Jetpack Compose Navigation3 - Destiination Nested sealed interface

1-nested_sealed_interface.kt

@Serializable
sealed interface AppDestination {
    val label: String
    @get:DrawableRes val iconRes: Int

    @Serializable
    data object Home : AppDestination {
        override val label = "Home"
        override val iconRes = R.drawable.ic_home
    }

    @Serializable
    data object Settings : AppDestination {
        override val label = "Settings"
        override val iconRes = R.drawable.ic_settings
    }

    @Serializable
    data class Detail(val id: String) : AppDestination {
        override val label = "Detail"
        override val iconRes = R.drawable.ic_detail
    }
}

2-navhost.kt

NavHost(navController = navController, startDestination = AppDestination.Home) {
    composable<AppDestination.Home> { HomeScreen() }
    composable<AppDestination.Settings> { SettingsScreen() }
    composable<AppDestination.Detail> { entry ->
        val dest = entry.toRoute<AppDestination.Detail>()
        DetailScreen(dest.id)
    }
}

Navigation3 時代の Destination 設計：sealed interface による型安全な実装パターンと使い分け
https://android.benigumo.com/20260304/navigation3-sealed-interface/