Flutter - Create a countdown widget

Question

I am trying to build a countdown widget. Currently, I got the structure to work. I only struggle with the countdown itself. I tried this approach using the countdown plugin:

Answer 1

based on @raju-bitter answer, alternative to use async/await on countdown stream

  void countdown() async {
    cd = new CountDown(new Duration(seconds:4));
    await for (var v in cd.stream) {
      setState(() => val = v.inSeconds);
    }
  }