[Android][SectionList/FlatList] scrollTo not working because offset is outside rendered "canvas"

[peterjuras]

Is this a bug report?

Yes

Have you read the Contributing Guidelines?

Yes

Environment

1. react-native -v: 0.46.4
2. node -v: 8.1.4
3. npm -v: 5.3.0
4. yarn --version: 0.27.5

Then, specify:

• Target Platform: Android

• Development Operating System: macOS

• Build tools: irrelevant for bug

Steps to Reproduce

In general, I am trying to preserve scroll position when a user navigates away from a ListView and then back again.

1. Display a or (I'm using SectionList for my use case) with 1000 items à ~50 pixels height
2. In componentDidMount scroll to an offset that is deep down the list (e.g. offset 1000). You can use the scrollTo method of the underlying ref (this.sectionList._wrapperListRef._listRef) or implement getItemLayout and use scrollToLocation*
3. Wrap the scrollTo* call in a setTimeout(... scrollTo ..., 0)

Expected Behavior

On Android it should scroll until the desired position, just like on iOS.

Actual Behavior

-> On iOS it is working, on Android it will only scroll until the 10th item, because only 10 items are rendered initally

Workaround: Setting initialNumToRender to 1000 will work, but this might crash on low end devices.

Reproducible Demo

Please check out this CRNA sample to reproduce the bug:
https://github.com/peterjuras/rn-list-scrollTo-bug

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Maybe the issue has been fixed in a recent release, or perhaps it is not affecting a lot of people. If you think this issue should definitely remain open, please let us know why. Thank you for your contributions.