Kotling Compose Equalizer setup

glims_compose_equalizer.kt

@Composable
fun EqualizerUI(equalizer: Equalizer) {
    val bandCount = equalizer.numberOfBands.toInt()
    val bandLevels = remember { mutableStateListOf<Short>() }

    LaunchedEffect(Unit) {
        bandLevels.clear()
        repeat(bandCount) {
            bandLevels.add(equalizer.getBandLevel(it.toShort()))
        }
    }

    Column(
        modifier = Modifier
            .fillMaxSize()
            .padding(16.dp),
        verticalArrangement = Arrangement.spacedBy(24.dp)
    ) {
        Text("Equalizer", style = MaterialTheme.typography.headlineMedium)

        repeat(bandCount) { band ->
            val bandLabel = "${equalizer.getCenterFreq(band.toShort()) / 1000} Hz"
            val min = equalizer.bandLevelRange[0]
            val max = equalizer.bandLevelRange[1]

            Column {
                Text(bandLabel)
                Slider(
                    value = bandLevels[band].toFloat(),
                    valueRange = min.toFloat()..max.toFloat(),
                    onValueChange = {
                        bandLevels[band] = it.toInt().toShort()
                        equalizer.setBandLevel(band.toShort(), it.toInt().toShort())
                    }
                )
            }
        }

        val presets = (0 until equalizer.numberOfPresets).map {
            equalizer.getPresetName(it.toShort())
        }

        var selectedPreset by remember { mutableStateOf("") }

        DropdownMenuBox(
            presets = presets,
            onPresetSelected = {
                val index = presets.indexOf(it)
                if (index >= 0) {
                    equalizer.usePreset(index.toShort())
                    selectedPreset = it
                }
            },
            selected = selectedPreset
        )
    }
}

glims_equalizer_fragment.kt

@AndroidEntryPoint
class EqualizerFragment : Fragment() {

    private var equalizer: Equalizer? = null
    private var audioSessionId: Int = 0

    private var _binding: FragmentEqualizerBinding? = null
    private val binding get() = _binding!!

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = FragmentEqualizerBinding.inflate(inflater, container, false)
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        // Get audio session ID from ExoPlayer (e.g., set in your player setup)
        val player = (requireActivity() as YourPlayerHolderActivity).exoPlayer
        audioSessionId = player.audioSessionId

        equalizer = Equalizer(0, audioSessionId).apply {
            enabled = true
        }

        binding.composeView.setContent {
            MaterialTheme {
                EqualizerUI(equalizer!!)
            }
        }
    }

    override fun onDestroyView() {
        super.onDestroyView()
        equalizer?.release()
        _binding = null
    }
}

glims_equalizer_view.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/equalizer_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.compose.ui.platform.ComposeView
        android:id="@+id/compose_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</FrameLayout>