SearchView from ArrayList kotlin

Output:

1/  Modify activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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/main"
    android:layout_margin="16dp"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


    <SearchView
        android:id="@+id/searchViewId"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:queryHint="Search"
        android:background="@color/white"
        style="@style/TextAppearance.Material3.SearchView"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ListView
        android:layout_marginTop="8dp"
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"
        android:layout_below="@+id/searchViewId"
        app:layout_constraintTop_toBottomOf="@+id/searchViewId"/>


</RelativeLayout>

2/  Modify MainActivity.kt

package com.zissofworks.searchviewfromarraylistkotlin

import android.os.Bundle
import android.widget.ArrayAdapter
import android.widget.ListView
import android.widget.SearchView
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat


class MainActivity : AppCompatActivity() {
    lateinit var listView: ListView
    lateinit var search_bar: SearchView
    lateinit var adapter: ArrayAdapter<String>
    val countryList: ArrayList<String> = ArrayList()


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }

        listView = findViewById(R.id.listView)
        search_bar = findViewById(R.id.searchViewId)

        countryList.add("Argentina")
        countryList.add("Qatar")
        countryList.add("Kuwait")
        countryList.add("Bangladesh")
        countryList.add("Saudi arabia")
        countryList.add("Baharain")
        countryList.add("Pakistan")
        countryList.add("Nepal")

        adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, countryList)
        listView.adapter = adapter

        search_bar.setOnQueryTextListener(object : SearchView.OnQueryTextListener{
            override fun onQueryTextSubmit(query: String?): Boolean {
                adapter.filter.filter(query)
                return true
            }

            override fun onQueryTextChange(query: String?): Boolean {
                adapter.filter.filter(query)
                return true
            }

        })

    }
}