Hello guys :android-wave: have you ever been in a situation where the compose preview in android studio won’t show up when you have

kotlin reflect

related codes in your composables? I’m trying to use a form validation library for compose which uses kotlin reflect under the hood and it makes the preview builds to be fail ☹️ I get the following stack trace from preview issues panel

java.lang.ClassCastException: class _layoutlib_._internal_.kotlin.jvm.internal.ClassReference cannot be cast to class _layoutlib_._internal_.kotlin.reflect.jvm.internal.KClassImpl (_layoutlib_._internal_.kotlin.jvm.internal.ClassReference and _layoutlib_._internal_.kotlin.reflect.jvm.internal.KClassImpl are in unnamed module of loader org.jetbrains.android.uipreview.ModuleClassLoader @447dcf4d)
	at _layoutlib_._internal_.kotlin.reflect.full.KClasses.getPrimaryConstructor(KClasses.kt:36)
	at me.naingaungluu.formconductor.FormImpl.constructorRequirementSatisfied(FormImpl.kt:135)
	at me.naingaungluu.formconductor.FormImpl.<init>(FormImpl.kt:46)
	at me.naingaungluu.formconductor.composeui.FormComposablesKt.form(FormComposables.kt:36)
	at com.memoto.mobileapp.feature.booking.checkin.guests.ComposableSingletons$CheckInGuestFormScreenKt$lambda-2$1.invoke(CheckInGuestFormScreen.kt:44)
	at com.memoto.mobileapp.feature.booking.checkin.guests.ComposableSingletons$CheckInGuestFormScreenKt$lambda-2$1.invoke(CheckInGuestFormScreen.kt:43)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:116)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
	at androidx.compose.foundation.lazy.LazyListScopeImpl$item$3.invoke(LazyListScopeImpl.kt:54)
	at androidx.compose.foundation.lazy.LazyListScopeImpl$item$3.invoke(LazyListScopeImpl.kt:54)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:135)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
	at androidx.compose.foundation.lazy.LazyListItemsSnapshot.Item(LazyListItemProviderImpl.kt:99)
	at androidx.compose.foundation.lazy.LazyListItemProviderImpl.Item(LazyListItemProviderImpl.kt:126)
	at ......

Is it possible to hide status-bar behind ModalNavigationDrawer?

I have a column with it's height set to maxSize. And I have 4 text composables in that column. I want to be able to say that the 2nd Text "if there is no room for all 4 texts on the screen, please hide this one text" How would I do that in compose? Essentially I feel like I want to create a

Modifier.onlyShowIfTheresEnoughSpace

Is there any particular reason why the default ime action on a text input is

Done

, but the actual callback does nothing? I would have expected the default behavior to at least close the keyboard. I’m writing a wrapper to configure a visual transformation for phone numbers, but i can’t even fill in the onDone action because closing the keyboard requires getting the software keyboard controller, which is in a composition local, and can’t be accessed in the parameter list:

keyboardActions: KeyboardActions = KeyboardActions(onDone = { …. } )

Just got some reports that animations no more runs on some devices for some users (Even simple CircularProgressIndicator without any change or infiniteTransition.animateColor) after Compose 1.4 A1 or A2 (needs to get more info). Since during those non working animation everything still works the main thread is not locked. Is there anyway to debug / identify what clock is supposed to run those so I can try to repro?

Are there any (Github) repo's where I can draw inspiration for how larger Compose applications are structured?

Hi guys, I have a mutableStateListOf named descriptionListState and I want LaunchedEffect to be triggered when the mutableStateListOf changes. I tried converting mutableStateListOf to list, but it didn't work. Is there any solution?

val descriptionListState = remember{ mutableStateListOf("") }

LaunchedEffect(descriptionListState.toList()) {
    alarmViewModel.changeCreateAlarmState(
        createAlarmState.copy(description = descriptionListState.joinToString(" "))
    )
}

Hello! Is it possible to listen to State from non composable function?

Hi folks, anyone who could help me with ConstraintLayout ?

I've got a lazy column of text lines wrapped with a SelectionContainer. It works quite nicely as long as I don't scroll, if I scroll, the selection simply stops working when the first selected item is no longer visible. Sample to reproduce it:

SelectionContainer {
        LazyColumn {
            items(100) {
                Text("Line number $it")
            }
        }
    }

The "copy" button also jumps around in the same situation. Seems like a compose bug but not completly sure. A normal column works without any issues (expected since everything is composed unlike the LazyColumn).

This message was deleted.

Can anyone assit me with thi sbackdrop issue 😄 https://stackoverflow.com/questions/74372019/how-to-employ-backdropscaffoldstate-offset-correctly-to-offset-front-contentlaye

ExposedDropdownMenu

has a field called

onDismissRequest

but it gets called even when I'm typing on the keyboard which makes implementing an AutocompleteTextView-esque composable impossible. Am I missing something here?

Hi, all. Is this a good place to ask questions about building cross-platform UIs with KMM? I’m hoping so.

I’m looking for a tutorial to get me started (I’m fairly new to Kotlin and KMM but am a seasoned programmer).

