For DolDurma

elastic.dart

import 'package:flutter/material.dart';
import 'package:flutter/physics.dart';
import 'dart:math';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "Spring Box",
      theme: ThemeData(),
      home: Scaffold(
        body: HomePage(),
        backgroundColor: Color(0xFFe8e8e8),
      ),
    );
  }
}

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  var _isExpanded = false;

  _toggleExpanded() {
    setState(() {
      _isExpanded = !_isExpanded;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.end,
      children: <Widget>[
        GestureDetector(
          onTap: _toggleExpanded,
          child: AnimatedContainer(
            curve: _isExpanded ? Curves.elasticOut : Curves.elasticIn,
            duration: Duration(milliseconds: 800),
            width: _isExpanded ? 300 : 80,
            color: Color(0xFF404bc4),
          ),
        )
      ],
    );
  }
}