How are people handling permission flows with compose? Right now I'm creating methods on my activity like

ensureFineLocation

that handles the whole permission flow and then passing a reference to the function down through the composables. This seems like it will scale pretty badly though, both in that the activity has a lot of unrelated methods and I've got to pass a lot of free functions. Also, since

registerForActivityResult

is global state I'm not sure the right way to handle repeated calls. I'm currently using a MutableState like so

private val fineLocationStatus = MutableState<Boolean?>(null)
    private val requestFineLocationLauncher =
        registerForActivityResult(ActivityResultContracts.RequestPermission()) { isGranted ->
            fineLocationStatus.value = isGranted
        }

   private fun ensureFineLocation(): Boolean {
       val initialCached = fineLocationStatus.value
       if (initialCached != null) {
           if (!initialCached) showFineLocationMissingError()
           return initialCached
       }

       val permission = Manifest.permission.ACCESS_FINE_LOCATION

        if (checkSelfPermission(permission) == PackageManager.PERMISSION_GRANTED) return true

        if (shouldShowRequestPermissionRationale(permission)) {
            if (!fineLocationRationalePrompt()) {
                fineLocationDeniedMsg()
                return false
            }
        }

        requestFineLocationLauncher.launch(permission)

        val cached = fineLocationStatus.filterNotNull().first()
        if (!cached) fineLocationDeniedMsg()
        return cached
   }

This is a little racy if there are multiple calls before a value is cached. I'm also not sure the value should be cached, so I considered clearing the mutable state before returning. Then I think I'd need to protect

ensureFineLocation

with a mutex, though. I feel like there has to be a better solution. Is there a reason why

registerForActivityResult

uses a global callback instead of giving each request a different requestCode so that you can have a suspend fun like

launcher.awaitResult

?

How can I provide

@Composable

functions from a compiled aar? Specifically, ensuring that the consuming application has all the necessary compose dependencies and configurations to handle its presence. I want to compose the UI with Compose and then expose it via my API either as a Composable method or as a traditional view component. I’m having trouble finding documentation on this.

I'm having some trouble integrating Compose

1.0.0-beta08

into an existing application with Kotlin

1.5.10

and AGP

7.1.0-alpha02

. I'm getting the following error and I'm not sure how to further debug it. More details in :thread-please:

java.lang.NoSuchMethodError: No static method setContent$default(...)

Anyone out there with knowledge of how to use Calabash/Cucumber testing in combination with Compose?

Hey guys, I'm using compose

1.0.0-beta08

but Im not able to use modifiers... every extension is just red on the IDE does someone is having the same issue?

Having some issues with Espresso and Compose interoperability will post code examples in thread. Espresso seems unable to find Compose elements even if I'm trying to find them by text rather than ID:s. There is the ComposeTestRule class but I can't use that because it does not seems to support launching activities with custom intents? I'm setting the Compose layouts inside fragments

What’s the expected behavior for components that merge their semantics but have children with content descriptions? It seems like the content description just gets dropped in the merged tree. So e.g. if you have an image inside a clickable, the image’s content description is hidden when reading the merged semantics tree. This seems to work fine for accessibility – talkback will read the content description – but for UI tests, you have to pass

useUnmergedTree=true

to the node matcher, which seems unintuitive.

👋 Hey, I’m seeing some overlap between

MutableState<T>

and

MutableStateFlow<T>

, when should I use each?

Hello, is there a way to have SystemUI (aka. navbar and statusbar) displayed in the Android Studio preview?

Hi guys, I have a question about

nestedScroll

thing. So I have a

ModalBottomSheetLayout

and a vertically scrollable column within that bottom sheet.

ModalBottomSheetLayout

participates in the nested scrolling (please see

PreUpPostDownNestedScrollConnection

). As far, as I understand the logic,

ModalBottomSheetLayout

consumes entire scroll delta through the

onPreScroll

, so the actual scroll target (the child column) doesn't receive any delta at all. This results into the bottom sheet being dragged vertically instead of the column being scrolled. Any suggestions?

How to detect when the user rise one finger and left the other one in Jetpack compose ?

👋 I am refactoring part of our app to use Compose, and trying to reuse our MVI viewmodels which a property of

StateFlow

of different states. e.g.

sealed class MyState{
   object Loading…
   class ShowList(val list:List<String> ) …
   class Itemselected( val item:String)...
   class Error( val message:String )…
}

and then on the content I want to display something like

@Composable
    fun MyPage(viewModel: MyViewModel) {
        val state: MyState by viewModel.getStateFlow()
            .collectAsState(initial = MyState.Loading)
        Column {
            Header("Home")
            PageBody(state) 
        }
    }
@Composable
fun PageBody(state: ServiceHubHomeState) {
    when (state) {
        MyState.Loading -> Header("Loading")
        is MyState.ShowList ->
            ListHub(serviceItems = state.list) 
        is MyState.ItemSelected -> { // do something else
        }
    }
}

So now, when I use .collectAsState, everything works all-right, BUT, when I have already published a value of Showlist, and a list is rendered, if a new state comes, e.g ItemSelected of course the list is cleaned up. My question is, how do I keep the already rendered list between the next state transitions? I am sure I have to keep the state somewhere but cannot see it 😞

anyone had problems with clicking on content, when using

BottomDrawer

?

