Android Jetpack Compose – Manage Audio Focus

Audio focus is important to manage while building an application that plays an audio file within the application. With the help of this, we can again play the audio file from where it was paused originally. In this article, we will take a look at How to manage audio focus in android applications using Jetpack Compose. A sample video is given below to get an idea about what we are going to do in this article.

Step by Step Implementation

Step 1: Create a New Project in Android Studio

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. While choosing the template, select Empty Compose Activity. If you do not find this template, try upgrading the Android Studio to the latest version. We demonstrated the application in Kotlin, so make sure you select Kotlin as the primary language while creating a New Project.

Step 2: Adding a new color to the Color.kt file

Navigate to app > java > your app’s package name > ui.theme > Color.kt file and add the below code to it.

Kotlin

package com.example.newcanaryproject.ui.theme

import androidx.compose.ui.graphics.Color

val Purple200 = Color(0xFF0F9D58)
val Purple500 = Color(0xFF0F9D58)
val Purple700 = Color(0xFF3700B3)
val Teal200 = Color(0xFF03DAC5)

// on below line we are adding different colors
val greenColor = Color(0xFF0F9D58)

Step 3: Working with the MainActivity.kt file

Go to the MainActivity.kt file and refer to the following code. Below is the code for the MainActivity.kt file. Comments are added inside the code to understand the code in more detail.

Kotlin

package com.example.testproject

import android.annotation.SuppressLint
import android.content.Context
import android.media.AudioAttributes
import android.media.AudioFocusRequest
import android.media.AudioManager
import android.media.AudioManager.OnAudioFocusChangeListener
import android.media.MediaPlayer
import android.os.Build
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.annotation.RequiresApi
import androidx.compose.foundation.layout.*
import androidx.compose.material.*
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp
import com.example.testproject.ui.theme.TestProjectTheme
import com.example.testproject.ui.theme.greenColor
import java.io.IOException

class MainActivity : ComponentActivity() {

    // media player instance to playback
    // the media file from the raw folder
    var mediaPlayer: MediaPlayer? = null

    // Audio manager instance to manage or
    // handle the audio interruptions
    var audioManager: AudioManager? = null

    // Audio attributes instance to set the playback
    // attributes for the media player instance
    // these attributes specify what type of media is
    // to be played and used to callback the audioFocusChangeListener
    var playbackAttributes: AudioAttributes? = null

    // media player is handled according to the
    // change in the focus which Android system grants for
    var audioFocusChangeListener =
        OnAudioFocusChangeListener { focusChange ->
            if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
                mediaPlayer!!.start()
            } else if (focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT) {
                mediaPlayer!!.pause()
                mediaPlayer!!.seekTo(0)
            } else if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {
                mediaPlayer!!.release()
            }
        }
    @RequiresApi(Build.VERSION_CODES.O)
    @SuppressLint("UnusedMaterialScaffoldPaddingParameter")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // get the audio system service for
        // the audioManager instance
        audioManager = getSystemService(AUDIO_SERVICE) as AudioManager

        // initiate the audio playback attributes
        playbackAttributes = AudioAttributes.Builder()
            .setUsage(AudioAttributes.USAGE_GAME)
            .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
            .build()

        // set the playback attributes for the focus requester

        // set the playback attributes for the focus requester
        val focusRequest = AudioFocusRequest.Builder(AudioManager.AUDIOFOCUS_GAIN)
            .setAudioAttributes(playbackAttributes!!)
            .setAcceptsDelayedFocusGain(true)
            .setOnAudioFocusChangeListener(audioFocusChangeListener)
            .build()


        // request the audio focus and
        // store it in the int variable
        val audioFocusRequest = audioManager!!.requestAudioFocus(focusRequest)

        // initiate the media player instance with
        // the media file from the raw folder
        mediaPlayer = MediaPlayer.create(getApplicationContext(), R.raw.music);


        setContent {
            TestProjectTheme {
                // on below line we are specifying background
                // color for our application
                Surface(
                    // on below line we are specifying modifier
                    // and color for our app
                    modifier = Modifier.fillMaxSize(), color = MaterialTheme.colors.background
                ) {

                    // on the below line we are specifying
                    // the theme as the scaffold.
                    Scaffold(

                        // in scaffold we are specifying the top bar.
                        topBar = {

                            // inside top bar we are specifying
                            // background color.
                            TopAppBar(backgroundColor = greenColor,

                                // along with that we are specifying
                                // title for our top bar.
                                title = {

                                    // in the top bar we are specifying
                                    // title as a text
                                    Text(
                                        // on below line we are specifying
                                        // text to display in top app bar.
                                        text = "GFG",

                                        // on below line we are specifying
                                        // modifier to fill max width.
                                        modifier = Modifier.fillMaxWidth(),

                                        // on below line we are specifying
                                        // text alignment.
                                        textAlign = TextAlign.Center,

                                        // on below line we are specifying
                                        // color for our text.
                                        color = Color.White
                                    )
                                })
                        }) {
                        // on below line we are calling our method to display UI
                        audioController(LocalContext.current,mediaPlayer,audioFocusRequest)
                    }
                }
            }

        }
    }
}

@Composable
fun audioController(
    context: Context,
    mediaPlayer: MediaPlayer?,
    audioFocusRequest: Int
) {

    // on below line we are creating a column,
    Column(
        // on below line we are adding
        // a modifier to it,
        modifier = Modifier
            .fillMaxSize()
            // on below line we are adding a padding.
            .padding(all = 30.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center,
    ) {
        // on below line we are adding a text for heading.
        Text(
            // on below line we are specifying text
            text = "Audio Focus Manager in Android",
            // on below line we are specifying text color,
            // font size and font weight
            color = greenColor, fontSize = 20.sp, fontWeight = FontWeight.Bold
        )

        // on below line adding a spacer.
        Spacer(modifier = Modifier.height(10.dp))

        // on below line creating a button.
        Button(onClick = {
            mediaPlayer!!.stop()

            try {
                // if the media-player is stopped then
                // it should be again prepared for
                // next instance of play
                mediaPlayer.prepare()
            } catch (e: IOException) {
                e.printStackTrace()
            }
        }, modifier = Modifier.width(300.dp)) {
            Text(text = "Stop", color = Color.White)
        }

        // on below line creating a spacer.
        Spacer(modifier = Modifier.height(10.dp))

        // on below line creating a button.
        Button(onClick = {
            mediaPlayer!!.pause()
        }, modifier = Modifier.width(300.dp)) {
            Text(text = "Pause", color = Color.White)
        }

        // on below line creating a spacer.
        Spacer(modifier =  Modifier.height(10.dp))

        Button(onClick = {
            // on below line we are starting our media player.
            if (audioFocusRequest == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
                mediaPlayer!!.start();
            }
        }, modifier = Modifier.width(300.dp)) {
            Text(text = "Play", color = Color.White)
        }

    }
}

Now run your application to see the output of it. 

Output: