Android recyclerview example with pagination using java.

activity_pagination.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_test"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <ProgressBar
        android:id="@+id/main_progress"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true" />
</RelativeLayout>

item_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="20dp">

    <TextView
        android:id="@+id/text_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

item_progress.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ProgressBar
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true" />

</RelativeLayout>

MainActivity.java

package com.example.salasuresh.androidpractice.pagination_practice;

import android.os.Bundle;
import android.os.Handler;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.ProgressBar;

import com.example.salasuresh.androidpractice.R;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private RecyclerView recyclerView;
    private MyListAdapter myListAdapter;
    private ProgressBar progressBar;
    private LinearLayoutManager linearLayoutManager;

    private boolean isLoading;

    private int pageCount;

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

        progressBar = findViewById(R.id.main_progress);

        recyclerView = findViewById(R.id.recycler_test);
        linearLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL));
        myListAdapter = new MyListAdapter();
        recyclerView.setAdapter(myListAdapter);

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

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

                int visibleItemCount = linearLayoutManager.getChildCount();
                int totalItemCount = linearLayoutManager.getItemCount();
                int firstVisibleItemPosition = linearLayoutManager.findFirstVisibleItemPosition();

                if (!isLoading) {
                    if ((visibleItemCount + firstVisibleItemPosition) >= totalItemCount
                            && firstVisibleItemPosition >= 0
                            && totalItemCount >= 10) {
                        isLoading = true;
                        new Handler().postDelayed(new Runnable() {
                            @Override
                            public void run() {
                                loadPage();
                            }
                        }, 1000);
                    }
                }
            }
        });
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                loadPage();
            }
        }, 1000);
    }

    private void loadPage() {
        List<String> names = getNames(myListAdapter.getItemCount());
        if (names == null) {
            myListAdapter.removeLoadingFooter();
            return;
        }
        progressBar.setVisibility(View.GONE);
        myListAdapter.removeLoadingFooter();
        isLoading = false;
        myListAdapter.addAll(names);
        myListAdapter.addLoadingFooter();
    }

    private List<String> getNames(int count) {
        pageCount += 1;
        if (pageCount > 3)
            return null;
        List<String> names = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            names.add("Name: " + (count == 0 ?
                    (count + 1 + i) : (count + i)));
        }
        return names;
    }
}

MyListAdapter.java

package com.example.salasuresh.androidpractice.pagination_practice;

import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.example.salasuresh.androidpractice.R;

import java.util.ArrayList;
import java.util.List;

public class MyListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private List<String> names = new ArrayList<>();

    private static final int ITEM = 0;
    private static final int LOADING = 1;

    private boolean isLoadingAdded = false;

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        switch (viewType) {
            case ITEM:
                return new ItemViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout, parent, false));
            case LOADING:
                return new LoadingViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.item_progress, parent, false));
        }
        return null;
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        switch (getItemViewType(position)) {
            case ITEM:
                ItemViewHolder itemViewHolder = (ItemViewHolder) holder;
                itemViewHolder.textName.setText(names.get(position));
                break;
            case LOADING:
                break;
        }
    }

    @Override
    public int getItemCount() {
        return names == null ? 0 : names.size();
    }

    @Override
    public int getItemViewType(int position) {
        return (position == names.size() - 1 && isLoadingAdded) ? LOADING : ITEM;
    }

    class ItemViewHolder extends RecyclerView.ViewHolder {
        private TextView textName;

        public ItemViewHolder(View itemView) {
            super(itemView);
            textName = itemView.findViewById(R.id.text_name);
        }
    }

    class LoadingViewHolder extends RecyclerView.ViewHolder {

        public LoadingViewHolder(View itemView) {
            super(itemView);
        }
    }

    public void add(String name) {
        names.add(name);
        notifyItemInserted(names.size() - 1);
    }

    public void addAll(List<String> namesList) {
        for (String name : namesList) {
            add(name);
        }
    }

    public void addLoadingFooter() {
        isLoadingAdded = true;
        add("");
    }

    public void removeLoadingFooter() {
        isLoadingAdded = false;

        int position = names.size() - 1;
        if (position <= 0) return;
        String name = names.get(position);

        if (name != null) {
            names.remove(position);
            notifyItemRemoved(position);
        }
    }
}