This talk was presented during the GDG DevFest Cerrado 2018, in Goiânia, GO - Brazil.

1. CREATE MODERNAPPS WITH
ANDROID JETPACK
Ramon Ribeiro Rabello

2. Hi, I’m Ramon Rabello | Bio
10 years in Android
GDG Floripa Organizer
Keen to Communities
Star Wars fan, I am!
Master Software Engineer |
about.me/ramonrabello
A keep-learner

3. We’re hiring | ArcTouch Brasil (Florianópolis Office)
arctouch.com/brjobs

4. DevFest Floripa 2018 | Coming soon

5. Android Dev Generations™

6. Android Dev 1st Gen | 2008-2012

7. Android Dev 1st Gen | Activity-centered development
public class MainActivity extends Activity {
private Button signInButton;
private Button signUpButton;
@Override
public void onCreate(Bundle savedInstanceState) {
signInButton = (TextView) findViewById(R.id.sign_in_button);
signUpButton = (TextView) findViewById(R.id.sign_up_button);
signInButton.setOnClickListener(new View.OnClickListener(){
// onClick()
signIn();
})
signUpButton.setOnClickListener(new View.OnClickListener(){
// onClick()
signUp();
})
private void signIn() { … }
private void signUp() { … }
God-Activity effect

8. Android Dev 1st Gen | Async programming was challenging
private class LoadDataTask extends AsyncTask<Params, Progress, Result> {
@Override void onPreExecute(){
showProgress(); // run on UI Thread
}
@Override public Result doInBackground(Params params…) {
return loadData(); // run on background Thread
}
@Override void onPostExecute(Result result){
if (uiComponent != null){ // needed to avoid NPE
updateView(result);
}
}
private void updateView(Result result) { … }

9. Android Dev 1st Gen | Lifecycle handling was error prone
@Override
public void onStart() {
super.onStart();
loadData();
}
@Override
public void onStop() {
super.onStop();
releaseData();
}
Race conditions & Memory Leaks

10. Android Dev 1st Gen | Java was the only supported language

11. Android Dev 1st Gen | The developer guide was poor

12. Android Dev 2nd Gen | 2013 - 2016

13. Android Dev 2nd Gen | Android Studio Preview was launched

14. Android Dev 2nd Gen | Gradle as a new build system

15. Android Dev 2nd Gen | Material Design as UI/UX guideline

16. Android Dev 2nd Gen | Plenty of 3rd-party libraries created
Networking
Retrofit
Glide
UIL
Okio
Picasso
ActionBarSherlock
SuperRecyclerView
AHBottomBar
…
OkHttp
Volley
HttpClient
Imaging
Fresco
JSON
Jackson
Gson
Moshi
DI
EventBus
RoboGuice
ButterKnife
AndroidAnnotations
Async
Dagger 1/2
ToothPick
Otto
RxJava
RxAndroid
Testing
Robolectric
Robotium
Espresso
UI
Database
GreenDAO
ActiveDroid
ORMLite
Realm
DBFlow
Mockito
Hamcrest
Firestore
CircleImageView

17. Android Dev 3rd Gen | 2017 - …

18. Android Dev 3rd Gen | MVP pattern matured in Android
interface AddNoteContract {
interface View {
fun updateNotesList()
fun showLoading()
fun hideLoading()
}
interface Presenter {
fun addNote(note: Note)
}
}

19. Android Dev 3rd Gen | Kotlin as a primary language for Android
data class Person(val name : String, val age: Int)
fun View.show() { visibility = View.VISIBLE }
fun View.gone() { visibility = View.GONE }
peopleRecyclerView.show()
loadingProgressBar.gone()
fun loadList(onSuccess:() -> Unit, onError:() -> Unit)
presenter.loadList(
onSuccess = { … },
onError = { … }
)
data classes
extension
functions
lambdas
high-order functions

