Re: IMAP IDLE command

[Dan Christensen <jdc@uwo.ca>]

You can get an external IDLE-aware program to notify Gnus using
emacsclient.  I used mail-notification for a while, and I've heard of
mswatch being used.

To avoid this happening while an IMAP command is already in progress, I
get emacsclient to call jdc-gnus-demon-scan-both below, which checks
the idle time.

One annoying thing: when emacsclient runs a function in emacs, it
seems to reset the idle time to zero.  So other things that you may
have set up to run after long idle times can get starved.  I don't
think this behaviour of emacs is correct:  unless there is human
interaction, I think emacs should be considered idle.

Dan


(defun jdc-gnus-demon-scan-both ()
  ; gnus-demon-idle-since returns the idle time in seconds as a float.
  ; These checks shouldn't be needed when this is run from gnus-demon, 
  ; but will help when it is run from ~/bin/mail-arrived.
  (when (and (not gnus-inhibit-demon)
	     (< 5 (gnus-demon-idle-since)))
    ; Setting gnus-inhibit-demon to t should prevent multiple occurrences from 
    ; running at once, either from mail-arrived or gnus-demon.  There is in 
    ; theory a race between the check above and setting the var below, but I 
    ; think emacs only allows context switches when waiting for
    ; output from a process.  In fact, if I cut and paste these into the shell:
    ;   emacsclient --no-wait --eval '(jdc-gnus-demon-scan-both)' &
    ;   emacsclient --no-wait --eval '(jdc-gnus-demon-scan-both)' &
    ; even without setting gnus-inhibit-demon to t here, still only one of 
    ; them does anything, probably because both the scan-mail and scan-news
    ; functions call functions that themselves inhibit the demon.  Still,
    ; better safe than sorry.
    (let ((gnus-inhibit-demon t))
      ; with-local-quit is used by gnus-demon, so do it here too for
      ; when we are called from mail-arrived:
      (with-local-quit
	(message "jdc-gnus-demon-scan-both running")
	(jdc-gnus-demon-scan-mail)
	(jdc-gnus-demon-scan-news)
	(message "jdc-gnus-demon-scan-both done")))))

; like stock function in gnus-demon.el, with a message, and also
; restricting to mail folders:  Hmm, the request-scan check seems to
; already limit to mainly mail servers, but also includes nnagent and
; nnweb.
(defun jdc-gnus-demon-scan-mail ()
  (interactive)
  (save-window-excursion
    (let ((servers gnus-opened-servers)
	  server
	  (nnmail-fetched-sources (list t)))
      (while (setq server (car (pop servers)))
	(and (member (car server) '(nnimap nnfolder nnml))
	     (gnus-check-backend-function 'request-scan (car server))
	     (or (gnus-server-opened server)
		 (gnus-open-server server))
	     (message "Scanning server: %s" server)
	     (gnus-request-scan nil server))))))

; like stock function, but limits to level <= 2.
; I think "news" is misleading; this is needed to update the 
; summary buffer when mail is fetched with jdc-gnus-demon-scan-mail.
; My version also has an extra save-excursion.
(defun jdc-gnus-demon-scan-news ()
  (interactive)
  (message "jdc-gnus-demon-scan-news running")
  (let ((win (current-window-configuration)))
    (unwind-protect
	(save-window-excursion
	  (when (gnus-alive-p)
	    (save-excursion
	      (with-current-buffer gnus-group-buffer
		(gnus-group-get-new-news 2)))))
      (set-window-configuration win))))