get input device in wayland

[Peter Hutterer]

On Tue, Nov 21, 2023 at 04:20:10PM +0800, weinan wang wrote:
> Hey Guys,
> We have an application that needs to get the touch device
> corresponding to the touch event, and on X11, we can get the device ID
> that sends this event according to the XI_Touch events, and then find
> the device we want according to this ID.  But on Wayland, it seems
> that neither wl_seat nor wl_touch can get device-related information,
> this application is a user permission, so we can't use libinput to get
> more low-level events.
> Please ask if there is any other way to get the device that sends the
> event?

This is not possible in wayland, physical devices are abstracted into
wl_pointer/wl_keyboard/wl_touch and the underlying device is not exposed
anywhere through wayland or even current wayland-protocols.

The sole exception is the wl_tablet protocol which is per physical
device but that's due to how tablets are being used.

You don't usually have access to the libinput context inside the
compositor either (because Wayland itself doesn't require libinput, it's
an implementation detail).

The question here is: what are you trying to achieve? maybe there's a
different way to do it than having access to the specific physical
device.

Cheers,
  Peter