It Just Works

These last years had been really exciting for app development. First, Android developers moved to Kotlin, then we had Kotlin Multiplatform where we managed to have our app’s business logic shared across iOS and desktop. Now with Compose we can go even further and reuse the UI. In this talk, I’m going to show you can create a library and the UI for your Android application and share it across a Desktop app and the web - it just works*.

Transcript

1. Photo by FarawayPictures on deviantART @cafonsomota IT JUST WORKS* (*RUNNING COMPOSE ON ANDROID, DESKTOP, AND THE WEB ALONG WITH KMP)
2. 👨💻 Android GDE 🗣 Founder @GDGCoimbra and co-founder @Kotlin_Knights ✍ Author @rwenderlich 🗺 Loves travel, photography and running 🍻 Looking to taste a Moretti with all of you @cafonsomota
3. 🖥 Slides speakerdeck.com/cmota/it-just-works 👉 Code github.com/cmota/alicerce github.com/cmota/unsplash 🍿 YouTube bit.ly/cmota-youtube Materials @cafonsomota
4. A Brief history of Time
5. 2008 2012 2018 2013 2011 2017 2006 2010 2009 2015 * Kotlin Multiplatform * @cafonsomota Mobile
6. 1996 2006 2018 2013 2017 1995 * * Kotlin Multiplatform Desktop 2008 @cafonsomota
7. 2012 2018 2014 2017 2006 2010 2009 2015 * * Kotlin Multiplatform Web @cafonsomota
8. myths of native, hybrid, and cross platform solutions
9. droiders 🤖 @cafonsomota
10. I’ve got a new app idea! droiders 🤖 @cafonsomota
11. Great!! Are you going to do it natively? I’ve got a new app idea! droiders 🤖 📱 @cafonsomota
12. Great!! Are you going to do it natively? I’ve got a new app idea! droiders 🤖 📱 Natively? You can use Xamarin and instead of android only, you get android and iOS @cafonsomota
13. Great!! Are you going to do it natively? I’ve got a new app idea! droiders 🤖 📱 Natively? You can use Xamarin and instead of android only, you get android and iOS For that, you should use Flutter! It has better performance! @cafonsomota
14. Great!! Are you going to do it natively? I’ve got a new app idea! droiders 🤖 📱 Natively? You can use Xamarin and instead of android only, you get android and iOS For that, you should use Flutter! It has better performance! But it uses Dart! You’re already familiar with Kotlin, you should try Kotlin Multiplatform! @cafonsomota
15. Great!! Are you going to do it natively? I’ve got a new app idea! droiders 🤖 📱 Natively? You can use Xamarin and instead of android only, you get android and iOS For that, you should use Flutter! It has better performance! But it uses Dart! You’re already familiar with Kotlin, you should try Kotlin Multiplatform! I’ve been using react native and it’s great! @cafonsomota
16. Great!! Are you going to do it natively? I’ve got a new app idea! droiders 🤖 📱 Natively? You can use Xamarin and instead of android only, you get android and iOS For that, you should use Flutter! It has better performance! But it uses Dart! You’re already familiar with Kotlin, you should try Kotlin Multiplatform! I’ve been using react native and it’s great! 12 people are typing @cafonsomota
17. How to develop an application?
18. How to decide? Team background and size Which language is your team familiar with? Do they want to learn new things? Can you have developers focused on each platform you’re targeting? Project type Are you developing an MVP? 1yr long project? 5yr? Never ending project? Constraints Time: It hasn’t started yet, and you’re already behind schedule? Budget: Can you hire/allocate more people? @cafonsomota
19. Framework dependent OS updates require the fw to be updated and launch a new app Missing features OS/device features depend on the fw support, you might need to write them Slower performance Commitment to one framework Common disadvantages @cafonsomota
