option for loading up a gui specific emacs daemon

option for loading up a gui specific emacs daemon

[Filipe Silva]

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Dear developers of the mighty emacs editor,

I'd like to load emacs with emacs --daemon=gui and then connect to it with
emacsclient -c --sever-file=gui.

This works almost right. The problem is that various popular packages make
extensive use of the (display-graphic-p) function/predicate to query frame
capabilities. For example, a theme package may query (display-graphic-p)
and assign gui or tty colors accordingly.

the thing is that(display-graphic-p) always returns nil in a emacs --deamon
type of loading, because emacs does not know if you are using emacsclient
with a gui or a tty.

Is there a way to say to emacs something like, "look, I'm starting you as a
daemon, but I promise I'll only connect to you with gui frames, so for all
intents and purposes, pretend that you are being started up as a gui".

If there is not a way to do that, maybe we could add that kind of option?

The impact of not having this options is that cosmetic packages that make
use of (display-graphic-p) always look off in a emacs --daemon loading
scenario.

thanks in advance,

Ninrod

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Re: option for loading up a gui specific emacs daemon

[Alex Hutcheson]

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Have you tried starting emacs with:
emacsclient -c -a ""

That should start a daemon if one isn't already running. I can't easily
check the value of (display-graphic-p) during loadup right now, but it
would be easy to try.

On Tue, Dec 13, 2016 at 6:02 PM, Filipe Silva <filipe.silva@gmail.com>
wrote:

> Dear developers of the mighty emacs editor,
>
> I'd like to load emacs with emacs --daemon=gui and then connect to it with
> emacsclient -c --sever-file=gui.
>
> This works almost right. The problem is that various popular packages make
> extensive use of the (display-graphic-p) function/predicate to query frame
> capabilities. For example, a theme package may query (display-graphic-p)
> and assign gui or tty colors accordingly.
>
> the thing is that(display-graphic-p) always returns nil in a emacs
> --deamon type of loading, because emacs does not know if you are using
> emacsclient with a gui or a tty.
>
> Is there a way to say to emacs something like, "look, I'm starting you as
> a daemon, but I promise I'll only connect to you with gui frames, so for
> all intents and purposes, pretend that you are being started up as a gui".
>
> If there is not a way to do that, maybe we could add that kind of option?
>
> The impact of not having this options is that cosmetic packages that make
> use of (display-graphic-p) always look off in a emacs --daemon loading
> scenario.
>
> thanks in advance,
>
> Ninrod
>



-- 
Alex Hutcheson
alexhutcheson@google.com

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Re: option for loading up a gui specific emacs daemon

[Kaushal Modi]

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On Wed, Dec 14, 2016, 4:33 AM Filipe Silva <filipe.silva@gmail.com> wrote:

> The problem is that various popular packages make extensive use of the
> (display-graphic-p) function/predicate to query frame capabilities. For
> example, a theme package may query (display-graphic-p) and assign gui or
> tty colors accordingly.
>

Which packages are those, how can one recreate the issue you are seeing in
an emacs -Q session (for the case of emacsclient, I am aware that emacs -Q
does not help, so one would need to temporarily move their ~/.emacs.d/ dir
to something else, and use a minimal config that just starts the server)
after loading those packages?

> --

Kaushal Modi

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Re: option for loading up a gui specific emacs daemon

[Noam Postavsky]

On Tue, Dec 13, 2016 at 6:02 PM, Filipe Silva <filipe.silva@gmail.com> wrote:
>
> Is there a way to say to emacs something like, "look, I'm starting you as a
> daemon, but I promise I'll only connect to you with gui frames, so for all
> intents and purposes, pretend that you are being started up as a gui".

Advise display-graphic-p?

Re: option for loading up a gui specific emacs daemon

[Filipe Silva]

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Noam, that looks promising. Is there a way to advise display-graphic-p to
always return true but only if I started emacs as emacs --daemon=gui?

On Tue, Dec 13, 2016 at 11:34 PM, Noam Postavsky <
npostavs@users.sourceforge.net> wrote:

> On Tue, Dec 13, 2016 at 6:02 PM, Filipe Silva <filipe.silva@gmail.com>
> wrote:
> >
> > Is there a way to say to emacs something like, "look, I'm starting you
> as a
> > daemon, but I promise I'll only connect to you with gui frames, so for
> all
> > intents and purposes, pretend that you are being started up as a gui".
>
> Advise display-graphic-p?
>

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Re: option for loading up a gui specific emacs daemon

[Filipe Silva]

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Kaushal, the zerodark theme by Nicolas Petton, for example:

https://github.com/NicolasPetton/zerodark-theme/blob/master/zerodark-theme.el#L158-L162

It is difficult to write a reproducible procedure because if you don't know
the theme, you think that colors are right. But they are not.

