[RFC PATCH v2] protocol: Extend wayland seat with interfaces for sensor inputs.

Stefan Schmidt s.schmidt at samsung.com
Fri Aug 23 07:51:52 PDT 2013


On 08/22/2013 09:20 PM, Bill Spitzak wrote:
> Jason Ekstrand wrote:
>>     One thing I'm still missing is a way to handle more than one sensor
>>     per type for the future. Input devices like the wii-remote with
>>     nunchuk comes to mind. Having two separate accelerometers which
>>     still would be a the same seat but could not be aggregated.
>> Yes, this is kind of an issue.  There was some work recently on adding
>> gamepad support and that faced similar issues.  For reference, see
>> http://lists.freedesktop.org/archives/wayland-devel/2013-May/009043.html
>> and the ~42 replies.
> It seems wrong to me that the count is split into two parts. For
> instance if there are two accelerometers:
>   1. The fact that it is non-zero is stored in a bit in the seat
> description

This is meant as a capability not a number of devices. Its the same with 
keyboards and such.

>   2. Whether it is 1, 2, 3, etc is in a different undefined api.

It depends from how you look at this. Getting all sensor objects 
available when requesting a sensor type gives the client the number as 
well as the possibility to deal with it.

You want and explicit API to get the number of sensors and request them 

> There have also been some worry about running out of bits in the seat
> flags, too.
> Why not have an api that takes a seat and returns a big list of every
> device and every event that each device can produce. Yes that seems big
> but it is on the order of thousands and would be sent in one big block,
> not as thousands of messages. I think the type of device can be
> determined from the set of events it produces, though I guess you can
> also put a type id on the device.

Hmm, an idea to think about. I guess you also want to have keyboard, 
pointer, touch, etc converted to this?

Stefan Schmidt

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