Custom Android's OnScrollListener to make FAB animate along with RecyclerView's scrolls

AnimateFabAccordingOnScrollListener.cs

using FloatingActionMenu = Clans.Fab.FloatingActionMenu;

public class AnimateFabAccordingOnScrollListener : Android.Support.V7.Widget.RecyclerView.OnScrollListener
{
    const int AnimationDuration = 150;

    readonly FloatingActionMenu _fab;
    int _lastY;
    bool _fabTranslated;
    readonly int _bottomBarHeight;

    public AnimateFabAccordingOnScrollListener(FloatingActionMenu fab) : base()
    {
        _fab = fab;

        _bottomBarHeight = _fab.Resources.GetDimensionPixelSize(Resource.Dimension.bottombar_height);
    }

    public override void OnScrolled(Android.Support.V7.Widget.RecyclerView recyclerView, int dx, int dy)
    {
        base.OnScrolled(recyclerView, dx, dy);

        if (dy > 0 && !_fabTranslated) // Scrolling down for 1st time...
        {
            _fab.Animate()
                .TranslationY(_bottomBarHeight);
            _fabTranslated = true;
        }
        else if (dy < 0 && _fabTranslated) // Scrolling up for 1st time...
        {
            _fabTranslated = false;
            _fab.Animate()
                .TranslationY(0);
        }

        _lastY = dy;
    }
}