splash ui 3

import 'dart:async';
import 'package:flutter/material.dart';

class MyCustomSplashScreen extends StatefulWidget {
  @override
  _MyCustomSplashScreenState createState() => _MyCustomSplashScreenState();
}

class _MyCustomSplashScreenState extends State<MyCustomSplashScreen>
    with TickerProviderStateMixin {
  double _fontSize = 2;
  double _containerSize = 1.5;
  double _textOpacity = 0.0;
  double _containerOpacity = 0.0;

  AnimationController _controller;
  Animation<double> animation1;

  @override
  void initState() {
    super.initState();

    _controller =
        AnimationController(vsync: this, duration: Duration(seconds: 3));

    animation1 = Tween<double>(begin: 40, end: 20).animate(CurvedAnimation(
        parent: _controller, curve: Curves.fastLinearToSlowEaseIn))
      ..addListener(() {
        setState(() {
          _textOpacity = 1.0;
        });
      });

    _controller.forward();

    Timer(Duration(seconds: 2), () {
      setState(() {
        _fontSize = 1.06;
      });
    });

    Timer(Duration(seconds: 2), () {
      setState(() {
        _containerSize = 2;
        _containerOpacity = 1;
      });
    });

    Timer(Duration(seconds: 4), () {
      setState(() {
        Navigator.pushReplacement(context, PageTransition(SecondPage()));
      });
    });
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    double _width = MediaQuery.of(context).size.width;
    double _height = MediaQuery.of(context).size.height;

    return Scaffold(
      backgroundColor: Colors.deepPurple,
      body: Stack(
        children: [
          Column(
            children: [
              AnimatedContainer(
                duration: Duration(milliseconds: 2000),
                curve: Curves.fastLinearToSlowEaseIn,
                height: _height / _fontSize
              ),
              AnimatedOpacity(
                duration: Duration(milliseconds: 1000),
                opacity: _textOpacity,
                child: Text(
                  'YOUR APP\'S NAME',
                  style: TextStyle(
                    color: Colors.white,
                    fontWeight: FontWeight.bold,
                    fontSize: animation1.value,
                  ),
                ),
              ),
            ],
          ),
          Center(
            child: AnimatedOpacity(
              duration: Duration(milliseconds: 2000),
              curve: Curves.fastLinearToSlowEaseIn,
              opacity: _containerOpacity,
              child: AnimatedContainer(
                duration: Duration(milliseconds: 2000),
                curve: Curves.fastLinearToSlowEaseIn,
                height: _width / _containerSize,
                width: _width / _containerSize,
                alignment: Alignment.center,
                decoration: BoxDecoration(
                  color: Colors.white,
                  borderRadius: BorderRadius.circular(30),
                ),
                // child: Image.asset('assets/images/file_name.png')
                child: Text(
                  'YOUR APP\'S LOGO',
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class PageTransition extends PageRouteBuilder {
  final Widget page;

  PageTransition(this.page)
      : super(
          pageBuilder: (context, animation, anotherAnimation) => page,
          transitionDuration: Duration(milliseconds: 2000),
          transitionsBuilder: (context, animation, anotherAnimation, child) {
            animation = CurvedAnimation(
              curve: Curves.fastLinearToSlowEaseIn,
              parent: animation,
            );
            return Align(
              alignment: Alignment.bottomCenter,
              child: SizeTransition(
                sizeFactor: animation,
                child: page,
                axisAlignment: 0,
              ),
            );
          },
        );
}

class SecondPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(
        brightness: Brightness.dark,
        backgroundColor: Colors.deepPurple,
        centerTitle: true,
        title: Text(
          'YOUR APP\'S NAME',
          style: TextStyle(
            color: Colors.white,
            fontWeight: FontWeight.bold,
            fontSize: 20,
          ),
        ),
      ),
    );
  }
}