Single-Activity: Create Login Credentials (Simple-Stack)

create-login-credentials-fragment-simple-stack.kt

class CreateLoginCredentialsFragment : KeyedFragment(R.layout.create_login_credentials_fragment) {
    private val viewModel by lazy { lookup<RegistrationViewModel>() }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        val binding = CreateLoginCredentialsFragmentBinding.bind(view)
        // ...
    }
}

create-login-credentials-key-simple-stack.kt

@Parcelize
class CreateLoginCredentialsKey : DefaultFragmentKey(), ScopeKey.Child {
    override fun instantiateFragment(): Fragment = CreateLoginCredentialsFragment()

    override fun getParentScopes(): List<String> = listOf(ServiceProvider.REGISTRATION_TAG)
}

create-login-credentials-registration-viewmodel.kt

class RegistrationViewModel(
    private val authenticationManager: AuthenticationManager,
    private val backstack: Backstack
) : Bundleable, ScopedServices.Registered {
    // ...
}

main-activity.kt

class MainActivity : AppCompatActivity(), SimpleStateChanger.NavigationHandler {
    private lateinit var fragmentStateChanger: DefaultFragmentStateChanger

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

        val binding = MainActivityBinding.inflate(layoutInflater)
        setContentView(binding.root)

        fragmentStateChanger =
            DefaultFragmentStateChanger(supportFragmentManager, R.id.rootContainer)

        Navigator.configure()
            .setStateChanger(SimpleStateChanger(this))
            .setScopedServices(ServiceProvider())
            .setGlobalServices(
                GlobalServices.builder()
                    .add(AuthenticationManager)
                    .build()
            )
            .install(this, binding.rootContainer, LoginKey())
    }

    override fun onBackPressed() {
        if (!Navigator.onBackPressed(this)) {
            super.onBackPressed()
        }
    }

    override fun onNavigationEvent(stateChange: StateChange) {
        fragmentStateChanger.handleStateChange(stateChange)
    }
}

service-provider.kt

class ServiceProvider : DefaultServiceProvider() {
    companion object {
        const val REGISTRATION_TAG = "registration"
    }

    override fun bindServices(serviceBinder: ServiceBinder) {
        super.bindServices(serviceBinder)

        val scope = serviceBinder.scopeTag

        with(serviceBinder) {
            when (scope) {
                REGISTRATION_TAG -> {
                    add(RegistrationViewModel(lookup(), backstack))
                }
                else -> {
                }
            }
        }
    }
}