(defcustom global-auto-revert-non-file-buffers nil
  "*When nil only file buffers are reverted by Global Auto-Revert Mode.

When non-nil, both file buffers and buffers with a custom
`revert-buffer-function' are reverted by Global Auto-Revert Mode."
  :group 'auto-revert
  :type 'boolean)

(defcustom global-auto-revert-ignore-modes '()
  "List of major modes Global Auto-Revert Mode should not check."
  :group 'auto-revert
  :type '(repeat sexp))

(defcustom auto-revert-load-hook nil
  "Functions to run when Auto-Revert Mode is first loaded."
  :tag "Load Hook"
  :group 'auto-revert
  :type 'hook)

(defvar global-auto-revert-ignore-buffer nil
  "*When non-nil, Global Auto-Revert Mode will not revert this buffer.

This variable becomes buffer local when set in any fashion.")
(make-variable-buffer-local 'global-auto-revert-ignore-buffer)


;; Internal variables:

(defvar auto-revert-buffer-list '()
  "List of buffers in Auto-Revert Mode.

Note that only Auto-Revert Mode, never Global Auto-Revert Mode, adds
buffers to this list.

The timer function `auto-revert-buffers' is responsible for purging
the list of old buffers.")

(defvar auto-revert-timer nil
  "Timer used by Auto-Revert Mode.")

(defvar auto-revert-remaining-buffers '()
  "Buffers not checked when user input stopped execution.")


;; Functions:

;;;###autoload
(defun auto-revert-mode (&optional arg)
  "Toggle reverting buffer when file on disk changes.

With arg, turn Auto Revert mode on if and only if arg is positive.
This is a minor mode that affects only the current buffer.
Use `global-auto-revert-mode' to automatically revert all buffers."
  (interactive "P")
  (make-local-variable 'auto-revert-mode)
  (put 'auto-revert-mode 'permanent-local t)
  (setq auto-revert-mode
	(if (null arg)
	    (not auto-revert-mode)
	  (> (prefix-numeric-value arg) 0)))
  (if (and auto-revert-verbose
	   (interactive-p))
      (message "Auto-Revert Mode is now %s."
	       (if auto-revert-mode "on" "off")))
  (if auto-revert-mode
      (if (not (memq (current-buffer) auto-revert-buffer-list))
	  (push (current-buffer) auto-revert-buffer-list))
    (setq auto-revert-buffer-list
	  (delq (current-buffer) auto-revert-buffer-list)))
  (auto-revert-set-timer)
  (when auto-revert-mode
    (auto-revert-buffers)
    (run-hooks 'auto-revert-mode-hook))
  auto-revert-mode)


;;;###autoload
(defun turn-on-auto-revert-mode ()
  "Turn on Auto-Revert Mode.

This function is designed to be added to hooks, for example:
  (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)"
  (auto-revert-mode 1))


;;;###autoload
(defun global-auto-revert-mode (&optional arg)
  "Revert any buffer when file on disk change.

With arg, turn Auto Revert mode on globally if and only if arg is positive.
This is a minor mode that affects all buffers.
Use `auto-revert-mode' to revert a particular buffer."
  (interactive "P")
  (setq global-auto-revert-mode
	(if (null arg)
	    (not global-auto-revert-mode)
	  (> (prefix-numeric-value arg) 0)))
  (if (and auto-revert-verbose
	   (interactive-p))
      (message "Global Auto-Revert Mode is now %s."
	       (if global-auto-revert-mode "on" "off")))
  (auto-revert-set-timer)
  (when global-auto-revert-mode
    (auto-revert-buffers)      
    (run-hooks 'global-auto-revert-mode-hook)))


(defun auto-revert-set-timer ()
  "Restart or cancel the timer."
  (if (timerp auto-revert-timer)
      (cancel-timer auto-revert-timer))
  (if (or global-auto-revert-mode auto-revert-buffer-list)
      (setq auto-revert-timer (run-with-timer auto-revert-interval
					      auto-revert-interval
					      'auto-revert-buffers))
    (setq auto-revert-timer nil)))


(defun auto-revert-buffers ()
  "Revert buffers as specified by Auto-Revert and Global Auto-Revert Mode.

Should `global-auto-revert-mode' be active all file buffers are checked.

