Laimiux

fun startStopButton(state: State, context: FormulaContext<State>): ButtonRenderModel {
    return if (state.isRunning) {
        ButtonRenderModel(
            text = "Stop",
            onSelected = context.callback {
                transition(state.copy(isRunning = false))    
            }
        )
    } else {
        ButtonRenderModel(

Laimiux

class StopwatchFormula : Formula<Unit, StopwatchFormula.State, StopwatchRenderModel> {

    data class State(
        val isRunning: Boolean
    )

    override fun initialState(input: Unit): State = State(
        isRunning = false
    )
    

Laimiux

class StopwatchFormula : Formula<Unit, StopwatchFormula.State, StopwatchRenderModel> {
    // We will use this a little later.   
    object State

    override fun initialState(input: Unit): State = State

    override fun evaluate(
        input: Unit,
        state: State,
        context: FormulaContext<State>

Laimiux

data class State(
  val isRunning: Boolean
)

Laimiux

Observable
  .interval(1, TimeUnit.MILLISECONDS)
  .observeOn(AndroidSchedulers.mainThread())

Laimiux

fun resetButton(state: State, context: FormulaContext<State>): ButtonRenderModel {
    return ButtonRenderModel(
        text = "Reset",
        onSelected = context.callback {
            transition(state.copy(timePassedInMillis = 0, isRunning = false))
        }
    )
}

Laimiux

data class State(  
  val timePassedInMillis: Long,
  val isRunning: Boolean
)

Laimiux

fun formatTimePassed(timePassedInMillis: Long): String {
  // TODO: actually format it
  return "${timePassedInMillis}ms" 
}

Laimiux

fun startStopButton(state: State): ButtonRenderModel {
  return ButtonRenderModel(
    text = if (state.isRunning) "Stop" else "Start",
    onSelected = { /* TODO: toggle the stopwatch */ }
  )
}

Laimiux

class StopwatchActivity : FragmentActivity() {

    private val disposables = CompositeDisposable()

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

        val renderView = StopwatchRenderView(findViewById(R.id.activity_content))
        val renderModels: Observable<StopwatchRenderModel> =