Build a Multiplatform Future with Kotlin (Craft Conference 2024)

Transcript

1. Build a Multiplatform Future with Kotlin Márton Braun Developer Advocate
2. iOS Android Desktop Web Server
3. iOS Android Desktop Web Server
4. Native Cross-platform VS
5. Native Best user experience Cross-platform VS Great performance Full platform capabilities
6. Native Reduced development time Consistent behavior Fewer bugs Best user experience Cross-platform VS Great performance Full platform capabilities
7. Native Reduced development time Consistent behavior Fewer bugs Great performance Best user experience Cross-platform & Full platform capabilities
8. kotl.in/kmp-case-studies
9. Agenda History and target platforms How it works UI sharing Ecosystem Tooling
10. 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
11. 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
12. Start of project 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
13. Start of project 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025 Kotlin/JVM .kt .class Java .java .class
14. Public announcement Start of project Open source 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025 Kotlin/JVM .kt .class Java .java .class
15. Public announcement Start of project Open source 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025 Kotlin/JVM .kt .class Kotlin 1.0
16. Kotlin 1.0 Public announcement Start of project Open source JavaScript 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025 Kotlin/JVM .kt .class Kotlin/JS .kt .js
17. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025 Kotlin/Native .kt .klib|.kexe
18. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025 Kotlin/Native .kt .so|.dll|.exe|.kexe|.etc
19. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025 Kotlin/Native .kt .klib|.kexe
20. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025 Kotlin/JVM .kt .class Kotlin/Native .kt .klib|.kexe Kotlin/JS .kt .js
21. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP alpha 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
22. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
23. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP stable KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
24. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP stable Wasm Kotlin/JVM .kt Kotlin/Native .kt Kotlin/JS .kt Kotlin/Wasm .kt .class .klib|.kexe .js .wasm KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
25. Kotlin/JVM .kt Kotlin/Native .kt Kotlin/JS .kt Kotlin/Wasm .kt .class .klib|.kexe .js .wasm
26. .class .klib|.kexe .js .wasm .kt .kt .kt .kt Kotlin/JVM Kotlin/Native Kotlin/JS Kotlin/Wasm
27. .kt .class .klib|.kexe .js .wasm .kt .kt .kt
28. .kt .class .klib|.kexe .js .wasm K2 frontend
29. .kt K2 frontend JVM backend Native backend JS backend Wasm backend .class .klib|.kexe .js .wasm
30. .kt K2 frontend JVM backend Native backend JS backend Wasm backend .class .klib|.kexe .js .wasm
31. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP stable Wasm KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
32. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP stable Wasm KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
33. Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP stable Wasm KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
35. Java + Kotlin Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP stable Wasm KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
36. Kotlin first Java + Kotlin Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP stable Wasm KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
37. Kotlin first, Jetpack Compose Java + Kotlin Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP stable Wasm KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
38. Jetpack KMP Kotlin first, Jetpack Compose Java + Kotlin Kotlin 1.0 Public announcement Start of project Open source Native JavaScript KMP stable Wasm KMP alpha KMP beta 2013 2014 2015 2016 2017 2018 2019 2020 2021 2012 2022 2010 2011 2023 2024 2025
40. How it works
41. iOS Android Desktop +
42. Desktop + Android iOS .kt .kt .class .framework
43. iOS .class .framework Desktop + Android .kt .kt
44. Common .kt .kt
45. .kt .kt .kt .kt Android Desktop iOS Common
46. .kt .kt .kt .kt Android Desktop iOS Common
47. .kt .kt .kt .kt Android Desktop iOS Common
48. .kt .kt .kt Android Desktop iOS Common .kt
49. .kt .kt .kt .kt Android Desktop iOS Common
50. .kt .kt .kt .kt Android Desktop iOS Common
51. .kt .kt .kt Android Desktop iOS Common class Person(val name: String, var age: Int) fun greet(person: Person) { println("Hello, ${person.name}") }
52. .kt .kt .kt Android Desktop iOS Common fun List<Person>.duplicates(): Map<String, Int> { return map { it.name.substringBefore(" ") } .groupingBy { it } .eachCount() .filter { (name, count) -> count > 1 } }
