ui: Fix scroll logic for non-scrollable content (bounds_size > content_size) to prevent jitter

[deanlee]

Previously, the scroll panel could overshoot and jitter because the out-of-bounds logic assumed the content was always larger than the viewport. This bug affects the OffroadAlert and Wifi list, causing invalid target offsets and incorrect snapping when the content is smaller than the viewport.

Reproducing the bug:

1. Write params/UpdateAvailable and params/UpdaterNewReleaseNotes.
2. Start the UI:

3. Drag the content — the alert notifier never returns to 0.0.

[github-actions]

raylib UI Preview

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[sshane]

does this fix the wifi panel sometimes starting not at the top?

i think there's also a problem where either the snapping or snap back doesn't land exactly at x/y=0 or max content width/height

[deanlee]

does this fix the wifi panel sometimes starting not at the top?

i think there's also a problem where either the snapping or snap back doesn't land exactly at x/y=0 or max content width/height

It might be caused by the large padding in the dialog layout.

openpilot/selfdrive/ui/mici/widgets/dialog.py

Line 321 in 946fd3f

self._scroller = Scroller([], horizontal=False, pad_start=100, pad_end=100, spacing=0)

[sshane]

That's to get it to roughly start at the middle. I think there's a bug somewhere in the Scroller

[sshane]

This is fixed with #36705, lmk if this PR is for something else

[deanlee]

@sshane It’s unrelated to this issue, and the problem isn’t fixed yet.

[sshane]

My bad, I was looking at the horizontal mis alignment in the screenshot. Is this ready?

[deanlee]

yes