[Emacs-diffs] Changes to arevert-xtra.texi

[Glenn Morris]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     Glenn Morris <gm>       07/09/06 04:33:39

Index: arevert-xtra.texi
===================================================================
RCS file: arevert-xtra.texi
diff -N arevert-xtra.texi
--- arevert-xtra.texi   21 Jan 2007 04:41:12 -0000      1.4
+++ /dev/null   1 Jan 1970 00:00:00 -0000
@@ -1,191 +0,0 @@
address@hidden This is part of the Emacs manual.
address@hidden Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, 
Inc.
address@hidden See file emacs.texi for copying conditions.
address@hidden
address@hidden This file is included either in emacs-xtra.texi (when producing 
the
address@hidden printed version) or in the main Emacs manual (for the on-line 
version).
address@hidden Autorevert
address@hidden Auto Reverting non-file Buffers
-
-Normally Global Auto Revert Mode only reverts file buffers.  There are
-two ways to auto-revert certain non-file buffers: enabling Auto Revert
-Mode in those buffers (using @kbd{M-x auto-revert-mode}) and setting
address@hidden to @code{t}.  The latter
-enables Auto Reverting for all types of buffers for which it is
-implemented, that is, for the types of buffers listed in the menu
-below.
-
-Like file buffers, non-file buffers should normally not revert while
-you are working on them, or while they contain information that might
-get lost after reverting.  Therefore, they do not revert if they are
-``modified''.  This can get tricky, because deciding when a non-file
-buffer should be marked modified is usually more difficult than for
-file buffers.
-
-Another tricky detail is that, for efficiency reasons, Auto Revert
-often does not try to detect all possible changes in the buffer, only
-changes that are ``major'' or easy to detect.  Hence, enabling
-auto-reverting for a non-file buffer does not always guarantee that
-all information in the buffer is up to date and does not necessarily
-make manual reverts useless.
-
-At the other extreme, certain buffers automatically auto-revert every
address@hidden seconds.  (This currently only applies to
-the Buffer Menu.)  In this case, Auto Revert does not print any
-messages while reverting, even when @code{auto-revert-verbose} is
address@hidden
-
-The details depend on the particular types of buffers and are
-explained in the corresponding sections.
-
address@hidden
-* Auto Reverting the Buffer Menu::
-* Auto Reverting Dired::
-* Supporting additional buffers::
address@hidden menu
-
address@hidden Auto Reverting the Buffer Menu
address@hidden Auto Reverting the Buffer Menu
-
-If auto-reverting of non-file buffers is enabled, the Buffer Menu
-automatically reverts every @code{auto-revert-interval} seconds,
-whether there is a need for it or not.  (It would probably take longer
-to check whether there is a need than to actually revert.)
-
-If the Buffer Menu inappropriately gets marked modified, just revert
-it manually using @kbd{g} and auto-reverting will resume.  However, if
-you marked certain buffers to get deleted or to be displayed, you have
-to be careful, because reverting erases all marks.  The fact that
-adding marks sets the buffer's modified flag prevents Auto Revert from
-automatically erasing the marks.
-
address@hidden Auto Reverting Dired
address@hidden Auto Reverting Dired buffers
-
-Auto-reverting Dired buffers currently works on GNU or Unix style
-operating systems.  It may not work satisfactorily on some other
-systems.
-
-Dired buffers only auto-revert when the file list of the buffer's main
-directory changes.  They do not auto-revert when information about a
-particular file changes or when inserted subdirectories change.  To be
-sure that @emph{all} listed information is up to date, you have to
-manually revert using @kbd{g}, @emph{even} if auto-reverting is
-enabled in the Dired buffer.  Sometimes, you might get the impression
-that modifying or saving files listed in the main directory actually
-does cause auto-reverting.  This is because making changes to a file,
-or saving it, very often causes changes in the directory itself, for
-instance, through backup files or auto-save files.  However, this is
-not guaranteed.
-
-If the Dired buffer is marked modified and there are no changes you
-want to protect, then most of the time you can make auto-reverting
-resume by manually reverting the buffer using @kbd{g}.  There is one
-exception.  If you flag or mark files, you can safely revert the
-buffer.  This will not erase the flags or marks (unless the marked
-file has been deleted, of course).  However, the buffer will stay
-modified, even after reverting, and auto-reverting will not resume.
