MainActivity.kt

package com.danielmalone.dansinvoicing

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.recyclerview.widget.LinearLayoutManager
import kotlinx.android.synthetic.main.activity_main.*
import kotlinx.android.synthetic.main.content_main.*

class MainActivity : AppCompatActivity() {

    lateinit var invoicesAdapter: InvoicesAdapter

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

        invoicesAdapter = InvoicesAdapter()

        invoices.apply {
            layoutManager = LinearLayoutManager(this@MainActivity)
            adapter = invoicesAdapter
        }

        val listOfInvoices = listOf(
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04"),
            Invoice("a837", "Android app development", "Jacob Holmes", "2020-01-04")
        )

        invoicesAdapter.submitList(listOfInvoices)
    }
}