Scroll.py issue where scrolling up with the mouse/track pad wraps back to the bottom

[gerberb]

I can use the scroll wheel on my trackball mouse in the scroll window, When using trackball scroll wheel scrolling down stops at the bottom, but scrolling up wraps and starts at the bottom. Would like it the behavior to stop at the top

[rndusr]

I don't know what your trackball does, but it doesn't seem to send the same byte sequences as my mouse wheel.

Maybe I can help you if you tell me how to reproduce this behaviour without having access to your trackball and setup.

[robertb-x]

I see this problem when using my Logitech Trackball Ergo MX and also using the trackpad on my macbook pro. it stops when going to the bottom, but when scrolling up, it wraps around and does not stop at the top.