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// 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 [ExpansionTile] and [ExpansionTileController].
void main() {
runApp(const ExpansionTileControllerApp());
}
class ExpansionTileControllerApp extends StatefulWidget {
const ExpansionTileControllerApp({super.key});
@override
State<ExpansionTileControllerApp> createState() => _ExpansionTileControllerAppState();
}
class _ExpansionTileControllerAppState extends State<ExpansionTileControllerApp> {
final ExpansionTileController controller = ExpansionTileController();
@override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(useMaterial3: true),
home: Scaffold(
appBar: AppBar(title: const Text('ExpansionTileController Sample')),
body: Column(
children: <Widget>[
// A controller has been provided to the ExpansionTile because it's
// going to be accessed from a component that is not within the
// tile's BuildContext.
ExpansionTile(
controller: controller,
title: const Text('ExpansionTile with explicit controller.'),
children: <Widget>[
Container(
alignment: Alignment.center,
padding: const EdgeInsets.all(24),
child: const Text('ExpansionTile Contents'),
),
],
),
const SizedBox(height: 8),
ElevatedButton(
child: const Text('Expand/Collapse the Tile Above'),
onPressed: () {
if (controller.isExpanded) {
controller.collapse();
} else {
controller.expand();
}
},
),
const SizedBox(height: 48),
// A controller has not been provided to the ExpansionTile because
// the automatically created one can be retrieved via the tile's BuildContext.
ExpansionTile(
title: const Text('ExpansionTile with implicit controller.'),
children: <Widget>[
Builder(
builder: (BuildContext context) {
return Container(
padding: const EdgeInsets.all(24),
alignment: Alignment.center,
child: ElevatedButton(
child: const Text('Collapse This Tile'),
onPressed: () {
return ExpansionTileController.of(context).collapse();
},
),
);
},
),
],
),
],
),
),
);
}
}