NoteDuration.parse constructor

NoteDuration.parse(bool isInChord, bool isGraceNote, String? durationText, int dots, String? type, double? tupletRatio, MusicXMLParserState state,)

Parse the duration of a note and compute timings.

Implementation

factory NoteDuration.parse(
  bool isInChord,
  bool isGraceNote,
  String? durationText,
  int dots,
  String? type,
  double? tupletRatio,
  MusicXMLParserState state,
) {
  durationText ??= '0';
  int duration = int.parse(durationText);
  double? midiTicks;
  double seconds;
  double timePosition;
  bool? _isGraceNote;

  // Due to an error in Sibelius' export, force this note to have the
  // duration of the previous note if it is in a chord
  if (isInChord) {
    duration = state.previousNote?.noteDuration.duration ?? 1;
  }

  midiTicks = duration.toDouble();
  midiTicks = midiTicks * (standardPpq / state.divisions);

  seconds = midiTicks / standardPpq;
  seconds = seconds * state.secondsPerQuarter;

  timePosition = state.timePosition;

  // Not sure how to handle durations of grace notes yet as they
  // steal time from subsequent notes and they do not have a
  // <duration> tag in the MusicXML
  _isGraceNote = isGraceNote;

  if (isInChord) {
    // If this is a chord, set the time position to the time position
    // of the previous note (i.e. all the notes in the chord will have
    // the same time position)
    timePosition =
        state.previousNote?.noteDuration.timePosition ?? timePosition;
  } else {
    // Only increment time positions once in chord
    state.timePosition += seconds;
  }

  return NoteDuration(
    duration,
    midiTicks,
    seconds,
    timePosition,
    dots,
    type ?? 'quarter',
    tupletRatio ?? 1.0,
    _isGraceNote,
  );
}