AppServiceLocator.kt

class AppServiceLocator : ServiceLocator {
    private val calculadorUseCase: CalculadorUseCase by lazy {
        CalculadorUseCaseImpl()
    }
    private val evaluadorUseCase: EvaluadorUseCase by lazy {
        EvaluadorUseCaseImpl(validadorUseCase, evaluadorExpresionUseCase)
    }
    private val evaluadorExpresionUseCase: EvaluadorExpresionUseCase by lazy {
        EvaluadorExpresionUseCaseImpl(calculadorUseCase)
    }
    private val validadorUseCase: ValidadorUseCase by lazy {
        ValidadorUseCaseImpl()
    }
    override val mainViewModelFactory: MainViewModelFactory by lazy {
        MainViewModelFactory(evaluadorUseCase)
    }
}

CalculadoraApplication.kt

class CalculadoraApplication : Application() , ServiceLocatorProvider {
    override val serviceLocator: ServiceLocator by lazy { AppServiceLocator() }
}

ServiceLocator.kt

interface ServiceLocator {
    val mainViewModelFactory : MainViewModelFactory
}

ServiceLocatorActivity.kt

interface ServiceLocatorActivity : ServiceLocatorProvider {
    val self: Activity

    override val serviceLocator: ServiceLocator
        get() = (self.application as? ServiceLocatorProvider)?.serviceLocator
            ?: throw IllegalStateException("Application must implement ServiceLocatorProvider in order to provide global service locator, or implement this property to provide your own ServiceLocator")
}

ServiceLocatorProvider.kt

interface ServiceLocatorProvider {
    val serviceLocator: ServiceLocator
}