shouldEmit method
Implementation
bool shouldEmit(double? fraction) {
if (fraction == null) return _tick();
if (fraction >= 1.0 && _last < 1.0) {
_mark(fraction);
return true;
}
if ((fraction - _last).abs() >= minDelta &&
_sw.elapsedMilliseconds >= _minIntervalMs) {
_mark(fraction);
return true;
}
return false;
}