Dart / Duration

main.dart

void main() {
  final sunrise = Duration.fromTime(
  	hours:8,
    seconds:39,
  );
  final dayLength = Duration.fromTime(
  	hours: 7,
    minutes: 51,
    seconds: 45
  );
  
  print(dayLength);
  print(dayLength * 0.5);
  print(sunrise + (dayLength * 0.5));
}

class Duration {
  final double seconds;
  
  Duration(this.seconds);
  
  factory Duration.fromTime({
    int hours = 0, 
    int minutes = 0,
    int seconds = 0,
  }) {
    //convert to seconds
    final s = hours * (60*60) + minutes * 60 + seconds;
    return Duration(s.toDouble());
  }
  
  Duration operator +(Duration other) {
    return Duration(seconds + other.seconds);
  }
  
  Duration operator -(Duration other) {
    return Duration(seconds - other.seconds);
  }
  
  Duration operator /(num other) {
    return Duration(seconds / other);
  }
  
  Duration operator *(num other) {
    return Duration(seconds * other);
  }
  
  String toString() {
    final h = (seconds / (60*60)).truncate();
    final m = (seconds / 60).truncate() % 60;
    final s = seconds % 60; 
    var str = "Duration($seconds)";
    
    if (h != 0) {
      str += 
        " {hours:$h "
        "minutes:$m "
        "seconds:$s}";
    } else if (m != 0) {
      str +=
        " {minutes:$m "
      	"seconds:$s}";
    }
    
    return str;
  }
}