class _ShimmerState extends State<Shimmer> with TickerProviderStateMixin {
  AnimationController controller;

  @override
  void initState() {
    super.initState();
    controller = AnimationController(vsync: this, duration: widget.period)
      ..addListener(() {
        setState(() {});
      })
      ..addStatusListener((status) {
        if (status == AnimationStatus.completed) {
          controller.repeat();
        }
      });
    controller.forward();
  }

  @override
  Widget build(BuildContext context) {
    return _Shimmer(
      child: widget.child,
      gradient: widget.gradient,
      percent: controller.value,
    );
  }

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

}