Should `auto-revert-mode' be active in some buffers, those buffers
are checked.

Non-file buffers that have a custom `revert-buffer-function' are
reverted either when Auto-Revert Mode is active in that buffer, or
when the variable `global-auto-revert-non-file-buffers' is non-nil
and Global Auto-Revert Mode is active.

This function stops whenever there is user input.  The buffers not
checked are stored in the variable `auto-revert-remaining-buffers'.

To avoid starvation, the buffers in `auto-revert-remaining-buffers'
are checked first the next time this function is called.

This function is also responsible for removing buffers no longer in
Auto-Revert mode from `auto-revert-buffer-list', and for canceling
the timer when no buffers need to be checked."
  (let ((bufs (if global-auto-revert-mode
		  (buffer-list)
		auto-revert-buffer-list))
	(remaining '())
	(new '()))
    ;; Partition `bufs' into two halves depending on whether or not
    ;; the buffers are in `auto-revert-remaining-buffers'.  The two
    ;; halves are then re-joined with the "remaining" buffers at the
    ;; head of the list.
    (dolist (buf auto-revert-remaining-buffers)
      (if (memq buf bufs)
	  (push buf remaining)))
    (dolist (buf bufs)
      (if (not (memq buf remaining))
	  (push buf new)))
    (setq bufs (nreverse (nconc new remaining)))
    (while (and bufs
		(not (and auto-revert-stop-on-user-input
			  (input-pending-p))))
      (let ((buf (car bufs)))
	(if (buffer-name buf)		; Buffer still alive?
	    (save-excursion
	      (set-buffer buf)
	      ;; Test if someone has turned off Auto-Revert Mode in a
	      ;; non-standard way, for example by changing major mode.
	      (if (and (not auto-revert-mode)
		       (memq buf auto-revert-buffer-list))
		  (setq auto-revert-buffer-list
			(delq buf auto-revert-buffer-list)))
	      (when (and
		     (or auto-revert-mode
			 (and
			  global-auto-revert-mode
			  (not global-auto-revert-ignore-buffer)
			  (not (memq major-mode
				     global-auto-revert-ignore-modes))))
		     (not (buffer-modified-p))
		     (if (buffer-file-name)
			 (and (file-readable-p (buffer-file-name))
			      (not (verify-visited-file-modtime buf)))
		       (and revert-buffer-function
			    (or (and global-auto-revert-mode
				     global-auto-revert-non-file-buffers)
				auto-revert-mode))))
		(if auto-revert-verbose
		    (message "Reverting buffer `%s'." buf))
		(revert-buffer t t t)))
	  ;; Remove dead buffer from `auto-revert-buffer-list'.
	  (setq auto-revert-buffer-list
		(delq buf auto-revert-buffer-list))))
      (setq bufs (cdr bufs)))
    (setq auto-revert-remaining-buffers bufs)
    ;; Check if we should cancel the timer.
    (when (and (not global-auto-revert-mode)
	       (null auto-revert-buffer-list))
      (cancel-timer auto-revert-timer)
      (setq auto-revert-timer nil))))


;; The end:

(unless (assq 'auto-revert-mode minor-mode-alist)
  (push '(auto-revert-mode auto-revert-mode-text)
	minor-mode-alist))
(unless (assq 'global-auto-revert-mode minor-mode-alist)
  (push '(global-auto-revert-mode global-auto-revert-mode-text)
	minor-mode-alist))

(provide 'autorevert)

(run-hooks 'auto-revert-load-hook)

;; This makes it possible to set Global Auto-Revert Mode from
;; Customize.
(if global-auto-revert-mode
    (global-auto-revert-mode 1))

