android kotlin - EditText hide keyboard after enter

MainActivity.kt

package com.example.jetpack

import android.app.Activity
import android.content.Context.INPUT_METHOD_SERVICE
import android.os.Bundle
import android.view.KeyEvent
import android.view.View
import android.view.inputmethod.InputMethodManager
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_main.*


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

        // initialize a new key listener instance
        val keyListener = View.OnKeyListener { p0, p1, p2 ->
             if(p2.action == KeyEvent.ACTION_DOWN && p1 == KeyEvent.KEYCODE_ENTER){
                 // perform action on enter key press
                 textView.text = "Enter Key Pressed \n\n${editText.text}"

                 // hide soft keyboard programmatically on enter key press
                 hideSoftKeyboard()

                 // optionally clear focus and hide cursor from edit text
                 editText.clearFocus()
                 editText.isCursorVisible = false

                 // optional, set focus on root constraint layout
                 constraintLayout.isFocusable = true

                 true
            }else{
                 false
             }
        }


        // add key listener for edit text
        editText.setOnKeyListener(keyListener)
    }
}


// extension function to hide soft keyboard programmatically
fun Activity.hideSoftKeyboard(){
    (getSystemService(INPUT_METHOD_SERVICE) as InputMethodManager).apply {
        hideSoftInputFromWindow(currentFocus?.windowToken, 0)
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/constraintLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#EDEAE0"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/editText"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginEnd="8dp"
        android:inputType="text"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.12" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="12dp"
        android:fontFamily="sans-serif-condensed-medium"
        android:gravity="center"
        android:padding="8dp"
        android:textColor="#4F42B5"
        android:textSize="25sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/editText"
        tools:text="TextView" />

</androidx.constraintlayout.widget.ConstraintLayout>