hitTest method
It reacts twice.
Implementation
@override
bool hitTest(Offset position) {
if (_hitTestFlg) {
double value = _data.circleSizeValue / 2;
angel(Size.zero, Size(position.dx - value, position.dy - value));
_hitTestFlg = false;
} else {
_hitTestFlg = true;
}
return true;
}