2022 I/O Extended Korea Android - Exploring Now in Android

2022 I/O Extended Korea Android - Exploring Now in Android.

1. Android Developer Advocate @ Stream Exploring Now in Android Jaewoong
2. skydoves @github_skydoves Android Developer Advocate @ Stream Jaewoong Eum Google Developer Expert
3. Now in Android
4. Now in Android
5. Now in Android Exploring Tech Stacks
6. Tech Stacks • 100% Compose (activity, foundation, material3, accompanist) • Navigation (Compose, Hilt) • WindowManager • Coil User Interface 01
7. Tech Stacks • 100% Compose (activity, foundation, material3, accompanist) • Navigation (Compose, Hilt) • WindowManager • Coil User Interface 01 • DataStore • Room Database • Retrofit • Kotlin Serialization • Kotlin Coroutines • WorkManager Business Works 02
8. Tech Stacks • 100% Compose (activity, foundation, material3, accompanist) • Navigation (Compose, Hilt) • WindowManager • Coil User Interface 01 • DataStore • Room Database • Retrofit • Kotlin Serialization • Kotlin Coroutines • WorkManager Business Works 02 • Baseline Profiles • Macrobenchmark • Hilt • App Startup Other Jetpacks 03
9. Now in Android Exploring App Architecture
10. Architecture Overview Unidirectional Data Flow • Higher layers react to changes in lower layers. • Events flow down. • Data flows up with data streams. (Kotlin Flows) Unidirectional Event Flow
11. Architecture - UI Layer
12. Architecture - UI Layer
13. Architecture - UI Layer
14. Architecture - UI Layer Modeling UI state • UI state always represents the underlying app data. • UI elements handle all possible states. Transforming streams into UI state • View models receive streams of data as Flows from data layers. • The single flow is converted to StateFlows, which enables UI elements to read the last state. Processing user interactions (Unidirectional event flow) • User actions are communicated from UI elements to view models. • View models execute business logic following the user interactions.
15. Architecture - Data Layer
16. Architecture - Data Layer UI layers must be prepared to react to data changes.
17. Reads are performed from local storage as the single source of truth. Architecture - Data Layer
18. A single source of truth principle is a philosophy of aggregating the data from many systems within an organization to a single location. Architecture - Data Layer
19. Architecture - Data Layer
20. interface Syncable { /** * Synchronizes the local database backing the repository with the network. * Returns if the sync was successful or not. */ suspend fun syncWith(synchronizer: Synchronizer): Boolean } Architecture - Sync
21. interface Syncable { /** * Synchronizes the local database backing the repository with the network. * Returns if the sync was successful or not. */ suspend fun syncWith(synchronizer: Synchronizer): Boolean } Architecture - Sync interface TopicsRepository : Syncable class OfflineFirstTopicsRepository @Inject constructor( .. ) : TopicsRepository { override suspend fun syncWith(synchronizer: Synchronizer): Boolean = synchronizer.changeListSync( ..
22. interface Syncable { /** * Synchronizes the local database backing the repository with the network. * Returns if the sync was successful or not. */ suspend fun syncWith(synchronizer: Synchronizer): Boolean } Architecture - Sync interface TopicsRepository : Syncable class OfflineFirstTopicsRepository @Inject constructor( .. ) : TopicsRepository { override suspend fun syncWith(synchronizer: Synchronizer): Boolean = synchronizer.changeListSync( .. Versioning each model
23. @HiltWorker class SyncWorker @AssistedInject constructor( ... ) : CoroutineWorker(appContext, workerParams), Synchronizer { override suspend fun doWork(): Result = withContext(ioDispatcher) { // First sync the repositories in parallel val syncedSuccessfully = awaitAll( async { topicRepository.syncWith(this) }, async { authorsRepository.syncWith(this) }, async { newsRepository.syncWith(this) }, ).all { it } if (syncedSuccessfully) Result.success() else Result.retry() } Architecture - Sync
24. @HiltWorker class SyncWorker @AssistedInject constructor( ... ) : CoroutineWorker(appContext, workerParams), Synchronizer { override suspend fun doWork(): Result = withContext(ioDispatcher) { // First sync the repositories in parallel val syncedSuccessfully = awaitAll( async { topicRepository.syncWith(this) }, async { authorsRepository.syncWith(this) }, async { newsRepository.syncWith(this) }, ).all { it } if (syncedSuccessfully) Result.success() else Result.retry() } Architecture - Sync Synchronize all repositories
25. class SyncInitializer : Initializer<Sync> { override fun create(context: Context): Sync { WorkManager.getInstance(context).apply { // Run sync on app startup and ensure only one sync worker runs at any time enqueueUniqueWork( SyncWorkName, ExistingWorkPolicy.REPLACE, SyncWorker.startUpSyncWork() ) } return Sync } override fun dependencies(): List<Class<out Initializer<*>>> = .. } Architecture - Sync Returns OneTimeWorkRequest
26. <provider android:name="androidx.startup.InitializationProvider" android:authorities="${applicationId}.androidx-startup" android:exported="false" tools:node="merge"> <meta-data android:name="com.google.samples.apps.nowinandroid.sync.initializers.SyncInitializer" android:value="androidx.startup" tools:node="remove" /> </provider> Architecture - Sync
27. Architecture - ForYou Screen
28. Architecture - ForYou Screen
29. Architecture - ForYou Screen
30. Architecture - ForYou Screen
31. Architecture - ForYou Screen The recommendations and best practices present in this architecture can be applied to a broad spectrum of apps to allow them to scale, improve quality and robustness, and make them easier to test. However, you should treat them as guidelines and adapt them to your requirements as needed.
32. Now in Android Exploring UI Layers with Compose
33. UI Layer - Material You
34. UI Layer - Material You Dynamic color extraction algorithm
35. UI Layer - Material You • Material Theme • Material Components • Dynamic Color Scheme
36. UI Layer - Material You
37. UI Layer - Material You
38. UI Layer - Material You
39. UI Layer - Material You
40. Material Theme (Color Scheme) • Primary • onPrimary • PrimaryContainer • onPrimaryContainer • Secondary • onSecondary • Tertiary • onTertiary • Bacground • onBackground • Surface • onSurface • SurfaceVariant • onSurfaceVariant … UI Layer - Theming
41. UI Layer - Theming Dynamic Theme Light Dark Custom Theme Default Theme Android 12 Specific General
42. private val LightDefaultColorScheme = lightColorScheme( primary = Purple40, onPrimary = Color.White, … private val DarkDefaultColorScheme = darkColorScheme( primary = Purple80, onPrimary = Purple20, … private val LightAndroidColorScheme = lightColorScheme( primary = Green40, onPrimary = Color.White, … private val DarkAndroidColorScheme = darkColorScheme( primary = Green80, onPrimary = Green20, …. UI Layer - Theming
43. @Composable fun NiaTheme( darkTheme: Boolean = isSystemInDarkTheme(), dynamicColor: Boolean = false, androidTheme: Boolean = false, content: @Composable() () -> Unit ) { val colorScheme = when { dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> { val context = LocalContext.current if (darkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context) } androidTheme && darkTheme -> DarkAndroidColorScheme androidTheme -> LightAndroidColorScheme darkTheme -> DarkDefaultColorScheme else -> LightDefaultColorScheme } UI Layer - Theming
44. @Composable fun NiaTheme( darkTheme: Boolean = isSystemInDarkTheme(), dynamicColor: Boolean = false, androidTheme: Boolean = false, content: @Composable() () -> Unit ) { val colorScheme = when { dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> { val context = LocalContext.current if (darkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context) } androidTheme && darkTheme -> DarkAndroidColorScheme androidTheme -> LightAndroidColorScheme darkTheme -> DarkDefaultColorScheme else -> LightDefaultColorScheme } UI Layer - Theming
45. @Composable fun NiaTheme( darkTheme: Boolean = isSystemInDarkTheme(), dynamicColor: Boolean = false, androidTheme: Boolean = false, content: @Composable() () -> Unit ) { val colorScheme = when { dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> { val context = LocalContext.current if (darkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context) } androidTheme && darkTheme -> DarkAndroidColorScheme androidTheme -> LightAndroidColorScheme darkTheme -> DarkDefaultColorScheme else -> LightDefaultColorScheme } UI Layer - Theming
46. UI Layer - Large Screen The large screens of tablets, foldables, and Chrome OS devices
47. UI Layer - Large Screen https://bit.ly/3Q0HGoS
48. UI Layer - Large Screen
49. dependencies { implementation "androidx.compose.material3:material3-window-size-class:1.0.0-alpha10" Implementation "androidx.window:window:1.0.0" } UI Layer - Large Screen
50. UI Layer - Large Screen
51. UI Layer - Large Screen
52. UI Layer - Large Screen
53. UI Layer - Large Screen
54. UI Layer - Large Screen Navigation Rail
55. UI Layer - Large Screen Compact Medium, Expanded
56. Now in Android Exploring App Performance
57. UI Layer - Compose Phases Which UI to draw Where to place UI. Measurement and placement How it renders
58. UI Layer - Recomposition
59. Composable functions can use the remember API to store an object in memory. A value computed by remember is stored in the Composition during initial composition, and the stored value is returned during recomposition. UI Layer - Remember
