Re: synaptics vs libinput and GNOME 3.20 no longer supporting synaptics

[Peter Hutterer <peter.hutterer@who-t.net>]

On 17/07/2016 05:49 , Theodore Ts'o wrote:
> On Thu, Jul 14, 2016 at 01:57:13PM +1000, Peter Hutterer wrote:
> > libinput is a lot smarter than synaptics when it comes to palm
> > detection.
>
> Question about libinput?  The main reason why I'm using synclient
> because I have a Thinkpad T540p which doesn't have hard buttons for
> the "mouse buttons".  It does have TrackPoint which I infinitely
> prefer to the !@#?! horrendo Trackpad on the T540p.  So I do the
> following to only use the Trackpad for buttons.
>
> synclient RightButtonAreaTop=0
> synclient RightButtonAreaRight=4858
> synclient RightButtonAreaBottom=5000
> synclient RightButtonAreaLeft=3500
>
> synclient MiddleButtonAreaTop=0
> synclient MiddleButtonAreaRight=3499
> synclient MiddleButtonAreaBottom=5000
> synclient MiddleButtonAreaLeft=2800
>
> synclient coastingFriction=50
> synclient coastingSpeed=15
>
> synclient areaTopEdge=6000
> synclient areaLeftEdge=0
> synclient VertEdgeScroll=0
> synclient HorizEdgeScroll=0
>
> Basically, I don't want to use the Trackpad for mouse events, not
> *ever*.  And even if the keyboard and trackpoint are quiscent, I don't
> want a random palm swipe to be registered a mouse or button event ---
> only when the pad is physically depressed.
>
> What's the equivalent way of doing the same thing with the libinput
> driver?  (Note: I'm still using the X server, not Wayland, and I'm
> using XFCE).

At runtime:
xinput set-prop "libinput Send Events Modes Enabled" 1 0

Static config:
cat > /etc/X11/xorg.conf.d/99-libinput-disable-touchpad.conf
Section "InputClass"
   Identifier "disable touchpad"
   MatchDriver "libinput"
   MatchIsTouchpad "on"
   Option "SendEventsMode" "disabled"
EndSection

Any typos in the above are of course fully intended ;)

Long explanation: libinput doesn't have a concept of disabling a device 
because in some cases (like the T540 series) a disabled device still 
needs to send events. So we named the "send events mode", i.e. it 
decides whether the device will send events or not.

On the Lenovo *40 series, libinput reroutes top button events already 
anyway, those buttons always come out of the trackpoint device.
when you disable the touchpad the top software buttons will still work 
since they are logically part of some other device. We'll also 
automatically increase the button area in that case to make the buttons 
easier to hit.

Cheers,
  Peter