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SliverList + separated
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import 'dart:math' as math; | |
import 'package:flutter/material.dart'; | |
extension SliverListEx on SliverList { | |
static SliverList separated({ | |
required int itemCount, | |
required NullableIndexedWidgetBuilder itemBuilder, | |
required NullableIndexedWidgetBuilder separatorBuilder, | |
}) { | |
return SliverList( | |
delegate: SliverChildBuilderDelegate( | |
(context, index) { | |
final itemIndex = index ~/ 2; | |
return index.isEven | |
? itemBuilder(context, itemIndex) | |
: separatorBuilder(context, itemIndex); | |
}, | |
childCount: math.max(0, itemCount * 2 - 1), | |
), | |
); | |
} | |
} | |
class StickyFixedHeightHeaderDelegate extends SliverPersistentHeaderDelegate { | |
const StickyFixedHeightHeaderDelegate({ | |
required this.height, | |
required this.child, | |
}); | |
final double height; | |
final Widget child; | |
@override | |
double get minExtent => height; | |
@override | |
double get maxExtent => height; | |
@override | |
Widget build( | |
BuildContext context, | |
double shrinkOffset, | |
bool overlapsContent, | |
) { | |
return child; | |
} | |
@override | |
bool shouldRebuild(StickyFixedHeightHeaderDelegate oldDelegate) { | |
return height != oldDelegate.height; | |
} | |
} | |
const Color darkBlue = Color.fromARGB(255, 18, 32, 47); | |
void main() { | |
runApp(MyApp()); | |
} | |
class MyApp extends StatelessWidget { | |
@override | |
Widget build(BuildContext context) { | |
return MaterialApp( | |
theme: ThemeData.dark().copyWith( | |
scaffoldBackgroundColor: darkBlue, | |
), | |
debugShowCheckedModeBanner: false, | |
home: const Page(), | |
); | |
} | |
} | |
class Page extends StatelessWidget { | |
const Page({super.key}); | |
@override | |
Widget build(BuildContext context) { | |
return Scaffold( | |
appBar: AppBar( | |
title: const Text('Page'), | |
), | |
body: CustomScrollView( | |
slivers: [ | |
SliverToBoxAdapter( | |
child: Container( | |
width: double.infinity, | |
height: 300, | |
color: Colors.red, | |
)), | |
SliverPersistentHeader( | |
pinned: true, | |
delegate: StickyFixedHeightHeaderDelegate( | |
height: 200, | |
child: Container( | |
color: Colors.green, | |
),), | |
), | |
SliverListEx.separated( | |
itemCount: 100, | |
itemBuilder: (_, index) => ListTile( | |
key: ValueKey(index), | |
title: Text('item: $index'), | |
), | |
separatorBuilder: (_, __) => const Divider( | |
color: Colors.blueGrey, | |
), | |
) | |
], | |
), | |
); | |
} | |
} |
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