BottomSheetDialogFragment 内的 LazyColumn 滚动问题

Question

I use LazyColumn inside BottomSheetDialogFragment , but if to scroll LazyColumn list UP then Bottom Sheet Dialog scrolls instead of LazyColumn list. Seems like BottomSheetDialogFragment intercepts user touch input.

That's how it looks:

How to properly use LazyColumn inside BottomSheetDialogFragment ?

MyBottomSheetDialogFragment.kt:

class MyBottomSheetDialogFragment : BottomSheetDialogFragment() {
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        return ComposeView(requireContext()).apply {
            setContent {
                Column(horizontalAlignment = Alignment.CenterHorizontally) {
                    Text("Header", color = Color.Black)
                    LazyColumn(
                        Modifier
                            .weight(1f)
                            .fillMaxWidth()) {
                        items(100) {
                            Text("Item $it", Modifier.fillMaxWidth(), Color.Black)
                        }
                    }
                }
            }
        }
    }
}

And show it using this code:

MyBottomSheetDialogFragment().show(activity.supportFragmentManager, null)

When we used the XML RecyclerView list, to fix this issue we had to wrap the RecyclerView list with NestedScrollView like described here , but how to fix it with Jetpack Compose?

Answer 1

Since compose 1.2.0-beta01 problem can be solved by using rememberNestedScrollInteropConnection :

Modifier.nestedScroll(rememberNestedScrollInteropConnection())

In my case BottomSheetDialogFragment is standard View and it has ComposeView with id container . In onViewCreated I do:

binding.container.setContent {
    AppTheme {
        Surface(
            modifier = Modifier.nestedScroll(rememberNestedScrollInteropConnection())
        ) {
            LazyColumn {
                // ITEMS
            }
        }
    }
}

And now the list is scrolling in a correct way.

Answer 2

If you're using compose within the activity that launched the bottom sheet dialog fragment, you might be better off simply sticking with a purely compose implementation and leveraging the compose equivalent bottom sheet component: ModalBottomSheetLayout

https://developer.android.com/reference/kotlin/androidx/compose/material/package-summary#ModalBottomSheetLayout(kotlin.Function1,androidx.compose.ui.Modifier,androidx.compose.material.ModalBottomSheetState,androidx.compose.ui.graphics.Shape,androidx.compose.ui.unit.Dp,androidx.compose.ui.graphics.Color,androidx.compose.ui.graphics.Color,androidx.compose.ui.graphics.Color,kotlin.Function0)

Answer 3

You might give a try to this https://gist.github.com/chrisbanes/053189c31302269656c1979edf418310 .

This is a workaround for https://issuetracker.google.com/issues/174348612 , which means that nested scrolling layouts in Compose do not work as nested scrolling children in the view system.

Sample usage in your case:

class MyBottomSheetDialogFragment : BottomSheetDialogFragment() {
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        return ComposeView(requireContext()).apply {
            setContent {
                Surface(
                    modifier = Modifier.nestedScroll(rememberViewInteropNestedScrollConnection())
                ){
                    LazyColumn(
                        Modifier
                            .weight(1f)
                            .fillMaxWidth()) {
                        items(100) {
                            Text("Item $it", Modifier.fillMaxWidth(), Color.Black)
                        }
                    }
                }
            }
        }
    }
}