Trying to use ModalBottomSheetLayout: ``` val s...

# compose

[Udi Oshi]

Trying to use ModalBottomSheetLayout:

val state = rememberModalBottomSheetState(ModalBottomSheetValue.HalfExpanded)
    val scope = rememberCoroutineScope()

    ModalBottomSheetLayout(
        modifier = Modifier.fillMaxSize(),
        sheetState = state,
        sheetContent = {
            Box(modifier = Modifier
                .height(120.dp)
                .background(color = Color.Red)) {
                Text(text = "Half expanded")
            }
        }) {
        //  Full screen content
    }

and keep getting:

java.lang.IllegalArgumentException: The initial value must have an associated anchor.

What am I doing wrong? 🙏

[Csaba Szugyiczki]

Make sure your content has size
https://stackoverflow.com/a/68624825

[Udi Oshi]

content is ConstraintLayout where its modifier set as fillMaxSize, isn’t that enough?

[Csaba Szugyiczki]

should be

[Udi Oshi]

Tried adding default height of 1.dp to it with not luck, tried also to wrap the content with box with min height of 1.dp, nothing works.

[Udi Oshi]

val state = rememberModalBottomSheetState(ModalBottomSheetValue.HalfExpanded)
    val scope = rememberCoroutineScope()

    ModalBottomSheetLayout(
        modifier = Modifier.fillMaxSize(),
        sheetState = state,
        sheetContent = {
            Box(
                modifier = Modifier
                    .height(120.dp)
                    .defaultMinSize(minHeight = 1.dp)
                    .background(color = Color.Red)
            ) {
                Text(text = "Half expanded")
            }
        }) {
        //  Full screen content
        Box(
            modifier = Modifier
                .defaultMinSize(minHeight = 1.dp)
                .fillMaxSize()
        ) {
            Text(text = "Hello content")
        }

Cleanest and still crashes

[Csaba Szugyiczki]

is it crashing if you start from Hidden state?

[Udi Oshi]

Don’t know but I hidden is not option for my UX behavior

[Csaba Szugyiczki]

I understand. Just to try narrowing down the problem. I can see no issues with your code 🤷

[Udi Oshi]

Not crashing, but doesn’t show the content, even after removing .defaultMinSize(minHeight = 1.dp).
Text (hello content) isn’t showing

[Udi Oshi]

I understand why text is not showing (black over black color)
but the state is really shi**y workaround, will need to change state in some launched effects

[Udi Oshi]

Another weird thing:

LaunchedEffect(key1 = state, block = {
        if (state.currentValue == ModalBottomSheetValue.Hidden) {
            state.animateTo(ModalBottomSheetValue.HalfExpanded)
        }
    })

crashes it with same exception
🙅

[Csaba Szugyiczki]

what if you set the width of your sheetContent to .fillMaxWidth?

[Udi Oshi]

Still crashing

[Udi Oshi]

Thought maybe device to render some stuff so I’ve added delay:

LaunchedEffect(key1 = state, block = {
        if (state.currentValue == ModalBottomSheetValue.Hidden) {
            scope.launch {
                delay(2500)
                state.animateTo(ModalBottomSheetValue.HalfExpanded)
            }
        }
    })

same result. How many workarounds we need to use in order to show this component? 😂

[Csaba Szugyiczki]

something must be wrong with the content then

[Udi Oshi]

I’ll continue investiagte later, and update here. thanks anyway for your time and effort @Csaba Szugyiczki

[jossiwolf]

ModalBottomSheetLayout/ModalBottomSheetState can have three states/values: Hidden, HalfExpanded, Expanded. HalfExpanded is only included if the sheet content is taller than 50% of the ModalBottomSheetLayout. At 120dp, given that your layout fills the entire screen, you will only have a Hidden and Expanded state as the sheet content is smaller than 50% of the container. This means you are essentially telling ModalBottomSheetState to move to a value it doesn't know, hence the exception.

[Csaba Szugyiczki]

The exception message could be more specific in this case. Is there a way to tell in advance if the HalfExpanded state exists?

[jossiwolf]

Yes, we've recently made some changes that will allow us to specify a better message here. There's no way to know "in advance" (except if your container/sheet content bright ratio is static) as the ModalBottomSheetState gets created before the data used to calculate the anchors is available. We have an open issue about this but have other higher priority work items in the backlog.

[Csaba Szugyiczki]

Thank you for the update!

[jossiwolf]

Star https://issuetracker.google.com/191884670 for updates :)

[Udi Oshi]

Thank you very much for this detailed explanation Jossi.