Control animation with chain

animation_chian.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);
  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
  late AnimationController con;
  late Animation<double> _animation;

  @override
  void initState() {
    super.initState();
    con = AnimationController(vsync: this)
      ..duration = const Duration(seconds: 1)
      ..addListener(() {
        setState(() {
          if (con.isCompleted) {
            con.stop();
          }
        });
      })
      ..forward();
    _animation = Tween(
      begin: 0.0,
      end: 1.0,
    ).chain(CurveTween(curve: Curves.slowMiddle)).animate(con);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Container(
          transform: Matrix4.translationValues(100 * _animation.value, 0, 0),
          color: Colors.blue,
          width: 100,
          height: 100,
        ),
      ),
    );
  }
}