try(pinch): Wave 2 — stepped layout-prop styles (scroll-source consolidation reverted)#30
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Three Android-Fabric-targeted perf/correctness fixes: 1. CalendarBody's horizontalLinesWrapperStyle (top/height layout props) and TimelineBoard's per-BodyItem horizontalLinesWrapperStyle (height + transform) now read a STEPPED zoomScale (10% increments via useDerivedValue) instead of the raw SV. On Fabric Android, parallel layout-prop animated styles commit via Yoga on a separate path from the inner-scale's transform commit; two paths racing per frame can land out of order, producing a one-frame visual mismatch. Stepping reduces the commit cadence ~10x with no visible artifact (10% step transitions in line position during smooth pinch are invisible). 2. Drop JS-thread _onScroll. Replace with a useAnimatedReaction on scrollOffsetLive that writes offsetY on the UI thread. Two sources writing to offsetY from different threads (JS onScroll alongside the worklet-event registration backing scrollOffsetLive) was an Android Fabric race source — the bridge marshalled events twice and the two paths could converge to different values mid-pinch.
… platforms The useAnimatedReaction-on-scrollOffsetLive approach for driving offsetY worked in theory but broke scroll in practice on both platforms. The library uses react-native-gesture-handler's ScrollView (not RN's stock), and dropping the JS onScroll prop appears to disconnect the native scroll-event emitter from useScrollViewOffset's worklet handler on the gh-ScrollView + Fabric path — scrollOffsetLive stays at 0, offsetY never updates, and downstream library state breaks. Android exhibits this as 'scroll dead even before pinch'; iOS exhibits as 'scroll sometimes stuck after pinch' (the lock state-machine reads stale live offset and the post-pinch reaction never re-syncs). Keep the Wave 2 stepped layout-prop changes — those were the actual perf win and don't touch scroll.
anton-patrushev
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Superseded by platform-split fix graduated into PR #28. Closing. |
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Experimental Wave 2 (revised) — Android pinch hardening, layered on Wave 1 (PR #29). Base: `try/pinch-drift-absorb-android` (Wave 1).
What's in / what's out
In (kept):
Out (reverted in this revision):
Consolidate scroll source: drop JS `_onScroll`, drive `offsetY` from `scrollOffsetLive` reaction— broke scroll on both platforms. The library uses `react-native-gesture-handler`'s ScrollView (not RN's); dropping the JS `onScroll` prop apparently disconnects the native scroll-event emitter from `useScrollViewOffset`'s worklet handler on the gh-ScrollView + Fabric path. `scrollOffsetLive` stays at 0, `offsetY` never updates. Android exhibited as "scroll dead even before pinch"; iOS as "scroll sometimes stuck after pinch."Test plan (revised)