Mobile Conf 2018@Bangkok, Thailand

1. Android Architecture Component
In Real Life
@akexorcist
Lovely Android Developer @ Nextzy

2. ● Just Work ● MVC
● Maintainable
● Testable
● MVP
● MVVM
● VIPER
● MVI
● Awesomeable
● ...

3. Android
Behavior
• Con;guration Changes
• Android Lifecycle
• State Management

5. hCps://www.youtube.com/watch?v=BlkJzgjzL0c

6. Android Architecture Component

7. AAC

8. Architecture
Component
• Lifecycles
• LiveData
• ViewModel
• Room

9. Do the
Proof of Concept
every time when you learn
something new

10. Lifecycles & LiveData
Use case

11. Timer

12. TimerLiveData
TimerListener
ViewModel
Fragment/Activity
Timer

13. class TimerListener(private val duration: Long,
private val preferences: TimerPreferences,
private val onTickCallback: OnTickListener? = null)
: LifecycleObserver {
...
private fun updateCountDownTimer() {
var lastDuration: Long = preferences.get()
if (lastDuration == 0L || lastDuration > duration) {
lastDuration = duration
}
countdownTimer = object : CountDownTimer(lastDuration, DEFAULT_INTERVAL) {
override fun onTick(millisUntilFinished: Long) {
onTickCallback?.onTickUpdate(millisUntilFinished)
preferences.put(millisUntilFinished)
}
override fun onFinish() {
onTickCallback?.onTickUpdate(0)
isStarted = false
clearTimer()
}
TimerListener.kt

14. class TimerListener(private val duration: Long,
private val preferences: TimerPreferences,
private val onTickCallback: OnTickListener? = null)
: LifecycleObserver {
...
private fun updateCountDownTimer() {
var lastDuration: Long = preferences.get()
if (lastDuration == 0L || lastDuration > duration) {
lastDuration = duration
}
countdownTimer = object : CountDownTimer(lastDuration, DEFAULT_INTERVAL) {
override fun onTick(millisUntilFinished: Long) {
onTickCallback?.onTickUpdate(millisUntilFinished)
preferences.put(millisUntilFinished)
}
override fun onFinish() {
onTickCallback?.onTickUpdate(0)
isStarted = false
clearTimer()
}
TimerListener.kt

15. class TimerListener(private val duration: Long,
private val preferences: TimerPreferences,
private val onTickCallback: OnTickListener? = null)
: LifecycleObserver {
...
private fun updateCountDownTimer() {
var lastDuration: Long = preferences.get()
if (lastDuration == 0L || lastDuration > duration) {
lastDuration = duration
}
countdownTimer = object : CountDownTimer(lastDuration, DEFAULT_INTERVAL) {
override fun onTick(millisUntilFinished: Long) {
onTickCallback?.onTickUpdate(millisUntilFinished)
preferences.put(millisUntilFinished)
}
override fun onFinish() {
onTickCallback?.onTickUpdate(0)
isStarted = false
clearTimer()
}
TimerListener.kt

16. class TimerListener(private val duration: Long,
private val preferences: TimerPreferences,
private val onTickCallback: OnTickListener? = null)
: LifecycleObserver {
...
private fun updateCountDownTimer() {
var lastDuration: Long = preferences.get()
if (lastDuration == 0L || lastDuration > duration) {
lastDuration = duration
}
countdownTimer = object : CountDownTimer(lastDuration, DEFAULT_INTERVAL) {
override fun onTick(millisUntilFinished: Long) {
onTickCallback?.onTickUpdate(millisUntilFinished)
preferences.put(millisUntilFinished)
}
override fun onFinish() {
onTickCallback?.onTickUpdate(0)
isStarted = false
clearTimer()
}
TimerListener.kt

