how to show/hide FAB on scroll Recycler view with coordinator parent

Question

I have an activity with coordinator layout.inside activity there is a fragment with Recycler view and float button.how can I show/hide float button when Scroll Recycler view and

Answer 1

Solution in Kotlin

recycler_view = findViewById(R.id.recycler_view)

        recycler_view.addOnScrollListener(object : RecyclerView.OnScrollListener(){
            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
                if(dy > 0){
                    fab.hide();
                } else{
                    fab.show();
                }
                super.onScrolled(recyclerView, dx, dy)

            }
        })