addPosition method Null safety
override
Adds a position as the given time to the tracker.
Implementation
@override
void addPosition(Duration time, Offset position) {
assert(() {
final _PointAtTime? previousPoint = _touchSamples[_index];
if (previousPoint == null || previousPoint.time <= time) {
return true;
}
throw FlutterError(
'The position being added ($position) has a smaller timestamp ($time) '
'than its predecessor: $previousPoint.',
);
}());
_index = (_index + 1) % _sampleSize;
_touchSamples[_index] = _PointAtTime(position, time);
}