MainActivity for tutorial https://youtu.be/JTTs4Xbthmc

MainActivity.kt

package com.example.bottomnavigationbar

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import androidx.core.content.ContextCompat
import com.fxn.ariana.ArianaBackgroundListener
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

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


        menu_bottom.setOnItemSelectedListener { id ->
            when (id) {
                R.id.home -> viewpager.currentItem = 0
                R.id.like -> viewpager.currentItem = 1
                R.id.search -> viewpager.currentItem = 2
                R.id.profile -> viewpager.currentItem = 3
            }
        }

        viewpager.setOnTouchListener(View.OnTouchListener { v, event -> true })
        viewpager.adapter = ViewPagerAdapter(supportFragmentManager).apply {
            list = ArrayList<String>().apply {
                add("Home")
                add("Like")
                add("Search")
                add("Profile")
            }
        }

        viewpager.addOnPageChangeListener(
            ArianaBackgroundListener(
                getColors(),
                img1,
                viewpager
            )
        )
    }

    private fun getColors(): IntArray {
        return intArrayOf(
            ContextCompat.getColor(this, R.color.home),
            ContextCompat.getColor(this, R.color.like),
            ContextCompat.getColor(this, R.color.search),
            ContextCompat.getColor(this, R.color.profile),
            ContextCompat.getColor(this, R.color.home)

        )
    }
}