Ubuntu – Adding a threshold to two-finger scrolling on touchpad

mouse scrollmulti-touchsynapticstouchpad

I accidentally trigger two-finger scrolling on my touchpad when I mean to tap-to-click. Can I add a minimum threshold to reduce accidental scroll events?

It causes issues when I:

  • hold my finger pressed to guide the cursor and then press my thumb down at the bottom of the touchpad to click (click-then-immediate-mega-scrolljump)
  • hold Control pressed and start moving the mouse cursor before releasing the key (Control+Scrolling causes page zoom in browsers)
  • when moving the cursor to click a tab in GNOME Edit/Terminal/Pidgin (scrolling on the tab bar in these apps changes tab, so I select the one adjacent to the one I clicked on instead)

    # model-information, Lenovo ThinkPad X1 Carbon (1st gen)
    Bus=0011 Vendor=0002 Product=0007 Version=01b1
    N: Name="SynPS/2 Synaptics TouchPad"

Best Answer

As per https://help.ubuntu.com/community/SynapticsTouchpad

You can determine your input devices (not just touchpad), by using the command xinput

From Terminal Using xinput

  1. First you want to see what number your device is labelled as. Use the command xinput list to see all of your devices. (You could probably shorten this to a command like xinput list |grep Synaptic -n2, or something similar)

  2. Note the id next to the Device.

  3. Determine your current settings by doing the command xinput --watch-props YOURDEVICEID (YOURDEVICEID being the device id you noted in previous step)
  4. You may wish to adjust sensitivity which is Synaptics Finger, but it is dependent on your actual touchpad. So you may have to tweak other ones as well. (Press Ctrl+C to exit).
  5. Once you determine what you want to change you will input it with the xinput with the --set-prop switch.

Same Example as from top source below

xinput --set-prop YOURDEVICEID "Synaptics Finger" 50 80 257

This will adjust the sensitivity of the pad in general.

From Terminal using synclient

You can also find a configuration with synclient

  1. Input the command synclient -l to view your current configuration. (You can also redirect this into an editable document if you want to manipulate it further with a command such as synclient -l > touchpadconfig)
  2. You can set the value by doing a command like synclient LeftEdge=130 to set left edge of the touchpad to a coordinate 130.

Unfortunately there are lot of settings which can be adjusted, and you may need to adjust them yourself. However the man synaptics explains each of the parameters which can be set in fairly human readable terms.

Further Reading from Debian wiki

Further Reading from Arch wiki