;;; autorevert.el ends here
Commit	Line	Data
e8af40ee	1	;;; autorevert.el --- revert buffers when files on disk change
4a35aff3	2
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
a468671a GM	7	;; Created: 1997-06-01
a468671a GM	8	;; Date: 1999-11-30
4a35aff3 RS	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'
4a35aff3 RS	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
4a35aff3 RS	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	;;
48764ae2 DL	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).
4a35aff3 RS	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	;;
48764ae2 DL	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:
4a35aff3 RS	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.
4a35aff3 RS	83
	84	Auto-Revert Mode can be activated for individual buffer.
	85	Global Auto-Revert Mode applies to all buffers."
f5f727f8 DN	86	:group 'files
f5f727f8 DN	87	:group 'convenience)
4a35aff3 RS	88
	89
	90	;; Variables:
	91
00d0fda8 DL	92	;; Autoload for the benefit of `make-mode-line-mouse-sensitive'.
00d0fda8 DL	93	;;;###autoload
4a35aff3 RS	94	(defvar auto-revert-mode nil
	95	"*Non-nil when Auto-Revert Mode is active.
	96
48764ae2 DL	97	Never set this variable directly, use the command `auto-revert-mode'
48764ae2 DL	98	instead.")
4a35aff3	99
6ea3b61f	100	;;;###autoload
4a35aff3 RS	101	(defcustom global-auto-revert-mode nil
	102	"When on, buffers are automatically reverted when files on disk change.
	103
48764ae2 DL	104	Set this variable using \\[customize] only. Otherwise, use the
48764ae2 DL	105	command `global-auto-revert-mode'."
4a35aff3 RS	106	:group 'auto-revert
	107	:initialize 'custom-initialize-default
	108	:set '(lambda (symbol value)
	109	(global-auto-revert-mode (or value 0)))
	110	:type 'boolean
	111	:require 'autorevert)
	112
	113	(defcustom auto-revert-interval 5
	114	"Time, in seconds, between Auto-Revert Mode file checks."
	115	:group 'auto-revert
	116	:type 'integer)
	117
	118	(defcustom auto-revert-stop-on-user-input t
	119	"When non-nil Auto-Revert Mode stops checking files on user input."
	120	:group 'auto-revert
	121	:type 'boolean)
	122
	123	(defcustom auto-revert-verbose t
	124	"When nil, Auto-Revert Mode will not generate any messages.
	125
	126	Currently, messages are generated when the mode is activated or
	127	deactivated, and whenever a file is reverted."
	128	:group 'auto-revert
	129	:type 'boolean)
	130
	131	(defcustom auto-revert-mode-text " ARev"
	132	"String to display in the mode line when Auto-Revert Mode is active.
	133
	134	\(When the string is not empty, make sure that it has a leading space.)"
	135	:tag "Auto Revert Mode Text" ; To separate it from `global-...'
	136	:group 'auto-revert
	137	:type 'string)
	138
	139	(defcustom auto-revert-mode-hook nil
	140	"Functions to run when Auto-Revert Mode is activated."
	141	:tag "Auto Revert Mode Hook" ; To separate it from `global-...'
	142	:group 'auto-revert
	143	:type 'hook)
	144
	145	(defcustom global-auto-revert-mode-text ""
	146	"String to display when Global Auto-Revert Mode is active.
	147
	148	The default is nothing since when this mode is active this text doesn't
48764ae2	149	vary over time, or between buffers. Hence mode line text
4a35aff3 RS	150	would only waste precious space."
	151	:group 'auto-revert
	152	:type 'string)
	153
	154	(defcustom global-auto-revert-mode-hook nil
	155	"Hook called when Global Auto-Revert Mode is activated."
	156	:group 'auto-revert
	157	:type 'hook)
	158
	159	(defcustom global-auto-revert-non-file-buffers nil
	160	"*When nil only file buffers are reverted by Global Auto-Revert Mode.
	161
	162	When non-nil, both file buffers and buffers with a custom
	163	`revert-buffer-function' are reverted by Global Auto-Revert Mode."
	164	:group 'auto-revert
	165	:type 'boolean)
	166
4a35aff3 RS	167	(defcustom global-auto-revert-ignore-modes '()
