RxBinding 사용 후

UsingRxBinding.kt

class MainActivity : AppCompatActivity() {

    private val compositeDisposable = CompositeDisposable()

    @SuppressLint("CheckResult")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val nicknameInputField = findViewById<EditText>(R.id.nicknameInputField)
        val passwordInputField = findViewById<EditText>(R.id.passwordInputField)
        val okButton = findViewById<Button>(R.id.okButton)
       
        compositeDisposable.add(Observable.merge(nicknameInputField.textChanges(), passwordInputField.textChanges())
            .subscribe { text -> // 입력 내용에 따라 버튼색 변하게 하기
                if (nicknameInputField.length() >= 4 && passwordInputField.length() >= 4) {
                    okButton.setBackgroundColor(Color.BLUE)
                } else {
                    okButton.setBackgroundColor(Color.GRAY)
                }
            })

        compositeDisposable.add(okButton.clicks()
            .throttleFirst(1, TimeUnit.SECONDS) // 버튼 클릭에 쿨타임 걸기
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe {
                when {
                    nicknameInputField.length() < 4 -> Toast.makeText(this, "닉네임 4글자 이상!", Toast.LENGTH_SHORT).show()
                    passwordInputField.length() < 4 -> Toast.makeText(this, "패스워드 4글자 이상!", Toast.LENGTH_SHORT).show()
                    else -> {
                        nicknameInputField.setText("")
                        passwordInputField.setText("")
                        Toast.makeText(this, "OK!", Toast.LENGTH_SHORT).show()
                    }
                }
            }
        )
    }

    override fun onDestroy() {
        compositeDisposable.clear()
        super.onDestroy()
    }
}