import 'package:flutter/material.dart';

const Color backgroundColor = Colors.orange;
const Color collapsedBackgroundColor = Colors.red;
const Color iconColor = Colors.green;
const Color collapsedIconColor = Colors.blue;
const Color textColor = Colors.black;
const Color collapsedTextColor = Colors.white;

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Material App',
      theme: ThemeData(
        expansionTileTheme: const ExpansionTileThemeData(
          backgroundColor: backgroundColor,
          collapsedBackgroundColor: collapsedBackgroundColor,
          tilePadding: EdgeInsets.fromLTRB(8, 12, 4, 10),
          expandedAlignment: Alignment.centerRight,
          childrenPadding: EdgeInsets.all(20.0),
          iconColor: iconColor,
          collapsedIconColor: collapsedIconColor,
          textColor: textColor,
          collapsedTextColor: collapsedTextColor,
        ),
      ),
      home: const ExpansionTileSample(),
    );
  }
}

class ExpansionTileSample extends StatefulWidget {
  const ExpansionTileSample({Key? key}) : super(key: key);

  @override
  State<ExpansionTileSample> createState() => _ExpansionTileSampleState();
}

class _ExpansionTileSampleState extends State<ExpansionTileSample> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('ExpansionTile Sample'),
      ),
      body: SingleChildScrollView(
        child: Column(
          children: const <Widget>[
            ExpansionTile(
              title: Text('Collapsed Tile'),
              children: <Widget>[Text('Tile 2')],
            ),
            ExpansionTile(
              initiallyExpanded: true,
              title: Text('Expanded Tile'),
              children: <Widget>[Text('Tile 1')],
            ),
          ],
        ),
      ),
    );
  }
}