lucanicoletti

/**
 * Created by Luca Nicoletti
 * © 17/10/2018
 * Copied from: https://gist.github.com/nesquena/d09dc68ff07e845cc622; added some little edits for Kotlin
 */

abstract class EndlessRecyclerViewScrollListener(private var visibleThreshold: Int = 5): RecyclerView.OnScrollListener() {
    private var currentPage = 0
    private var previousTotalItemCount = 0
    private var loading = true

lucanicoletti

sealed class MyViewState {
	class Error(val cause: String): MyViewState()
	object Loading: MyViewState()
	class DataLoaded(data: Data): MyViewState()
}

[...MyView...]
fun render(viewState: MyViewState) {
	when (viewState) {
		MyViewState.Error -> { // handle error state 

lucanicoletti

sealed class MVIJetpackComposeViewState {
    @Composable
    abstract fun buildUI()

    object Loading : MyViewState() {
        @Composable
        override fun buildUI() {
            // Loading which is not provided yet
        }
    }

lucanicoletti

class MVIJetpackComposeViewModel : ViewModel() {
    private val _jetpackComposeViewState = MutableLiveData<MVIJetpackComposeViewState>()
    private val useCase = UseCase()
    val jetpackComposeViewState: LiveData<MVIJetpackComposeViewState>
        get() = _jetpackComposeViewState
   
    init {
        loadData()
    }

lucanicoletti

class MVIJetpackComposeActivity : AppCompatActivity() {

    lateinit var myViewModel: MVIJetpackComposeViewModel

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        myViewModel = // factory to instantiate viewmodel
        // just call setContent once
        setContent {
            CraneWrapper {

lucanicoletti

@Composable
fun MyApp() {
   MaterialTheme { Text("Hello there!") }
}

lucanicoletti

class MyActivity: Activity() {    
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContent { 
        CraneWrapper { 
          MyApp() 
        } 
      }
   }
}

lucanicoletti

sealed class MVIViewState {
   object Loading: MVIViewState()
   class Error(val reason: String): MVIViewState()
   class Success(val result: String): MVIViewState()
}

lucanicoletti

class MVIViewModel : ViewModel() {
  val viewState: MutableLiveData<MVIViewState>()
   
  fun fetchData() {
    myDataSource.fetchData()
      .doOnSubscribe {
        viewState.postValue(MVIViewState.Loading)
      }
      .observe(
        {

lucanicoletti

class MyActivity: Activity() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setupViewModel()
  }
  private fun setupViewModel() {
     viewModel = //factory fancy way to get the instance of ViewModel
     viewModel.viewState.observe(this, Observer {
       when (it) {
         MVIViewState.Loading -> { // show loading