Hi guys, i have a performance problems with my app. I have two mobile devices, an android 10 and an android 11, in my android 11 it goes very well but in my android 10 it goes very badly, I have been following all the rules of compose for better maintenance, but even so in one of the devices it goes very bad. What could I do?

Hi everyone, I'm working on a simple Compose Desktop app with a ribbon, content view, and bottom tray for showing progress of long running tasks. Right now a Scaffold is the main component I'm using for this and that's working well as advertised. What I'm stuck on is how to allow any part of the app to show and update the progress indicator. Is this a case for an App-level state holder that gets passed around? Maybe I just stick with callbacks? I appreciate any insight or examples you can share!

Does compose look native (look and feel) on iOS, or like material design?

Does anyone know of a tutorial or something to ask for foreground and background location permissions in compose for all SDK versions?

⚠️ After upgrading to

1.4.0-alpha02

, you may run into issues if youre using

value ?: return

in your composables. Ive reported it already, just sharing this since I didnt manage to detect the issue myself until it was too late!

hi all, just a quick question about using list.forEach inside a row or column to emit composables. i remember a while back it was recommended to not do this, and in fact it wasnt possible because calling a composable inside forEach would raise a compilation error as you were calling a Composable function inside a non-composable one. But now i've seen it be done in snippets online, and also there is no longer a compilation error (maybe there never was?) so my question is, is it ok to use? i dont always want to rely on lazy rows or columns if i dont have to, just unclear about the "best practice"

Hi guys is there going to be a way to style the Titles on MediumAppBar ? I want to style them differently

Hi, is there a way to add a onclick listener applied to a whole constraintlayout? in compose? i could not find an onclick parameter on it

I am struggling with the implementation of

dimensionResource(...)

. At the moment i am setting a custom LocalDensity if the device has a certain width. The reason I am setting a custom density is to achieve the autoscaling of composables, e.g. when an image has a size in COMPACT mode from 50.dp (e.g. =150px) it should be bigger in MEDIUM mode (e.g. =150px * 1.2 = 180px)

val density = LocalDensity.current.density
val fontScale = LocalDensity.current.fontScale
val scaleFactor = if (windowSizeClass == MEDIUM) 1.2F else 1.0F

CompositionLocalProvider(
  LocalDensity provides Density(density = scaleFactor * density, fontScale = fontScale)
) {
   val dpDirectly = 130.dp
   val dpViaResources = dimensionResource(id = R.dimen.dimen_130)
   
   // windowSizeClass == COMPACT
   // dpDirectly = 130.dp
   // dpViaResources = 130.dp

   // windowSizeClass == MEDIUM
   // dpDirectly = 130.dp
   // dpViaResources = 108.33333.dp -> WRONG VALUE!!!!
}

The problem is the dimensionResource function, because here the displayMetrics are used and they have a different density than the LocalDensity:

fun dimensionResource(@DimenRes id: Int): Dp {
    val context = LocalContext.current
    val density = LocalDensity.current
    val pxValue = context.resources.getDimension(id) // this returns the wrong value because here the DisplayMetrics are used
    return Dp(pxValue / density.density) -> this tries to get the correct value by dividing through the LocalDensity
}

The main problem is the LocalDensity and DisplayMetrics have different density values. Two questions: 1. Can it be done like this 2. If not what is the best way to achieve autoscaling of dp and sp values?

What is the best way to detect if user-initiated (not programmatical!) scroll was performed on

LazyColumn

? I need only to detect this fact and not interfere with the gesture itself in any way. Should I use lower level gesture detection modifiers?

Hi i am trying to implement a compose

debounce

for clickables and have this

Modifier

extension...

hi all, have the feeling im doing something a bit backwards wrt handling events.

LaunchedEffect(key1 = event) {
        when (event) {
            ManualPaymentEvent.LoadingError -> {
                scaffoldState.snackbarHostState.showSnackbar(
                    message = snackbarMessage,
                    actionLabel = snackbarAction,
                    duration = SnackbarDuration.Indefinite
                )
                viewModel.onSnackBarDismissClicked()
            }
            ManualPaymentEvent.NavigateBack ->
                navigateUp()
            is ManualPaymentEvent.NavigateWithCards ->
                navigateToSelectCard(event.amount, event.cards)

            is ManualPaymentEvent.NavigateWithoutCards ->
                navigateToAddCard(event.amount)

            null -> Unit
        }
        viewModel.eventConsumed()
    }

viewModel.eventConsumed()

sets the event to null again, to show it has been consumed.

onSnackbarDismissClicked

updates the uiState with

uiState = uiState.copy(event = ManualPaymentEvent.NavigateBack)

. the intent here is that the NavigateBack event triggers the

navigateUp()

function but this never happens. The issue appears to be that the event is first set to NavigateBack. then before this LaunchedEvent can trigger, the event is first set to null, and this NavigateBack event is ignored. What should i be doing? would this be resolved if i was holding my state in a Flow of some kind?

Hello, How could I achieve animated content using Compose? (without custom layout)

We added a

AndroidView

inside

LazyList

. And the list started janking when scrolled fast. Profiled and noticed that android view is inflating the view every-time a new item comes becomes visible. Is there a way to make them recycle views? have added key and content type to list items but that doesn’t help.