	168	"List of major modes Global Auto-Revert Mode should not check."
	169	:group 'auto-revert
	170	:type '(repeat sexp))
	171
	172	(defcustom auto-revert-load-hook nil
	173	"Functions to run when Auto-Revert Mode is first loaded."
	174	:tag "Load Hook"
	175	:group 'auto-revert
	176	:type 'hook)
	177
	178	(defvar global-auto-revert-ignore-buffer nil
f1e3ff80	179	"*When non-nil, Global Auto-Revert Mode will not revert this buffer.
4a35aff3	180
48764ae2	181	This variable becomes buffer local when set in any fashion.")
4a35aff3 RS	182	(make-variable-buffer-local 'global-auto-revert-ignore-buffer)
	183
	184
	185	;; Internal variables:
	186
	187	(defvar auto-revert-buffer-list '()
	188	"List of buffers in Auto-Revert Mode.
	189
	190	Note that only Auto-Revert Mode, never Global Auto-Revert Mode, adds
	191	buffers to this list.
	192
	193	The timer function `auto-revert-buffers' is responsible for purging
	194	the list of old buffers.")
	195
	196	(defvar auto-revert-timer nil
	197	"Timer used by Auto-Revert Mode.")
	198
	199	(defvar auto-revert-remaining-buffers '()
	200	"Buffers not checked when user input stopped execution.")
	201
	202
	203	;; Functions:
	204
	205	;;;###autoload
	206	(defun auto-revert-mode (&optional arg)
48764ae2	207	"Toggle reverting buffer when file on disk changes.
4a35aff3	208
48764ae2 DL	209	With arg, turn Auto Revert mode on if and only if arg is positive.
48764ae2 DL	210	This is a minor mode that affects only the current buffer.
4a35aff3 RS	211	Use `global-auto-revert-mode' to automatically revert all buffers."
	212	(interactive "P")
	213	(make-local-variable 'auto-revert-mode)
afa95cac	214	(put 'auto-revert-mode 'permanent-local t)
4a35aff3 RS	215	(setq auto-revert-mode
	216	(if (null arg)
	217	(not auto-revert-mode)
	218	(> (prefix-numeric-value arg) 0)))
	219	(if (and auto-revert-verbose
	220	(interactive-p))
	221	(message "Auto-Revert Mode is now %s."
	222	(if auto-revert-mode "on" "off")))
	223	(if auto-revert-mode
	224	(if (not (memq (current-buffer) auto-revert-buffer-list))
	225	(push (current-buffer) auto-revert-buffer-list))
	226	(setq auto-revert-buffer-list
	227	(delq (current-buffer) auto-revert-buffer-list)))
	228	(auto-revert-set-timer)
	229	(when auto-revert-mode
	230	(auto-revert-buffers)
39d62e7a GM	231	(run-hooks 'auto-revert-mode-hook))
39d62e7a GM	232	auto-revert-mode)
4a35aff3 RS	233
	234
	235	;;;###autoload
	236	(defun turn-on-auto-revert-mode ()
	237	"Turn on Auto-Revert Mode.
	238
	239	This function is designed to be added to hooks, for example:
	240	(add-hook 'c-mode-hook 'turn-on-auto-revert-mode)"
	241	(auto-revert-mode 1))
	242
	243
	244	;;;###autoload
	245	(defun global-auto-revert-mode (&optional arg)
	246	"Revert any buffer when file on disk change.
	247
48764ae2 DL	248	With arg, turn Auto Revert mode on globally if and only if arg is positive.
48764ae2 DL	249	This is a minor mode that affects all buffers.
4a35aff3 RS	250	Use `auto-revert-mode' to revert a particular buffer."
	251	(interactive "P")
	252	(setq global-auto-revert-mode
	253	(if (null arg)
	254	(not global-auto-revert-mode)
	255	(> (prefix-numeric-value arg) 0)))
	256	(if (and auto-revert-verbose
	257	(interactive-p))
f1e3ff80	258	(message "Global Auto-Revert Mode is now %s."
4a35aff3 RS	259	(if global-auto-revert-mode "on" "off")))
	260	(auto-revert-set-timer)
	261	(when global-auto-revert-mode
	262	(auto-revert-buffers)
	263	(run-hooks 'global-auto-revert-mode-hook)))
	264
	265
	266	(defun auto-revert-set-timer ()
	267	"Restart or cancel the timer."
	268	(if (timerp auto-revert-timer)
	269	(cancel-timer auto-revert-timer))
	270	(if (or global-auto-revert-mode auto-revert-buffer-list)
	271	(setq auto-revert-timer (run-with-timer auto-revert-interval
	272	auto-revert-interval
	273	'auto-revert-buffers))
