scrollingtouchpad
I have a Thinkpad which has both a TrackPoint mouse pointer (the little red thing between the G and H keys) and a Synaptics Touchpad.
I don't really like the Touchpad, and in fact keep swiping it accidentally, so I turned it off. But, there's one feature that's really nice: the two-finger scroll gesture.
Is there a way to make it so only this gesture works and all other input is ignored?
The feature you are talking about is called "Auto-Scrolling". It lets you press and hold the middle mouse button and move your mouse to scroll smoothly. In Linux, the default behavior for this action (pressing middle mouse button) is generally pasting text.
However, there is a preference setting in Firefox and an extension available for Chrome/Chromium which would let you use the middle mouse button for scrolling and activate this feature.
Open the "Options" tab: "≡" (Open menu) → "Options".
Navigate to "General" (it should open to "General" by default).
Scroll down to "Browsing". Under "Browsing", you will find the "Use autoscrolling" option. Put a check mark beside this to activate this functionality in Firefox.
Or just search for "autoscrolling" using the search bar.
For Chrome/Chromium we can use an Extension called "AutoScroll" (from kaescripts.blogspot.com).
Go to this link on Chrome Web Store (obviously using Chrome/Chromium).
Click on the button labeled "+ ADD TO CHROME" to install this extension.
Click on "Add" in the Confirmation Dialog Box.
As far as other applications are concerned, I haven't yet found a solution for them. Anyways, it's the tall webpages that create most of the problems for which both Firefox and Chrome/Chromium have a solution.
Feature is called "Coasting speed". To disable it you can use:
xinput --set-prop --type=float "<your device>" "Synaptics Coasting Speed" 0 0
to list devices you can use:
xinput list
alternative variant (for touchpads) is synclient options (there are 3 of them):
CornerCoasting = 0
CoastingSpeed = 0
CoastingFriction = 0
Best Answer
I couldn't get only two-finger scrolling to work, but I was able to expand the edge scrolling so it takes over the whole pad. That works for me. Here's what I did:
1) Enable edge scrolling vertically and horizontally, but not "coasting":
2) Set the left and right "edges" of the trackpad to be 0. They default to being some value in the thousands, making a little border. Use
xinput --list-propsto find the initial values — the4282value for the bottom edge comes from that. I've also set the top edge to 0, on the grounds that that doesn't hurt.3) Set the scrolling distance (amount your finger has to move before triggering a scroll event) to about double the default, because that was too fast:
With this, I can use the touchpad just to scroll, without it moving the cursor around. (And the high distance set above keeps me from triggering it accidentally.)