(require 'timer)
(eval-when-compile (require 'cl))
(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)
(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.")
(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" :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" :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)
(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.")
(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)
(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))
(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 '()))
(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) (save-excursion
(set-buffer buf)
(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)))
(setq auto-revert-buffer-list
(delq buf auto-revert-buffer-list))))
(setq bufs (cdr bufs)))
(setq auto-revert-remaining-buffers bufs)
(when (and (not global-auto-revert-mode)
(null auto-revert-buffer-list))
(cancel-timer auto-revert-timer)
(setq auto-revert-timer nil))))
(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)
(if global-auto-revert-mode
(global-auto-revert-mode 1))