	274	(setq auto-revert-timer nil)))
	275
	276
	277	(defun auto-revert-buffers ()
	278	"Revert buffers as specified by Auto-Revert and Global Auto-Revert Mode.
	279
	280	Should `global-auto-revert-mode' be active all file buffers are checked.
	281
	282	Should `auto-revert-mode' be active in some buffers, those buffers
	283	are checked.
	284
	285	Non-file buffers that have a custom `revert-buffer-function' are
	286	reverted either when Auto-Revert Mode is active in that buffer, or
	287	when the variable `global-auto-revert-non-file-buffers' is non-nil
	288	and Global Auto-Revert Mode is active.
	289
48764ae2	290	This function stops whenever there is user input. The buffers not
4a35aff3 RS	291	checked are stored in the variable `auto-revert-remaining-buffers'.
	292
	293	To avoid starvation, the buffers in `auto-revert-remaining-buffers'
	294	are checked first the next time this function is called.
	295
48764ae2	296	This function is also responsible for removing buffers no longer in
4a35aff3 RS	297	Auto-Revert mode from `auto-revert-buffer-list', and for canceling
	298	the timer when no buffers need to be checked."
	299	(let ((bufs (if global-auto-revert-mode
	300	(buffer-list)
	301	auto-revert-buffer-list))
	302	(remaining '())
	303	(new '()))
	304	;; Partition `bufs' into two halves depending on whether or not
	305	;; the buffers are in `auto-revert-remaining-buffers'. The two
	306	;; halves are then re-joined with the "remaining" buffers at the
	307	;; head of the list.
	308	(dolist (buf auto-revert-remaining-buffers)
	309	(if (memq buf bufs)
	310	(push buf remaining)))
	311	(dolist (buf bufs)
	312	(if (not (memq buf remaining))
	313	(push buf new)))
	314	(setq bufs (nreverse (nconc new remaining)))
	315	(while (and bufs
	316	(not (and auto-revert-stop-on-user-input
	317	(input-pending-p))))
	318	(let ((buf (car bufs)))
	319	(if (buffer-name buf) ; Buffer still alive?
	320	(save-excursion
	321	(set-buffer buf)
	322	;; Test if someone has turned off Auto-Revert Mode in a
	323	;; non-standard way, for example by changing major mode.
	324	(if (and (not auto-revert-mode)
	325	(memq buf auto-revert-buffer-list))
	326	(setq auto-revert-buffer-list
	327	(delq buf auto-revert-buffer-list)))
	328	(when (and
	329	(or auto-revert-mode
	330	(and
	331	global-auto-revert-mode
	332	(not global-auto-revert-ignore-buffer)
	333	(not (memq major-mode
	334	global-auto-revert-ignore-modes))))
	335	(not (buffer-modified-p))
	336	(if (buffer-file-name)
	337	(and (file-readable-p (buffer-file-name))
	338	(not (verify-visited-file-modtime buf)))
	339	(and revert-buffer-function
	340	(or (and global-auto-revert-mode
	341	global-auto-revert-non-file-buffers)
	342	auto-revert-mode))))
	343	(if auto-revert-verbose
	344	(message "Reverting buffer `%s'." buf))
a468671a	345	(revert-buffer t t t)))
4a35aff3 RS	346	;; Remove dead buffer from `auto-revert-buffer-list'.
	347	(setq auto-revert-buffer-list
	348	(delq buf auto-revert-buffer-list))))
	349	(setq bufs (cdr bufs)))
	350	(setq auto-revert-remaining-buffers bufs)
	351	;; Check if we should cancel the timer.
	352	(when (and (not global-auto-revert-mode)
	353	(null auto-revert-buffer-list))
	354	(cancel-timer auto-revert-timer)
	355	(setq auto-revert-timer nil))))
	356
	357
	358	;; The end:
	359
	360	(unless (assq 'auto-revert-mode minor-mode-alist)
	361	(push '(auto-revert-mode auto-revert-mode-text)
	362	minor-mode-alist))
	363	(unless (assq 'global-auto-revert-mode minor-mode-alist)
	364	(push '(global-auto-revert-mode global-auto-revert-mode-text)
	365	minor-mode-alist))
	366
	367	(provide 'autorevert)
	368
	369	(run-hooks 'auto-revert-load-hook)
	370
	371	;; This makes it possible to set Global Auto-Revert Mode from
	372	;; Customize.
	373	(if global-auto-revert-mode
	374	(global-auto-revert-mode 1))
	375
e8af40ee	376	;;; autorevert.el ends here