endless RecyclerView Adapter

File name: EndlessRecyclerViewScrollListener

import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.StaggeredGridLayoutManager;

public abstract class EndlessRecyclerViewScrollListener extends RecyclerView.OnScrollListener {
    // The minimum amount of items to have below your current scroll position
    // before loading more.
    private int visibleThreshold = 2;
    // The current offset index of data you have loaded
    private int currentPage = 0;
    // The total number of items in the dataset after the last load
    private int previousTotalItemCount = 0;
    // True if we are still waiting for the last set of data to load.
    private boolean loading = true;
    // Sets the starting page index
    private int startingPageIndex = 0;

    RecyclerView.LayoutManager mLayoutManager;

    public EndlessRecyclerViewScrollListener(LinearLayoutManager layoutManager) {
        this.mLayoutManager = layoutManager;
    }

    public EndlessRecyclerViewScrollListener(GridLayoutManager layoutManager) {
        this.mLayoutManager = layoutManager;
        visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
    }

    public EndlessRecyclerViewScrollListener(StaggeredGridLayoutManager layoutManager) {
        this.mLayoutManager = layoutManager;
        visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
    }

    public int getLastVisibleItem(int[] lastVisibleItemPositions) {
        int maxSize = 0;
        for (int i = 0; i < lastVisibleItemPositions.length; i++) {
            if (i == 0) {
                maxSize = lastVisibleItemPositions[i];
            }
            else if (lastVisibleItemPositions[i] > maxSize) {
                maxSize = lastVisibleItemPositions[i];
            }
        }
        return maxSize;
    }

    // This happens many times a second during a scroll, so be wary of the code you place here.
    // We are given a few useful parameters to help us work out if we need to load some more data,
    // but first we check if we are waiting for the previous load to finish.
    @Override
    public void onScrolled(RecyclerView view, int dx, int dy) {
        int lastVisibleItemPosition = 0;
        int totalItemCount = mLayoutManager.getItemCount();

        if (mLayoutManager instanceof StaggeredGridLayoutManager) {
            int[] lastVisibleItemPositions = ((StaggeredGridLayoutManager) mLayoutManager).findLastVisibleItemPositions(null);
            // get maximum element within the list
            lastVisibleItemPosition = getLastVisibleItem(lastVisibleItemPositions);
        } else if (mLayoutManager instanceof GridLayoutManager) {
            lastVisibleItemPosition = ((GridLayoutManager) mLayoutManager).findLastVisibleItemPosition();
        } else if (mLayoutManager instanceof LinearLayoutManager) {
            lastVisibleItemPosition = ((LinearLayoutManager) mLayoutManager).findLastVisibleItemPosition();
        } 

        // If the total item count is zero and the previous isn't, assume the
        // list is invalidated and should be reset back to initial state
        if (totalItemCount < previousTotalItemCount) {
            this.currentPage = this.startingPageIndex;
            this.previousTotalItemCount = totalItemCount;
            if (totalItemCount == 0) {
                this.loading = true;
            }
        }
        // If it’s still loading, we check to see if the dataset count has
        // changed, if so we conclude it has finished loading and update the current page
        // number and total item count.
        if (loading && (totalItemCount > previousTotalItemCount)) {
            loading = false;
            previousTotalItemCount = totalItemCount;
        }

        // If it isn’t currently loading, we check to see if we have breached
        // the visibleThreshold and need to reload more data.
        // If we do need to reload some more data, we execute onLoadMore to fetch the data.
        // threshold should reflect how many total columns there are too
        if (!loading && (lastVisibleItemPosition + visibleThreshold) > totalItemCount) {
            currentPage++;
            onLoadMore(currentPage, totalItemCount, view);
            loading = true;
        }
    }
    
    // Call this method whenever performing new searches
    public void resetState() {
        this.currentPage = this.startingPageIndex;
        this.previousTotalItemCount = 0;
        this.loading = true;
    }

    // Defines the process for actually loading more data based on page
    public abstract void onLoadMore(int page, int totalItemsCount, RecyclerView view);

}

create xml:layout_progressbar.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:orientation="vertical"
    android:padding="10dp">

