Fix flatlist initialscrollindex 54409 #54466
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- Fix setFeedbackUnderlay method to properly set view background - Resolves issue where ripple drawable was created but not applied - Fixes regression introduced by new background drawable system - Addresses issue facebook#54372
- Fix _initialRenderRegion to render all items when itemCount <= initialNumToRender - Fix _createRenderMask to apply scroll-to-top optimization for small lists with initialScrollIndex - Resolves issue where items before initialScrollIndex were not rendered - Ensures proper rendering order when entire list fits in viewport - Addresses issue facebook#54409
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- Fix missing items before initialScrollIndex when entire list fits in viewport - Add validation for empty lists to prevent crashes - Preserve large list performance and accessibility behavior Fixes facebook#54409
- Limit fix to small lists (≤15 items) to preserve virtualization - Require initialScrollIndex > 0 to maintain accessibility focus - Prevent scroll UP issues and first item rendering problems - Maintain original behavior for larger lists Addresses reported issues while keeping the core bug fix
- Only apply fix when getItemLayout is provided to prevent virtualization issues - Reduce item limit to 10 for more conservative approach - Fixes scroll UP issues and jumping behavior without getItemLayout - Maintains original behavior for lists without getItemLayout Resolves scroll and focus issues while preserving the core bug fix
cipolleschi
reviewed
Nov 9, 2025
| @JvmStatic | ||
| public fun setFeedbackUnderlay(view: View, drawable: Drawable?) { | ||
| ensureCompositeBackgroundDrawable(view).withNewFeedbackUnderlay(drawable) | ||
| view.background = ensureCompositeBackgroundDrawable(view).withNewFeedbackUnderlay(drawable) |
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I don't think this change is related to the list behavior. Could you revert this?
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I don't think this change is related to the list behavior. Could you revert this?
Hey actually i did this to resolve another issue that is #54455 .
can you check that PR too?
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@cipolleschi review that PR too and this one and merge it?
@cipolleschi If you want i can revert it here?
lunaleaps
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Nov 13, 2025
| if (itemCount > 0 && | ||
| itemCount <= Math.min(initialNumToRender, 10) && | ||
| props.initialScrollIndex > 0 && | ||
| props.getItemLayout != null) { |
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Why do you do a check here for getItemLayout?
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Summary:
Fixes #54409
When using
initialScrollIndexwith a FlatList where all items fit within the viewport, items before theinitialScrollIndexwere not being rendered. This caused missing items and incorrect rendering behavior.Root Cause: The
_initialRenderRegionmethod calculated the initial render region starting frominitialScrollIndexwithout considering if the entire list could fit in the viewport. Additionally, the_createRenderMaskmethod skipped the "scroll-to-top" optimization wheninitialScrollIndex > 0, preventing all items from being rendered.Solution:
_initialRenderRegionto render all items (0 to itemCount-1) whenitemCount <= initialNumToRenderandinitialScrollIndexis set_createRenderMaskto apply the scroll-to-top optimization for small lists even wheninitialScrollIndex > 0Changelog:
[GENERAL] [FIXED] - Fix FlatList initialScrollIndex missing items when entire list fits in viewport
Test Plan:
Test Case 1: Bug Reproduction