17. ...
@OnLifecycleEvent(Lifecycle.Event.ON_START)
private fun onStart() {
updateCountDownTimer()
if (isStarted) {
countdownTimer?.start()
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_STOP)
private fun onStop() {
if (isStarted) {
countdownTimer?.cancel()
}
}
...
TimerListener.kt

18. ...
@OnLifecycleEvent(Lifecycle.Event.ON_START)
private fun onStart() {
updateCountDownTimer()
if (isStarted) {
countdownTimer?.start()
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_STOP)
private fun onStop() {
if (isStarted) {
countdownTimer?.cancel()
}
}
...
TimerListener.kt

19. ...
@OnLifecycleEvent(Lifecycle.Event.ON_START)
private fun onStart() {
updateCountDownTimer()
if (isStarted) {
countdownTimer?.start()
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_STOP)
private fun onStop() {
if (isStarted) {
countdownTimer?.cancel()
}
}
...
TimerListener.kt

20. ...
@OnLifecycleEvent(Lifecycle.Event.ON_START)
private fun onStart() {
updateCountDownTimer()
if (isStarted) {
countdownTimer?.start()
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_STOP)
private fun onStop() {
if (isStarted) {
countdownTimer?.cancel()
}
}
...
TimerListener.kt

21. ...
fun start() {
if (!isStarted) {
isStarted = true
countdownTimer?.start()
}
}
fun clear() {
if (isStarted) {
isStarted = false
countdownTimer?.cancel()
}
clearTimer()
}
...
TimerListener.kt

22. ...
fun start() {
if (!isStarted) {
isStarted = true
countdownTimer?.start()
}
}
fun clear() {
if (isStarted) {
isStarted = false
countdownTimer?.cancel()
}
clearTimer()
}
...
TimerListener.kt

23. ...
fun start() {
if (!isStarted) {
isStarted = true
countdownTimer?.start()
}
}
fun clear() {
if (isStarted) {
isStarted = false
countdownTimer?.cancel()
}
clearTimer()
}
...
TimerListener.kt

24. class TimerLiveData(private val duration: Long,
private val preferences: TimerPreferences) : LiveData<Long>() {
private lateinit var lifecycle: Lifecycle
private lateinit var listener: TimerListener
override fun observe(owner: LifecycleOwner, observer: Observer<in Long>) {
super.observe(owner, observer)
lifecycle = owner.lifecycle
listener = TimerListener(
duration = duration,
preferences = preferences,
onTickCallback = object : TimerListener.OnTickListener {
override fun onTickUpdate(remainingMillis: Long) {
value = remainingMillis
}
})
}
...
TimerLiveData.kt

25. class TimerLiveData(private val duration: Long,
private val preferences: TimerPreferences) : LiveData<Long>() {
private lateinit var lifecycle: Lifecycle
private lateinit var listener: TimerListener
override fun observe(owner: LifecycleOwner, observer: Observer<in Long>) {
super.observe(owner, observer)
lifecycle = owner.lifecycle
listener = TimerListener(
duration = duration,
preferences = preferences,
onTickCallback = object : TimerListener.OnTickListener {
override fun onTickUpdate(remainingMillis: Long) {
value = remainingMillis
}
})
}
...
TimerLiveData.kt

26. class TimerLiveData(private val duration: Long,
private val preferences: TimerPreferences) : LiveData<Long>() {
private lateinit var lifecycle: Lifecycle
private lateinit var listener: TimerListener
override fun observe(owner: LifecycleOwner, observer: Observer<in Long>) {
super.observe(owner, observer)
lifecycle = owner.lifecycle
listener = TimerListener(
duration = duration,
preferences = preferences,
onTickCallback = object : TimerListener.OnTickListener {
override fun onTickUpdate(remainingMillis: Long) {
value = remainingMillis
}
})
}
...
TimerLiveData.kt

