stop ScrollCoastDuration by tapping?

[beckend]

this is how it behaves in osx, basically it continues to scroll until you tap the touchpad and it cancels the ScrollCoasting.

right now if you set it to for example 2000 and you start scrolling, you have to wait for it to finish otherwise it's kind of messed up

[p2rkw]

I plan to refactor coasting anyways, so I will see what can I do about it.