I am working on an immersive mode app that contains a CustomAlertDialog. I have done everything I could to keep the app in immersive mode after opening the Alert. I have found solutions that would work on Android 14 devices, but I have not found a solution for Android 8 device (API 26). On API 26 device after opening the dialog the navigation bar becomes visible and only disappears after closing the Dialog. All that I need is to have a button that keeps the navigation bar hidden when pressed and then opens up a container with options. I have tried using DropdownMenus or Popups, but nothing worked.

Bottom line: I would like to know if it is possible to create a fully immersive mode Android app with kotlin that would support API26+ and would contain dialogs that when opened don’t break the immersive mode.

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        hideSystemBars()
        setContent {
            FullScreenTheme {
                Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding ->
                    Greeting(
                        name = "Android",
                        modifier = Modifier.padding(innerPadding)
                    )
                }
            }
        }
    }

    override fun onWindowFocusChanged(hasFocus: Boolean) {
        super.onWindowFocusChanged(hasFocus)
        if (hasFocus) {
            hideSystemBars()
        }
    }

    override fun onResume() {
        super.onResume()
        hideSystemBars()
    }

    fun hideSystemBars() {
        WindowCompat.setDecorFitsSystemWindows(window, false)
        val controller = WindowInsetsControllerCompat(window, window.decorView)
        controller.hide(WindowInsetsCompat.Type.systemBars())
        controller.systemBarsBehavior = WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
    }
}

@Composable
fun Greeting(name: String, modifier: Modifier = Modifier) {
    var showDialog by remember { mutableStateOf(false) }
    val activity = LocalContext.current as? MainActivity

    Column(
        modifier = modifier
            .fillMaxSize()
            .padding(16.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center
    ) {
        Text(text = "Hello $name!")

        Spacer(modifier = Modifier.height(16.dp))

        Button(onClick = { showDialog = true }) {

            Text(text = "Open Dialog")
        }

        if (showDialog) {
            CustomAlertDialog(
                onDismissRequest = { showDialog = false },
                title = { Text(text = "Dialog Title") },
                text = { Text(text = "This is a simple dialog.") },
                confirmButton = {
                    Button(
                        onClick = { showDialog = false }
                    ) {
                        Text(text = "Confirm")
                    }
                },
                dismissButton = {
                    Button(
                        onClick = { showDialog = false }
                    ) {
                        Text(text = "Dismiss")
                    }
                },
                activity = activity
            )
        }
    }
}

@Composable
fun CustomAlertDialog(
    onDismissRequest: () -> Unit,
    title: @Composable () -> Unit,
    text: @Composable () -> Unit,
    confirmButton: @Composable () -> Unit,
    dismissButton: @Composable () -> Unit,
    activity: MainActivity?
) {
    SideEffect {
        activity?.hideSystemBars()
    }

    DisposableEffect(Unit) {
        activity?.hideSystemBars()
        onDispose { activity?.hideSystemBars() }
    }

    AlertDialog(
        onDismissRequest = onDismissRequest,
        title = title,
        text = text,
        confirmButton = confirmButton,
        dismissButton = dismissButton
    )
}