How to check whether a headset is plugged into an Android device using Kotlin?

This example demonstrates how to check whether a headset is plugged into an Android device using Kotlin.

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   tools:context=".MainActivity">
   <TextView
      android:id="@+id/text"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="70dp"
      android:background="#008080"
      android:padding="5dp"
      android:text="TutorialsPoint"
      android:textColor="#fff"
      android:textSize="24sp"
      android:textStyle="bold" />
   <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:text="Headphones connection status"
      android:textColor="@android:color/holo_purple"
      android:textSize="16sp"
      android:textStyle="bold" />
</RelativeLayout>

Step 3 − Add the following code to src/MainActivity.kt

import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
   var broadcastReceiver: BroadcastReceiver? = null
   var microphonePluggedIn = false
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      broadcastReceiver = object : BroadcastReceiver() {
         override fun onReceive(context: Context?, intent: Intent) {
            val action = intent.action
            val int: Int
            if (Intent.ACTION_HEADSET_PLUG == action) {
               int = intent.getIntExtra("state", -1)
               if (int == 0) {
                  microphonePluggedIn = false
                  Toast.makeText(applicationContext, "Headphones not plugged in", Toast.LENGTH_LONG).show()
               }
               if (int == 1) {
                  microphonePluggedIn = true
                  Toast.makeText(applicationContext, "Headphones plugged in", Toast.LENGTH_LONG).show()
               }
            }
         }
      }
      val receiverFilter = IntentFilter(Intent.ACTION_HEADSET_PLUG)
      registerReceiver(broadcastReceiver, receiverFilter)
   }
}

Step 4 − Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.example.q11">
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <vaction android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click the Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen