Re: GtkApplication and argc/arv

[Tristan Van Berkom <tvb gnome org>]

On Fri, Feb 25, 2011 at 8:25 AM, jose aliste gmail com
<jose aliste gmail com> wrote:
> Hi,
>
> On Tue, Feb 22, 2011 at 6:45 AM, Murray Cumming <murrayc murrayc com> wrote:
>> On Mon, 2011-02-21 at 21:57 +0100, Murray Cumming wrote:
>>> I'm trying to wrap GtkApplication for gtkmm but I can't really do that
>>> until I understand how it's meant to be used.
>>>
>>> In general, I find the documentation lacks overview and advice, partly
>>> because it's spread between GApplication and GtkApplication and mentions
>>> some concepts without explaining them first. So I have some questions.
>>>
>>> 1.
>>> Are we still meant to call gtk_init(&argc, &argv) when using
>>> GtkApplication, which takes argc/argv again via g_application_run(). Or
>>> is gtk_init() then superfluous?
>>>
>>> Mathias mentioned that gtk_init(NULL, NULL) is best anyway, though I
>>> don't understand why:
>>>   http://bugzilla.gnome.org/show_bug.cgi?id=639925#c3
>>>
>>> 2.
>>> How should we use GOptionContext to parse command line arguments from
>>> argc/argv when using GtkApplication. Is this the ideal way, using the
>>> command-line signal?
>>>   http://git.gnome.org/browse/totem/tree/src/totem.c#n187
>>> It seems a little long-winded.
>>
>> And more simply:
>>
>> 3. Will we recommend that all GTK+ applications generally use
>> GtkApplication?
>>
>> 4. Do we believe that all (GTK+) applications should be single-instance
>> applications?
>
> Just to point out  an example, Evince does not use GtkApplication and
> it's not single instanced (there is one process per each document you
> see) and I don't think there are plans to make it single instanced.

Right,
  however as I mentioned it would not hurt evince if it was a single
instance, we would save on memory and gain in startup time for every
document that evince is invoked for, without harming evince in any way.

Furthermore using GtkApplication everywhere "opens up the door" for
more sophisticated integration that could hypothetically happen
in the future.

  - it would allow for system watchdogs to be implemented without any explicit
    cooperation on the part of the application for one,

  - it could serve to provide some basic system messaging for the
    desktop and applications, like updating the input method for all
    running applications, or even changing the desktop locale and
    retranslating messages (albeit runtime translation switching would
    of course require more api, but GtkLabel for instance could be
    given a translatable format and retranslate itself automatically whenever
    the desktop language changes...).

I'm not saying that everybody should hurry up and do extra work they dont
need to... however I do think having a unified GtkApplication api with as many
apps using it as possible seems to be a step in the right direction (whether
its the GNOME Shell that communicates with the GtkApplication, or
MyCustomHandPhoneShell that uses it... having a well defined/unified
api for this stuff seems like a good thing to have).

Cheers,
       -Tristan