60. UI Layer - Remember
61. UI Layer - Remember High costs in every recomposition
62. UI Layer - Remember Recompose when key values changed
63. UI Layer - Lazy Lists Column LazyColumn
64. UI Layer - Lazy Lists
65. UI Layer - Lazy Lists
66. UI Layer - Lazy Lists
67. UI Layer - Lazy Lists
68. Performance - Baseline Profiles It seems to be janky for the first couple of seconds!
69. Performance - Baseline Profiles Compose is a library — it does not participate in system resource sharing.
70. Performance - Baseline Profiles Baseline Profiles Android Runtime
71. Performance - Baseline Profiles
72. Performance - Baseline Profiles
73. Performance - Baseline Profiles Total: 7059 lines (baseline-prof.txt) HSPLandroidx/compose/animation/AndroidFlingSpline$FlingResult;-><init>(FF)V HSPLandroidx/compose/animation/AndroidFlingSpline;-><clinit>()V HSPLandroidx/compose/animation/AndroidFlingSpline;-><init>()V HSPLandroidx/compose/animation/AndroidFlingSpline;->flingPosition(F)Landroidx/compose/animation/AndroidFlingSpline$FlingResult; HSPLandroidx/compose/animation/CrossfadeKt$$ExternalSyntheticOutline0;->m(Landroidx/compose/runtime/Composer;)V HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$1;-><init>(Ljava/lang/Object;Landroidx/compose/ui/Modifier;Landroidx/comp ose/animation/core/FiniteAnimationSpec;Lkotlin/jvm/functions/Function3;II)V HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$1;->invoke(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object; HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$2;-><clinit>()V HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$2;-><init>()V HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$2;->invoke(Ljava/lang/Object;)Ljava/lang/Object; HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$3$1;-><init>(Landroidx/compose/animation/core/Transition;)V HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$3$1;->invoke(Ljava/lang/Object;)Ljava/lang/Object; HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$4$1$$ExternalSyntheticOutline0;->m(Landroidx/compose/runtime/Compose r;III)V HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$4$1$1$1;-><init>(Landroidx/compose/runtime/State;)V HSPLandroidx/compose/animation/CrossfadeKt$Crossfade$4$1$1$1;->invok HSPLandroidx/compose/animation/CrossfadeKt;->Crossfade(Landroidx/compose/animation/core/Transition;Landroidx/compose/ui/Modifier; Landroidx/compose/animation/core/FiniteAnimationSpec;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function3;Landroidx/compose /runtime/Composer;II)V ….
74. References • Now in Android ◦ https://github.com/android/nowinandroid • Exploring App Architecture ◦ https://github.com/android/nowinandroid/blob/main/docs/ArchitectureLearningJourney.md • Exploring UI Layer ◦ https://material.io/blog/start-building-with-material-you ◦ https://getstream.io/blog/material-you-jetpack-compose/ ◦ https://getstream.io/blog/jetpack-windowmanager-foldable/ ◦ https://developer.android.com/guide/topics/large-screens/support-different-screen-sizes ◦ https://youtu.be/EOQB8PTLkpY ◦ https://developer.android.com/jetpack/compose/performance • Performance ◦ https://developer.android.com/jetpack/compose/phases ◦ https://developer.android.com/topic/performance/baselineprofiles ◦ https://developer.android.com/topic/performance/benchmarking/macrobenchmark-overview
75. Thank you! Android Developer Advocate @ GetStream Google Developer Expert skydoves skydoves2@gmail.com @github_skydoves Contacts Jaewoong Eum