MVVM Navigation fragments switch, but change is not visible - kotlin

Question

I am trying to build a simple app in Kotlin using MVVM architecture, and I'm struggling with switching fragments. I get it to "change" - on a button press it does nothing, and on a second press it crashes saying "Navigation action/destination MAIN_to_RESULT cannot be found from the current destination RESULT" - so it clearly changed the fragments from MAIN to RESULT, but I still see the MAIN fragment)
Here is my MAIN fragment:
class MainFragment : Fragment() {
private lateinit var viewModel: MainViewModel
lateinit var binding: FragmentMainBinding
companion object {
fun newInstance() = MainFragment()
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
viewModel = (activity as MainActivity).viewModel
binding.setVariable(myViewModel, viewModel)
viewModel.bnd = binding
binding.button2.setOnClickListener { viewModel.chng() }
binding.submitButton.setOnClickListener {
val controller = NavHostFragment.findNavController(this)
controller.navigate(R.id.action_mainFragment_to_resultFragment)
}
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View {
binding = DataBindingUtil.inflate(inflater, R.layout.fragment_main, container, false)
binding.setLifecycleOwner(this)
return binding.root
}
}
OTHER fragment:
class ResultFragment : Fragment() {
private lateinit var viewModel: MainViewModel
lateinit var binding: FragmentMainBinding
companion object {
fun newInstance() = ResultFragment()
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View {
binding = DataBindingUtil.inflate(inflater, R.layout.fragment_main, container, false)
binding.setLifecycleOwner(this)
return binding.root
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
viewModel = (activity as MainActivity).viewModel
binding.setVariable(BR.myViewModel, viewModel)
binding.button2.setOnClickListener { viewModel.chng() }
viewModel.bnd = binding
}
}
MainViewModel:
class MainViewModel(application: Application) : AndroidViewModel(application) {
val rps = Repository()
lateinit var bnd : FragmentMainBinding
var changing = false
var SPEED_OF_CHANGING = 100L
var actualCountedCards = 0
var numberOfCardsToRotate = 0
var numberOfRotatedCards = 0
lateinit var actualCard : Card
var mainHandler: Handler = Handler(Looper.getMainLooper())
private val changeCard = object : Runnable {
override fun run() {
if (changing) {
actualCard = rps.Cards.random()
bnd.cardView.setImageResource(actualCard.image)
actualCountedCards += actualCard.power
numberOfRotatedCards += 1
Log.d("tagicek", "${numberOfRotatedCards}/${numberOfCardsToRotate}, ${actualCountedCards}")
if (numberOfRotatedCards >= numberOfCardsToRotate) {
chng()
bnd.editTextTextPersonName.visibility = View.VISIBLE
bnd.submitButton.visibility = View.VISIBLE
bnd.button2.visibility = View.INVISIBLE
}
mainHandler.postDelayed(this, SPEED_OF_CHANGING)
}
}
}
fun chng() {
if (changing == true) {
mainHandler.removeCallbacks(changeCard)
actualCountedCards = 0
numberOfRotatedCards = 0
bnd.cardView.setImageResource(R.drawable.bg)
changing = false
} else {
numberOfCardsToRotate = (1..51).random()
mainHandler.post(changeCard)
changing = true
}
}
}
MainActivity:
class MainActivity : AppCompatActivity() {
lateinit var viewModel: MainViewModel
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
viewModel = ViewModelProvider(this)[MainViewModel::class.java]
if (savedInstanceState == null) {
supportFragmentManager.beginTransaction()
.replace(R.id.container, MainFragment.newInstance())
.commitNow()
}
}
}
I am pretty sure the problem is with my bindings and views, but I can't wrap my head around it. I have tried probably every positioning of defining the NavController and the different views passed into it, but it still doesn't work.