Hi, when I have two instances of a composable with FilledTextField, I'm getting this error:

java.lang.IllegalArgumentException: Key -1277534736 was already registered. Please call unregister before registering again
        at androidx.ui.savedinstancestate.UiSavedStateRegistryImpl.registerProvider(UiSavedStateRegistry.kt:96)
        at androidx.ui.savedinstancestate.ValueProvider.updateAndReturnValue(RememberSavedInstanceState.kt:103)
        at androidx.ui.savedinstancestate.RememberSavedInstanceStateKt.rememberSavedInstanceState(RememberSavedInstanceState.kt:68)

Any thoughts? Thanks 🙂

Is there a way to add Snapping behavior for

Horizontal Scroller

just like how

ViewPager

snaps per page?

Hi, is it possible to create shared element transition between one compose to a new compose function that replace previous one? Also i struggle to keep my head around how to animate a view from minimum width to fillMaxSize. Is that kind of animation possible with dev15?

Ok y’all, how do you draw a view that has no children but has a color background?

Surface(
    color = Color(0xFFFF0000),
    modifier = Modifier.width(5.dp).fillMaxHeight()
) {
    Text("")
}

I’ve got this, but if I remove the Text item the color isn’t drawn which is really all I care about

Does it makes sense to pass a

mutableStateOf<User>

to the children as parameter so some

Composables

in the hierarchy can update that state so that all the hierarchy will be recomposed? In this case, I have a screen/composable that will sign-in the user, and when the user is signed in I’d like to update the rest of the hierarchy that it happened. The goal is to show all my screens if a user signed-in or not (I’m using

compose-router

for the backstack)

Is there a modifier im missing to get the snackbar to align to the bottom?

Is there any example project that combines backstack + keeping screen state + dependency injection via params? ie, a regular app we're used to. more than the simple examples

Is there an example of a working TextField composable for something like username and password input using a standard keyboard? I'm not sure how to limit entry to one line either

My team uses Android Studio 4.0.1 and we don't use compose. We're building a new set of components in the current android ui toolkit, but we're interested in building composables at the same time. Is there a chance that we can build the composables in the same project or do we have to force everyone to use 4.2.0 canary (updating agp, etc). I'd really like to continue opening the project with AS stable to build/dev/deploy, but if I open in AS canary I can see the library of composables we're building out. Is that possible or just asking for trouble? The simpler thing to do would just to have a separate repo, but I'd like to stay away from that if possible as I would prefer to have old/new components in the same repo.

Should we not be able to call

launchInComposition() {}

inside a

@Composable

extension function? The extension function looks like the following:

@Composable
fun <I, O> ActivityResultRegistry.activityResultLauncher(): : ActivityResultLauncher<I> {}

But inside of it inside another

Composable

, I am unable to call

launchInComposition

(see screenshot).

I found that if I don't include a ComponentActivity in my AndroidManifest, then using createComposeRule() means that test stalls and eventually bombs out with "activity never becomes requested state "[destroyed, resumed, created, started]" I wonder would it be better to have a more explicit exception message here, as it took me quite a while to figure out what I'd done wrong? Something like "ComponentActivity not found - have you included it in your AndroidManifest?".

Working with LazyColumnItems with a flowable provided backing list I'm hitting a weird UI state where triggering a delete() of

test9

causes

test8

to also be removed visually but remain in the list at the repository level as well as the list that the UI is fed. The

test8

gets added back on "undo" and

test9

gets returned on scroll

My understanding is that

@Compose

does not support backstack handling automatically, like

FragmentManager

does, and that we would be forced to track backstack behavior ourselves in business logic (which makes more sense, as it’s just so flexible). Assuming I’m correct about this, is there any documentation or information anywhere that advocates managing backstack logic ourselves in a

@Compose

world? Like representing a backstack like

listOf(screen1, screen2)

? I’m looking to share this info with colleagues rather than argue for it myself haha

I believe existing UI libraries (e.g., custom

RecyclerView

) would not work with a

Composable

function. Anyone knows if there is any guide at this stage to convert such libraries to

Compose

?

