How to detect when RecyclerView is scrolled to most top position

Question

I have RecyclerView above that i have an AppBarLayout whose height is larger than 255 px. When user scrolls RecyclerView, AppBarLayout has an fling issue. To avoid that i decided to expand AppBarLayout manually. My RecyclerView made of GridLayoutManager with span of 3. I used below code to listen RecyclerView top reach

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);
        if (newState == RecyclerView.SCROLL_STATE_IDLE) {
            int firstVisiblePosition = ((LinearLayoutManager)recyclerView.getLayoutManager()).findFirstCompletelyVisibleItemPosition();
            if (firstVisiblePosition == 0) {
                appBarLayout.setExpanded(true, true);
            }
        }
    }
});

Mogul

Answer 1

    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);

            int firstVisibleItem = gridLayoutManager.findFirstCompletelyVisibleItemPosition();

            if(firstVisibleItem == 0){
                // your code
            }
        }
    });

Nguyen

i want to get top reached on scroll up – Mogul

nope i have an appbar above recyclerview, when scrolled down appbar manually expanded and when scrolled up app bar collapsed manually – Mogul

place your code in onScrolled() instead of onScrollStateChanged() – Nguyen

@HafizMuneeb my list size is greater than the screen size , in this cast the method always gets called , how can i detect recyclerview scrolled to top most item in this case ? – Ware

Answer 2

This answer will help you. Yours truly

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
        @Override
        public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {

            super.onScrollStateChanged(recyclerView, newState);
        }

        @Override
        public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);

            totalItemCount = layoutManager.getItemCount();
            visibleItemCount = layoutManager.getChildCount();
            pastVisiblesItems = layoutManager.findFirstVisibleItemPosition();
            if ((visibleItemCount + pastVisiblesItems) >= totalItemCount ) {

                Log.d(TAG, "scroll down");



            }
            else{
                Log.d(TAG, "scroll up");
            }
        }
    });

Aimless

Answer 3

I found a brilliant solution here. You could implement it inside your RecyclerView.OnScrollListener like this:

binding.recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
        super.onScrolled(recyclerView, dx, dy)

        if (!recyclerView.canScrollVertically(-1)) {
            Log.d(TAG, "THE TOP")
        } else {
            Log.d(TAG, "NOT TOP")
        }
    }
})

Nephograph