SplashScreen with animate logo

main.dart

List<CameraDescription> cameras;

Future<Null> main() async {
  cameras = await availableCameras();
  runApp(new MaterialApp(
    debugShowCheckedModeBanner: false,
    theme: new ThemeData(
      brightness: Brightness.light,
      primaryColor: Colors.green,
      secondaryHeaderColor: Colors.green,
      accentColor: Color(0xFF73bc42),
    ),
    home: new SplashScreen(),
    routes: <String, WidgetBuilder>{
      '/screens/LoginScreen': (BuildContext context) => new LoginScreen(),      
      '/screens/SignUpScreen': (BuildContext context) => new SignUpBasicScreen(cameras)
    },
  ));
}

class SplashScreen extends StatefulWidget {
  @override
  _SplashScreenState createState() => new _SplashScreenState();
}

class _SplashScreenState extends State<SplashScreen>
    with SingleTickerProviderStateMixin {
  AnimationController _logoAnimationController;
  Animation<double> _logoAnimation;

  startTime() async {
    var _duration = new Duration(seconds: 3);
    return new Timer(_duration, navigationPage);
  }

  void navigationPage() {
    Navigator.of(context).pushReplacementNamed('/screens/LoginScreen');
  }

  @override
  void initState() {
    super.initState();
    _logoAnimationController = new AnimationController(
        vsync: this, duration: new Duration(milliseconds: 300));
    _logoAnimation = new CurvedAnimation(
        parent: _logoAnimationController, curve: Curves.easeOut);
    _logoAnimation.addListener(() => this.setState(() {}));
    _logoAnimationController.forward();
    startTime();
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
        backgroundColor: Colors.white,
        body: new Stack(
          fit: StackFit.expand,
          children: <Widget>[
            new Column(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.center,
              children: <Widget>[
                new Image.asset('images/ic_logo_name.png',
                    width: _logoAnimation.value * 200.0,
                    height: _logoAnimation.value * 100.0)
              ],
            )
          ],
        )        
        );
  }
}