Formatting a Duration like HH:mm:ss

You can use Duration and implement this method:

String _printDuration(Duration duration) {
  String twoDigits(int n) => n.toString().padLeft(2, "0");
  String twoDigitMinutes = twoDigits(duration.inMinutes.remainder(60));
  String twoDigitSeconds = twoDigits(duration.inSeconds.remainder(60));
  return "${twoDigits(duration.inHours)}:$twoDigitMinutes:$twoDigitSeconds";
}

Usage:

final now = Duration(seconds: 30);
print("${_printDuration(now)}");

You can start creating a format yourself, come on this one:

String sDuration = "${duration.inHours}:${duration.inMinutes.remainder(60)}:${(duration.inSeconds.remainder(60))}"; 

Just a quick implementation.

This will display the Duration in [DD]d:[HH]h:[mm]m:[ss]s format, and will ignore the leading element if it was 0. But seconds will always present.

For example:

1d:2h:3m:4s

2h:3m:4s

3m:4s

4s

0s

  /// Returns a formatted string for the given Duration [d] to be DD:HH:mm:ss
  /// and ignore if 0.
  static String formatDuration(Duration d) {
    var seconds = d.inSeconds;
    final days = seconds~/Duration.secondsPerDay;
    seconds -= days*Duration.secondsPerDay;
    final hours = seconds~/Duration.secondsPerHour;
    seconds -= hours*Duration.secondsPerHour;
    final minutes = seconds~/Duration.secondsPerMinute;
    seconds -= minutes*Duration.secondsPerMinute;

    final List<String> tokens = [];
    if (days != 0) {
      tokens.add('${days}d');
    }
    if (tokens.isNotEmpty || hours != 0){
      tokens.add('${hours}h');
    }
    if (tokens.isNotEmpty || minutes != 0) {
      tokens.add('${minutes}m');
    }
    tokens.add('${seconds}s');

    return tokens.join(':');
  }