bouncing_ball.dart

import 'package:flutter/material.dart';

void main() {
  runApp(
    MaterialApp(
      home: BouncyBall(),
    ),
  );
}

class BouncyBall extends StatefulWidget {
  @override
  State<BouncyBall> createState() => BouncyBallState();
}

class BouncyBallState extends State<BouncyBall> with SingleTickerProviderStateMixin{
  AnimationController controller;
  Animation animation;
  
  @override
  void initState(){
    super.initState();
    controller = AnimationController(duration: Duration(milliseconds: 800), vsync: this);
    controller.repeat(reverse: true);
    animation = CurvedAnimation(parent: controller, curve: Curves.decelerate);
    controller.forward().whenComplete(()=>controller.repeat(reverse: true),);
    animation.addListener(()=>setState((){}));
  }
  
 
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Center(
            child: Transform.translate(
              offset: Offset(0, animation.value * -200),
              child: Container(
                decoration: BoxDecoration(
                  shape: BoxShape.circle,
                  color: Colors.deepOrange[800],
//                   boxShadow: [
//                     BoxShadow(
//                       color: Colors.black,
//                       offset: Offset(-2, 2), 
//                       blurRadius: 3
//                     ),
//                   ],
                ),
                height: 100,
                width: 100,
              ),
            ),
          ),
          Transform.scale(
            scale: 1 - animation.value,
            child: Container(
              decoration: BoxDecoration(
                color: Colors.black12.withOpacity(1 - animation.value),
                borderRadius: BorderRadius.all(
                  Radius.elliptical(100, 10),
                ),
              ),
              width: 100,
              height: 10,
              
            ),
          ),
          SizedBox(height: 20),
          Text(
            "Loading".padRight("Loading".length + (animation.value * 3).round(), ' .'),
            textAlign: TextAlign.start,
            style: TextStyle(
              color: Colors.deepOrange[800],
              fontSize: 15,
              fontWeight: FontWeight.bold,
              fontStyle: FontStyle.italic,
            ),
          ),
        ],
      ),
    
    );
  }
}