[PATCH libinput 5/7] tablet: add support for relative x/y motion deltas

Peter Hutterer peter.hutterer at who-t.net
Tue Jan 19 17:16:21 PST 2016

On Tue, Jan 19, 2016 at 05:02:51PM -0800, Bill Spitzak wrote:
> On Tue, Jan 19, 2016 at 4:27 PM, Peter Hutterer <peter.hutterer at who-t.net>
> wrote:
> >
> > > I am well aware of the wacom command, and use it. Setting a working
> > > relative mode is really painful, and also does not survive reboot or
> > > sleep/wakeup.
> >
> > xorg.conf snippets? or, better, let your desktop environment handle this.
> >
> Gnome, Unity, and Mate have all failed to remember the fixes to make the
> relative area square, and always reset it to the size of the monitors. I
> think one of them had a broken ability to fiddle with the scaling in
> relative mode but it did not result in any usable controls and it never
> remembered the setting.

did you file bugs for it?

> I'm not sure xorg.conf snippets will fix this and have not bothered to
> figure them out. 

please do bother.

> One problem is that the desktop config is obviously
> writing over this and I'm not sure if I can force my command to be after
> the desktop. I just keep a terminal in which I hit uparrow and return to
> run the command each time.
> >
> > you want to control two side-by-side monitors with the same tablet - yes
> > that is a fairly niche use-case. it's probably not unique, but I avoid the
> > term unique anyway because human ingenuity knows no bounds (or reason). see
> > the xkcd workflow comic for reference.
> >
> Running more than one monitor is not uncommon. I seem to recall that
> Wayland has explicit support for this already.
> I see no attempt by any software I am using on Linux or Windows to restrict
> popup windows to some subset of the available screen area, therefore the
> only way to use them with the pen is to allow it to click anywhere on the
> outputs. If restricting the pen to one of the monitors was a popular
> setting then I think the software would try to keep all the popups on the
> same monitor.
> >
> > so let me state that now: mapping a 8:6 tablet to a 4:1 output is not a
> > use-case that we will focus on. the only way to make this useful is by
> > reducing the tablet area so much that most of it becomes useless.
> >
> I'm not sure what you mean by this being "useless". My entire intention is
> to reduce the tablet area to a small rectangle. I don't like the idea that
> you think my requirement is "useless".

read my sentence again.


> > this is policy that belongs into the compositor. and frankly, this is a
> > niche case that is not worth auto-detecting, it's a single checkbox away if
> > the user needs it and the compositor wants to support that use case.
> >
> Possibly, that would match other operating systems. As far as I can tell
> Windows 7 just has a checkmark per tool, but no control over the scaling.
> The default scaling seems to be about a 1:1 and square. OS/X has a
> checkmark per tool and a lot of controls over the resulting scaling.
> I did think something to automatically decide would be a nice improvement,
> neither system supports switching to absolute if the client program decides
> to limit the tablet to a small area, which I think would actually be a good
> idea. I agree that there is no need to worry about this in Wayland now,
> except to not make any decision that makes that impossible.
> I agree the compositor needs to do this, but to avoid user frustration the
> control better be in the same control panel as the one that fiddles with
> libinput stuff!

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