带有snaphelper的水平回收器视图，如何将第一个和最后一个元素居中？

public class CenterSnapHelper extends LinearSnapHelper {
    @Override
    public int[] calculateDistanceToFinalSnap(@NonNull RecyclerView.LayoutManager layoutManager, @NonNull View targetView) {
        int[] out = super.calculateDistanceToFinalSnap(layoutManager, targetView);

        int position = layoutManager.getPosition(targetView);
        int itemCount = layoutManager.getItemCount();

        if (position == 0) { // 第一个元素
            int viewWidth = targetView.getWidth();
            int containerWidth = layoutManager.getWidth();
            out[0] -= (containerWidth - viewWidth) / 2; // 左对齐改为居中对齐
        } else if (position == itemCount - 1) { // 最后一个元素
            int viewWidth = targetView.getWidth();
            int containerWidth = layoutManager.getWidth();
            out[0] += (containerWidth - viewWidth) / 2; // 右对齐改为居中对齐
        }

        return out;
    }
}