@Composable
fun startScreen() {
   FlowComponent(sflow = myfirstFlow())
}

@Composable
fun FlowComponent(sflow: Flow<String>){
       val cnt:String by sflow.collectAsState("")
       val sl =state { mutableListOf<String>()}
       sl.value.add(cnt)
       Box(Modifier.preferredHeight(150.dp)){
          sl.value.forEach {
            Text(it)
        }
    }
}

fun myfirstFlow()=flow<String>{
    val t=110L
   emit("task 1 succeded")
    delay(t)
   emit("task 2 failed")
    delay(t)
    emit("task 3 succeded")
    delay(t)
    emit("task 4 failed")
    delay(t)
    //emit("uuu"+getNewsPapers(null))

This is a startup screen as I run several functions I intend to emit a string to the flow component that will add it to a list of stings and then write them on screen. And it works but only if I add a certain delay between emits, if the delay is to small or null then I only get the first and last emit. I I'm wrong if i believe that this should work without any delay at all?

Hello! The latest Jetpack Compose minor release, dev16, has just been released! You can get it now on Google’s Maven Repository. Release notes are available at https://developer.android.com/jetpack/androidx/releases/compose and https://developer.android.com/jetpack/androidx/releases/ui. Please note that the major refactoring continued and the updated mapping can be found here: https://developer.android.com/jetpack/androidx/releases/compose#package-refactor. As always, feedback is welcome; please log issues at https://issuetracker.google.com/issues/new?component=612128!

https://github.com/romainguy/sample-materials-shop is updated to work with dev16 if you need an example of the new imports to use and what compiler version to use

Is there any thing similar to DataTable which I believe was in dev08 ?

I’m getting an error in previews with dev16 and AS 4.2 canary 7. Is it worth filing a bug?

I’m getting an error trying to build:

Caused by: java.lang.IllegalStateException: Couldn't obtain compiled function body for public final inline fun <get-current>(): T defined in androidx.compose.runtime.Ambient[PropertyGetterDescriptorImpl@6d6b1e59]

I have noticed some composables have a content field, and they also have a body for content. Should the children composables go in their content field or written in their body? For example surface:

@Composable
fun Surface(
    modifier: Modifier = Modifier,
    shape: Shape = RectangleShape,
    color: Color = MaterialTheme.colors.surface,
    contentColor: Color = contentColorFor(color),
    border: Border? = null,
    elevation: Dp = 0.dp,
    content: @Composable () -> Unit
)

Another question, how to refer to the current composable in a Modifier? For example, trying to change the text value of a Text modifier using a clickable modifier.

Text(text = "Hello Android!", modifier = Modifier.clickable(onClick =  /*Code to change the text Hello Android */))

I've been having some problems with font weights for a while now. It seems like having multiple fonts with different weights in a fontFamily just picks the font with the closest weight and ignores the others. On dev-16 and core-ktx 1.5.0-alpha01 now, and it stopped working properly somewhere around dev-12 or 13.

Updated to dev16 today and I cannot do this anymore. Why is mutableStateOf not allowing property delagates anymore? Am i missing something?

class Position(x: Int, y: Int) {
    var x by mutableStateOf(x)
    var y by mutableStateOf(y)
}

I can't seem to be able to update dev15 and dev16, I have these repositories in place:

maven(url =  "<https://dl.bintray.com/kotlin/kotlin-eap/>")
jcenter()
google()

Some packages were renamed, maybe check that?

I have a small compose example app that I've been updating as the dev releases are made, and dev15 and dev16 have been challenging. Specifically, I'm finding on dev16 with Android Studio 4.2 Canary 7, I can no longer see any previews. The preview window just keeps telling me to compile the app. The app was based off the Empty Compose Activity example initially, and the code compiles. Would be happy to drop the code somewhere if people want it.

Can compose be used on arbitrary trees now?

I work on an app that has a feature in debug builds where we dump the entire view hierarchy of the main window in certain cases, e.g. for crash reports or manually via a special debug menu. This can be really helpful for figuring out the state of the UI when things go wrong. Is it possible to do this with Compose? What would that look like? One option would be to walk the semantics tree, although I’m not sure that would contain enough information for debugging the UI itself. Another option would be getting access to the root

LayoutNode

and walking the node tree, but many Composables just wrap other Composables and don’t have their own `LayoutNode`s, modifiers are often contributed from multiple composables for a single node, etc, so that’s not ideal either. I’ve seen some work being done for Android Studio tooling around extracting some data about stuff like this by inspecting the slot table directly. Would it be reasonable to request a public API for exposing that parsing in debug builds?