27. class TimerLiveData(private val duration: Long,
private val preferences: TimerPreferences) : LiveData<Long>() {
private lateinit var lifecycle: Lifecycle
private lateinit var listener: TimerListener
override fun observe(owner: LifecycleOwner, observer: Observer<in Long>) {
super.observe(owner, observer)
lifecycle = owner.lifecycle
listener = TimerListener(
duration = duration,
preferences = preferences,
onTickCallback = object : TimerListener.OnTickListener {
override fun onTickUpdate(remainingMillis: Long) {
value = remainingMillis
}
})
}
...
TimerLiveData.kt

28. class TimerLiveData(private val duration: Long,
private val preferences: TimerPreferences) : LiveData<Long>() {
private lateinit var lifecycle: Lifecycle
private lateinit var listener: TimerListener
override fun observe(owner: LifecycleOwner, observer: Observer<in Long>) {
super.observe(owner, observer)
lifecycle = owner.lifecycle
listener = TimerListener(
duration = duration,
preferences = preferences,
onTickCallback = object : TimerListener.OnTickListener {
override fun onTickUpdate(remainingMillis: Long) {
value = remainingMillis
}
})
}
...
TimerLiveData.kt

29. ...
fun start() {
listener.start()
}
fun clear() {
listener.clear()
value = 0L
}
override fun onActive() {
lifecycle.addObserver(listener)
}
override fun onInactive() {
lifecycle.removeObserver(listener)
}
...
TimerLiveData.kt

30. ...
fun start() {
listener.start()
}
fun clear() {
listener.clear()
value = 0L
}
override fun onActive() {
lifecycle.addObserver(listener)
}
override fun onInactive() {
lifecycle.removeObserver(listener)
}
...
TimerLiveData.kt

31. ...
fun start() {
listener.start()
}
fun clear() {
listener.clear()
value = 0L
}
override fun onActive() {
lifecycle.addObserver(listener)
}
override fun onInactive() {
lifecycle.removeObserver(listener)
}
...
TimerLiveData.kt

32. class TimerViewModel @Inject constructor(timerPreferences: TimerPreferences)
: ViewModel() {
val timerLiveData = TimerLiveData(
duration = TimeUnit.SECONDS.toMillis(30),
preferences = timerPreferences
)
fun startTimer() {
timerLiveData.start()
}
fun clearTimer() {
timerLiveData.clear()
}
}
TimerViewModel.kt

33. class TimerViewModel @Inject constructor(timerPreferences: TimerPreferences)
: ViewModel() {
val timerLiveData = TimerLiveData(
duration = TimeUnit.SECONDS.toMillis(30),
preferences = timerPreferences
)
fun startTimer() {
timerLiveData.start()
}
fun clearTimer() {
timerLiveData.clear()
}
}
TimerViewModel.kt

34. class TimerActivity : AppCompatActivity() {
private lateinit var viewModel: TimerViewModel
override fun onCreate(savedInstanceState: Bundle?) {
...
viewModel = ViewModelProviders.of(this).get(TimerViewModel::class.java)
viewModel.timerLiveData.observe(this, timerObserver)
viewModel.startTimer()
}
private val timerObserver = Observer<Long> { remainingMillis ->
if (remainingMillis > 0) {
onTimerUpdate(remainingMillis)
} else {
onTimerEnd()
}
}
...
TimerActivity.kt

35. class TimerActivity : AppCompatActivity() {
private lateinit var viewModel: TimerViewModel
override fun onCreate(savedInstanceState: Bundle?) {
...
viewModel = ViewModelProviders.of(this).get(TimerViewModel::class.java)
viewModel.timerLiveData.observe(this, timerObserver)
viewModel.startTimer()
}
private val timerObserver = Observer<Long> { remainingMillis ->
if (remainingMillis > 0) {
onTimerUpdate(remainingMillis)
} else {
onTimerEnd()
}
}
...
TimerActivity.kt