One would have to install the theme, load up emacs gui normally, and then
load up emacs with --daemon and compare the differences.



On Tue, Dec 13, 2016 at 10:02 PM, Kaushal Modi <kaushal.modi@gmail.com>
wrote:

>
>
> On Wed, Dec 14, 2016, 4:33 AM Filipe Silva <filipe.silva@gmail.com> wrote:
>
>> The problem is that various popular packages make extensive use of the
>> (display-graphic-p) function/predicate to query frame capabilities. For
>> example, a theme package may query (display-graphic-p) and assign gui or
>> tty colors accordingly.
>>
>
> Which packages are those, how can one recreate the issue you are seeing in
> an emacs -Q session (for the case of emacsclient, I am aware that emacs -Q
> does not help, so one would need to temporarily move their ~/.emacs.d/ dir
> to something else, and use a minimal config that just starts the server)
> after loading those packages?
>
>> --
>
> Kaushal Modi
>

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Re: option for loading up a gui specific emacs daemon

[Eli Zaretskii]

> From: Filipe Silva <filipe.silva@gmail.com>
> Date: Tue, 13 Dec 2016 21:02:15 -0200
> 
> I'd like to load emacs with emacs --daemon=gui and then connect to it with emacsclient -c --sever-file=gui.
> 
> This works almost right. The problem is that various popular packages make extensive use of the
> (display-graphic-p) function/predicate to query frame capabilities. For example, a theme package may query
> (display-graphic-p) and assign gui or tty colors accordingly. 
> 
> the thing is that(display-graphic-p) always returns nil in a emacs --deamon type of loading, because emacs
> does not know if you are using emacsclient with a gui or a tty. 

If you remove the test from those packages, does everything else in
the package work correctly without signaling any errors?

You see, these tests are supposed to be made before calling APIs that
would otherwise signal an error or otherwise barf on non-GUI frames.
If removing the tests makes the package work fine in the daemon mode
or on a text-mode frame, it means the test is redundant and should
simply be removed.  Very few Emacs features really require GUI frames,
so it could be that these tests, or at least some of them, are
remnants from distant past, when many more features would only work in
GUI mode.

OTOH, if these tests are indeed required, then making them work in the
daemon will not provide any relief for you, because it will just delay
the error until later.

Does the above make sense?

Re: option for loading up a gui specific emacs daemon

[Noam Postavsky]

On Wed, Dec 14, 2016 at 6:11 AM, Filipe Silva <filipe.silva@gmail.com> wrote:
> Noam, that looks promising. Is there a way to advise display-graphic-p to
> always return true but only if I started emacs as emacs --daemon=gui?
>

(Untested)

(defun gui-daemon-or-other-p (other &rest args)
  (if (equal (daemonp) "gui") t
    (apply other args)))
(advice-add 'display-graphic-p :around #'gui-daemon-or-other-p)

Re: option for loading up a gui specific emacs daemon

[Ken Raeburn]

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On Dec 13, 2016, at 18:02, Filipe Silva <filipe.silva@gmail.com> wrote:

> Dear developers of the mighty emacs editor, 
> 
> I'd like to load emacs with emacs --daemon=gui and then connect to it with emacsclient -c --sever-file=gui.
> 
> This works almost right. The problem is that various popular packages make extensive use of the (display-graphic-p) function/predicate to query frame capabilities. For example, a theme package may query (display-graphic-p) and assign gui or tty colors accordingly. 
> 
> the thing is that(display-graphic-p) always returns nil in a emacs --deamon type of loading, because emacs does not know if you are using emacsclient with a gui or a tty.

Daemon mode isn’t the only time a graphical display can be added when one wasn’t initially in use.  A tty-mode Emacs can still run M-x make-frame-on-display or run a server.

If a package is assuming that the characteristics of the current frame (like the result of display-graphic-p) when the package is loaded will apply to every frame ever in that Emacs session, the package has a bug….

Ken

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