20. How to develop an application? Spoilers
21. How to develop an application?
22. It’s Kotlin ❤ Take advantage of all the language features (that you’re already familiar with) Low risk Decide what’s worth to share across platforms Consistency across platforms One tech-stack Strong community support KOtlin Multiplatform @cafonsomota
23. Kotlin Multiplatform
24. Kotlin Multiplatform shares your business logic @cafonsomota
25. presentation presentation presentation presentation model model model model parser parser parser parser view network view network view network view network desktop web iOS android @cafonsomota
26. business logic business logic business logic model parser network presentation model parser network presentation model parser network presentation model parser network presentation business logic view view view view desktop web iOS android @cafonsomota
27. android iOS desktop model parser network presentation common view view view view java/kotlin objective-c/ swift (kotlin) JS supported in jvm web @cafonsomota
28. Kotlin Multiplatform: Platform Specific Code src/commonMain/sample/Platform.kt expect object Platform { val name: String } :shared @cafonsomota
29. src/commonMain/sample/Platform.kt expect object Platform { val name: String } You need to de fi ne actual per target actual for Android actual for Desktop actual for JS Kotlin Multiplatform: Platform Specific Code :shared @cafonsomota
30. src/commonMain/sample/Platform.kt expect object Platform { val name: String } src/androidMain/sample/Platform.kt actual object Platform { actual val name: String = "android" } Kotlin Multiplatform: Platform Specific Code :shared @cafonsomota
31. src/commonMain/sample/Platform.kt expect object Platform { val name: String } src/androidMain/sample/Platform.kt actual object Platform { actual val name: String = “android” } Kotlin Multiplatform: Platform Specific Code :shared @cafonsomota
32. src/commonMain/sample/Platform.kt :shared expect object Platform { val name: String } src/androidMain/sample/Platform.kt src/desktopMain/sample/Platform.kt src/webMain/sample/Platform.kt actual object Platform { actual val name: String = “android” } actual object Platform { actual val name: String = “desktop” } actual object Platform { actual val name: String = “web” } Kotlin Multiplatform: Platform Specific Code @cafonsomota
33. *.kt common expect JVM actual *.kt, *.java, *.jar Native *.kt, *C, Swift, Framework JS *.kt, *.js, NPM actual actual
34. How to develop an application?
35. Compose
36. developer.android.com/jetpack/compose
37. Compose
38. 🤔 Compose
39. Jetpack Compose compose.animation compose.material compose.foundation compose.ui compose.runtime compose.compiler
40. Jetpack Compose compose.animation compose.material compose.foundation compose.ui compose.runtime compose.compiler Compose Compiler Compose Runtime Compose UI Toolkit (Android) Compose Animation Compose UI Compose Foundation Compose Material
41. Jetpack Compose compose.animation compose.material compose.foundation compose.ui compose.runtime compose.compiler Compose Compiler Compose Runtime Compose UI Toolkit (Android) Compose Animation Compose UI Compose Foundation Compose Material
42. Compose Compiler Compose Runtime Compose UI Toolkit (Android) Compose Animation Compose UI Compose Foundation Compose Material Compose compiler android.googlesource.com/platform/frameworks/support/+/HEAD/compose/compiler Written in Kotlin Transforms @Composable into UI Doesn’t use the Annotation Processor The plugin works at system/code generation level Doesn’t impact build times Open source Available in the AOSP
43. Compose Runtime Platform agnostic Doesn’t know what Android or UI are Tree management solution Compose Compiler Compose Runtime Compose UI Toolkit (Android) Compose Animation Compose UI Compose Foundation Compose Material
44. Compose UI Toolkit Compose Compiler Compose Runtime Compose UI Toolkit (Android) Compose Animation Compose UI Compose Foundation Compose Material compose.ui Handles input management, Drawing, Layouts, etc. compose.foundation Contains Basic building: Column, Text, Image, etc. compose.material Material design system to use on components compose.animation Animations to use easily and out side of the box
45. Compose UI Raspberry pi Compose Compiler Compose Runtime Compose UI Android Compose UI Desktop Compose UI Web Compose UI Console Compose
46. blog.jetbrains.com/kotlin/2021/10/compose-multiplatform-goes-beta/
47. Android, desktop, and Web
48. @cafonsomota :androidApp
49. :androidWearApp
50. @cafonsomota :desktopApp
51. :webApp
52. Now that we’ve got the android app ready, How quickly can we have desktop and web apps? - all the dreamers out there
53. SELECT YOUR LEVEL I just want to see the story. I want a lighter experience. Give me the full challenge! @cafonsomota
54. SELECT YOUR LEVEL I just want to see the story. I want a lighter experience. Give me the full challenge! 👉 @cafonsomota
55. SELECT YOUR LEVEL I just want to see the story. I want a lighter experience. Give me the full challenge! 👉 @cafonsomota
56. SELECT YOUR LEVEL I just want to see the story. I want a lighter experience. Give me the full challenge! 👉 @cafonsomota
57. Kotlin Multiplatform shares your business logic Compose shares your (native) UI @cafonsomota
58. Kotlin Multiplatform shares your business logic Compose shares your (native) UI @cafonsomota
59. KOtlin Multiplatform: Targets jvm JS android android 
 NDK iOS watchOS tvOS macOS Linux Windows Web Assembly @cafonsomota
60. KOtlin Multiplatform: Libraries Kotlinx.x Coroutines, serialization, datetime, atomicfu, etc. Network Ktor: github.com/ktorio/ktor Storage Database: github.com/cashapp/sqldelight Others Curated list: github.com/AAkira/Kotlin-Multiplatform-Libraries @cafonsomota