    <ProgressBar
        android:id="@+id/pb"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

Custom Adapter

import android.content.Context;
import android.os.Build;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.TextView;

import androidx.annotation.Keep;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.recyclerview.widget.RecyclerView;

import com.squareup.picasso.Picasso;

import java.util.ArrayList;


@Keep
public class VideoAdapter extends RecyclerView.Adapter {
    private final int VIEW_ITEM = 1;
    private final int VIEW_PROG = 0;
    public Context context;
    private ArrayList<Cat_Object> arrayList;
    Click click;
    Myclick myclick;
    Myclick myclick2;
    Myclick myclick3;

    public VideoAdapter(Context context, ArrayList<Cat_Object> arrayList, Click click, Myclick myclick, Myclick myclick2, Myclick myclick3) {
        this.context = context;
        this.arrayList = arrayList;
        this.click = click;
        this.myclick = myclick;
        this.myclick2 = myclick2;
        this.myclick3 = myclick3;
    }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        if (viewType == VIEW_ITEM) {
            View itemView = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.cat_item_file, parent, false);
            return new MyViewHolder(itemView);
        } else {
            View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_progressbar, parent, false);
            return new ProgressViewHolder(v);
        }
    }

    @Override
    public void onBindViewHolder(@NonNull final RecyclerView.ViewHolder holder, final int position) {
        if (holder instanceof MyViewHolder) {

            Picasso.get().load(arrayList.get(position).getUri()).into(((MyViewHolder) holder).avtar);
            ((MyViewHolder) holder).title.setText(arrayList.get(position).getTitel());
            ((MyViewHolder) holder).avtar.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    click.getId(arrayList.get(position).getVideo_link());
                }
            });
            ((MyViewHolder) holder).dw.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    myclick.getdw(arrayList.get(position).getVideo_link(),arrayList.get(position).getTitel());
                }
            });
            ((MyViewHolder) holder).wp.setOnClickListener(new View.OnClickListener() {
                @RequiresApi(api = Build.VERSION_CODES.KITKAT)
                @Override
                public void onClick(View v) {
                    myclick.getdw3(arrayList.get(position).getVideo_link(),arrayList.get(position).getTitel());
                }
            });
            ((MyViewHolder) holder).sh.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    myclick.getdw2(arrayList.get(position).getVideo_link(),arrayList.get(position).getTitel());

                }
            });


        } else {
            if (getItemCount() == 1) {
                ProgressViewHolder.progressBar.setVisibility(View.GONE);
            }
        }
    }

    @Override
    public long getItemId(int id) {
        return id;
    }

    @Override
    public int getItemCount() {
        return arrayList.size() + 1;
    }

    public void hideHeader() {
        ProgressViewHolder.progressBar.setVisibility(View.GONE);
    }

    public boolean isHeader(int position) {
        return position == arrayList.size();
    }

    @Override
    public int getItemViewType(int position) {
        return isHeader(position) ? VIEW_PROG : VIEW_ITEM;
    }

    private static class ProgressViewHolder extends RecyclerView.ViewHolder {
        private static ProgressBar progressBar;

        private ProgressViewHolder(View v) {
            super(v);
            progressBar = v.findViewById(R.id.pb);
        }
    }

    class MyViewHolder extends RecyclerView.ViewHolder {
        ImageView avtar;
        ImageView play;
        TextView title;
        ImageView dw,sh,wp;

        public MyViewHolder(@NonNull View itemView) {
            super(itemView);
            avtar = itemView.findViewById(R.id.avtar2);
            title = itemView.findViewById(R.id.titel2);
            play = itemView.findViewById(R.id.play);
            dw=itemView.findViewById(R.id.dw);
            sh=itemView.findViewById(R.id.sh);
            wp=itemView.findViewById(R.id.wp);
        }
    }

    public interface Click {

        void getId(String id);
    }
    public interface Myclick{
        void getdw(String link, String tital);

        void getdw3(String video_link, String titel);

        void getdw2(String video_link, String titel);
    }


}

call Adapter:

cat_adapter = new VideoAdapter(getActivity(), recentlist, (VideoAdapter.Click) this,this,this,this);
rv.setAdapter(cat_adapter);