TimeBuilder.countdown constructor

TimeBuilder.countdown({ Key? key, required DateTime start, required int seconds, required CountdownWidgetBuilder builder, })

Creates a countdown, from the given start DateTime. Will call the builder, which is a CountdownWidgetBuilder, once per second, util the countdown reaches zero.

TimerWidget.countdown(
   reference: DateTime.now(),
   builder: (BuildContext context, int seconds, bool isFinished) => ...;
)

Implementation

factory TimeBuilder.countdown({
  Key? key,
  required DateTime start,
  required int seconds,
  required CountdownWidgetBuilder builder,
}) {
  return TimeBuilder(
    //
    key: key,
    //
    ifRebuilds: ({
      required DateTime currentTime,
      required DateTime? lastTime,
      required int ticks,
    }) {
      return (lastTime == null || (currentTime.second != lastTime.second));
    },
    //
    isFinished: ({
      required DateTime currentTime,
      required DateTime? lastTime,
      required int ticks,
    }) {
      if (lastTime != null && (currentTime.second == lastTime.second)) return false;

      int _seconds = (start.add(Duration(seconds: seconds))).difference(currentTime).inSeconds;

      return _seconds <= 0;
    },
    //
    builder: (
      BuildContext context,
      DateTime now,
      int ticks,
      bool isFinished,
    ) {
      int _seconds = (start.add(Duration(seconds: seconds))).difference(now).inSeconds;
      return builder(context, now, ticks, isFinished, countdown: _seconds);
    },
    //
  );
}