nativescript-community / nativescript-community/ui-collectionview
Strange scroll event scrollOffset
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- Dominant language
- TypeScript
- Stars
- 62
- Forks
- 19
- Avg merge
- 2d 15h
- Merged PRs (30d)
- 2
Description
When we declare a scroll event in a CollectionView with multiple templates and without rowHeight we have a strange behavior in the scrollOffset data.
If you scroll down there are times when scrollOffset is less than the previous one, which should not happen since if it is a downward scroll it should always increase.
Reproduction repository:https://github.com/vallemar/collectionview-bug
Remove this rowHeight and you will see in the console when you scroll down: DETECTED CHANGE IN SCROLL (it shouldn't appear until you go up the list)
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Research direction
Start with the reproduction repository and inspect src/components/Home.vue around line 52. Remove rowHeight, run the example, and observe the scroll event values while scrolling downward. Trace the CollectionView scroll-offset handling to identify why values decrease, then verify that downward scrolling produces monotonic scrollOffset values without the reported console warning.
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Assessment
- Tech stack
- typescript
- Domain
- frontend, mobile-dev
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100