Re: org-x11idle-exists-p with emacs --daemon

[Max Nikulin]

On 28/10/2022 11:28, Ihor Radchenko wrote:
> * lisp/org-clock.el (org-x11idle-exists-p): Do not check if load-time
> `window-system' is `x'.  Instead, rely on the check in
> `org-user-idle-seconds'.

I would say that even there it is not strictly correct to test 
`window-system', perhaps `x-display-list' is a bit better since 
particular frame may be a terminal one running in xterm, but user has x 
frames. In server.el I found

    (frame-parameter frame 'display)

that might be even better and should work with daemon having a single 
frame in xterm. I can not figure out if --display command line option 
affects some variable of Emacs daemon.

Another tricky case is multiple x connection to different displays. It 
seems GTK3 have some limitations (pgtk build) and such rarely used 
configuration will become completely obsolete.

> diff --git a/lisp/org-clock.el b/lisp/org-clock.el
> index e98a34f0d..ca026c44f 100644
> --- a/lisp/org-clock.el
> +++ b/lisp/org-clock.el
> @@ -1201,8 +1201,7 @@ (defun org-mac-idle-seconds ()
>  
>  (defvar org-x11idle-exists-p
>    ;; Check that x11idle exists
> -  (and (eq window-system 'x)
> -       (eq 0 (call-process-shell-command
> +  (and (eq 0 (call-process-shell-command
>                (format "command -v %s" org-clock-x11idle-program-name)))

I joined to this discussion presuming (by some confusion) that such 
variable should be lazily initialized on first call of 
`org-user-idle-seconds'. I considered `window-system' test as a way to 
distinguish GUI and text Emacs sessions. Actually such parameter is 
dynamic. Remotely running Emacs may be disconnected from one X server 
and connected to another session.

Actually `window-system' check has another role: skip command 
availability test on systems other than Linux.

What is the result of "command -v" on Windows? Should it be executed 
there at all (unconditionally at load time)?

P.S. There are a number of X11 servers for Windows. I am unsure if Emacs 
builds for Windows and X11 frames are supported. I am lost how to 
properly test such cases in the code.