how to get the root view instance？

I have looked at some tutorials for implementing shimmer loading in compose but can't decide the best way to set it up code wise.

@Composable
fun MyList(items: List<Items>, isLoading: Boolean)

I thought about using a flag as shown above and then if-else to determine if it should show the real view or just the shimmer variant. If you have implemented shimmer loading what worked best for you? Did you perhaps find a more elegant solution?

I want to add a Repeat button. Is it possible to restart flow like this? It seems to work, but Composable is not updated.

val user by viewModel.loadingUser.collectAsState(initial = null)
when {
    user.isSucceeded -> navController.navigate(NavScreen.Home.route)
    user.isError -> ErrorConnect { viewModel.repeat() }
    else -> Splash()
}

Hi, how do we access the samples mentioned in the code documentation? When I hover over it, it’s not clickable

I'm having issue with

Accompanist

image loading library, I am using compose pagination in combination with

LazyColumn

and

LazyRow

, But when i scroll up and down images of row which is immediate above current viewing elements got disappear and when i scroll back after sometimes items reappeared, Is this bug in accompanist or

LazyColumn

? I guess this is Issue in image loading only because in that row text is visible but not the image, strange isn't it?

How to test LazyColumn items? Looks like items are not wrapped. See thread …

I'm curious why compose keeps using the old

inline class

syntax and suppressing the deprecated warning as shown here instead of replacing it with

value class

after supporting Kotlin 1.5? I tried using value classes (with snapshot version of compose) in my app and there seems no problem.

Is there any way to set the width of an EditText in characters?

A lot of classes and functions that we could use to build our own components are

internal

or

private

. I know the reason for limiting the public API but an optIn annotation might be enough. Right now we have to copy huge amounts of code in order to have a working custom component. Code that won't get maintained or fixed easily. If we could opt in to them, our code would break on upgrades but we would still get the benefits and fixes after fixing them.

Testing with compose: is there a way to match a node by tag only if it's a child of another node? Hypothetical situation:

Column: tag A
  TextField: tag field
  Text: tag error
Column: tag B
  TextField: tag field
  Text: tag error
Column: tag C
  TextField: tag field
  Text: tag error

If i want to match the TextField tagged "field" inside the column tagged "B", how do I write the SemanticMatcher?

What would be a good way to react to an mvi-style events flow within a composable? The IDE tells me I need to use a launched effect but I don't understand why and what I should use as a key.

Did anybody meet exception [thread] on recomposition? Let me explain

Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkNotNullParameter

This parameter declared as default argument in function body and not passed in calling place. If i passing exactly the same value into funtion call app works well and not crashes on recomposition. Looks like default argument of composable function stores somewhere and GC (or somethig else) remove it when composable is recomposing, but ref stay the same and i get this error.

I recently tried to explain some of the APIs that compose uses to make its state management work. It’s all based on something called “snapshots”. You probably won’t ever need to actually use these they’re a bit lower level, but knowing how this works might help you reason about how your code is running. Read more here.

Can someone explain to me how this works? First of all, everything works fine, just as I need, but I don't understand why. I have a

composable

function

@Composable
fun modified(
object1: A,
object2: B) : Boolean {...}

Where

A

is a Data Class,

B

is a regular class with

MutableState

variables. I use this function to control the

Button

, so it's enabled only if there are any differences between the objects.

Button(
...
enabled = modified(object1, object2)
...
)

How does it work? Any changes to

MutableState

variables of

object2

trigger the

modified

function?

Is there any difference between

LaunchedEffect

and

DisposableEffect

when you don't actually need any cleanup? I've seen in the official samples some `DisposableEffect`s with an empty

onDispose {}

, and that makes me think

LaunchedEffect

should be a better option, but I'm in doubt 🤔

Hi guys! I’m trying to navigate to a composable using navigation compose. It’s worked fine until i tried to navigate to a screen from a button inside a

ModalBottomSheetLayout

, the app crashed. Has anyone had the same problem?

Hey everyone, I have a RecyclerView with items; each item has an imagePath; in onBindViewHolder, a new coroutine is launched, to check if the image is already stored locally. If it is, it sets the image. If it isn't, it downloads and sets the image. This is the code inside onBindViewHolder:

lifecycleScope.launch {
    val bitmap = withContext(<http://Dispatchers.IO|Dispatchers.IO>) {
        getLocalImageAsBitmap(imageName) ?: run {
            val file = requireContext().cacheDir.resolve("places").apply { mkdirs() }.resolve(imageName)
            try {
                repository.downloadFile(imageName, file)
                getLocalImageAsBitmap(imageName)
            } catch (e: Exception) {
                e.printStackTrace()
                null
            }
        } ?: return@withContext null
    }
    binding.imageView.setImageBitmap(bitmap)
}

How can I migrate this to Compose (LazyColumn)?

