Simpler generic RecyclerView.Adapter and RecyclerView.ViewHolder with click listener, easy to use, no boilerplate code

RecyclerAdapter.java

package com.sumeet.gehi;

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

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class RecyclerAdapter<A extends RecyclerAdapter.ITEM> extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> {
    private List<A> items;
    private Context context;
    private int layout = 0;
    private OnItemClick<A> listener;

    public RecyclerAdapter(Context context, int layoutId, OnItemClick<A> listener) {
        this(context, layoutId, new ArrayList<>(), listener);
    }

    public RecyclerAdapter(Context context, int layoutId, List<A> list, OnItemClick<A> listener) {
        super();
        this.context = context;
        this.listener = listener;
        this.items = list;
        this.layout = layoutId;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {
        return new ViewHolder(LayoutInflater.from(context).inflate(layout, viewGroup, false), listener);
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerAdapter.ViewHolder holder, int position) {
        A a = getItem(position);
        if (a != null)
            a.setData(holder);
    }

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

    public A getItem(int index) {
        return ((items != null && index < items.size()) ? items.get(index) : null);
    }

    public void addAll(List<A> list) {
        if (items == null)
            items = new ArrayList<A>();
        items.addAll(list);
        notifyDataSetChanged();
    }

    public void reset() {
        items.clear();
        notifyDataSetChanged();
    }

    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        private Map<Integer, View> views;
        OnItemClick<A> listener;
      
        public ViewHolder(View view, OnItemClick<A> listener) {
            super(view);
            views = new HashMap<>();
            views.put(0, view);
            this.listener = listener;

            if (listener != null)
                view.setOnClickListener(this);
        }

        @Override
        public void onClick(View view) {
            if (listener != null)
                listener.onClick(getItem(getAdapterPosition()), getAdapterPosition());
        }

        private void initViewById(int id) {
            View view = (getView() != null ? getView().findViewById(id) : null);

            if (view != null)
                views.put(id, view);
        }

        public View getView() {
            return getView(0);
        }

        public View getView(int id) {
            Logger.e("RecyclerAdapter", "View getView " +id);
            if (views.containsKey(id))
                return views.get(id);
            else
                initViewById(id);

            return views.get(id);
        }
    }
  
  public interface OnItemClick<A> {
    public void onClick(A item, int pos);
  }
    
  public static abstract class ITEM {
        abstract public void setData(RecyclerAdapter.ViewHolder holder);
  }
}

TestActivity.java

// in Activity class ....

 recyclerView.setLayoutManager(...)
 recyclerView.setAdapter(new RecyclerAdapter<Item>(context, R.layout.list_item, list, listner{
 })



public class Item extends RecyclerAdapter.ITEM {
    public String name;
    public String type;
    public String desc;
    public boolean clickable = true

    public Item(String n, String d, String t) {
        super();
        name = n;
        desc = d;
        type = t; 
    }
  
  @Override
  pubilc void setData(ViewHolder holder){
    (TextView holder.getView(R.id.tv_title)).setText(name);
    (TextView holder.getView(R.id.tv_desc)).setText(desc);
    (TextView holder.getView(R.id.tv_type)).setText(type);
     ...
  }
}

TestActivity.kt

//or in kotlin

        val list = ArrayList<Items>()
        list.add(Items(....))
        .
        .
        .
        val adapter = RecyclerAdapter<Items>(this, R.layout.list_item, list, { item, position ->

        });
        recyclerView.layoutManager = LinearLayoutManager(this)
        val horizontalDecoration = DividerItemDecoration(recyclerView.context, DividerItemDecoration.VERTICAL)
        recyclerView.addItemDecoration(horizontalDecoration)
        
        // set adapter
        recyclerView.adapter = adapter;
        
        
        
    class Items(val name: String, val desc: String, val type: String?) : RecyclerAdapter.ITEM() {

        override fun setData(holder: RecyclerAdapter<*>.ViewHolder?) {
            (holder?.getView(R.id.tv_title) as TextView?)?.text = name
            (holder?.getView(R.id.tv_desc) as TextView?)?.text = desc
            (holder?.getView(R.id.tv_type) as TextView?)?.text = type
        }
    }