53. Android Desktop iOS actual Common expect actual actual
54. Android Desktop iOS Common expect actual actual actual
55. Android Desktop iOS Common fun getPlatform(): String expect actual actual actual
56. Android Desktop iOS Common fun getPlatform(): String fun getPlatform(): String = "Java ${System.getProperty("java.version")}" expect actual actual actual
57. Android iOS fun getPlatform(): String = "Android ${Build.VERSION.SDK_INT}" actual actual Common fun getPlatform(): String expect Desktop fun getPlatform(): String = "Java ${System.getProperty("java.version")}" actual
58. Android iOS fun getPlatform(): String = "iOS ${UIDevice.currentDevice.systemVersion}" fun getPlatform(): String = "Android ${Build.VERSION.SDK_INT}" actual actual Common fun getPlatform(): String expect Desktop fun getPlatform(): String = "Java ${System.getProperty("java.version")}" actual
59. Android Desktop iOS Common fun getPlatform(): String fun getPlatform(): String = "Java ${System.getProperty("java.version")}" fun getPlatform(): String = "iOS ${UIDevice.currentDevice.systemVersion}" fun getPlatform(): String = "Android ${Build.VERSION.SDK_INT}" expect actual actual actual
60. Multiplatform libraries
61. .kt .kt .kt Android Desktop iOS Common import io.ktor.client.* suspend fun loadHtml(): String { val client = HttpClient() val response = client.get("https://kotlinlang.org") return response.body<String>() }
62. Shared logic
63. Shared logic Swing Desktop logic Jetpack Compose Android logic SwiftUI iOS logic
64. Shared logic Swing Desktop logic Jetpack Compose Android logic SwiftUI iOS logic
65. Shared logic Swing Desktop logic Jetpack Compose Android logic SwiftUI iOS logic
66. Shared logic Swing Desktop logic Jetpack Compose Android logic SwiftUI iOS logic
67. jb.gg/compose Compose Multiplatform
68. Compose Multiplatform jb.gg/compose
69. @Composable fun SquaresGalleryView( images: List<PictureData>, selectedImage: PictureData, onSelect: (PictureData) -> Unit, ) { LazyVerticalGrid( modifier = Modifier.padding(top = 4.dp), columns = GridCells.Adaptive(minSize = 130.dp), verticalArrangement = Arrangement.spacedBy(1.dp), horizontalArrangement = Arrangement.spacedBy(1.dp) ) { itemsIndexed(images) { _, picture -> SquareThumbnail( picture = picture, onClick = { onSelect(picture) }, isHighlighted = selectedImage === picture ) } } }
70. @Composable fun SquaresGalleryView( images: List<PictureData>, selectedImage: PictureData, onSelect: (PictureData) -> Unit, ) { LazyVerticalGrid( modifier = Modifier.padding(top = 4.dp), columns = GridCells.Adaptive(minSize = 130.dp), verticalArrangement = Arrangement.spacedBy(1.dp), horizontalArrangement = Arrangement.spacedBy(1.dp) ) { itemsIndexed(images) { _, picture -> SquareThumbnail( picture = picture, onClick = { onSelect(picture) }, isHighlighted = selectedImage === picture ) } } }
71. Swing Desktop logic Jetpack Compose Android logic SwiftUI iOS logic Shared logic
72. Desktop logic Android logic iOS logic Shared logic Shared UI Compose Multiplatform
73. Desktop logic Android logic iOS logic Shared logic Shared UI Compose Multiplatform Swing Android Views SwiftUI
74. Desktop logic Android logic iOS logic Shared logic Shared UI Compose Multiplatform Swing Android Views SwiftUI
75. Mix and match UI Compose view embedded in SwiftUI Floating SwiftUI TextField
76. Latest developments Resources 1.6.0+ Lifecycle Navigation 2.8.0-rc03 2.7.0-alpha07 ViewModel 2.8.0-rc03
77. ViewModel org.jetbrains.androidx.lifecycle:lifecycle-viewmodel-compose package androidx.lifecycle public abstract class ViewModel { protected open fun onCleared() public fun addCloseable(key: String, closeable: AutoCloseable) public open fun addCloseable(closeable: AutoCloseable) } public val ViewModel.viewModelScope: CoroutineScope
78. Navigation org.jetbrains.androidx.navigation:navigation-compose val navController: NavHostController = rememberNavController() NavHost( navController, startDestination = "list" ) { composable("list") { ListScreen(navController) } composable("detail/{objectId}") { backStackEntry -> val objectId = backStackEntry.arguments?.getString("objectId")?.toInt() DetailScreen(navController, objectId!!) } }
79. Multiplatform libraries
80. Networking
81. Data storage
82. Key-value stores
83. Dependency injection
84. Navigation
85. Image loading
86. Themes
87. github.com/terrakok/kmp-awesome
88. Tooling
89. Public Preview
103. Kotlin Multiplatform JetBrains tooling Flexible code sharing Best of native + cross-platform Stable and production-ready
104. jb.gg/kmp-samples Official sample apps
105. kmp.jetbrains.com
106. kmp.jetbrains.com
107. Kotlin Multiplatform jb.gg/kmp Compose Multiplatform jb.gg/compose Fleet jb.gg/fleet Build a Multiplatform Future with Kotlin zsmb.co/talks Márton Braun @zsmb13@androiddev.social