-This is because, if you flag or mark files, you may be working on the
-buffer and you might not want the buffer to change without warning.
-If you want auto-reverting to resume in the presence of marks and
-flags, mark the buffer non-modified using @kbd{M-~}.  However, adding,
-deleting or changing marks or flags will mark it modified again.
-
-Remote Dired buffers are not auto-reverted.  Neither are Dired buffers
-for which you used shell wildcards or file arguments to list only some
-of the files.  @samp{*Find*} and @samp{*Locate*} buffers do not
-auto-revert either.
-
address@hidden Supporting additional buffers
address@hidden Adding Support for Auto-Reverting additional Buffers.
-
-This section is intended for Elisp programmers who would like to add
-support for auto-reverting new types of buffers.
-
-To support auto-reverting the buffer must first of all have a
address@hidden  @xref{Definition of
-revert-buffer-function,, Reverting, elisp, the Emacs Lisp Reference Manual}.
-
-In addition, it @emph{must} have a @code{buffer-stale-function}.
-
address@hidden buffer-stale-function
-The value of this variable is a function to check whether a non-file
-buffer needs reverting.  This should be a function with one optional
-argument @var{noconfirm}.  The function should return address@hidden
-if the buffer should be reverted.  The buffer is current when this
-function is called.
-
-While this function is mainly intended for use in auto-reverting, it
-could be used for other purposes as well.  For instance, if
-auto-reverting is not enabled, it could be used to warn the user that
-the buffer needs reverting.  The idea behind the @var{noconfirm}
-argument is that it should be @code{t} if the buffer is going to be
-reverted without asking the user and @code{nil} if the function is
-just going to be used to warn the user that the buffer is out of date.
-In particular, for use in auto-reverting, @var{noconfirm} is @code{t}.
-If the function is only going to be used for auto-reverting, you can
-ignore the @var{noconfirm} argument.
-
-If you just want to automatically auto-revert every
address@hidden seconds, use:
-
address@hidden
-(set (make-local-variable 'buffer-stale-function)
-     #'(lambda (&optional noconfirm) 'fast))
address@hidden example
-
address@hidden
-in the buffer's mode function.
-
-The special return value @samp{fast} tells the caller that the need
-for reverting was not checked, but that reverting the buffer is fast.
-It also tells Auto Revert not to print any revert messages, even if
address@hidden is address@hidden  This is important, as
-getting revert messages every @code{auto-revert-interval} seconds can
-be very annoying.  The information provided by this return value could
-also be useful if the function is consulted for purposes other than
-auto-reverting.
address@hidden defvar
-
-Once the buffer has a @code{revert-buffer-function} and a
address@hidden, several problems usually remain.
-
-The buffer will only auto-revert if it is marked unmodified.  Hence,
-you will have to make sure that various functions mark the buffer
-modified if and only if either the buffer contains information that
-might be lost by reverting or there is reason to believe that the user
-might be inconvenienced by auto-reverting, because he is actively
-working on the buffer.  The user can always override this by manually
-adjusting the modified status of the buffer.  To support this, calling
-the @code{revert-buffer-function} on a buffer that is marked
-unmodified should always keep the buffer marked unmodified.
-
-It is important to assure that point does not continuously jump around
-as a consequence of auto-reverting.  Of course, moving point might be
-inevitable if the buffer radically changes.
-
-You should make sure that the @code{revert-buffer-function} does not
-print messages that unnecessarily duplicate Auto Revert's own messages
-if @code{auto-revert-verbose} is @code{t} and effectively override a
address@hidden value for @code{auto-revert-verbose}.  Hence, adapting a
-mode for auto-reverting often involves getting rid of such messages.
-This is especially important for buffers that automatically
-auto-revert every @code{auto-revert-interval} seconds.
-
-Also, you may want to update the documentation string of
address@hidden
-
address@hidden
-Finally, you should add a node to this chapter's menu.  This node
address@hidden ifinfo
address@hidden
-Finally, you should add a section to this chapter.  This section
address@hidden ifnotinfo
-should at the very least make clear whether enabling auto-reverting
-for the buffer reliably assures that all information in the buffer is
-completely up to date (or will be after @code{auto-revert-interval}
-seconds).
-
address@hidden
-   arch-tag: 2983e613-a272-45f6-9593-3010ad7f865e
address@hidden ignore