ViewModel

VM

Model

interface Command {
    fun executableProperty() 
    fun runningProperty()
    operator fun invoke()
}

class LoginViewModel {
    // username field
    var username: String
    fun usernameProperty(): StringProperty

    // password field
    var password: String
    val passwordProperty(): StringProperty

    // login button
    // commands can be disabled and can be long running
    fun loginCommand(): Command
}

View

Fragment

username

usernameProperty

get

set

usernameProperty.value