MVP to MVVM: New Data Observer implementation

NewDataObserverImpl.kt

class MainPresenter(val service: GithubService) {
    .
    .
    val progressVisibilityObserver = DataObserver<Int>()

    private fun onSearchResultReceived(apiResponse: ApiResponse?) {
        .
        .
        progressVisibilityObserver.value = 0
        
    }

}

class MainActivity : AppCompatActivity() {
    .
    .
    val presenter: MainPresenter by currentScope.inject()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        .
        .
        presenter.progressVisibilityObserver.observe {
            when(it) {
                0 -> progress_circular.hide()
                1 -> progress_circular.show()
            }
        }
        
    }

}