61. How to Start?
62. KOtlin Multiplatform: Creating a new KMM project 1. Install the KMM plugin on Android Studio 2. Create a new KMM Application ⚠ There’s a version that supports Mac M1 :shared :shared @cafonsomota
63. KOtlin Multiplatform: Project Structure androidApp/ iosApp/ shared/ :shared @cafonsomota
64. KOtlin Multiplatform: Project Structure androidApp/ iosApp/ shared/ :shared @cafonsomota
65. KOtlin Multiplatform: Project Structure androidApp/ iosApp/ shared/ :shared @cafonsomota
66. KOtlin Multiplatform: Project Structure androidApp/ desktopApp/ webApp/ shared/ :shared @cafonsomota
67. KOtlin Multiplatform: Project Structure androidApp/ desktopApp/ webApp/ shared/ :shared @cafonsomota
68. androidApp/ desktopApp/ webApp/ shared/ KOtlin Multiplatform: Project Structure androidMain/ commonMain/ iosMain/ :shared @cafonsomota
69. androidApp/ desktopApp/ webApp/ shared/ KOtlin Multiplatform: Project Structure your common code (logic) androidMain/ commonMain/ desktopMain/ jsMain/ :shared @cafonsomota
70. androidApp/ desktopApp/ webApp/ shared/ KOtlin Multiplatform: Project Structure your platform speci fi c code (engine, drivers, etc.) :shared androidMain/ commonMain/ desktopMain/ jsMain/ @cafonsomota
71. KOtlin Multiplatform: Adding new Targets kotlin {a android() iOS()1 }b shared/build.gradle.kts :shared
72. shared/build.gradle.kts KOtlin Multiplatform: Adding new Targets kotlin {a android() jvm("desktop") js(IR) {c browser() binaries.executable() }d }b :shared
73. shared/build.gradle.kts KOtlin Multiplatform: Refactoring to KMP kotlin { ... sourceSets { val commonMain by getting dependencies implementation(“io.ktor:ktor-client-core:1.6.4") val androidMain by getting dependencies implementation("io.ktor:ktor-client-android:1.6.4") val desktopMain by getting val jsMain by getting dependencies implementation("io.ktor:ktor-client-js:1.6.4") } } Network ✅ Migrating to Ktor :shared
74. shared/build.gradle.kts ✅ Migrating to SQLDelight KOtlin Multiplatform: Refactoring to KMP kotlin { ... sourceSets { val commonMain by getting val androidMain by getting dependencies implementation("com.squareup.sqldelight:android-driver:1.5.1") val desktopMain by getting dependencies implementation("com.squareup.sqldelight:native-driver:1.5.1") val jsMain by getting dependencies implementation("com.squareup.sqldelight:sqljs-driver:1.5.1") } } :shared
75. kotlin { ... sourceSets { val commonMain by getting dependencies implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.3.0") val androidMain by getting val desktopMain by getting val jsMain by getting } } shared/build.gradle.kts ✅ Migrating to kotlinx.serialization KOtlin Multiplatform: Refactoring to KMP :shared
76. kotlin { ... sourceSets { val commonMain by getting dependencies implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.3.0") val androidMain by getting val desktopMain by getting val jsMain by getting } } shared/build.gradle.kts ✅ Migrating to kotlinx.serialization KOtlin Multiplatform: Refactoring to KMP shared module And of course, Also migratE the API Calls
