Scroll-to-token is causing my browser to jump around erratically when the window is relatively small

[ara4n]

I assume something in the layout or wrapping logic is causing the scroll-to-token stuff to break badly - at seemingly random points the window scroll offset jumps up half a page - e.g. when alt-tabbing away and back again, or when someone speaks in the room, or when you speak, etc. It's screwing up a demo i'm trying to record, so going to temporarily kill it on develop just so I can demo it properly.

https://matrix.org/_matrix/media/v1/download/matrix.org/jrQJJXgvXmnnmYxWRHvosjxZ

[richvdh]

oh, arse. sorry, I'll take a look.

[ara4n]

This superficially looks like it might be linked to me disabling permenant scrollbars in OSX this morning, which in turn disables gemini, and could be introducing new DOM layout changes which get confused for scroll events by ScrollPanel...

[richvdh]

For the record: I was able to reproduce this on Linux by editing gemini-scrollbar/index.js to return 0 early in getScrollBarWidth(). It seems you also need to have messages of a certain minimum length in the room (enough to wrap?) to repro it.

[ara4n]

looks like 3c659dc fixed it, thankfully. #947 seems to be intimately connected - something to do with the fact that the text would layout without wrapping with infinite width, and then flexbox would later layout and cause it to wrap down, changing the vertical height and causing a pseudo-scroll event. Not entirely sure how the overflow-x: auto on middle panel fixes it, but it allows the horizontal flexboxing of left/middle/right to not be pushed out enormously by middle.