Base recyclerview adapter class containing a progressbar item by default.

AbstractRecyclerViewAdapter.java

package com.got2goto.android.components;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ProgressBar;

import com.got2goto.android.BaseApplication;

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

/**
 * Abstract RecyclerView adapter class containing ProgressBar item and other helper functions.
 *
 * Created by Rafay Ali on 7/18/2016.
 */
public abstract class AbstractRecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{

    public static final int ITEM_TYPE_PROGRESS_BAR = 0;

    protected boolean               isProgressBarVisible = false;
    protected ProgressBar           progressBar;
    protected Context               context;
    protected List<Object>          itemsList = new ArrayList<>();

    public AbstractRecyclerViewAdapter(Context context){
        this.context = context;
        progressBar = new ProgressBar(this.context);
    }

    @Override
    public int getItemViewType(int position) {
        if (itemsList.get(position) instanceof ProgressBar)
            return ITEM_TYPE_PROGRESS_BAR;

        return -1;
    }

    @Override
    public int getItemCount() {
        return itemsList.size();
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        switch (viewType){
            case ITEM_TYPE_PROGRESS_BAR:
                View progressBarView = ((LayoutInflater) BaseApplication.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(getProgressBarLayoutResId(), parent, false);
                return new ProgressBarViewHolder(progressBarView);
        }

        return null;
    }

    public void addItem(Object item){
        itemsList.add(item);
    }

    public void addAllItems(List itemsList){
        this.itemsList.addAll(itemsList);
    }

    public void removeItem(Object item){
        itemsList.remove(item);
    }

    public void removeItemAtPosition(int position){
        itemsList.remove(position);
    }

    public void removeAllItems(){
        itemsList.clear();
    }

    public void showProgressBar(){
        if (!isProgressBarVisible)
            itemsList.add(progressBar);
        isProgressBarVisible = true;
    }

    public void hideProgressBar(){
        if (isProgressBarVisible)
            itemsList.remove(progressBar);
        isProgressBarVisible = false;
    }

    public abstract int getProgressBarLayoutResId();
}