close method
Animates the sheet to a fully closed state.
duration: Optional duration for the closing animation.
Implementation
void close({Duration? duration}) {
if (isEnabled) {
final newPosition = viewportHeight;
final _duration = duration?.inMilliseconds ??
math.max((_extent.offset - newPosition).abs().round(), 150).toInt();
_startAnimation(
_extent.offset, newPosition, Curves.easeOutExpo, _duration);
}
}