Jetpack released new features in 2021 including: - Compose integrations with libraries like Hilt, Paging, and Navigation. - Improvements to CameraX, Room, DataStore, Navigation, and other libraries. - New libraries like AppSearch, Macrobenchmark, and Google Shortcuts. - Support for additional form factors with updates to libraries like Window and Wear. - Many libraries reached stable versions or added new capabilities in alpha/beta stages.

1. Android
Jetpack, with new
features in 2021

2. 02 New in Stable
01 Overview
04 Debut in Alpha
05 Additional Talks
03 Up to Beta

3. Workshop Host
Jetpack,
with new features in 2021
Wonyoung Choi - AVP, Mobile Developer, OCBC
@TORU_0239

4. android
jetpack

5. Of top 1K apps
using two or more non-core Jetpack
Libraries
How increased?
97%
2021
47%
2020

6. Pre-release cycles and what they mean for developers
Versioning
Alpha, Beta

7. • Active development
• API may be added,
changed, removed
• Tested and highly-
functional
• Feature Stabilization
• No API changes
• APIs changed only in
response to critical
issues or community
feedback
Alpha Beta

8. Metadata that helps tools and other developers
understand your code
Experimental Annotations
Metadata

9. androix:annotation:annotation-experimental
builder.setAutoCloseTimeout(2000, SECONDS)
@ExperimentalRoomApi
Or
@OptIn(ExperimentalRoomApi::class)
The Opt-in usage should be marked with
either one from the right.
[UnsafeOptInUsageError]

10. androix:annotation:annotation-experimental
@OptIn(ExperimentalRoomApi::class)
builder.setAutoCloseTimeout(2000, SECONDS)

11. 02 New in Stable
01 Overview
03 Up to Beta
04 Debut in Alpha
05 Additional Talks

12. Unified API surface for accessing camera functionality
across the various OS versions and devices
CameraX
Hardware

13. • Adjusting exposure compensation
• Access to the information about
camera state and features
• Interoperability via Camera2Interop
CameraX
The latest improvements to the
common requests
androidx.camera:camera

14. CameraX
• HDR (High Dynamic Range) preview*
• Zoom ratio controls
• Do-Not-Disturb
Supports for the latest device and
OS features
* Supported for Pixel 4A and 5 only, but soon on more devices
androidx.camera:camera

15. CameraX
• Faster image capture
• Faster initialization*
Performace enhancement for
better experience
* Up to 25% on legacy devices, according to Google
androidx.camera:camera

16. // Set up the CameraController
val cameraController = LifecycleCameraController(context)
cameraController.bindToLifecycle(lifecycleOwner)
// Attach the CameraController to PreviewView
val previewView = findViewById(R.id.previewView)
previewView.setController(cameraController)
// Use the CameraController
cameraController.takePicture(...)

17. Simplified dependency injection solution
built on top of Dagger2, for Jetpack
Architecture
Hilt

18. • ViewModel support into the core Hilt
• SavedStateHandle added as a default
• Integrated with Navigation and
Compose
Hilt
Reached Stable stage with changes
androidx.hilt:hilt

19. @HiltViewModel
class MyViewModel @Inject constructor(
val handle: SavedStateHandle,
val repository: Repository
) : ViewModel {
// ...
}

20. @HiltViewModel
class MyViewModel @Inject constructor(
val handle: SavedStateHandle,
val repository: Repository
) : ViewModel {
// ...
}
@AndroidEntryPoint
class MyFragment : Fragment() {
val viewModel: MyViewModel by viewModels()
val navigationGraphScoped: MyViewModel by
hiltNavGraphViewModels(R.id.nav_graph)
}

21. @HiltWorker
class MyWorker @AssistInject constructor(
@Assisted context: Context,
@Assisted params: WorkerParameters,
repo: Repository
) : Worker {
// ...
}

22. @HiltAndroidTest
@UninstallModules(RepositoryModule::class)
@RunWith(AndroidJUnit4::class)
class Test {
@Module
@InstallIn(ApplicationComponent::class)
object FakeRepositoryModule {
@Provides
fun provideRepo() = FakeRepository()
}
}

23. @Module
@TestInstallIn(
components = SingletonComponent::class,
replaces = RepositoryModule::class
)
object FakeRepositoryModule {
@Provides
fun provideRepo() = FakeRepository()
}

24. The recommended data persistence layer, providing increased usability and safety
over the platform
Architecture
Room

25. Experimental support for Kotlin Symbol Processing
Built-in support for enums and RxJava3
Introduction to QueryCallback
New annotation @ProviderTypeConverter
Room
2.3.0 Stable version
androidx.room:room
Support for Auto-Migrations
2.4.0 Alpha version

