Re: [PATCH 0/2] HID: huion: add libinput support

From: Peter Hutterer
Date: Sun Feb 22 2015 - 18:28:55 EST

On Sun, Feb 22, 2015 at 02:33:53PM +0200, Nikolai Kondrashov wrote:
> On 02/20/2015 07:34 AM, Peter Hutterer wrote:
> >On Thu, Feb 19, 2015 at 01:54:17PM +0200, Nikolai Kondrashov wrote:
> >[...]
> >>>>>Last, I think we could add these tablets in the libwacom project, so that there
> >>>>>will be a nice GUI to configure the buttons.
> >>>>
> >>>>That would be a very welcome change, without doubt, thank you.
> >>>>
> >>>>However, I can't help wondering, would it be more productive to allow libwacom
> >>>>to work with just any basic tablet, without the need to add each one to the
> >>>>database?
> >>>
> >>>Actually, libwacom is not tight to Wacom devices at all (or should not
> >>>be). It is just a database of devices to add what the kernel doesn't or
> >>>can not provide. The things that are in the db are for example how the
> >>>buttons are physically mapped on the device, what is the actual layout
> >>>(one svg file), if there are LEDs attached to the tablet.
> >>>
> >>>All this needs a fine per-device tuning. We can add a generic
> >>>Huion/UClogic tablet too, but having a specific per-device definition
> >>>allows to show the exact mapping of the buttons on the overlay when
> >>>setting the functions.
> >>
> >>I agree, that's a nice feature. However, I think being able to configure all
> >>the applicable Wacom driver features relatively comfortably, even if the
> >>tablet on screen doesn't exactly match your tablet, is still a win, compared
> >>to not being able to do it.
> >>
> >>For the unknown tablets we can just draw abstract tablets, emphasising that
> >>control locations on the screen don't map to the actual locations. For
> >>example, have the tablet drawn like an exploded diagram: surface, buttons,
> >>dials - all separate. Something like this:
> >>
> >> Buttons: * * * * * * *
> >> Dials: O O
> >> Work area: +------------+
> >> | |
> >> | |
> >> | |
> >> +------------+
> >>
> >>I think the users will be able to figure out the mapping by experimentation.
> >>
> >>While it's just about possible to keep an up-to-date database of Wacom
> >>tablets, I don't think we'll ever be able to list all those generic tablets
> >>out there. Meanwhile a lot of people are left in the cold of xsetwacom and
> >>xinput.
> >
> >not a reason to give up, IMO. most of these generic tablets are relatively
> >simple, so adding a libwacom entry should be a matter of minutes.
> >we'll never get full support of everything, but perfect is the enemy of good
> >here.
> Hmm, I see having all the tablets listed in the database as perfect and having
> generic tablet handling as more practical, i.e. the other way around.
> It might be easy for us to add a tablet entry, but not for the general user.
> They will need to figure out they need to add that entry first and they'll
> need to figure out what to put there and how. This will need to go through us
> in the end and we'll need to extract all the information from the user, which
> will likely require several e-mails for *each* tablet.

yeah, but the thing is: those emails are only necessary _once_ per tablet.
if they're not in the database, you'll get those questions for the lifetime
of the tablet :)

Also note that libwacom_new_from_path() has a fallback option, you can get a
generic tablet from it and then proceed as normal. gnome-settings-daemon
already uses this.


> Meanwhile most users just want to draw.
> I might be misunderstanding something, though.
> Regardless, Benjamin work is making it all better, I cannot complain :)
> Nick
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