Endless RecyclerView OnScrollListener

EndlessRecyclerOnScrollListener.java

import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

public abstract class EndlessRecyclerOnScrollListener extends RecyclerView.OnScrollListener {
    public static String TAG = EndlessRecyclerOnScrollListener.class.getSimpleName();

    private int previousTotal = 0; // The total number of items in the dataset after the last load
    private boolean loading = true; // True if we are still waiting for the last set of data to load.
    private int visibleThreshold = 5; // The minimum amount of items to have below your current scroll position before loading more.
    int firstVisibleItem, visibleItemCount, totalItemCount;

    private int current_page = 1;

    private LinearLayoutManager mLinearLayoutManager;

    public EndlessRecyclerOnScrollListener(LinearLayoutManager linearLayoutManager) {
        this.mLinearLayoutManager = linearLayoutManager;
    }

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

        visibleItemCount = recyclerView.getChildCount();
        totalItemCount = mLinearLayoutManager.getItemCount();
        firstVisibleItem = mLinearLayoutManager.findFirstVisibleItemPosition();

        if (loading) {
            if (totalItemCount > previousTotal) {
                loading = false;
                previousTotal = totalItemCount;
            }
        }
        if (!loading && (totalItemCount - visibleItemCount)
                <= (firstVisibleItem + visibleThreshold)) {
            // End has been reached

            // Do something
            current_page++;

            onLoadMore(current_page);

            loading = true;
        }
    }

    public abstract void onLoadMore(int current_page);
}

SampleActivity.java

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

public class SampleActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sample);

        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.list);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.setOnScrollListener(new EndlessRecyclerOnScrollListener(linearLayoutManager) {
            @Override
            public void onLoadMore(int current_page) {
                // do something...
            }
        });
    }
}

It works. Thanks!
It was not working for me because I was wrapping the recycler view in a scroll view in my layout file. I spent days to find that it was the root cause of the issue and that I should remove the scroll view.

Great work!
I'm using kotlin and i was stuck on this one.
Thank

You should add a reset method:

public void reset(int previousTotal, boolean loading) {
  this.previousTotal = previousTotal;
  this.loading = loading;
}

And call it on onResume() in SampleActivity:

@Override
  public void onResume() {
    super.onResume();
    endlessScrollListener.reset(0, true);
}

Because after you pause the activity and resume again, the condition !loading && (totalItemCount - visibleItemCount) <= (firstVisibleItem + visibleThreshold) is always false, thus onLoadMore is never called.

Thanks...Worked like a pro

change if (totalItemCount > previousTotal) to if (totalItemCount != previousTotal) will be better for dataset changing.

Thanks, you saved my time

Thanks you