Back press handler in ModalBottomSheet in Compose M3 1.1

The new M3 1.1 compose brings the ModalBottomSheet, however a BackHandler doesn't work when it is visible. How can this be implemented? I want a backpress to close the app, and not the modalsheet.

This is a bug in ModalBottomSheet, and even though Google marked it as fixed on Oct 31, 2023 and released it, the issue still occurs on Material3 1.2.0.

I have found a workaround though. It consists in intercepting the key event, doing the same checks that ModalBottomSheetWindow.dispatchKeyEvent would do, and then delegating that to the OnBackPressedDispatcherOwner manually.

@Composable
fun ModalBottomSheetWithBackHandling(
    onDismissRequest: () -> Unit,
    modifier: Modifier = Modifier,
    sheetState: SheetState = rememberModalBottomSheetState(),
    properties: ModalBottomSheetProperties = ModalBottomSheetDefaults.properties(),
    content: @Composable ColumnScope.() -> Unit,
) {
    val scope = rememberCoroutineScope()

    BackHandler(enabled = sheetState.targetValue != SheetValue.Hidden) {
        // Always catch back here, but only let it dismiss if shouldDismissOnBackPress.
        // If not, it will have no effect.
        if (properties.shouldDismissOnBackPress) {
            scope.launch { sheetState.hide() }.invokeOnCompletion {
                if (!sheetState.isVisible) {
                    onDismissRequest()
                }
            }
        }
    }

    val requester = remember { FocusRequester() }
    val backPressedDispatcherOwner = LocalOnBackPressedDispatcherOwner.current

    ModalBottomSheet(
        onDismissRequest = onDismissRequest,
        modifier = modifier
            .focusRequester(requester)
            .focusable()
            .onPreviewKeyEvent {
                if (it.key == Key.Back && it.type == KeyEventType.KeyUp && !it.nativeKeyEvent.isCanceled) {
                    backPressedDispatcherOwner?.onBackPressedDispatcher?.onBackPressed()
                    return@onPreviewKeyEvent true
                }
                return@onPreviewKeyEvent false
            },
        properties = ModalBottomSheetDefaults.properties(
            securePolicy = properties.securePolicy,
            isFocusable = properties.isFocusable,
            // Set false otherwise the onPreviewKeyEvent doesn't work at all.
            // The functionality of shouldDismissOnBackPress is achieved by the BackHandler.
            shouldDismissOnBackPress = false,
        ),
        content = content,
    )

    LaunchedEffect(Unit) {
        requester.requestFocus()
    }
}