Android RecyclerView example using Kotlin

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.suresh.recyclerviewpractice.MainActivity"
    tools:layout_editor_absoluteY="81dp">

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

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:orientation="horizontal"
    android:padding="5dp">

    <ImageView
        android:id="@+id/image_picture"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:src="@mipmap/ic_launcher_round" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:padding="5dp">

        <TextView
            android:id="@+id/text_name"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Name"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/text_message"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Message" />
    </LinearLayout>

</LinearLayout>

MainActivity.kt

package com.example.suresh.recyclerviewpractice

import android.os.Bundle
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.widget.Toast

class MainActivity : AppCompatActivity(), MyRecyclerView.itemClickListener {
    val names: ArrayList<String> = ArrayList()
    val message: ArrayList<String> = ArrayList()
    val picture: ArrayList<Int> = ArrayList()
    override fun onItemClick(position: Int) {
        Toast.makeText(this, "${names.get(position)}", Toast.LENGTH_SHORT).show()
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        for (i in 1..10) {
            names.add("name " + i)
            message.add("message " + i)
            picture.add(R.mipmap.ic_launcher)
        }
        val recyclerView: RecyclerView = findViewById(R.id.recycler_names)
        recyclerView.layoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)
        recyclerView.addItemDecoration(DividerItemDecoration(this, DividerItemDecoration.VERTICAL))
        val myAdapter = MyRecyclerView(names, message, picture, this, this)
        recyclerView.adapter = myAdapter
    }
}

MyRecyclerView.kt

package com.example.suresh.recyclerviewpractice

import android.content.Context
import android.os.Build
import android.support.annotation.RequiresApi
import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView

/**
 * Created by Dumadu on 23-Oct-17.
 */
class MyRecyclerView(val names: ArrayList<String>, val message: ArrayList<String>,
                     val picture: ArrayList<Int>, val context: Context, val itemClick: itemClickListener) : RecyclerView.Adapter<MyRecyclerView.MyViewHolder>() {

    interface itemClickListener {
        fun onItemClick(position: Int)
    }

    override fun getItemCount(): Int {
        return names.size
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(R.layout.item_layout, parent, false)
        return MyViewHolder(view, context, itemClick)
    }

    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        holder.bindData(names, message, picture, position, context)
    }

    class MyViewHolder(itemView: View, val context: Context, val itemClick: itemClickListener) : RecyclerView.ViewHolder(itemView) {
        val mTextName: TextView = itemView.findViewById(R.id.text_name)
        val mTextMessage: TextView = itemView.findViewById(R.id.text_message)
        val mImagePicture: ImageView = itemView.findViewById(R.id.image_picture)

        @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
        fun bindData(names: ArrayList<String>, message: ArrayList<String>, picture: ArrayList<Int>, position: Int, context: Context) {
            mTextName.text = names.get(position)
            mTextMessage.text = message.get(position)
            mImagePicture.setImageDrawable(context.getDrawable(picture.get(position)))
            itemView.setOnClickListener(View.OnClickListener {
                itemClick.onItemClick(adapterPosition)
            })
        }
    }
}