@Composable
fun Screen() = Scaffold {
    BottomDrawer(
        drawerContent = { DrawerContent() },
        content = { ScreenContent() },
    )
}

I have Swipeable switching between 3 states. Inside it there's a LazyColumn. What is the best way to initiate scroll to item 3 in that column once swipeable settles on a certain state? I imagine running LaunchedEffect, but at what point? Should I somehow store previousSwipeableState and check it against a new state and if they differ — fire away? But how to store previous state?

Does anyone know why after this code my list still filled {0,1,2}

var test = mutableStateOf<List<Int>>(emptyList())
/**
 I add some values to test {0,1,2}
**/
test = emptyList()

This message was deleted.

What is the cause for this crash? This happens when I click on a LazyColumn item to navigate to a Composable screen destination, it happens randomly..

I have a composable which consists of 2 parts: The upper part which should have it's height between wrapContent and 33% of the parent height, and a second part that should fill the remaining space, but also take space from the upper part if this second part is larger than the 67% of height left. If there's still more space needed it should turn into a vertical scroller. This is my current code but it's not working, how can I achieve something like my idea?

I have an

Image

which has

fillMaxSize()

and

contentScale = FillBounds

, but the painter is still drawn in center of the image, why is that? It seems that contentScale is completely ignored (example in the thread)

Basic question: I want a column half width against the right side of the view/parent. The fillMaxWidth(0.5f) is perfect for the width, but there is no offsetMaxWidth and the offset(x = ) expects dp. What is the simplest way to calc the offset or have it start in the middle? Thanks!

LazyListState

has

animateBy

which accepts an

AnimationSpec

and it also has

animateScrollToItem

which doesn't accept

AnimationSpec

and hardcodes it to

spring()

. Is this asymmetry on purpose? Or can I request this feature?

Hey all, I just ran into a weird issue with

LazyColumn

and I'm wondering if it's intended behavior. I am observing a

LiveData

as

State

and whenever it gets updated, the UI should update as expected. The weird thing though is that my

LazyColumn

won't update properly unless I use the

key

property in the

items

extension within the

LazyListScope

. Sample code in the thread

Bumping this since I think it got lost in the scrollback last night. Is it intentional that

contentDescription

doesn’t get merged up? More details in the thread on the original message.

I'm struggling to handle the permission request flow. I think I need to pass down a callback or make my activity a CompositionLocal to access

shouldShowRequestPermissionRationale()

. What are people doing?

anyone have solution to this https://stackoverflow.com/questions/63157554/duplicate-class-found-in-modules. I'm stuck with same problem, old modules using paging-2 and I'm migrating screens to compose which implements

androidx.paging:paging-compose:1.0.0-alpha10

Hello guys, I'm using jetpack compose on a project and it's awesome. I'm displaying a Linechart correctly but I believe the performance of the drawing can be improved with coroutines... I'm doing something like this 👇 but it crash with an

UnsupportedException

, does anybody has trying to do the same and actually succeed?

@Composable
fun LinearTransactionsChart(
    modifier: Modifier = Modifier,
    transactionsPerSecond: TransactionsPerSecond,
    defaultDispatcher: CoroutineDispatcher
) {
    if (transactionsPerSecond.transactions.isEmpty()) return

    val composableScope = rememberCoroutineScope()

    Canvas(modifier = modifier) {
        composableScope.launch(Dispatchers.Main) {
            emitTransactions(
                defaultDispatcher = defaultDispatcher,
                maxTransaction = transactionsPerSecond.maxTransaction,
                transactions = transactionsPerSecond.transactions,
                canvasWidth = size.width,
                canvasHeight = size.height
            ) { start, end ->
                drawLine(
                    start = start,
                    end = end,
                    color = Color(0xFFFFFFFF)
                )
            }
        }
    }
}

// The list can have like 1K ~ 2K items...
suspend fun emitTransactions(
    defaultDispatcher: CoroutineDispatcher,
    maxTransaction: Double,
    transactions: List<TransactionRate>,
    canvasWidth: Float,
    canvasHeight: Float,
    dots: (start: Offset, end: Offset) -> Unit
) {
	// ... Do some heavy computation for creating the start and end Offset...
    withContext(defaultDispatcher) {       
        transactions.forEachIndexed { index, transactionRate ->           
            dots(Offset(x, y), Offset(x, y)) 
        }
    }
}

Please help. I'm stuck in a endless loop. Gradle Syncs not issue but can't build a test app. e: This version (1.0.0-beta07) of the Compose Compiler requires Kotlin version 1.4.32 but you appear to be using Kotlin version 1.5.10 which is not known to be compatible.     Yet I have.

buildscript {
    ext {
        compose_version = "1.0.0-beta08"
        kotlin_version = "1.5.10"
    }

Not sure where it's getting beta07 from I can't find it anywhere in the project

Let’s see if the community will answer… 😛 https://stackoverflow.com/questions/67929861/fillviewport-behavior-in-jetpack-compose-column

Lets say I have a Composable that represents an input field and this input field has some sort of restriction in what it can take in. It could be

@Composeable fun MyEmailInputField() { ... }

@Composeable fun MyPhoneInputField() { ... }

@Composeable fun MyPasswordInputField() { ... }

Would you have: 1️⃣ the validation/restriction of chars is built into the Composable 2️⃣ the validation/restriction of chars is built into your "ViewModel"