Re: [Linuxwacom-discuss] Invert the scroll direction of a touch device?

[Peter H. <pet...@wh...>]

On Tue, Mar 12, 2013 at 12:39:44PM +0100, Alexander Maret-Huskinson wrote:
> Am Dienstag, 12. März 2013, 14:32:30 schrieb Peter Hutterer:
> > On Mon, Mar 11, 2013 at 09:32:27AM -0700, Jason Gerecke wrote:
> > > On Sat, Mar 9, 2013 at 6:31 AM, Alexander Maret-Huskinson 
> <al...@ma...>wrote:
> > > > Hi,
> > > > 
> > > > I'm one of the developers of the KDE wacom KCM. We are currently in the
> > > > process of preparing a new release and are fixing/removing all features
> > > > which
> > > > do no longer work.
> > > > 
> > > > With previous versions of xsetwacom it was possible to invert the scroll
> > > > direction of a touch device by swapping the button numbers, e.g.:
> > > > 
> > > > xsetwacom --set $TOUCH_DEV button 4 5
> > > > xsetwacom --set $TOUCH_DEV button 5 4
> > > > 
> > > > This however has not been working for quite some time now and I'm
> > > > wondering if
> > > > this is a feature or a bug? Is there currently any way to invert the
> > > > scroll
> > > > direction of a touch device or has this feature been removed completely
> > > > from
> > > > xsetwacom?
> > > > 
> > > > Greetings,
> > > > Alex
> > > 
> > > Using the button assignment to change the scroll direction was never
> > > intended, but worked for a quite some time as a consequence of our
> > > implementation. At the moment I'm not aware of any way to swap the scroll
> > > direction, and I'm not sure if we want to add one in given that our
> > > eventual goal is to have gestures handled entirely out-of-driver (via e.g.
> > > apps like Touchegg or framework integration like GTK).
> > 
> > you could take a negative scroll distance as a signal to invert scrolling
> > (that's what we do in the synaptics driver).
> > 
> > having said that, the button 4/5 swap should still work since wacom doesn't
> > use smooth scrolling. what does xev say?
> > 
> > Cheers,
> >    Peter
> 
> 
> The negative scroll distance is a very nice idea. Currently scrolling gets 
> disabled if you set a negative scroll distance.
> 
> The button 4/5 swap does not work because xsetwacom does not allow you to set 
> it. If you try to swap the buttons you get an error message: "Unsupported 
> offset into 'Wacom Button Actions' property.". Maybe we could map it with 
> "xinput set-button-map" as scrolling seems to send normal button 4/5 events 
> according to xev:
> 
> ------------
> ButtonPress event, serial 35, synthetic NO, window 0x6200001,
>     root 0x290, subw 0x6200002, time 1566013, (39,35), root:(2830,555),
>     state 0x0, button 4, same_screen YES
> 
> ButtonRelease event, serial 35, synthetic NO, window 0x6200001,
>     root 0x290, subw 0x6200002, time 1566013, (39,35), root:(2830,555),
>     state 0x800, button 4, same_screen YES
> 
> ButtonPress event, serial 35, synthetic NO, window 0x6200001,
>     root 0x290, subw 0x6200002, time 1567491, (39,35), root:(2830,555),
>     state 0x0, button 5, same_screen YES
> 
> ButtonRelease event, serial 35, synthetic NO, window 0x6200001,
>     root 0x290, subw 0x6200002, time 1567491, (39,35), root:(2830,555),
>     state 0x1000, button 5, same_screen YES
> -----------

button mapping is handled in the server, so a xinput set-button-map should
just work here.

xsetwacom changes physical button mappings, not the logical ones*. thus
button 4 would refer to physical button 4, which you likely don't have on
the touch device. xinput changes logical buttons, and buttons 4-7 are
reserved for scrolling. so physical button 4 is actually logical button 8.

Cheers,
   Peter
 

* Jason, correct me if that has changed recently, you re-did a lot of that
code