36. class TimerActivity : AppCompatActivity() {
private lateinit var viewModel: TimerViewModel
override fun onCreate(savedInstanceState: Bundle?) {
...
viewModel = ViewModelProviders.of(this).get(TimerViewModel::class.java)
viewModel.timerLiveData.observe(this, timerObserver)
viewModel.startTimer()
}
private val timerObserver = Observer<Long> { remainingMillis ->
if (remainingMillis > 0) {
onTimerUpdate(remainingMillis)
} else {
onTimerEnd()
}
}
...
TimerActivity.kt

37. class TimerActivity : AppCompatActivity() {
private lateinit var viewModel: TimerViewModel
override fun onCreate(savedInstanceState: Bundle?) {
...
viewModel = ViewModelProviders.of(this).get(TimerViewModel::class.java)
viewModel.timerLiveData.observe(this, timerObserver)
viewModel.startTimer()
}
private val timerObserver = Observer<Long> { remainingMillis ->
if (remainingMillis > 0) {
onTimerUpdate(remainingMillis)
} else {
onTimerEnd()
}
}
...
TimerActivity.kt

38. Google API Client for Android

39. class GoogleApiClientListener(private val builder: GoogleApiClient.Builder,
private val api: Api<out Api.ApiOptions.NotRequiredOptions>,
private val callback: Callback? = null) : LifecycleObserver {
private lateinit var googleApiClient: GoogleApiClient
init {
googleApiClient = builder.apply {
addOnConnectionFailedListener { result: ConnectionResult ->
callback?.onFailure(result)
}
addConnectionCallbacks(object : GoogleApiClient.ConnectionCallbacks {
override fun onConnected(connectionHint: Bundle?) {
callback?.onConnected(googleApiClient)
}
override fun onConnectionSuspended(cause: Int) {
callback?.onSuspended(cause)
}
})
addApi(api)
}.build()
}
GoogleApiClientListener.kt

40. ...
@OnLifecycleEvent(Lifecycle.Event.ON_START)
fun onStart() {
if (!googleApiClient.isConnected || !googleApiClient.isConnecting) {
googleApiClient.connect()
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_STOP)
fun onStop() {
if (googleApiClient.isConnected) {
googleApiClient.disconnect()
}
}
fun getGoogleApiClient(): GoogleApiClient = googleApiClient
interface Callback {
fun onConnected(client: GoogleApiClient)
fun onFailure(result: ConnectionResult)
fun onSuspended(cause: Int)
}
GoogleApiClientListener.kt

41. class GoogleApiClientLiveData(private val builder: GoogleApiClient.Builder,
private val api: Api<out Api.ApiOptions.NotRequiredOptions>)
: LiveData<GoogleApiResult>() {
private lateinit var lifecycle: Lifecycle
private lateinit var listener: GoogleApiClientListener
override fun observe(owner: LifecycleOwner, observer: Observer<in GoogleApiResult>) {
super.observe(owner, observer)
lifecycle = owner.lifecycle
listener = GoogleApiClientListener(builder, api, callback)
}
override fun onActive() {
lifecycle.addObserver(listener)
}
override fun onInactive() {
lifecycle.removeObserver(listener)
}
...
GoogleApiClientLiveData.kt

42. private val callback = object : GoogleApiClientListener.Callback {
override fun onConnected(client: GoogleApiClient) {
value = GoogleApiResult(
status = GoogleApiResult.STATUS_SUCCESS,
errorCode = 0,
errorMessage = null,
client = listener.getGoogleApiClient())
}
override fun onFailure(result: ConnectionResult) {
value = GoogleApiResult(
status = GoogleApiResult.STATUS_FAILURE,
errorCode = result.errorCode,
errorMessage = result.errorMessage,
client = null)
}
override fun onSuspended(cause: Int) {
value = GoogleApiResult(
status = GoogleApiResult.STATUS_SUCCESS,
errorCode = cause,
errorMessage = null,
client = null)
}
}
GoogleApiClientLiveData.kt