26. @ProvidedTypeConverter
class TimeStampConverter(timeformat: String) {
@TypeConverter
fun fromTimestamp(value: Long) {
// implementation
}
}
Room.inMemoryDatabaseBuilder(context, CacheDatabase::class)
.addTypeConverter(TimeStampConverter(getPreferredTimeStamp()))
.build()

27. Support for Auto-Migrations
Room
2.4.0 Alpha version
androidx.room:room

28. @Database(
- version = 1,
+ version = 2,
entities = { Penang.class },
+ autoMigrations = {
+ @AutoMigration (from = 1, to = 2)
+ }
)
public abstract class DoggosDatabase extends RoomDatabase { }

29. Load and display small chunks of data to improve
network and system resource consumption
UI
Paging Library

30. Complete rewrite in Kotlin, supported for Kotlin coroutines and Flow
Asynchronous loading with RxJava and Guava primitives
Improvements to the repository and presentation layers
Supports for headers, footers, separators, and loading state
Paging Library
androidx.paging:paging

31. Paging Library
androidx.paging:paging
RxPagingSource for RxJava Flow for stream

32. Paging Library
androidx.paging:paging
ListenableFuturePagingSource for ListenableFuture

33. Safely and easily encrypt files
and SharedPreferences
Data
Security Crypto

34. val prefs: SharedPreferences = EncryptedSharedPreferences.create(
context,
"preference_file_name",
mainKey,
prefKeyEncryptionScheme = AES256_SIV,
prefValueEncryptionScheme = AES256_GCM,
)
// Use the resulting SharedPreferences object as usual.
prefs.edit()
.putBoolean("launch_completed", true)
.apply()

35. Can it be combined with
Room or DataStore?
Encrypted DataStore will be provided, Room can already be used with SQLCipher, not decided
yet if it’ll be included out of the box.
Answer

36. Schedule deferrable, asynchronous
tasks that must be run reliably
Architecture
WorkManager

37. WorkManager
androidx:work.work
Support in version 2.5 and later for apps that use multiple processes
Version 2.7 handles Android S foreground restrictions
Newly introduced Workmanager Inspector

38. androidx:work.work
WorkManager Inspector
Available in Android Studio Arctic Fox

39. Flexible, intuitive system for positioning
and animating user interfaces
UI
ConstraintLayout

40. • Reached 2.0.0 stable
• MotionLayout to provide rich
animation and state management
ConstraintLayout
ConstraintLayout 2.0.0 stable
androidx:constraintlayout:constraintlayout

41. MotionLayout
What’s new in design tools
androidx:constraintlayout:constraintlayout

42. Abstraction for segmenting an user interface
into reusable components
UI
Fragment

43. Clean up the internal implementation
Reduce undocumented behaviour and Increase stability
Fragment
Androidx:fragment:fragment
• Don’t forget to read the release note before updating to fragment:1.3.0
ActivityResult Integration

44. // Obtain the fragment manager. May be a childFragmentManager,
// if in a fragment, to observe child attachment.
val fm = supportFragmentManager
val listener = FragmentOnAttachListener{
fragmentManager, fragment ->
// Respond to the fragment being attached.
}
fm.addFragmentOnAttachListener(listener)
onAttachFragment() has been deprecated.
onAttachFragment()

45. 02 New in Stable
01 Overview
03 Up to Beta
04 Debut in Alpha
05 Additional Talks

46. Data storage solution that allows you to store key-value pairs
or typed object with protocol buffers
Data
DataStore

47. Fully asynchronous with Kotlin
coroutine / Flow support, RxJava
2&3
DataStore
Key-values pairs
Protocol buffers (strongly typed)
Your own plugin (Kotlin serialization)
Replacement for SharedPreference Multiple backing implementations
androidx.datastore:datastore

48. SharedPreferences DataStore
Asynchronous API
Synchronous API
Safe to call on UI thread
Call signal errors
Safe from runtime exceptions
Transactional API with strong
consistency guarantees
Handles data migration
Type safety
O only for change listener O via coroutine, RxJava
O O via runBlocking
X O
X O
X O
X O
X O
X O

49. // At the top level of your kotlin file:
val Context.dataStore: DataStore<Preferences> by preferencesDataStore(name = "settings")
Create a preferences Datastore

50. val EXAMPLE_COUNTER = intPreferencesKey("example_counter")
val exampleCounterFlow: Flow<Int> = context.dataStore.data
.map { preferences ->
// No type safety.
preferences[EXAMPLE_COUNTER] ?: 0
}
Read from a Preferences Datastore

51. suspend fun incrementCounter() {
context.dataStore.edit { settings ->
val currentCounterValue = settings[EXAMPLE_COUNTER] ?: 0
settings[EXAMPLE_COUNTER] = currentCounterValue + 1
}
}
Write to a Preferences DataStore