77. Do I need to refactor The entire Project?
78. Do I need to refactor The entire Project? NO
79. KOtlin Multiplatform You don’t need to commit your entire codebase to KMP The goal is to share your business logic Di ff erent apps share di ff erent parts of their code - what makes sense to them! Space *Adapted from: KotlinConf 2019: Opening Keynote by Andrey Breslav Full KMP Cash App Shares: business logic Yandex Maps Shares: business logic, wrappers for C++ libraries PlanGrid Planboard Workspace Shares: business logic, sync logic, mgmnt o ffl ine data Shares: business logic Shares: business logic, networking, o ffl ine caching lyrs
80. KOtlin Multiplatform: ‘Suggestions’ Start small You’re going to develop a new feature? There’s part of your app that needs to be refactored? Want to improve your test coverage? why not do it on the shared module? @cafonsomota
81. What ‘challenges’ will you find?
82. KOtlin Multiplatform: ‘Challenges’ 🟡 Not all libraries are available on KMP Those who are might not support all targets They might not be compatible with your Kotlin version @cafonsomota
83. KOtlin Multiplatform: ‘Challenges’ 🟡 Not all libraries are available for KMP Those who are might not support all targets They might not be compatible with your Kotlin version 🟠 Project initial setup requires some time Invalidate cache and restart is needed sometimes to recover code auto-complete There are properties that you need to con fi gure: export (iOS), @JsName (JS), etc. Especially when targeting Web, you should enable the IR compiler @cafonsomota
84. KOtlin Multiplatform: ‘Challenges’ 🟡 Not all libraries are available for KMP Those who are might not support all targets They might not be compatible with your Kotlin version 🟠 Project initial setup requires some time Invalidate cache and restart is needed sometimes to recover code auto-complete There are properties that you need to con fi gure: export (iOS), @JsName (JS), etc. Especially when targeting Web, you should enable the IR compiler 🔴 Generated library might need to lose some weight Especially when targeting Web, they can easily gain several MB’s @cafonsomota
85. Kotlin Multiplatform shares your business logic Compose shares your (native) UI @cafonsomota
86. How to Start?
87. Compose: Getting Ready If you’re starting Compose for the fi rst time Start by developing fi rst on Android Once done, you can move it to a shared module If you’re already familiar with it Create a shared-ui module that will de fi ne the UI for the di ff erent platforms @cafonsomota
88. Compose: Getting Ready 1. Create a new module called shared-ui 2. You can just copy-paste shared Rename it to shared-ui Remove all of it’s .kt classes @cafonsomota
89. Compose To share your Compose UI you’ll need to do a bit of KMP Di ff erent platforms, mean di ff erent behaviours For instance, you can resize a window on the desktop but not on your phone* You have di ff erent input types, etc. * well, you can have the app in split screen mode, yes 🙂 @cafonsomota
90. Compose Compose for Android androidx.compose @cafonsomota
91. Compose Compose for Android androidx.compose Compose for Desktop/Web org.jetbrains.compose @cafonsomota
92. Compose src/shared-ui/build.gradle.kts :shared-ui plugins { kotlin("multiplatform") id("org.jetbrains.compose") version “1.0.0-beta5" id("com.android.library") kotlin("plugin.serialization") }
93. Compose src/shared-ui/build.gradle.kts :shared-ui plugins { kotlin("multiplatform") id("org.jetbrains.compose") version “1.0.0-beta5" id("com.android.library") kotlin("plugin.serialization") } kotlin { ... sourceSets { val commonMain by getting { dependencies { api(compose.foundation) api(compose.runtime) api(compose.foundation) api(compose.material) api(compose.materialIconsExtended) api(compose.ui) api(compose.uiTooling) } } } }
94. Compose 💥 Duplicated class androidx.compose.* ... BUILD FAILED @cafonsomota
95. Compose You’re using two di ff erent versions of Compose androidx.compose org.jetbrains.compose @cafonsomota
96. Compose src/androidApp/build.gradle.kts :androidApp plugins { id("org.jetbrains.compose") version “1.0.0-beta5" id("com.android.application") kotlin("android") }
97. Do I need to refactor The entire Project?
98. Do I need to refactor The entire Project? NO
99. Compose Compose is interoperable with XML You don’t need to rewrite your entire app with Compose You’ll only be able to share the features that are using Compose @cafonsomota