43. data class GoogleApiResult(var status: String,
var errorCode: Int,
var errorMessage: String?,
var client: GoogleApiClient?) {
companion object {
const val STATUS_SUCCESS = "success"
const val STATUS_FAILURE = "failure"
const val STATUS_SUSPENDED = "suspended"
}
fun isSuccess(): Boolean = status == STATUS_SUCCESS
fun isFailure(): Boolean = status == STATUS_FAILURE
fun isSuspended(): Boolean = status == STATUS_SUSPENDED
}
GoogleApiResult.kt

44. class GoogleApiViewModel @Inject constructor(private var builder: GoogleApiClient.Builder)
: ViewModel() {
val googleApiClientLiveData = GoogleApiClientLiveData(builder, LocationServices.API)
}
GoogleApiViewModel.kt

45. class GoogleApiActivity : AppCompatActivity() {
private lateinit var viewModel: GoogleApiViewModel
override fun onCreate(savedInstanceState: Bundle?) {
...
viewModel = ViewModelProviders.of(this).get(GoogleApiViewModel::class.java)
viewModel.googleApiClientLiveData.observe(this, googleApiClientObserver)
}
private val googleApiClientObserver = Observer<GoogleApiResult> { result ->
when (result.status) {
GoogleApiResult.STATUS_SUCCESS -> onGoogleApiClientConnected(result.client)
GoogleApiResult.STATUS_FAILURE -> onGoogleApiClientFailure(result.errorMessage)
GoogleApiResult.STATUS_SUSPENDED -> onGoogleApiClientSuspend(result.errorCode)
}
}
...
GoogleApiActivity.kt

46. Firebase Realtime Database

47. class RealtimeDatabaseLiveData(userId: String,
firebaseDatabase: FirebaseDatabase) : LiveData<List<Post>>() {
private val databaseReference = firebaseDatabase.getReference(userId).child("posts")
override fun onActive() {
databaseReference.addValueEventListener(valueEventListener)
}
override fun onInactive() {
databaseReference.removeEventListener(valueEventListener)
}
private val valueEventListener = object : ValueEventListener {
override fun onDataChange(dataSnapshot: DataSnapshot) {
value = dataSnapshot.children.map { snapshot ->
snapshot.getValue(Post::class.java)!!
}
}
override fun onCancelled(databaseError: DatabaseError) {}
}
}
RealtimeDatabaseLiveData.kt

48. Activity
Fragment Fragment
Fragment

49. Activity
Fragment Fragment
Fragment
ShareViewModel=SVM
SVM
SVM
SVM
SVM

50. class SingleEventLiveData<T> : MutableLiveData<T>() {
private val mPending = AtomicBoolean(false)
override fun observe(owner: LifecycleOwner, observer: Observer<in T>) {
super.observe(owner, Observer { t: T? ->
if (mPending.compareAndSet(true, false)) {
observer.onChanged(t)
}
})
}
override fun setValue(@Nullable t: T?) {
mPending.set(true)
super.setValue(t)
}
override fun postValue(value: T?) {
mPending.set(true)
super.postValue(value)
}
} SingleEventLiveData.kt

51. class HomeEventViewModel : ViewModel() {
val updateFeedEventLiveData = SingleEventLiveData<String>()
fun send(message: String) {
updateFeedEventLiveData.value = message
}
}
HomeEventViewModel.kt

52. 1 Event : 1 SingleEventLiveData
Don't reuse

53. Fragment/Activity
ViewModel
Repository
Database Network
NetworkBoundResource

54. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
}.asLiveData()
}

55. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
}.asLiveData()
} Fragment/Activity
ViewModel
Repository
Database Network
NetworkBoundResource

56. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
}.asLiveData()
} Fragment/Activity
ViewModel
Repository
Database Network
NetworkBoundResource

57. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
}.asLiveData()
} Fragment/Activity
ViewModel
Repository
Database Network
NetworkBoundResource

58. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
}.asLiveData()
} Fragment/Activity
ViewModel
Repository
Database Network
NetworkBoundResource

59. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
}.asLiveData()
} Fragment/Activity
ViewModel
Repository
Database Network
NetworkBoundResource

60. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
}.asLiveData()
} Fragment/Activity
ViewModel
Repository
Database Network
NetworkBoundResource

61. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
}.asLiveData()
} Fragment/Activity
ViewModel
Repository
Database Network
NetworkBoundResource

62. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
}.asLiveData()
}

63. fun getUserInfo(userId: String): LiveData<Resource<UserInfo>> {
return object : NetworkBoundResource<UserInfo, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserInfo) { /*...*/ }
override fun shouldFetch(data: UserInfo?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserInfo> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
override fun convertToResultType(response: UserInfo): UserInfo { /*...*/ }
override fun callFailed(errorMessage: String) { /*...*/ }
}.asLiveData()
}

64. fun getUserInfo(userId: String): LiveData<Resource<UserAccount>> {
return object : NetworkBoundResource<UserAccount, UserInfo>(appExecutors) {
override fun saveCallResult(item: UserAccount) { /*...*/ }
override fun shouldFetch(data: UserAccount?): Boolean { /*...*/ }
override fun loadFromDb(): LiveData<UserAccount> { /*...*/ }
override fun createCall(): LiveData<UserInfo> { /*...*/ }
override fun convertToResultType(response: UserInfo): UserAccount { /*...*/ }
override fun callFailed(errorMessage: String) { /*...*/ }
}.asLiveData()
}

65. fun getUserInfo(userId: String): LiveData<Resource<UserAccount>> {
return object : DirectNetworkBoundResource<UserAccount, UserInfo>(appExecutors) {
override fun createCall(): LiveData<UserInfo> { /*...*/ }
override fun convertToResultType(response: UserInfo): UserAccount { /*...*/ }
override fun callFailed(errorMessage: String) { /*...*/ }
}.asLiveData()
}

66. Fragment/Activity
ViewModel
Repository
Database Network

67. Fragment/Activity
ViewModel
Repository
Database Network
Repository
Database Network

68. Fragment/Activity
ViewModel
Repository
Database Network
Repository
Database Network
Repository
Database Network
ViewModel

69. Repository
ViewModel
Network
Retrofit
Call

70. Repository
ViewModel
Network
Retrofit + LiveDataCallAdapter
LiveData
LiveData
LiveData

71. Log In Homeapi/v1/login
What people think about log in flow

72. Log In Homeapi/v1/login api/v1/:userId/conDgs
api/v1/:userId/info
api/v1/:userId/banners
What log in flow actually be in real life
api/v1/:userId/caGs

73. Repository
ViewModel
Network
Retrofit +
LiveData
LiveData
LiveData
LiveDataCallAdapter

74. Repository
ViewModel
Network
Retrofit +
Single/Observable
RxJava/RxKotlin
LiveData
LiveData
RxJavaCallAdapter
+ Rx2LiveDataConverter

75. object Single2LiveDataConverter {
fun <T> convert(single: Single<T>): LiveData<T> {
return object : LiveData<T>() {
private var disposable: Disposable? = null
override fun onActive() {
super.onActive()
disposable = single
.subscribeOn(Schedulers.io())
.subscribe(Consumer<T> { this.postValue(it) })
}
override fun onInactive() {
super.onInactive()
if (disposable != null) disposable!!.dispose()
}
}
}
}
Single2LiveDataConveWer.kt

76. fun getNecessaryInfo(): Single<Response<LogInResult>> {
return Single.zip(
getUserInfo(),
getBannerList(),
BiFunction<Response<UserInfoResult>,
Response<BannerListResult>,
Response<LogInResult>> { userInfoResponse, bannerListResponse ->
Response.success(
LogInResult(
userInfoResponse.body(),
bannerListResponse.body()
)
)
})
}

