Created
March 18, 2023 18:47
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Infinite scrollable widget with generics
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import 'package:flutter/material.dart'; | |
import 'package:infinite_scroll_pagination/infinite_scroll_pagination.dart'; | |
class InfiniteScrollableTable<T extends Object> extends StatefulWidget { | |
final Future<List<T>> Function(int) fetchPage; | |
final int pageSize; | |
final Widget Function(BuildContext, T, int) itemBuilder; | |
const InfiniteScrollableTable( | |
{Key? key, required this.fetchPage, this.pageSize = 20, required this.itemBuilder}) | |
: super(key: key); | |
@override | |
_InfiniteScrollableTableState<T> createState() => _InfiniteScrollableTableState<T>(); | |
} | |
class _InfiniteScrollableTableState<T extends Object> extends State<InfiniteScrollableTable<T>> { | |
final PagingController<int, T> | |
_pagingController = PagingController(firstPageKey: 0); | |
@override | |
void initState() { | |
_pagingController.addPageRequestListener((pageKey) { | |
_fetchPage(pageKey); | |
}); | |
super.initState(); | |
} | |
Future<void> _fetchPage(int pageKey) async { | |
try { | |
int pageIndex = pageKey ~/ widget.pageSize; | |
List<T> newItems = await widget.fetchPage(pageIndex) as List<T>; | |
final isLastPage = newItems.length < widget.pageSize; | |
if (isLastPage) { | |
_pagingController.appendLastPage(newItems); | |
} else { | |
final nextPageKey = pageKey + newItems.length; | |
_pagingController.appendPage(newItems, nextPageKey); | |
} | |
} catch (error) { | |
_pagingController.error = error; | |
} | |
} | |
@override | |
Widget build(BuildContext context) => | |
// Don't worry about displaying progress or error indicators on screen; the | |
// package takes care of that. If you want to customize them, use the | |
// [PagedChildBuilderDelegate] properties. | |
PagedListView<int, T>( | |
pagingController: _pagingController, | |
builderDelegate: PagedChildBuilderDelegate<T>( | |
itemBuilder: (BuildContext context, T item,int index) => widget.itemBuilder(context, item, index) | |
), | |
); | |
@override | |
void dispose() { | |
_pagingController.dispose(); | |
super.dispose(); | |
} | |
} |
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