CODEWITHSUNDEEP
androidkotlin
Rarity7-
Rarity7-

Reputation: 187

How to call function from object?

I can't call function of my class from object inside this class. How should i do this ?

 class LoginActivity: AppCompatActivity(){
    override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            setContentView(R.layout.activity_login)
        }

     private fun disableLoginButton(){
            button_login.isEnabled = false
     }

     private object textChangeListener: TextWatcher{

            override fun afterTextChanged(p0: Editable?) {
            }

            override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            }

            override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
                //Here i cannot call function
                disableLoginButton() // unresolved reference. 
            }

        }
    }

But when i call LoginActivity().disableLoginButton() instead disableLoginButton()it's visible, but fails with

NullPointerException

on login_button

Upvotes: 0

Views: 93

Answers (2)

Kalpesh Rupani
Kalpesh Rupani

Reputation: 1049

Try this :

    class LoginActivity: AppCompatActivity(){
        override fun onCreate(savedInstanceState: Bundle?) {
                super.onCreate(savedInstanceState)
                setContentView(R.layout.activity_login)

        editTextSample.addTextChangedListener(object : TextWatcher {

                override fun afterTextChanged(s: Editable) {}

                override fun beforeTextChanged(s: CharSequence, start: Int,
                                               count: Int, after: Int) {
                }

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

            }




        }

     private fun disableLoginButton(){
                button_login.isEnabled = false
         }

Upvotes: 2

Mohammed Aquib Azad
Mohammed Aquib Azad

Reputation: 634

EDIT: Doesn't work

From jetbrains team:

In Java and Kotlin, "inner" means "capturing the outer instance", where as "nested" means simply declared inside something else. Java's static classes are only nested, non-static nested classes are inner. In Kotlin you have to explicitly declare something as "inner" (we reversed the Java's convention). So, your object is not inner, btu only nested. And no named object can be inner, in fact: named objects are singletons, so the can not depend on any kind of outer instance.

Try specifying the object as inner:

private inner object textChangeListener: TextWatcher{

     override fun afterTextChanged(p0: Editable?) {
     }

    override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
     }

     override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int {
          //Here i cannot call function
           disableLoginButton() // unresolved reference. 
     }
}

This should allow you to access the outer scope.

Upvotes: 0

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