Weston : ideas about xdg_sell, and implementation for a taskbar

[Manuel Bachmann]

Well, having read Jasper's comment, he has some valid points, the most
important being in my opinion :

>  it matches user expectations. If the user clicks minimize on a window,
they want it hidden

It the logic of what should *really* happen when a window is minimized is
implemented client-side, that means the UI experience will differ among
client applications. Some may hide, some may iconify, some may just do
nothing...

One could object that the logic is to be implemented in the toolkit, so all
applications using the same toolkit will end up doing the same. But that
still means that if we have, for example, an application using GTK+,
another one using EFL, another one using toytoolkit (weston-terminal),
they'll behave differently.... ? We'd really like to avoid that.

Maybe a middle ground can be found if :

1) the desktop-shell-component can force a behaviour which WON'T touch any
wl_surface nor wl_shell_surface state (i.e. no switch to any new MINIMIZED
or whatever state, surface still considered fullscreen or maximized if it
was before)

2) the client application can still get the response back, and react the
way it wants

Which would imply, taking the case of Weston :

- if no desktop_shell_taskbar or whatever manager plugin is present as a
module, then client app just gets its response, and react the way it wants ;

- if it is present, then this plugin communicates with the compositor to
enforce some behaviour, BUT the client app still react the way it wants.

What do you think of that ?

Regards,
Tarnyko


2014-01-31 Manuel Bachmann <manuel.bachmann at open.eurogiciel.org>:

> Hi Bill, and thanks a lot for sharing your thoughts,
>
> > You must allow a "toplevel" to become a non-toplevel and vice-versa
>
> That's true ; the current implementation doesn't address this case.
>
> > My recommendation is that a surface has a "parent" that can be changed
> at any time to any other surface or to NULL
>
> So for an application having a "main" surface (let's say, the first that
> has been created) and child (transient ?) surfaces, the schema would be :
> NULL -> shell_surface -> shell_surface -> shell_surface
>                                      |->shell_surface
>
> In that case, an implementation *could* just display a button for the
> first shell_surface on the left, and minimize it and all its children at
> the same time. Well, I suppose it's really something up to the actual
> implementation, so a sample impl. could just do it the easiest way.
>
> > NO! The compositor must only send a "hide request" to the client. The
> client MUST be in final control over when and how it's surfaces disappear.
>
> Have just been reading the other (old) thread on this issue, so I get your
> objection :-).
> I suppose I'll have to write a sample client application able to process
> such a request. GTK+ seems to have an impl, so I will check what it does.
>
> > I'm not clear on why the former api can't do this and you felt a new api
> had to be added.
>
> Well it's just a demo, I don't really feel like it should be merged in
> this state.In fact,  I'd like to avoid adding any API.
> ----
>
> Taking your comments into account, here's what I think I should do next :
>
> - write a sample client able to send "xdg_shell_set_minimized()" requests,
> and process the responses to it ;
> - write a minimal implementation for a "taskbar/main_shell_surfaces_list"
> (?) in the "shell" directory, and allow it to be built on demand ;
> - make sure these 2 components communicate and react well.
>
> Thank you ; any further recommendation appreciated !
>
> Regards,
> Manuel
>
>
> 2014-01-31 Bill Spitzak <spitzak at gmail.com>:
>
>
>>  - When the compositor creates a shell_surface having the TOPLEVEL type,
>>> it sets a numeral ID for it, and sends a "map" event to the
>>> desktop_shell client ;
>>>
>>
>> You must allow a "toplevel" to become a non-toplevel and vice-versa,
>> otherwise useful api for rearranging windows is impossible. My
>> recommendation is that a surface has a "parent" that can be changed at any
>> time to any other surface or to NULL, the only restriction is that a loop
>> cannot be created. In any case please do not make a "type" called TOPLEVEL.
>>
>>
>>  - if it should be hidden, then the compositor sends the shell_surface to
>>> a new
>>> weston_layer named "taskbar_layer". This layer is not displayed at all.
>>>
>>
>> NO! The compositor must only send a "hide request" to the client. The
>> client MUST be in final control over when and how it's surfaces disappear.
>> This is to allow it to atomically remove child surfaces or to reparent them
>> to other surfaces that are not being hidden.
>>
>>
>>  When their "minimize" button is pressed, they now call a
>>> taskbar_move_surface()
>>> function which will do the former, and additionally send a hint to the
>>> desktop_shell
>>> that this has been done (so the corresponding taskbar button stays
>>> tuned).
>>>
>>
>> I'm not clear on why the former api can't do this and you felt a new api
>> had to be added.
>>
>
>
>
> --
> Regards,
>
>
>
> *Manuel BACHMANN Tizen Project VANNES-FR*
>



-- 
Regards,



*Manuel BACHMANN Tizen Project VANNES-FR*
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/wayland-devel/attachments/20140131/452fd3b0/attachment.html>