Hello everyone! I've finish my Item Indicator for the Accompanist

HorizontalPager

. The idea is extend it in the future for

LazyRow

. If you like you can check my Jetpack Compose animations repo here https://github.com/rodrirepresa/ComposeAnimations

I'm animating the progress of this meter from 0 to 100 infinitely. When some data from the network is loaded, containing the progress value, I want it to transition to that value and stop the infinite animation. How can I achieve this? Code in thread.

How do people indicate when the combination of multiple fields in a form is invalid, when it isn't clear which one specifically is invalid? I'm thinking about just marking every fields as an error with the red outline, or outlining the group of fields in red (Context is a bit esoteric. I'm making an entry form for UTM coordinates. You basically specify one of a bunch of sections of the globe, and also where in that section. Different sections have different sizes. If you specify somewhere outside the section you either specified the wrong sub-position or the wrong section or both. Also users will generally be copying all the fields from somewhere else).

I know it’s a recurrent question here… but is there a way to remove this extra padding from

TextField

without implement it from

BasicTextView

? Or have this “LineTextField” + everything from “Material Design TextField” (label, leading icon, trailing icon, …)?

I may be doing something wrong with LazyColumn or I've triggered a bug by using this code for transition animations:

Anyone have idea about this, kindly guide me. https://stackoverflow.com/questions/67793793/i-want-to-add-parallax-effect-in-jetpack-compose

@cb Do you have any plan to support (un)hiding status bar & navigation bar or to go full-screen in

Insets

API?

Why does JetSnack declare Jetsnack Theme? https://github.com/android/compose-samples/blob/main/Jetsnack/app/src/main/java/com/example/jetsnack/ui/theme/Theme.kt#L113

Is Jetpack Compose backward compatible including Android 8.1?

What is the best way to get the colors from an Image Composable? I load the image with Coil from a url. In jetcaster example, they seem to Reload the image on touch to get the colors with palette api, how do I get the colors immediately instead without calling the url again?

Hello guys, I am having troubles with the animated vectors. When I launch the animation it seems that not every <objectAnimator> are launched and I don't understand why. Here is my code to launch an animated vector resource :

val image = animatedVectorResource(id = R.drawable.avd_pathmorph_arrowoverflow_arrow_to_overflow)
val atEnd by remember { mutableStateOf(false) }
Image(
  painter = image.painterFor(atEnd = atEnd),
  contentDescription = null,
)             
LaunchedEffect(Unit) {
  atEnd = !atEnd
}

The drawable comes from here : https://github.com/SmartToolFactory/Animation-Tutorials/blob/master/Tutorial2-1Ani[…]/res/drawable/avd_pathmorph_arrowoverflow_arrow_to_overflow.xml When I run this code, it seems that only the first object animator is done : It moves the point but does not morph to become lines etc. Android Studio Canary's Design window can run the animation correctly but when I run it in my code it fails. Am I launching it correctly ? Do I misunderstand something ?

I’ve been migrating our code to compose-navigation. We’re using MVVM but the navigation does not go through the ViewModel and we delegate it directly to the composable up to the navigation graph. For user interaction that does some processing before navigation (such as login) we expose a

suspend fun

which returns the operation’s result and navigate accordingly. Works fine so far, and now I encountered a new use-case integrating with non-Kotlin code. I use CameraX ImageCapture use case with takes a listener for successful capture, I can’t use suspend fun to wait for the result. So now I’m looking for options. I wonder if we could represent capture events from the ViewModel, and I remember discussions on SingleLiveEvents and we now prefer representing state instead of events in Compose. For example we now use state for snackbar or dialog visibility instead of SingleLiveEvent. I’m not sure how to do this for navigation events. I’ve seen articles suggesting

StateFlow

,

SharedFlow

,

Channel

for navigation events, but I’m curious what the Compose team thinks. I haven’t found an official example where the navigation is handled within the ViewModel, is it deliberate that we want to decouple ViewModels from the Views’ navigations completely (no mention of “navigation” within a ViewModel)? We’re also having internal discussions how to handle navigation in our Compose+MVVM architecture and we’re split on what we need to do about whether we should call the navigation lambda directly on user event (like onClick) or whether we should keep our Composables pure&passive.

Is there a way to tell compose class is

@Stable

or

@Immutable

on a class you don't own?