IssueTracker

Hia!

When changing a ModalBottomSheetLayout's sheetContent and then calling ModalBottomSheetState#show directly after (from an effect), the sheet will expand to the EXPANDED state. It looks like the anchors aren't calculated correctly. You can repro it with this code:

@OptIn(ExperimentalMaterialApi::class)
private enum class State(
    val content: @Composable ColumnScope.(sheetState: ModalBottomSheetState) -> Unit
) {
    ONE(
        { SheetContent(items = 10, "test", it) }
    ),
    TWO(
        { SheetContent(items = 50, "test two", it) }
    )
}

@Sampled
@Composable
@OptIn(ExperimentalMaterialApi::class)
fun ModalBottomSheetSample() {
    val state = rememberModalBottomSheetState(ModalBottomSheetValue.Hidden)
    var sheetContent by remember { mutableStateOf<State?>(null) }
    ModalBottomSheetLayout(
        sheetState = state,
        sheetContent = {
            if (sheetContent != null ) {
                sheetContent!!.content(this, state)
            } else {
                Box(Modifier.height(1.dp))
            }
        }
    ) {
        Column(
            modifier = Modifier.fillMaxSize().padding(16.dp),
            horizontalAlignment = Alignment.CenterHorizontally
        ) {
            Text("Rest of the UI")
            Spacer(Modifier.height(20.dp))
            Button(
                onClick = {
                    sheetContent = when (sheetContent) {
                        State.ONE -> State.TWO
                        State.TWO -> State.ONE
                        null -> State.ONE
                    }
                }
            ) {
                Text("Click to show sheet")
            }
        }
    }
}

@OptIn(ExperimentalMaterialApi::class)
@Composable
private fun SheetContent(items: Int, prefix: String, sheetState: ModalBottomSheetState) {
    val scope = rememberCoroutineScope()
    DisposableEffect(items, prefix) {
        scope.launch {
            sheetState.show()
        }
        onDispose {
            scope.launch { sheetState.hide() }
        }
    }
    LazyColumn {
        items(items) {
            ListItem(
                text = { Text("$prefix $it") },
                icon = {
                    Icon(
                        Icons.Default.Favorite,
                        contentDescription = "Localized description"
                    )
                }
            )
        }
    }
}

The sheet should go to the HALF_EXPANDED state instead. I attached a video of the behavior.

Is there any workaround that you can think of?