Prepend is ignored if page size is less than prefetch index #8
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| reverse ? index >= itemCount - fetchIndex : index <= fetchIndex; | ||
| final nearBottom = | ||
| reverse ? index == fetchIndex : index == itemCount - fetchIndex; | ||
| reverse ? index <= fetchIndex : index >= itemCount - fetchIndex; |
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Hey, thank you for the PR but this will also trigger notification for all the items after the prefetch item. A better solution would be to count the items of last or first page based on reverse and then match it with
min(fetchIndex, length).
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Hello, thank you for reply! It seems that checking exact item index with == will still not work even for min(fetchIndex, length). There is an example that will break it:
- Suppose id of message is the key of page (e.g. start page from message with id = ?)
- Initial key = 20 (message id), page size = 45, prefetchIndex = 22
- We cannot use == with min(fetchIndex, len) since we have not reached item with index 22 (because we are loaded page from item=20, but it has initial index = 0, meaning that we have to scroll down to item 20+22=42 to trigger prepend operation)
Solution seems to be straightforward: in PageFetcher we disallow to trigger multiple _doLoad calls (we cannot do it on Ui, because of WidgetsBinding.instance.addPostFrameCallback { pager.load(...) }), which will protect pager from multiple requests of items that have passed fetchIndex
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Hey @dinaraparanid , can you try this PR #9 and check if this fixes your issue? Thanks |
Fixes #7