Using keyboard shortcuts to navigate between replies causes topic to be "stuck"

saquetim · February 13, 2026, 2:02am

UX: Improve post stream scrolling stability and layout control (#37788)

main ← dev/smoother-post-stream-scroll

merged 05:58PM - 18 Feb 26 UTC

## Summary - Improves scroll position stability when loading posts above the vi…ewport by using `scrollBy`-based compensation instead of `scrollTo` + `offsetCalculator` - Dynamically hides banners, notices, and footer content when the user is in the middle of a long topic via a new `scrollState` service and `{{hideScrollableContent}}` helper - Triggers loading more posts when navigating to boundary posts via keyboard (`j`/`k` keys) - Prevents load-more sentinel from re-triggering during scroll compensation with a `suppressLoadAbove` flag ## Details ### Scroll compensation When new posts are prepended above the viewport, the component captures the anchor post's position via `getBoundingClientRect()` before DOM insertion (using a `beforePrepend` callback in `prependMore()`), then compensates with `window.scrollBy()` after insertion. This keeps the reading position visually stable. ### Content hiding A `scrollState` service tracks ref-counted hide requests. The `{{hideScrollableContent}}` class-based helper registers with the service and automatically cleans up via `registerDestructor`. The `application.gjs` and `topic.gjs` templates wrap scrollable content in `{{#unless shouldHideScrollableContentAbove/Below}}` blocks. The helper invocations live in `topic.gjs` outside the `{{#unless loadingFilter}}` guard so content stays hidden during timeline jumps that temporarily unmount `<PostStream>`. ### Keyboard navigation `updateKeyboardSelectedPostNumber` now checks if the selected post is at a loaded boundary (`firstAvailablePost` / `lastAvailablePost`) and triggers `loadMoreAbove` / `loadMoreBelow`. Double-loading is prevented by existing `canPrependMore` / `canAppendMore` guards.

The PR above addresses this issue.

Topic		Replies	Views
Keyboard navigation doesn't scroll beyond last post Bug keyboard , keyboard-shortcuts	4	1156	May 6, 2016
Keyboard navigation doesn't work after landing on a status post at the end of a topic Bug	3	634	April 12, 2019
Scrolling through large topics with 'j' instead of mouse sometimes gets stuck Bug	11	2793	June 2, 2017
Scrolling fast and hard to the bottom of a long topic makes replies keep coming: without stopping Bug pr-welcome	10	431	January 13, 2025
Change in shortcuts focus on posts UX	5	710	April 10, 2018

Using keyboard shortcuts to navigate between replies causes topic to be "stuck"

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