Partial AuthenticatorActivity for a custom UI

AuthenticatorActivity.kt

class AuthenticatorActivity : Activity(), AuthenticationHandler {
    companion object {
        private val TAG: String = this::class.java.simpleName
    }

    /**
     * The identityManager for this application
     */
    private val identityManager: IdentityManager by inject()

    /**
     * Called when the activity is starting. This is where most initialization should go: calling
     * setContentView(int) to inflate the activity's UI, initializing any view models, etc.
     */
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_authenticator)

        // We should be able to close this activity, in which case we go back
        // to the prior activity.
        authenticator_cancel_button.onClick { [email protected]() }

        // Hook up validator for email address and password.  In this case, we
        // do a minimal validation for the input as it will be checked by the
        // Amazon Cognito system as well.
        loginform_username.validate({ s -> isUsernameValid(s) }, "Valid email address required")

        // Now do the same for password.  We require a minimum length of 6 characters
        loginform_password.validate({ s -> isPasswordValid(s) }, "Minimum 6 characters required")

        // We only enable the login button when both the email address and password are both
        // valid.  To do this, we wire up an additional text listener on both to call the
        // checker
        loginform_username.afterTextChanged { checkLoginEnabled() }
        loginform_password.afterTextChanged { checkLoginEnabled() }

        // Wire up the form buttons
        loginform_signin_button.onClick { handleLogin() }
        loginform_signup_button.onClick { Log.d(TAG, "Sign-up not implemented") }
        loginform_forgotpassword_button.onClick { Log.d(TAG, "Forgot Password not implemented") }
    }

    /**
     * Checks the loginform_username and loginform_password.  If both of them are
     * valid, then enable the signin button
     */
    private fun checkLoginEnabled() {
        loginform_signin_button.isEnabled =
                isUsernameValid(loginform_username.getContent())
             && isPasswordValid(loginform_password.getContent())
    }

    /**
     * Checks to see if the username is valid
     */
    private fun isUsernameValid(s: String): Boolean = s.isValidEmail()

    /**
     * Checks to see if the password is valid
     */
    private fun isPasswordValid(s: String): Boolean = s.length >= 6
}