public void Move(ImmutablePoint p)
{
double sx = SelectionStartPoint.X;
double sy = SelectionStartPoint.Y;
double x = _itemController.Snap(p.X, _state.Options.SnapSize);
double y = _itemController.Snap(p.Y, _state.Options.SnapSize);
_blockHelper.SetLeft(TempEllipse, Math.Min(sx, x));
_blockHelper.SetTop(TempEllipse, Math.Min(sy, y));
_blockHelper.SetWidth(TempEllipse, Math.Abs(sx - x));
_blockHelper.SetHeight(TempEllipse, Math.Abs(sy - y));
}