Two-Finger Scrolling on ThinkPad X220 + Ubuntu 12.04 (precise)

The TrackPoint on a ThinkPad laptop is one of the main reasons why I kept buying laptops from them. However, as a heavy laptop user who refused to carry around one extra mouse, the constant usage of TrackPoint can cause a significant amount of pain to my fingertip, which is very unpleasant. An once-in-a-while quick movement is okay, but scrolling up/down takes longer and requires more pressure, which is the main cause of discomfort.

As a possible solution, I’ve tried to enable TouchPad and two-finger scrolling. However, for some reason it didn’t work by setting it in gnome-control-center, so instead I used the old faithful xinput. From the output of xinput list-props "SynPS/2 Synaptics TouchPad", it’s easy to spot “Synaptics Two-Finger Scrolling”, and the two parameters can enable vertical and horizontal scrolling, respectively.

The default setting of two-finger scrolling was far from intuitive — normally people would expect it to work just like the way it works on touch devices: you touch the screen, then you can push the document up by moving your finger up. That means scrolling down when your finger is moving up. But on my laptop, moving two fingers up means scrolling up, which causes the document to move down!

To make this problem worse, there is no setting in gnome-control-center to inverse this. Again, this can be solved with xinput by simply changing the values of “Synaptics Scrolling Distance” from 100 100 to -100 -100.

Here is my current .xsessionrc:

xinput set-prop "TPPS/2 IBM TrackPoint" "Evdev Wheel Emulation" 1
xinput set-prop "TPPS/2 IBM TrackPoint" "Evdev Wheel Emulation Button" 2
xinput set-prop "TPPS/2 IBM TrackPoint" "Device Accel Velocity Scaling" 50
xinput set-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Scrolling" 1 1
xinput set-prop "SynPS/2 Synaptics TouchPad" "Synaptics Scrolling Distance" -100 -100

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