100. What ‘challenges’ will you find?
101. Compose: ‘Challenges’ 🟠 Initial setup is… challenging You’ll need to use JetBrains Compose plugin Adding the wrong con fi guration might increase building times in several minutes @cafonsomota
102. Compose: ‘Challenges’ 🟠 Initial setup is… challenging You’ll need to use JetBrains Compose plugin Adding the wrong con fi guration might increase building times in several minutes 🟠 Libraries depend on the Compose version You’ll need to use a compatible one @cafonsomota
103. Compose: ‘Challenges’ 🟠 Initial setup is… challenging You’ll need to use JetBrains Compose plugin Adding the wrong con fi guration might increase building times in several minutes 🟠 Libraries depend on the Compose version You’ll need to use a compatible one 🟠 Not all features are available for Desktop/ Web There’s no direct support for i18n, fonts and other resources LiveData, ViewModels, etc. are only available through third-party libraries @cafonsomota
104. Compose: ‘Challenges’ 🔴 Web… is in it’s initial stages Not all Compose functions are ported to the Web The ones that are, often require that you use DOM elements to manipulate them Adding this abstraction manually will be really time consuming @cafonsomota
105. How to Solve them
106. Compose: ‘Challenges’ Accompanist A set of libraries that provide Compose ready features Examples: Insets, Paging, Permissions, Swipe to refresh, etc. 📐 Insets 🍫 System UI Controller 🎨 AppCompat Theme Adapter 🧭✨Navigation-Animation 📫 Permissions ⏳ Placeholder 🌊 Flow Layouts 🧭🎨 Navigation-Material 🖌 Drawable Painter ⬇ Swipe to Refresh 📖 Pager @cafonsomota
107. Accompanist A set of libraries that provide Compose ready features Examples: Insets, Paging, Permissions, Swipe to refresh, etc. Compose: ‘Challenges’
108. Accompanist A set of libraries that provide Compose ready features Examples: Insets, Paging, Permissions, Swipe to refresh, etc. Not all Compose libraries are supported on Desktop and Web… for now! Compose: ‘Challenges’
109. Compose: ‘Challenges’ Accompanist A set of libraries that provide Compose ready features Examples: Insets, Paging, Permissions, Swipe to refresh, etc. Not all Compose libraries are supported on Desktop and Web… for now! Community to the rescue! 🚀
110. Accompanist (by Syer10) A subset of accompanist libraries ported by Syer10 to Desktop Available at: syer10.github.io/accompanist Compose: ‘Challenges’
111. Accompanist (by Syer10) A subset of accompanist libraries ported by Syer10 to Desktop Available at: syer10.github.io/accompanist ⚠ only works on Desktop Compose: ‘Challenges’
112. Compose: ‘Challenges’ Accompanist (by Syer10) A subset of accompanist libraries ported by Syer10 to Desktop Available at: syer10.github.io/accompanist ⚠ only works on Desktop Why? 😭
113. plugins { kotlin("multiplatform") id("org.jetbrains.compose") version "1.0.0-alpha3" } kotlin { api(compose.material) api(compose.ui) } Syer10 Accompanist Syer10/accompanist/build.gradle.kts Compose: ‘Challenges’
114. plugins { kotlin("multiplatform") id("org.jetbrains.compose") version "1.0.0-alpha3" } kotlin { api(compose.material) api(compose.ui) } Syer10 Accompanist Syer10/accompanist/build.gradle.kts Compose: ‘Challenges’ ⚠ Not exported to Android
115. plugins {1 kotlin("multiplatform") id("org.jetbrains.compose") version “1.0.0-alpha3" id("com.android.library") }2 kotlin {a api(compose.material) api(compose.ui) }b Syer10 Accompanist Syer10/accompanist/build.gradle.kts Compose: ‘Challenges’
116. plugins {1 kotlin("multiplatform") id("org.jetbrains.compose") version “1.0.0-alpha3" id("com.android.library") }2 kotlin {a android {b publishLibraryVariants("release", “debug") }c jvm(“desktop") }d Syer10 Accompanist Syer10/accompanist/build.gradle.kts Compose: ‘Challenges’
117. plugins {1 kotlin("multiplatform") id("org.jetbrains.compose") version “1.0.0-alpha3" id("com.android.library") }2 kotlin {a android {b publishLibraryVariants("release", “debug") }c jvm(“desktop”)e sourceSets {f val commonMain by getting {g dependencies {h api(compose.material) api(compose.ui) }i }j val androidMain by getting val desktopMain by getting }d Syer10 Accompanist Syer10/accompanist/build.gradle.kts Compose: ‘Challenges’
