Lifecycle Compose

Compose Multiplatform wiring for lifecycle: drives LifecycleSubscribable.subscribe / unsubscribe from the current Compose host on Android, iOS, and macOS.

Installing

This library is available on Maven Central. You can import Kaluga Lifecycle Compose as follows:

repositories {
    // ...
    mavenCentral()
}
// ...
dependencies {
    // ...
    implementation("com.splendo.kaluga:lifecycle-compose:$kalugaVersion")
}

Usage

Check out the full documentation

Call AttachToCompose() on any LifecycleSubscribable inside a composition. Each platform actual dispatches based on the concrete subtype:

  • Android — ActivityLifecycleSubscribable subscribes with the Activity from LocalContext and the LifecycleOwner from LocalLifecycleOwner.
  • iOS — ViewControllerLifecycleSubscribable subscribes with LocalUIViewController.current.
  • macOS — WindowLifecycleSubscribable subscribes with the NSWindow exposed via this module’s LocalNSWindow composition local.

Any subscribable whose subtype isn’t recognised on the current platform is a no-op, so a single common-source builder can be safely attached on every target.

@Composable
fun SomeScreen(builder: SomeBuilder) { // implements one of the LifecycleSubscribable subtypes
    builder.AttachToCompose()
    // ...
}

LifecycleViewModel

LifecycleViewModel is an optional androidx.lifecycle.ViewModel base class that holds a list of LifecycleSubscribables. The screen-side composable calls AttachToCompose() on the ViewModel and all of them get wired in one call:

class SomeViewModel(builder: SomeBuilder) : LifecycleViewModel(subscribables = listOf(builder))

@Composable
fun SomeScreen() {
    val vm = viewModel<SomeViewModel>().AttachToCompose()
    // ...
}

Extending LifecycleViewModel is not required — any ViewModel can hold a subscribable and call field.AttachToCompose() manually.

macOS host setup

Compose Multiplatform exposes WindowScope.window as a receiver but ships no built-in LocalNSWindow. Install one at the host’s Window { … } entry point so subscribables further down the tree can read it:

Window(title = "App") {
    ProvideNSWindow {
        AppRootScreen()
    }
}

WindowLifecycleSubscribable.AttachToCompose() silently no-ops when LocalNSWindow is not installed.