Timeline scrolling broken on macOS with Touchpad

[Hamid_M]

Attempting to scroll through the Timeline at the bottom of the screen using two fingers on the Touchpad results in two behaviors depending on where you place the cursor when you're scrolling:

1. If you place the mouse cursor over the actual Timeline, the scrolling is broken. It seems there are two mechanisms competing - one to scroll in the direction of the gesture, and one to scroll against it. As a result the Timeline just jumps around instead of actually scrolling.
   (see attached video Broken.mov)
2. If you place the mouse cursor just above the Timeline, on the scrollbar of the timeline (hard to see it but it is there) then the scrolling works perfectly.
   (see attache video WorksFine.mov)

[lance.carocci]

Hi @Hamid_M, I think I can reproduce this. To confirm, it looks like when the timeline is near the beginning or end, continuing to swipe will cause a "bouncing" effect that does not appear when the cursor is placed slightly higher. If I'm in the middle, there is no issue.

It seems like there is a space in between the scroll bar and timeline where swiping is inverted - left moves right, etc. This is perhaps what's causing the conflict.

I will investigate further - thanks for your report!

[Hamid_M]

Hi Lance, the effect is most noticeable at the two ends of the timeline, but the jerky scrolling happens everywhere.
Just compare how smooth the scrolling is by placing the mouse pointer directly on top of the timeline where is will scroll very rough, then move the mouse pointer *above* the timeline just a few pixels to where the scroll bar is, and scroll again. Buttery smooth. You can see the difference in the videos I attached.