I've upgraded to

navigation-compose 2.4.0-alpha05

and my LazyColumns were broken. I've investigated and it looks like

rememberSaveable

usage without a key has been broken. Upon navigation and back it is not restored because

currentCompositeKeyHash

has changed. This means

rememberLazyListState()

doesn't work if you leave a list into a detail and than back it scrolls back up cause it creates a new

LazyListState

@Ian Lake I'm tagging you because I saw you are on top of this kind of issues in other comments and I suppose this information can help you solve other issues with this release. If you do not want me to ping like that I won't do it again. I can (and will) create a bug report: just do not have time now and just wanted to let you guys know of the issue as fast as I could. -- I'll link it here in a response Other issues I noticed: I had a login flow working like this: routes: • EntryPoint • Login • Registration the Entry point sent directly to either login or registration with a

LaunchedEffect

controlled by a StateFlow in the viewmodel. When entering the screen I would mark it to exit when coming back. This allowed me to handle the logic of setting backStackEntry arguments as results of the auth flow. with the old navigation after navigating to login the launched effect didn't receive the "go back" event until the user re-entered the entry point screen while with alpha05 it immediately execute the back call. This was fixed using

lifecycle.whenStarted { }

to handle the navigation back -- but you might wanna mention this as side effect in the release notes.

How can I know if a

ScrollableState

is scrollable aka all the content is already being shown?

[Poor image quality on rotated Icon] I have a compass icon that I want to rotate so that it is always pointing to north. When the rotation is 0 everything is nice, my icon is displayed sharp. But when the rotation value is different, the icon becomes heavily pixelated. The icon is a vector image loaded with

painterResource

Is it possible to apply antialiasing or something similar to improve image quality?

Icon(
    painterResource(R.drawable.ic_map_compass),
    contentDescription = stringResource(R.string.map_compass_button_content_desription),
    tint = Color.Unspecified,
    modifier = Modifier.rotate(
        -bearing
    )
)

What's the recommended way to repeat a vector as a pattern on the background of a composable? Should I convert the vector to a bitmap and draw it in a canvas with a TileMode.REPEATED Paint?

Hi folks. Will compose have your own code style guide or we must keep using Kotlin/Android style guide?

Has anyone tried compose on release build with debuggable on? I am getting crashes related to profileInstaller but not really sure what is the issue and it just print some native memory logs.

Hello everyone, how can I get the screen width in px inside of a composable?

Hi ! I am creating a custom composable, and would like to get available width/height from the given modifier : is it possible ? My goal is to implement a kind of

FlowLayout

using the

Layout

composable. But for this to work, I need the available width.

Hi guys just noticed something weird with compose navigation. My app crashes when i add 13

composables

in the

NavHost

have you noticed this as well? it works fine with 12 or less

java.lang.ArrayIndexOutOfBoundsException: length=13; index=13

Hi! Im using

AnimatedVisibility

and notice some weird behavior for

expandVertically

and

shrinkVertically

Is this expected?

What would you guys recommend to stack rotated text ? I've tried simply using a column but it seems that the rotated texts are merged. In addition, I've notice that the width of the column is still equal to the initial width of the texts.

Is there a restriction for navigation hierarchies in Compose? This code works as expected:

@Composable
fun ApplicationRoot() {
    val navController = rememberNavController()
    MaterialTheme {
        NavHost(navController = navController, startDestination = "home") {
            composable("home") {
                HomeScreen()
            }
        }
    }
}

@Composable
fun HomeScreen(viewModel: ApplicationViewModel = viewModel()) {
    val applicationState by viewModel.applicationStateStore.observeAsState()
    ...

But if I refactor

applicationState

as a parameter then it doesn't work correctly, no recomposition happens if

viewModel.applicationStateStore

is modified:

@Composable
fun ApplicationRoot(viewModel: ApplicationViewModel = viewModel()) {
    val applicationState by viewModel.applicationStateStore.observeAsState()
    val navController = rememberNavController()
    MaterialTheme {
        NavHost(navController = navController, startDestination = "home") {
            composable("home") {
                HomeScreen(applicationState)
            }
        }
    }
}

@Composable
fun HomeScreen(applicationState: ApplicationState) {
    ...

Thanks.

This question might have been asked before. Is there any catalogue of material components in Compose? Trying to find a Rating Bar composable like we have in the xml widgets.

Any guides to compose navigation with bottomNav with a sign in flow? I used these docs when setting up my app https://developer.android.com/jetpack/compose/navigation#bottom-nav but now when I open the app on a cold launch (and the user isn't logged in), I see my HomeScreen for a split second with my bottom nav and then I go to my sign in screen which doesn't have bottom nav and it's just kinda jarring from the user POV. Curious if there's some best practices with bottom nav and sign in combined.

what should I use to make mutableList updated properly in compose?

In a column with an

animatedVisiblity

and a

Button

composable, how do I prevent the Button from moving to the space occupied by the

animatedVisiblity

when it is invisible.

wanted to give it one more try if anyone had some insights. https://kotlinlang.slack.com/archives/CJLTWPH7S/p1627628600020700

I have a Settings screen which shows list of settings item and under each item there will be more settings which shows/hides on parent click but Compose doesn't allow to use

NestedScrollable

inside

Column

or

LazyColumn

code in 🧵

Is it possible to make an Accompanist

FlowRow

scrollable ? Or to add Scrollbars automatically around it ?

Let's suppose I have a

swipeableState

like in this example: https://developer.android.com/jetpack/compose/gestures#swiping . Since

swipeableState.snapTo(...)

is a suspend function, I probably need to call it from a side effect. Whats the correct way to call this function inside of a composable?

Is it currently not supported smart-cast inside

when

for the

sealed class

with

LiveData.observeAsState

like this code in 🧵?

What should I use in order to make a

@Composable

scrollable ?

Is there a way to measure composable without ever displaying or using it? Use case is in 🧵

How can I use a timer in Compose to for example increment a ticker? The following code does not work:

var inc by remember{ mutableStateOf(0)}
    remember{object: CountDownTimer(100L, 1L){
        override fun onTick(millisUntilFinished: Long) {
            inc++
        }

override fun onFinish() {

}

}.start() }

I have a text field in a screen that is part of a navigation graph accessed through a bottom nav. When I type something in the text field, and switch to another tab, and then back again, the text field is empty. I was expecting the state to be saved, but if I need to save this text in a ViewModel or something, that's fine. Any ideas what's happening here?

is there any way to have a

DropdownMenu

appear in the position of a click? I'd like to capture the x, y position of a click event and have the

DropdownMenu

anchored to that position, rather than it just anchoring itself in the default position

Is it just me or is

LazyColumn

rather laggy on first scroll? Compared to Column with scroll (obviously since those are eagerly loaded), but also compared to RecyclerView (by feel, didnt measure though) and fling animation is also kind of messed up, but then fixes it self after few swipes up and down; as if something heavy was loading on main thread

I just updated all my compose dependencies to the latest ones and my one (and only) composable screen that has a dynamic destination string and a viewmodel has issues. It launches without issues but crashes when I want to go back. I cant find how to fix it anywhere including here. Details on the thread: