Jetpack Compose is a new UI toolkit for Android, utilizing Kotlin and a declarative style to create UIs as functions rather than objects. It requires specific versions of Android Studio, the Android Gradle plugin, and Kotlin, along with certain dependencies to operate correctly. Resources and sample states for Jetpack Compose are available, indicating ongoing development and community interest.

1. Jetpack Compose
#KotlinEverywhere Android Development
Lutas Lin

2. What is Jetpack Compose?
• Is a Kotlin Compiler Plugin
• Is a new UI Toolkit
• Declarative UI
• Unbundle from OS
• Pre-Alpha

5. Declarative UI
Flutter Swift UI

6. Compose Hello World
@Composable
fun Hello() {
MaterialTheme {
Text(text = "Hello")
}
}

7. UI as Function
• View / Xml -> UI as Object
• Compose -> UI as Function

8. UI = f(s)

9. UI = f(s)
Composable function
State

10. How to use Jetpack
Compose?
• https://adambennett.dev/2019/10/jetpack-compose-now-on-maven/
• Android Studio Version >= 3.5.1
// Use Jvm 1.8
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = "1.8"
}
// Kotlin Reflect
implementation “org.jetbrains.kotlin:kotlin-reflect"
// Compose
kapt "androidx.compose:compose-compiler:0.1.0-dev01"
implementation "androidx.compose:compose-runtime:0.1.0-dev02"
// Compose UI
implementation "androidx.ui:ui-core:0.1.0-dev02"
implementation "androidx.ui:ui-layout:0.1.0-dev02"
implementation "androidx.ui:ui-material:0.1.0-dev01"

11. But…Something Broken?
• @Model observing失效了了！！！
Compose requires:
• An unreleased version of the Android Gradle Plugin
• An unreleased version of Android Studio
• An unreleased EAP version of Kotlin
• Build via AOSP
• https://engineering.q42.nl/try-jetpack-compose-today/

12. Sample

14. State
• https://youtu.be/VsStyq4Lzxo?t=1541

15. What Next?
• Kotlin/Compose vs Dart/Flutter ?
• What’s new in Jetpack Compose (https://
developer.android.com/dev-summit/schedule/day1)