Google I/O Extended 2023: What's New in Kotlin for Android

Google I/O Extended 2023: What's New in Kotlin for Android.

Transcript

1. What's New in Kotlin for Android
2. Jaewoong Eum (엄재웅) Lead Android Developer Advocate, Stream Google Developer Expert skydoves @github_skydoves
3. Index 1. State of Kotlin 2. Kotlin 2.0 Compiler 3. Kotlin DSL for Gradle 4. Code Generation (KAPT, KSP) 5. Kotlin Multiplatform
4. State of Kotlin
5. State of Kotlin 2017 goo.gle/5-years-of-kotlin
6. State of Kotlin goo.gle/kotlin-first 2019
7. State of Kotlin • 15M+ lines of Kotlin code • 70+ Android apps by Google built with Kotlin • Thousands of Google engineers write Kotlin
8. State of Kotlin
9. State of Kotlin
10. State of Kotlin
11. State of Kotlin
12. State of Kotlin 95% of top 100 apps use Kotlin 70% of top 1000 apps use Kotlin in their own code 55% of apps that use Kotlin use coroutines in their own code
13. State of Kotlin
14. State of Kotlin github.com/Kotlin/KEEP
15. State of Kotlin kotlinconf.com/talks/374446/
16. The Kotlin 2.0 Compiler
17. Kotlin 2.0 compiler The K2 compiler frontend is not just a refactoring of the old compiler frontend, but a complete rewrite from scratch based on the new architecture.
18. Kotlin 2.0 compiler Kotlin 2.0 compiler performance Project Kotlin 1.8 compiler Kotlin 2.0 compiler Improvement Kotlin 5m 40s 2.0 KLOC/s 2m 37s 6.3 KLOC/s ~2.2x IntelliJ IDEA Ultimate 34m 15s 2.5 KLOC/s 16m 59s 5.0 KLOC/s ~2.0x
19. 2022 2023 2024 Kotlin releases 1.7.0 K2 Alpha 1.9.x K2 Beta Compose & KSP 1.8.20 "lang ver 2.0" 2.0 K2 Default K2 integration in Android Studio Kotlin 2.0 compiler
20. Kotlin 2.0 compiler 2022 2023 2024 Kotlin releases 1.7.0 K2 Alpha 1.9.x K2 Beta Compose & KSP 1.8.20 "lang ver 2.0" 2.0 K2 Default K2 integration in Android Studio
21. Kotlin 2.0 compiler // build.gradle.kts (module) kotlin { sourceSets.all { languageSettings { languageVersion = "2.0" } } }
22. Kotlin 2.0 compiler
23. 2022 Kotlin 2.0 compiler 2022 2023 2024 Kotlin releases 1.7.0 K2 Alpha 1.9.x K2 Beta Compose & KSP 1.8.20 "lang ver 2.0" 2.0 K2 Default K2 integration in Android Studio
24. Kotlin 2.0 compiler Will it break my code? Kotlin changes with every language version update. New language features get introduced and old bugs get fixed. We always try to minimize the number and impact of breaking changes and follow the Kotlin language evolution process. Kotlin 2.0 will be no different in that respect.
25. Kotlin 2.0 compiler
26. Kotlin 2.0 compiler
27. Kotlin 2.0 compiler Separately, a syntax tree (PSI) & a table with semantic info (BindingContext)
28. Kotlin 2.0 compiler
29. Kotlin 2.0 compiler https://youtu.be/wUGfuWHCqrc https://youtu.be/iTdJJq_LyoY
31. Kotlin DSL for Gradle
32. Kotlin DSL for Gradle Builds
33. Kotlin DSL for Gradle Builds
34. Kotlin DSL for Gradle Builds
35. Kotlin DSL for Gradle Builds plugins { id("com.android.application") id("org.jetbrains.kotlin.android") } android { namespace = "com.skydoves.balloon" compileSdk = 33 defaultConfig { applicationId = "com.skydoves.balloon" minSdk = 21 } buildFeatures { compose = true } }
36. Kotlin DSL for Gradle Builds plugins { id("com.android.application") id("org.jetbrains.kotlin.android") } android { namespace = "com.skydoves.balloon" compileSdk = 33 asdf = "asdf" defaultConfig { applicationId = "com.skydoves.balloon" minSdk = 21 } buildFeatures { compose = true } } Unresolved reference: asdf
37. Kotlin DSL for Gradle Builds
38. Kotlin DSL for Gradle Builds
39. Kotlin DSL for Gradle Builds
40. Kotlin DSL for Gradle Builds Kotlin DSL [Default] Write your build scripts in Kotlin, with editor support in the IDE Kotlin DSL with Version Catalogs [Experimental] Manage dependencies and plugins in a maintainable and scalable way goo.gle/migrate-to-kts goo.gle/migrate-to-catalogs
41. A fully functional Android app built entirely with Kotlin and Jetpack Compose. You can find out Kotlin DSL scripts, Version Catalogs, and build logic examples! Now in Android goo.gle/nia
42. Kotlin Code Generation
43. Kotlin Code Generation JSR 269: Pluggable Annotation Processing API
44. Kotlin Code Generation
45. Kotlin Code Generation
46. Kotlin Code Generation
47. Kotlin Code Generation Kapt Kotlin Annotation Processing Tool Generates Java stubs from Kotlin code, allowing annotations processors written for Java to work with Kotlin.
48. Kotlin Code Generation Kapt Kotlin Annotation Processing Tool Generates Java stubs from Kotlin code, allowing annotations processors written for Java to work with Kotlin. Kotlin code Java stubs Java Annotation Processors Kapt uses Java compiler to run annotation processors.
49. Kotlin Code Generation KSP Kotlin Symbol Processing A Kotlin-first alternative to kapt, directly analyzing Kotlin code.
50. Kotlin Code Generation KSP Kotlin Symbol Processing A Kotlin-first alternative to kapt, directly analyzing Kotlin code. Kotlin code KSP Processors KSP uses Kotlin compiler to run annotation processors.
51. Kotlin Code Generation Up to 2x speed No stub generation step required Better typing Understands Kotlin specific language features, such as nullability Multiplatform-ready Doesn't depend on Java source code Advantages of KSP
52. Kotlin Code Generation KSP Migration Strategy
53. Kotlin Code Generation KSP Migration Strategy
54. Kotlin Code Generation KSP Migration Strategy
55. Kotlin Code Generation KSP Support ✅ Jetpack Room ✅ Glide ✅ Moshi ✅ … and more!
56. Kotlin Code Generation KSP Support ✅ Jetpack Room ✅ Glide ✅ Moshi ✅ … and more! goo.gle/ksp-support
57. Kotlin Code Generation
58. Kotlin Code Generation KSP for Dagger & Hilt is coming!
59. Kotlin Multiplatform
60. Kotlin Multiplatform Shared business logic written in Kotlin between platforms
61. Kotlin Multiplatform
62. Kotlin Multiplatform jetbrains.com/lp/compose-multiplatform • iOS (Alpha) • Android (via Jetpack Compose) • Desktop (Windows, MacOS, Linux) • Web (Experimental)
63. Kotlin Multiplatform github.com/JetBrains/compose-multiplatform
64. Kotlin Multiplatform
65. Kotlin Multiplatform Jetpack Libraries • Annotations • Collections • DataStore
66. Kotlin Multiplatform Jetpack Libraries • Annotations • Collections • DataStore Network • Ktor • Ktrofit • .. Database • SQLDelight • Realm • KStore Dependency Injection • Koin • Kodein • kotlin-inject Kotlin • Serialization • Coroutines • ..
67. Kotlin Multiplatform kotlinlang.org/lp/multiplatform/case-studies
68. Thank you! Lead Android Developer Advocate @ GetStream Jaewoong Eum (엄재웅) Google Developer Expert