How can I change the visibility of an xml object in ViewModel?

I have a question about how the visibility of an object in the ViewModel will change.

I expose my case: I have a login interface that has two Edittext and two buttons, a button and an Edittext are invisible by default, and I want to press the button that is visible to make the first Edittext and the button invisible that I have pressed and make visible the second button and the second Edittext. And here comes the problem, all this would know to do in the Activity, but I need to do it in ViewModel and I have no idea how to access the xml components from there.

I know all this is messy so I went to send the classes and if someone could tell me how to do this I would appreciate it. Thanks.

Login XML:

<data>
    <variable
        name="viewModel"
        type="com.quobis.sippo.ecco.viewmodel.LoginViewModel"/>
</data>
<android.support.constraint.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="LoginUser">

    <ImageView
        android:layout_width="250dp"
        android:layout_height="200dp"
        android:src="@drawable/logom"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.2"
    />


    <EditText
        android:id="@+id/usr"
        android:layout_width="200dp"
        android:layout_height="50dp"
        android:hint="@string/hint_user"
        android:textSize="18sp"
        android:textColorPrimary="@color/colorLetterLogin"
        android:backgroundTint="@color/colorBackButtLogin"
        android:elevation="20dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginLeft="60dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.6"
        app:addTextChangedListener="@{viewModel.emailTextWatcher}"
    />

    <Button
        android:id="@+id/btn_usr"
        android:layout_width="55dp"
        android:layout_height="50dp"
        android:background="@color/colorBackButtLogin"
        android:drawableBottom="@drawable/ic_keyboard_arrow_right"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginLeft="260dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.6"
        android:onClick="@{viewModel::onUserClicked}"
    />

    <EditText
        android:id="@+id/pass"
        android:layout_width="200dp"
        android:layout_height="50dp"
        android:hint="@string/hint_pass"
        android:textSize="18sp"
        android:shape="rectangle"
        android:inputType="textPassword"
        android:textColorPrimary="@color/colorLetterLogin"
        android:backgroundTint="@color/colorBackButtLogin"
        android:elevation="20dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginLeft="60dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.6"
        android:visibility="invisible"
        android:onClick="@{viewModel::onLoginClicked}"
        />

    <Button
        android:id="@+id/btn_pass"
        android:layout_width="55dp"
        android:layout_height="50dp"
        android:background="@color/colorBackButtLogin"
        android:drawableBottom="@drawable/ic_keyboard_arrow_right"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginLeft="260dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.6"
        android:visibility="invisible"
        />

    <Spinner
        android:id="@+id/spinner_usr"
        android:layout_width="120dp"
        android:layout_height="40dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginLeft="40dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.85"
    />
</android.support.constraint.ConstraintLayout>

ViewModel:

private val user: UserModel
var userp ="jorge "


init {
    this.user= UserModel(email = "")
}


fun emailTextWatcher(): TextWatcher {
    return object : TextWatcher {
        override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
            user.setEmail(s.toString())
        }

        override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {

        }


        override fun afterTextChanged(s: Editable) {

        }
    }

}

fun onUserClicked(v: View) {


}

fun onLoginClicked(v:View) {
    if (user.getEmail() == userp)
        listener.onSucces("Correcto")
    else
        listener.onError("Fallo")
}

Note: the method to change visibility would be onUserClicked.

Main activity:

lateinit var binding: ActivityLoginUserBinding

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    binding = DataBindingUtil.setContentView(this, R.layout.activity_login_user)
    binding.viewModel = ViewModelProviders.of(this, LoginViewModelFactory(this)).get(LoginViewModel::class.java)


    var languages = arrayOf("English", "Español", "Galego")
    val spinner = binding.spinnerUsr
    if (spinner != null) {
        val arrayAdapter = ArrayAdapter(this, R.layout.spinner_item, languages)
        spinner.adapter = arrayAdapter
    }

}


override fun onSucces(message: String) {
    Toast.makeText(this,"Login bueno", Toast.LENGTH_SHORT).show()
}

@SuppressLint("ResourceAsColor")
override fun onError(message: String) {
    binding.btnUsr
    btn_usr.setBackgroundColor(R.color.colorFailLogin)
}