IIRC the inconsistent 'reversed scrolling' behaviour even across the default (x)ubuntu apps was due to the different scroll handling in GTK2 and GTK3. Don't know if that still applies..
Anyway, I just found out the "old xinput trick" still works (xUbuntu 18.04.1, xinput version 1.6.2), so I might as well share how it works. And how to make it persist reboots.
Test / temporary solution
List all your currently available pointers and keyboards:
xinput list
Something like this will appear:
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ Logitech USB Laser Mouse id=9 [slave pointer (2)]
⎜ ↳ TPPS/2 IBM TrackPoint id=12 [slave pointer (2)]
⎜ ↳ SynPS/2 Synaptics TouchPad id=11 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
↳ Power Button id=6 [slave keyboard (3)]
↳ Video Bus id=7 [slave keyboard (3)]
↳ Power Button id=8 [slave keyboard (3)]
↳ AT Translated Set 2 keyboard id=10 [slave keyboard (3)]
↳ ThinkPad Extra Buttons id=13 [slave keyboard (3)]
Pick the id of the pointer in question, list all its device properties:
xinput list-props 12
Device 'TPPS/2 IBM TrackPoint':
Device Enabled (143): 1
Coordinate Transformation Matrix (145): 1.000000, ...
libinput Natural Scrolling Enabled (281): 1
libinput Natural Scrolling Enabled Default (282): 0
libinput Scroll Methods Available (283): 0, 0, 1
libinput Scroll Method Enabled (284): 0, 0, 1
libinput Scroll Method Enabled Default (285): 0, 0, 1
libinput Button Scrolling Button (286): 2
...
This is what we need: libinput Natural Scrolling Enabled (281)
To enable natural scrolling globally i.e. for "TPPS/2 IBM TrackPoint" (for the current session), first turn it OFF in 'Mouse & Touchpad' preferences.
Enter one of those two lines below, hit Enter. (both do the same, because to read or write a property you can use either its entire(!) name or its ID)
xinput set-prop 12 "libinput Natural Scrolling Enabled" 1
xinput set-prop 12 "281" 1
Now test it in applications where naturalscroling wouldn't work via system preferences.
Permanent solution
If the above test worked on your machine, you can apply the changes everytime you log into your session with a small startup script. The script part that matches deviceName is from this answer about button maps by @zerobandwidth).
Save the code below as natural_scrolling.sh in your home directory or in /any/path/youLike
#!/bin/bash
# Find all xinput devices whose name matches any of the arguments passed here,
# then set the Natural Scrolling' property to '1' regardless of its
# current state.
# expect multiple arguments, store them as array
deviceNames="$@"
# exit if no argument is passed
if [ "$deviceNames" = "" ]; then
echo "No argument received, exiting."
echo "Call this script with argument(s) like 'Logitech' that match"
echo "any of your attached pointer devices."
exit 1
fi
for deviceName in $deviceNames
do
deviceId=$(xinput --list | awk -v search="$deviceName" \
'$0 ~ search {match($0, /id=[0-9]+/);\
if (RSTART) \
print substr($0, RSTART+3, RLENGTH-3)\
}'\
)
# set device-specific property (works i.e for 'TrackPoint' & 'Logitech')
xinput set-prop $deviceId "libinput Natural Scrolling Enabled" 1
done
Mark the script executable:
chmod +x natural_scrolling.sh
Call it with unique(!) device_name string(s) as argument:
/any/path/youLike/natural_scrolling.sh Logitech TrackPoint
Add it to your startup applications, i.e via Session & Startup preferences in xfce and test it by logging out & back in again.