118. plugins {1 kotlin("multiplatform") id("org.jetbrains.compose") version “1.0.0-alpha3" id("com.android.library") }2 kotlin {a android {b publishLibraryVariants("release", “debug") }c jvm(“desktop”)e sourceSets {f val commonMain by getting {g dependencies {h api(compose.material) api(compose.ui) }i }j val androidMain by getting val desktopMain by getting }d android { compileSdk = 31 sourceSets["main"].manifest.srcFile("src/androidMain/AndroidManifest.xml") defaultConfig { minSdk = 21 targetSdk = 31 } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } Syer10 Accompanist Syer10/accompanist/build.gradle.kts Compose: ‘Challenges’
119. plugins { kotlin("multiplatform") id("org.jetbrains.compose") version “1.0.0-alpha3" id("com.android.library") } kotlin { android { publishLibraryVariants("release", “debug") } jvm(“desktop") sourceSets { val commonMain by getting { dependencies { api(compose.material) api(compose.ui) } } val androidMain by getting val desktopMain by getting } android { compileSdk = 31 sourceSets["main"].manifest.srcFile("src/androidMain/AndroidManifest.xml") defaultConfig { minSdk = 21 targetSdk = 31 } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } Syer10 Accompanist Syer10/accompanist/build.gradle.kts Compose: ‘Challenges’ ✅ Supports Android and Desktop
120. Compose: Image Loading Coil-Compose Image loading library implemented in Kotlin (and using Coroutines) @cafonsomota
121. Compose: Image Loading Coil-Compose Image loading library implemented in Kotlin (and using Coroutines) Not all Compose libraries are supported on Desktop and Web… for now?
122. Not all Compose libraries are supported on Desktop and Web… for now? Compose: Image Loading Coil-Compose Image loading library implemented in Kotlin (and using Coroutines) Community to the rescue! 🚀
123. Compose: Image Loading Kamel Asynchronous media loading library for Android and Desktop Uses Ktor in the background Get it from: github.com/alialbaali/Kamel @cafonsomota
124. Compose: Image Loading val request = ImageRequest.Builder(LocalContext.current) .data(url) .crossfade(true) .build() val painter = rememberImagePainter(request) when (val resource = lazyPainterResource(url)) { is ImagePainter.Loading -> { AddImagePreviewLoading(modifier) } is ImagePainter.Success -> { Image( painter = painter, contentScale = ContentScale.Crop, contentDescription = "Image preview", modifier = modifier) } is ImagePainter.Failure -> { AddImagePreviewFailure(modifier) } Coil
125. Compose: Image Loading when (val resource = lazyPainterResource(url)) { is Resource.Loading -> { AddImagePreviewLoading(modifier) } is Resource.Success -> { KamelImage( resource = resource, contentScale = ContentScale.Crop, contentDescription = "Image preview", modifier = modifier, crossfade = true ) } is Resource.Failure -> { AddImagePreviewFailure(modifier) } Kamel
126. Compose: Resources Resources Imagine that you want to show an image @cafonsomota
127. Compose: Resources Resources Imagine that you want to show an image Hello world!
128. Compose: Resources Resources Imagine that you want to show an image Hello world! Image( painter = painterResource(id = R.drawable.ic_launcher), contentDescription = stringResource(id = R.string.app_name) )
129. Compose: Resources Resources Imagine that you want to show an image Implementation shared-ui/commonMain contains the expect implementation shared-ui/androidMain contains the xml fi les (vectors) and actual implementation shared-ui/desktopMain contains the images (png’s) and actual implementation @cafonsomota
130. @Composable public expect fun icAbout(): Painter @Composable public expect fun icHome(): Painter Resources: Images shared-ui/commonMain/Icons.kt Compose: Resources
131. @Composable public actual fun icAbout() = painterResource(R.drawable.ic_about) @Composable public actual fun icHome() = painterResource(R.drawable.ic_home) Resources: Images shared-ui/androidApp/Icons.kt Compose: Resources
132. @Composable public actual fun icAbout() = painterResource("images/ic_about.png") @Composable public actual fun icHome() = painterResource("images/ic_home.png") Resources: Images shared-ui/desktopApp/Icons.kt Compose: Resources
133. Compose: Resources Resources Imagine that you want to set a custom font @cafonsomota
134. Compose: Resources Resources Imagine that you want to set a custom font Hello world! Hello world!
135. Compose: Resources Resources Imagine that you want to set a custom font Hello world! Text( text = “Hello World!”, style = typography.h4 ) Hello world!
