CMP Bottom Bar is a Compose Multiplatform library containing a shared bottom-bar model and several visual styles. It targets Android, iOS, desktop, and WebAssembly.

Style modules depend on coreBottomBar; the demo app brings the styles together.

The development API keeps immutable item configuration separate from composable state:

• BottomBarItem contains only visuals shared by selectable items.
• BottomBarInteraction defines whether an item is enabled and whether selection should select, toggle, or remain unchanged.
• BottomBarClickListener<T> and BottomBarHoverListener<T> provide typed callbacks without unsafe casts or empty listener objects.
• Selection indexes and selected state are owned by the rendering composable, not stored in item models.
• Style-specific configuration, such as Basic bar additional items and hover text styling, lives in its corresponding style module.

This API is a breaking change intended for the next 0.5.x release line.

The Basic style exposes state explicitly and supports horizontal or vertical placement:

val state = rememberBasicBarState(initialSelectedIndex = 0)

BasicBottomBar(
    items = items,
    state = state,
    config = BasicBarConfig(position = BasicBarPosition.HorizontalBottom),
) { item, index ->
    // `index` is null for an optional start or end action.
}

BasicBarState.select(null) clears selection. Item interaction modes are respected, including toggle and non-selecting actions. Empty item lists render safely.

The currently configured Maven Central artifacts are:

implementation("io.github.mejdi14:cmp-bottombar-core:0.4.3")
implementation("io.github.mejdi14:cmp-bottombar-basic:0.4.3")
implementation("io.github.mejdi14:cmp-bottombar-tinyGlide:0.4.3")
implementation("io.github.mejdi14:cmp-bottombar-aztopia:0.4.3")

expandableBottomBar and gooeyBottomBar are included as local experimental modules and are not currently configured for publication.

The development toolchain currently uses:

• Gradle 8.14.5
• Kotlin 2.4.10
• Compose Multiplatform 1.11.1
• Android Gradle Plugin 8.13.2
• Android compile/target SDK 36

Use JDK 17 or 21, then run:

./gradlew :composeApp:assembleDebug
./gradlew :composeApp:run
./gradlew :composeApp:wasmJsBrowserDevelopmentRun

On macOS, open iosApp/iosApp.xcodeproj to run the iOS demo.

Supported Apple targets are iOS ARM64 devices and Apple Silicon simulators. The obsolete Apple x86_64 target was removed because current Compose Multiplatform releases no longer publish it.

Compose Multiplatform 1.12 requires API 37 and the AGP 9 Android-KMP architecture. That upgrade is intentionally deferred until the Android application can be extracted from the shared multiplatform module.

Publishing is handled by .github/workflows/publish.yml. Maven Central credentials and the GPG private key must remain in GitHub Actions secrets; they must never be added to gradle.properties or committed files.

Licensed under the Apache License 2.0. See LICENSE.