HideFabScrollListener.java

public class HideFabScrollListener extends RecyclerView.OnScrollListener {

    private static final int TRANSLATE_HIDE_DURATION_MILLIS = 200;
    private static final int TRANSLATE_SHOW_DURATION_MILLIS = 170;

    private View fab;

    private Animator hideAnimator;
    private Animator showAnimator;

    public HideFabScrollListener(View fab) {
        this.fab = fab;
    }

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        if (dy > 0 && hideAnimator == null) {
            if (showAnimator != null ) {
                showAnimator.cancel();
            }

            CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) fab.getLayoutParams();
            float translation = fab.getHeight() +  params.bottomMargin;
            hideAnimator = ObjectAnimator.ofFloat(fab, "translationY", fab.getTranslationY(), translation);
            hideAnimator.setDuration(TRANSLATE_HIDE_DURATION_MILLIS);
            hideAnimator.setInterpolator(new AccelerateInterpolator());
            hideAnimator.addListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationCancel(Animator animation) {
                    super.onAnimationCancel(animation);
                    hideAnimator = null;
                }

                @Override
                public void onAnimationEnd(Animator animation) {
                    super.onAnimationEnd(animation);
                    hideAnimator = null;
                }
            });
            hideAnimator.start();
        } else if (dy < 0 && showAnimator == null) {
            if (hideAnimator != null) {
                hideAnimator.cancel();
            }

            showAnimator = ObjectAnimator.ofFloat(fab, "translationY", fab.getTranslationY(), 0);
            showAnimator.setDuration(TRANSLATE_SHOW_DURATION_MILLIS);
            showAnimator.setInterpolator(new DecelerateInterpolator());
            showAnimator.addListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationCancel(Animator animation) {
                    super.onAnimationCancel(animation);
                    showAnimator = null;
                }

                @Override
                public void onAnimationEnd(Animator animation) {
                    super.onAnimationEnd(animation);
                    showAnimator = null;
                }
            });
            showAnimator.start();
        }
    }
}