BackCompatHandler.kt

/**
 * See Also: BackHandler { onBack() }
 */
@Composable
fun BackCompatHandler(
    enabled: Boolean = true,
    onBack: () -> Unit = {}
) {
    val currentOnBack by rememberUpdatedState(onBack)
    val backCallback = remember {
        object : OnBackPressedCallback(enabled) {
            override fun handleOnBackPressed() {
                currentOnBack()
            }
        }
    }

    SideEffect {
        backCallback.isEnabled = enabled
    }

    val localOnBackPressedDispatcherOwner = LocalOnBackPressedDispatcherOwner.current
    val view = LocalView.current
    val lifecycleOwner = LocalLifecycleOwner.current
    val context = LocalContext.current
    val backPressedDispatcher =
        (((lifecycleOwner as? DialogFragment)
            ?: (view.ancestorFragments.filterIsInstance<DialogFragment>().firstOrNull()))
        ?.dialog as? ComponentDialog)?.onBackPressedDispatcher
        ?: localOnBackPressedDispatcherOwner?.onBackPressedDispatcher
        ?: ((lifecycleOwner as? ComponentActivity)
        ?: (lifecycleOwner as? Fragment)?.activity as? ComponentActivity
        ?: context as? ComponentActivity
        ?: context.activity as? ComponentActivity)?.onBackPressedDispatcher

    if (enabled) {
        backPressedDispatcher?.addCallback(lifecycleOwner, backCallback)
    }

    LaunchedEffect(enabled) {
        if (!enabled) { backCallback.remove() }
    }

    DisposableEffect(lifecycleOwner.lifecycle, backPressedDispatcher) {
        onDispose { backCallback.remove() }
    }
}