52. val Context.prefStore: DataStore<Prefrences> by preferencesDataStore(
name = USER_PREFERENCES_NAME,
produceMigrations = { context ->
// Since we're migrating from SharedPreferences, add
// a migration based on the SharedPrefernces name
listOf(SharedPreferencesMigration(context, USER_PREFERENCES_NAME))
}
Migrate to DataStore

53. 02 New in Stable
01 Overview
03 Up to Beta
04 Debut in Alpha
05 Additional Talks

54. High performance full-text search for
app-local and device-wide use cases
Data
AppSearch

55. Prefix Indexing
Relevance ranking
Usage scoring
AppSearch
Fuzzy matching
Query expansion
Language support
Full featured vs. SQL Advanced full-text search
androix:appsearch:appsearch

56. Includes schemas for common object types
Centralised storage on Android S and later for
integrating into device-wide search
androix:appsearch:appsearch
AppSearch

57. Framework for navigating between destinations
within an app, now with multiple backstack
UI
Navigation

58. • Added in Navigation 2.4.0
• Utilising APIs which has been added to Fragment 1.4.0 internally.
Navigation
Multiple backstack
androidx.navigation:navigation
saveBackStack() restoreBackStack()
and

59. <action
android:id=”@+id/swap_stack”
app:destination=”@id/second_stack”
app:restoreState=”true”
app:popUpTo=”@id/first_stack_start_destination”
app:popUpToSaveState=”true” />

60. // Use the navigate() method that takes a navOptions DSL Builder
navController.navigate(selectedBottomNavRoute) {
launchSingleTop = true
restoreState = true
popUpTo(navController.graph.startDestinationId) {
saveState = true
}
}

61. Dynamic shortcuts for Google Assistant
and other Google services
UI
Google Shortcuts

62. androidx:core:core-google-shortcuts
// expose a "Cappuccino" action to Google Assistant and other services
ShortcutInfoCompat siCompat =
ShortcutInfoCompat.Builder(ctx, "id_cappuccino")
.setShortLabel("Cappuccino")
.setIntent(Intent(ctx, OrderCappuccino::class.java))
.addCapabilityBinding(
"actions.intent.ORDER_MENU_ITEM",
"menuItem.name",
asList("cappuccino")
)
.build()
ShortcutManagerCompat.pushDynamicShortcut(ctx, siCompat)

63. All the emoji, everywhere! 😉🎉
UI
EmojiCompat

64. EmojiCompat
androidx:emoji2:emoji2-views*
Modern emoji on API 19+ to new artifact emoji2:emoji2
Automatic configuration based on the AppStartup library
* Included in AppCompat 1.4.0 and later by default

65. Accurately measure apps startup and integrated
behaviours, both locally and in CI
Performance
Macrobenchmark

66. Macrobenchmark
androidx.benchmark.macro:macro
Viewable performance profiling result in Android Studio
Check for regressions in CI before they hit users

67. @get:Rule
val benchmarkRule = MacrobenchmarkRule()
@Test
fun startup() = benchmarkRule.measureRepeated(
packageName = "mypackage.myapp",
metrics = listOf(StartupTimingMetric()),
iterations = 5,
startupMode = StartupMode.COLD
) { // this = MacrobenchmarkScope
pressHome()
val intent = Intent()
intent.setPackage("mypackage.myapp")
intent.setAction("mypackage.myapp.myaction")
startActivityAndWait(intent)
}

68. Metrics are displayed directly in Android Studio

69. 02 New in Stable
01 Overview
03 Up to Beta
04 Debut in Alpha
05 Additional Talks

70. Compose
Integrations

71. Compose Integrations
Jetpack Compose Jetpack Libraries in Compose
New UI toolkit without XML • Hilt
• Paging
• Navigation
• Activity
• ViewModel
• ConstraintLayout

72. Compose Integrations
Jetpack Compose Jetpack Libraries in Compose

73. Form
factors

74. Form factors
What’s new in Foldables, Tablets, and Large Screens
Now is the Time: What’s New With Wear OS by Googlee
• androidx.window
• androidx.slidingpanelayout
• androidx.wear

75. Much More
Things…

76. Compose
Hilt
Security Keystore
Security Crypto
EmojiCompat
Google Shortcuts
Core
Room
AppSearch
Paging
Macrobenchmark
DataStore
Window
SlidingPaneLayout
Navigation
Fragment
Activity
Lifecycle
CameraX
ConstraintLayout
ConstraintLayout Compose
SplashScreen
Wear
Wear Tiles
Wear Phone Interaction
Wear Remote Interaction
Wear Input

77. Thank you!
developers.android.com/jetpack
androidx.dev
Resources
Wonyoung Choi - AVP, OCBC bank
@TORU_0239