// Copyright 2014 The Flutter Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. import 'package:flutter/material.dart'; /// Flutter code sample for [SliverAnimatedOpacity]. void main() => runApp(const SliverAnimatedOpacityExampleApp()); class SliverAnimatedOpacityExampleApp extends StatelessWidget { const SliverAnimatedOpacityExampleApp({super.key}); @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( appBar: AppBar(title: const Text('SliverAnimatedOpacity Sample')), body: const Center( child: SliverAnimatedOpacityExample(), ), ), ); } } class SliverAnimatedOpacityExample extends StatefulWidget { const SliverAnimatedOpacityExample({super.key}); @override State<SliverAnimatedOpacityExample> createState() => _SliverAnimatedOpacityExampleState(); } class _SliverAnimatedOpacityExampleState extends State<SliverAnimatedOpacityExample> with SingleTickerProviderStateMixin { bool _visible = true; @override Widget build(BuildContext context) { return CustomScrollView(slivers: <Widget>[ SliverAnimatedOpacity( opacity: _visible ? 1.0 : 0.0, duration: const Duration(milliseconds: 500), sliver: SliverFixedExtentList( itemExtent: 100.0, delegate: SliverChildBuilderDelegate( (BuildContext context, int index) { return Container( color: index.isEven ? Colors.indigo[200] : Colors.orange[200], ); }, childCount: 5, ), ), ), SliverToBoxAdapter( child: FloatingActionButton( onPressed: () { setState(() { _visible = !_visible; }); }, tooltip: 'Toggle opacity', child: const Icon(Icons.flip), )), ]); } }