20. Android Dev 3rd Gen | RxJava + MVVM = reactive apps
class NoteListViewModel {
fun getNoteList(): Subscription {
return repository.getNoteList()
}
}
class NoteListActivity: AppCompatActivity() {
private val viewModel = AddNoteViewModel()
private val compositeSubscription = CompositeSubscription()
private fun subscribeToNoteListChanges(): Subscription {
return viewModel.getNoteList()
.observeOn(AndroidSchedulers.mainThread())
.subscribe(adapter::updateList, this::handleError)
}
override fun onResume() {
super.onResume()
compositeSubscription.add(subscribeToNoteListChanges())
}
override fun onPause() {
compositeSubscription.clear()
super.onPause()
}
}

21. NOW ANDROID HAS 10 YEARS!

22. Here comes Android Jetpack!

23. Android Jetpack | Overview
Simplify complex tasks
A collection of Android software components
Follow best practices
Free you from writing boilerplate code
Comprises the androidx.* packages

24. Android Jetpack | Components
Architecture
Foundation Behaviour
UI
•

25. Jetpack Components | Foundation
AppComponent
Android KTX
Multidex
Test
Architecture
Foundation Behaviour
UI
•
NEW

26. Jetpack Components | Architecture
DataBinding
Lifecycles
LiveData
Navigation
Paging
Room
ViewModel
WorkManager
Architecture
Foundation Behaviour
UI
•
NEW
NEW
NEW

27. Jetpack Components | UI
Animation & transitions
Auto
Emoji
Fragment
Layout
Palette
TV
Wear OS by Google
Architecture
Foundation Behaviour
UI
•

28. Jetpack Components | Behaviour
Download manager
Media & playback
Notifications
Permissions
Sharing
Slices
Architecture
Foundation Behaviour
UI
•
NEW

29. androidx

30. androidx | Overview

31. androidx | Migrating to androidx
Manually
Automagically
Add both androidX=true and enableJetfier=true to
gradle.properties file
In Android Studio 3.2.1: Refactor -> Migrate to AndroidX…

32. android-ktx

33. ANDROIDX.CORE:CORE-KTX

34. KOTLIN
sharedPreferences.edit()
.putBoolean("key", value)
.apply()

35. KOTLIN + ANDROID KTX
sharedPreferences.edit {
putBoolean("key", value)
}

36. KOTLIN
view.viewTreeObserver.addOnPreDrawListener(
object : ViewTreeObserver.OnPreDrawListener {
override fun onPreDraw(): Boolean {
viewTreeObserver.removeOnPreDrawListener(this)
actionToBeTriggered()
return true
}
}
)

37. KOTLIN + ANDROID KTX
view.doOnPreDraw {
actionToBeTriggered()
}

38. WorkManager

39. BASICS

40. CREATE A WORKER
class UploadPhotoWorker(context: Context, params:
WorkerParameters) : Worker(context, params) {
override fun doWork(): Result {
uploadPhoto()
return Result.SUCCESS
}
}

41. CREATE A WORKER REQUEST
val uploadWork =
OneTimeRequestBuilder<CompressWorker>().build()
WorkerManager.getInstance().enqueue(uploadWork)

42. OBSERVING WORK STATUS
WorkManager.getInstance().getStatusById(uploadWork.id)
.observe(lifecycleOwner, Observer { workStatus ->
if (workStatus != null && workStaus.state.isFinished) {
// do something according to the status
}
}

43. Who has already adopted
Android Jetpack?

44. Android Jetpack adoption | top apps

45. Demo ramonrabello
Android-Jetpack-Playground
AndroidX
Architecture Components
Material Theming
Coroutines
Retrofit 2
Gson
Kotlin 1.3

46. What’s next?

47. What’s next? | Learn more
Modern Android development: Android Jetpack, Kotlin, and more
(Google I/O 2018)
https://www.youtube.com/watch?v=IrMw7MEgADk
Android X | Android Developers
https://developer.android.com/jetpack/androidx/
Android Jetpack | Android Developers
https://developer.android.com/jetpack/
Android KTX | Android Developers
https://developer.android.com/kotlin/ktx

48. Q & A

49. THANK YOU.
https://about.me/ramonrabello