class AddActivity : AppCompatActivity() {

    lateinit var viewModel: MyDataViewModel

    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_add)

        viewModel = ViewModelProvider(this).get(MyDataViewModel::class.java)

        val addBtn = findViewById<Button>(R.id.add)
        addBtn.setOnClickListener {
            val addText = findViewById<EditText>(R.id.addText).text.toString()
            val myData = MyData(addText)
            viewModel.insert(myData)
        }

        val removeBtn = findViewById<Button>(R.id.remove)
        removeBtn.setOnClickListener {
            viewModel.removeAll()
        }

    }

}