thealmikey

import com.tinder.StateMachine

sealed class HumanState {
    object PureBliss : HumanState()
    object Happy : HumanState()
    object Bored : HumanState()
    object Sad : HumanState()
}

sealed class HumanAction {

thealmikey

Using Tinder's Finite State Machine Library to wrap Android's MediaPlayer

When developing software, it's sometimes very easy to get overwhelmed by complexity due to the number of interacting pieces.

This is a problem that's prevalent in all software development from Server-Side development, Front-End development and all the way to Android development.

In a bid to tame complexity software engineers building complex software have looked up to tools that help reduce this burden. One such tool is design using Finite State Machines.

In this tutorial we'll be using Tinder's State Machine to model an Entity and handle complexity of dealing with the many possible states it can be in a manner that makes it almost effortless.

thealmikey

regularMike.emotionalState.transition(HumanAction.GiveTherapy)
    println(regularMike.emotionalState.state)
    //Goodwork report
    // HumanState$Bored@28c97a5

    regularMike.emotionalState.transition(HumanAction.GiveTherapy)
    println(regularMike.emotionalState.state)
    //Goodwork report
    // HumanState$Happy@736e9adb

thealmikey

fun main() {

    var regularMike = Human("Mike Regular")

    regularMike.emotionalState.transition(HumanAction.Entertain)
    println(regularMike.emotionalState.state)
    // Hapiness message
    // HumanState$Happy@5b37e0d2

    regularMike.emotionalState.transition(HumanAction.GiveLecture)

thealmikey

import com.tinder.StateMachine

sealed class HumanState {
    object PureBliss : HumanState()
    object Happy : HumanState()
    object Bored : HumanState()
    object Sad : HumanState()
}

sealed class HumanAction {

thealmikey

val emotionalState = StateMachine.create<HumanState, HumanAction, UseResult> {
        initialState(HumanState.Bored)
        state<HumanState.Bored> {
            on<HumanAction.Entertain> {
                transitionTo(HumanState.Happy, UseResult.ReportHappiness)
            }
            on<HumanAction.GiveTherapy> {
                transitionTo(HumanState.Happy, UseResult.ReportGoodWork)
            }
            on<HumanAction.Annoy> {

thealmikey

onTransition {
            val validTransition = it as? StateMachine.Transition.Valid ?: return@onTransition
            when (validTransition.sideEffect) {
                UseResult.ReportHappiness -> println("Hapiness message") //ourService.log("Hapiness message")
                UseResult.ReportBoredness -> println("BoredNess message") //anotherService.log("BoredNess message")
                UseResult.ReportSadness -> println("Bad vibes message") //ourService.log("Bad vibes message")
                UseResult.ReportGoodWork -> println("Goodwork report") //anotherService.log("Goodwork report")
                UseResult.ReportVibeKiller -> println("Please don't kill my vibe")
            }
        }

thealmikey

import com.tinder.StateMachine

sealed class HumanState {
    object PureBliss : HumanState()
    object Happy : HumanState()
    object Bored : HumanState()
    object Sad : HumanState()
}

sealed class HumanAction {

thealmikey

sealed class HumanState {
    object PureBliss : HumanState()
    object Happy : HumanState()
    object Bored : HumanState()
    object Sad : HumanState()
}

sealed class HumanAction {
    object Entertain : HumanAction()
    object GiveLecture : HumanAction()

thealmikey

import com.tinder.StateMachine

val stateMachine = StateMachine.create<State, Action, SideEffect>