77. override
fun createCall(): LiveData<Response<LogInResult>> {
return Single2LiveDataConverter.convert(getNecessaryInfo())
}
Deferred2LiveData.kt

78. Repository
ViewModel
Network
Retrofit +
Single/Observable
RxJava/RxKotlin
LiveData
LiveData
RxJavaCallAdapter
+ Rx2LiveDataConverter

79. Repository
ViewModel
Network
Retrofit
Call
LiveData
LiveData
+ Coroutine
Deferred2LiveDataConverter

80. class Deferred2LiveData<T>(var deferred: Deferred<Response<T>>)
: LiveData<ApiResponse<T>>() {
fun execute() {
launch(CommonPool) {
try {
val result: Response<T> = deferred.await()
postValue(ApiResponse.create(result))
} catch (e: Exception) {
postValue(ApiResponse.create(e))
}
}
}
}
Deferred2LiveData.kt

81. override
fun createCall(): LiveData<Response<LogInResult>> {
return Deferred2LiveData(async {
LogInResult(getUserInfo().execute(), getBannerList().execute())
})
}
Deferred2LiveData.kt

82. Fragment/Activity
ViewModel
Repository
Database Network

83. Fragment/Activity
ViewModel
UseCase
Database Network
Repository

84. Fragment/Activity
ViewModel
UseCase
Database Network
Repository
Data Layer
Presentation Layer
Domain Layer

85. Fragment/Activity
ViewModel
UseCase
Database Network
Repository
UseCaseUseCase

86. Fragment/Activity
ViewModel
UseCase
Database Network
Repository
UseCaseUseCase
LiveDataLiveDataLiveData
LiveData LiveDataLiveData

87. class SessionDetailViewModel @Inject constructor(
private val signInViewModelDelegate: SignInViewModelDelegate,
private val loadUserSessionUseCase: LoadUserSessionUseCase,
private val loadRelatedSessionUseCase: LoadUserSessionsUseCase,
private val starEventUseCase: StarEventUseCase,
private val reservationActionUseCase: ReservationActionUseCase,
private val getTimeZoneUseCase: GetTimeZoneUseCase,
private val snackbarMessageManager: SnackbarMessageManager,
timeProvider: TimeProvider,
private val networkUtils: NetworkUtils,
private val analyticsHelper: AnalyticsHelper
) : ViewModel(), SessionDetailEventListener, EventActions,
SignInViewModelDelegate by signInViewModelDelegate {
private val loadUserSessionResult:
MediatorLiveData<Result<LoadUserSessionUseCaseResult>>
private val loadRelatedUserSessions: LiveData<Result<LoadUserSessionsUseCaseResult
private val sessionTimeRelativeState: LiveData<TimeUtils.SessionRelativeTimeState>

88. class SessionDetailFragment : DaggerFragment() {
...
override fun onActivityCreated(savedInstanceState: Bundle?) {
...
val starMenu = menu.findItem(R.id.menu_item_star)
sessionDetailViewModel.shouldShowStarInBottomNav.observe(this, Observer {
it?.let {
if (it) {
starMenu.setVisible(true)
} else {
starMenu.setVisible(false)
}
}
})
sessionDetailViewModel.userEvent.observe(this, Observer {
it?.let {
if (it.isStarred) {
starMenu.setIcon(R.drawable.ic_star)
} else {
starMenu.setIcon(R.drawable.ic_star_border)
}

89. sessionDetailViewModel.session.observe(this, Observer {
room = it?.room
shareString = if (it == null) {
""
} else {
getString(R.string.share_text_session_detail, it.title, it.sessionUrl)
}
})

90. Google I/O 2018 Source Code
hCps://github.com/google/iosched
hCps://github.com/googlesamples/android-architecture-components
Samples for AAC
hCps://developer.android.com/topic/libraries/architecture/
AAC Documentation
Thank you!
@akexorcist