Animated Container with Animation

 import "package:flutter/material.dart";

void main()
{
  runApp(const MyApp());
}
class MyApp extends StatelessWidget
{
  const MyApp({super.key});

  @override
  Widget build(BuildContext context)
  {
    return MaterialApp(
      title: "Hello",
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blueGrey,
      ),
      home: const FlutterApp(),
    );
  }
}

class FlutterApp extends StatefulWidget
{
  const FlutterApp({super.key});

  @override
  State<FlutterApp> createState()
  {
    return FlutterState();
  }
}
class FlutterState extends State<FlutterApp>
{
  var _width = 300.0;
  var _height = 100.0;

  bool flag = true;

  //var bgColor = Colors.blueGrey;

  Decoration myDecor = BoxDecoration(
    borderRadius: BorderRadius.circular(2),
    color: Colors.blueGrey,
  );

  @override
  Widget build(BuildContext context)
  {
    return Scaffold(
      drawer: const Drawer(),
      appBar: AppBar(
        title: const Text("Animate Containers"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            AnimatedContainer(
              width: _width,
              height: _height,
              decoration: myDecor,
              //curve: Curves.slowMiddle,
              //curve: Curves.fastOutSlowIn,
              //curve: Curves.bounceOut,
              curve: Curves.bounceInOut,
              duration: const Duration(seconds: 2,),
              child: const FlutterLogo(size: 75,),
            ),

            const SizedBox(height: 50,),

            ElevatedButton(
              onPressed: (){

                setState((){
                  if(flag){
                    _width = 100;
                    _height = 300;
                    flag = false;
                    myDecor = BoxDecoration(
                      borderRadius: BorderRadius.circular(21),
                      color: Colors.amber,
                    );
                    //bgColor = Colors.orange;

                  }else {
                    _width = 300;
                    _height = 100;
                    flag = true;
                    myDecor = BoxDecoration(
                      borderRadius: BorderRadius.circular(2),
                      color: Colors.blueGrey,
                    );
                    //bgColor = Colors.blueGrey;
                  }
                },);
              },
              style: ElevatedButton.styleFrom(
                backgroundColor: Colors.blue,
              ),
              child: const Text("Animate",
                style: TextStyle(fontWeight: FontWeight.bold, color: Colors.white),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

/*This is the another example of "AnimatedContainers"*/
/*class FlutterState extends State<FlutterApp>
{
  bool _shape = true;

  @override
  Widget build(BuildContext context)
  {
    return Scaffold(
      drawer: const Drawer(),
      appBar: AppBar(
        title: const Text("Flutter Animation"),
      ),
      body: Center(
        child: InkWell(
          onTap: (){
            setState((){
              _shape = !_shape;
            });
          },
          child: AnimatedContainer(
            width: _shape ? 200 : 350,
            height: _shape ? 500 : 150,
            color: _shape ? Colors.amberAccent : Colors.black,
            duration: const Duration(seconds: 1),
            child: const FlutterLogo(size: 40,),
          ),
        ),
      ),
    );
  }
}*/