Gamepad focus model (Re: Input and games.)

[Pekka Paalanen]

On Thu, 9 May 2013 10:49:03 +0000 (UTC)
Rick Yorgason <rick at firefang.com> wrote:

> Pekka Paalanen <ppaalanen at ...> writes:
> > From the game's point of view, it will need to iterate over all
> > wl_seats. For each seat with the gamepad capability bit set, create a
> > wl_gamepad_manager, receive all wl_gamepad objects, and for each
> > wl_gamepad receive the player id. Create your surfaces, wait for foci
> > to arrive, and fire away.
> 
> So, the purpose of wl_gamepad_manager is to allow multiple gamepads to share
> one application focus. That seemed weird to me (why is it only gamepads that
> would want that ability?) which is why I started thinking about wl_seat
> parenting, and I apologize if that caused more heat than light.
> 
> But now I'm seriously wondering, does the compositor really need *any*
> protocol support to handle this case? I think we've been assuming that each
> seat will get its own free reign over the desktop, but isn't the compositor
> free to *not* do that? And instead to have some seats which only interact
> with the focused application?
> 
> We could have one wl_gamepad per wl_seat, just like wl_pointer, wl_keyboard,
> or wl_touch, put the player ID in wl_seat instead of wl_gamepad, and give
> compositor writers a few suggestions:
> 
> * Not all seats need to have a desktop pointer or the ability to control
> their own focus. It can be useful to allow "second class" seats which follow
> the focus of another seat, in which case neither the pointer nor any other
> event from that seat should be allowed outside of the focused application.
> 
> * Each gamepad should automatically be put in a separate seat, either by
> putting it in an existing seat without a gamepad, or automatically creating
> a new seat.
> 
> * If a seat is automatically created for a gamepad, it should ideally be of
> the "second class" type by default. Users can always reconfigure their seat
> if they want control over the desktop.
> 
> Wouldn't that allow everything we want? It allows every user to have a full
> set of devices, and users don't have to worry about focus issues unless they
> want to. It also means the protocol doesn't need the contrivances of
> wl_gamepad_manager or seat parenting.

Yes. If I recall correctly, I originally started with a similar scheme,
but Daniel did not like it. Daniel?


Thanks,
pq


ps. please don't cut the cc list unless explicitly requested.