136. Compose: Resources Resources Imagine that you want to set a custom font Hello world! private val HollywoodHillsFontFamily = FontFamily( Font(R.font.sf_hollywood_hills) ) h4 = TextStyle( color = colorAccent, fontFamily = HollywoodHillsFontFamily, fontSize = fontSizeLarge ) Hello world!
137. Compose: Resources Resources Imagine that you want to set a custom font Implementation shared-ui/commonMain/resources contains the font fi les shared-ui/commonMain/platform de fi nes the expect function shared-ui/androidMain/platform de fi nes the actual function shared-ui/desktopMain/platform de fi nes the actual function @cafonsomota
138. @Composable expect fun Font( name: String, res: String ): Font Resources: Font shared-ui/commonMain/platform/PlatformFont.kt Compose: Resources
139. @Composable actual fun Font( name: String, res: String, ): Font { val context = LocalContext.current val id = context.resources.getIdentifier(res, "font", context.packageName) return Font(id) } Resources: Font shared-ui/androidMain/platform/PlatformFont.kt Compose: Resources
140. @Composable actual fun Font( name: String, res: String ): Font { androidx.compose.ui.text.platform.Font("font/$res.ttf") } shared-ui/desktopMain/platform/PlatformFont.kt Resources: Font Compose: Resources
141. Compose: Lifecycle, ViewModel, LiveData and Navigation PreCompose (by Tlaster) Lifecycle, ViewModel, LiveData and Navigation are Android components They now have been ported to Compose desktop Get it from: github.com/Tlaster/PreCompose
142. Compose: WebApp What about Web? @cafonsomota
143. Compose: WebApp What about Web? Is in an initial stage and the paradigm is di ff erent It’s focused on DOM rendering Only a set of components are available: Box, Button, Column, Row, Slider, Text @cafonsomota
144. Compose: WebApp Div({ style { position(Position.Relative) width(100.percent) height(400.px) flexGrow(1.0) marginBottom(10.px) } }) { Image(resource = image) } :webApp
145. Compose: WebApp @Composable fun Column(content: @Composable () -> Unit) { Div({ style { display(DisplayStyle.Flex) alignItems(AlignItems.Center) flexGrow(1.0) } }) { content() } } :webApp webApp/components/Column.kt
146. Compose: WebApp Sharing logic Works without any issue The generated JS fi le might be up to several MBs Sharing UI It’s going to be time consuming to share everything You’re going to need to create several components Most of the libraries don’t support it (yet) Nevertheless… it’s fun to see how long we’ll be able to go in a couple of months! @cafonsomota
147. Getting everything together
148. Status 🟢 Kotlin Multiplatform Mobile is stable-ish Can be used in production although part of it is in alpha/beta 🟢 Compose (Android) is stable Go on! It’s time to dive-in into declarative UI 🟡 Compose (Desktop) is alpha-ish 🔴 Compose (Web) is alpha 🟠 Documentation and samples 🟢 Community and support @cafonsomota
149. Resources
150. Jetpack Compose samples (Google) github.com/android/compose-samples Jetpack Compose samples (JetBrains) https://github.com/JetBrains/compose-jb/ Jetpack/JetBrains Compose Playground foso.github.io/Jetpack-Compose-Playground/ Jetpack Compose Internals Kotlin Slack Resources @cafonsomota
151. There’s one more thing?
152. SELECT YOUR LEVEL I just want to see the story. I want a lighter experience. Give me the full challenge! 👉 @cafonsomota
153. SELECT YOUR LEVEL I just want to see the story. I want a lighter experience. Give me the full challenge! 👉 @cafonsomota
154. Kotlin Multiplatform and Compose template Alicerce In Portuguese alicerce means foundation A Kotlin Multiplatform with Compose template Currently supports: Android and Desktop Contains an initial project con fi guration along with the libraries mentioned here Open to feedback and contributions! Alicerce
155. Photo by FarawayPictures on deviantART @cafonsomota IT JUST WORKS* (*RUNNING COMPOSE ON ANDROID, DESKTOP, AND THE WEB ALONG WITH KMP)