| // 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. |
| |
| // Flutter code sample for [SliverOpacity]. |
| |
| import 'package:flutter/material.dart'; |
| |
| void main() => runApp(const MyApp()); |
| |
| class MyApp extends StatelessWidget { |
| const MyApp({super.key}); |
| |
| static const String _title = 'Flutter Code Sample'; |
| |
| @override |
| Widget build(BuildContext context) { |
| return const MaterialApp( |
| title: _title, |
| home: MyStatefulWidget(), |
| ); |
| } |
| } |
| |
| class MyStatefulWidget extends StatefulWidget { |
| const MyStatefulWidget({super.key}); |
| |
| @override |
| State<MyStatefulWidget> createState() => _MyStatefulWidgetState(); |
| } |
| |
| class _MyStatefulWidgetState extends State<MyStatefulWidget> { |
| static const List<Widget> _listItems = <Widget>[ |
| ListTile(title: Text('Now you see me,')), |
| ListTile(title: Text("Now you don't!")), |
| ]; |
| |
| bool _visible = true; |
| |
| @override |
| Widget build(BuildContext context) { |
| return Scaffold( |
| appBar: AppBar( |
| title: const Text('SliverOpacity demo'), |
| ), |
| body: CustomScrollView( |
| slivers: <Widget>[ |
| const SliverToBoxAdapter( |
| child: ListTile(title: Text('Press on the button to toggle the list visibility.')), |
| ), |
| const SliverToBoxAdapter( |
| child: ListTile(title: Text('Before the list...')), |
| ), |
| SliverOpacity( |
| opacity: _visible ? 1.0 : 0.0, |
| sliver: SliverList( |
| delegate: SliverChildListDelegate(_listItems), |
| ), |
| ), |
| const SliverToBoxAdapter( |
| child: ListTile(title: Text('Before the list...')), |
| ), |
| ], |
| ), |
| floatingActionButton: FloatingActionButton( |
| child: const Icon(Icons.disabled_visible), |
| onPressed: () { |
| setState(() { |
| _visible = !_visible; |
| }); |
| }, |
| ), |
| ); |
| } |
| } |