Did someone notice that 

Scaffold(bodyContent = { // code here is called twice })

 is called twice? I'm using dev13 but same problem with dev12. I can't test the other versions because my project fails otherwise.

Hi all, is there any way to disable text selection for

Text()

composable?

On Start

ScannerScreenContent

ist called twice and everytime

val state by viewModel.device.observeAsState()

is triggered,

ScannerScreenContent

is called again which leads to a list with always 1 item. Does someone have an idea?

hi, I get that

This version of the Android Support plugin for IntelliJ IDEA (or Android Studio) cannot open this project, please retry with version 4.2 or newer.

but I already have the latest version of canary installed, what should I do?

I've tried peeking at the internals of the layout system but can't figure out where the rule is and how to override it.

I'm trying to update project here (that's using dev13 of Compose) to 1.4-M2 but getting

Class 'kotlin.Unit' is compiled by a pre-release version of Kotlin and cannot be loaded by this version of the compiler

I'm using AS 4.2 Canary 1.....and if I just use new project option to create "Empty Compose Activity" I see same issue (it also creates project with dev13 of Compose and Kotlin 1.4-M2). If I create say basic fragment/viewmodel project then it builds/runs fine. Anyone else seeing this?

Could compose by any chance cause problem when used along with data binding. There is another part of the code that uses data binding. I am getting an error related to data binding after installing compose. I have created a gist of the stack trace here. I am still struggling to make compose work with my existing project. Any clue would be appreciated. I have added the following to my build.gradle

composeOptions {
        kotlinCompilerVersion "1.3.70-dev-withExperimentalGoogleExtensions-20200424"
        kotlinCompilerExtensionVersion "0.1.0-dev13"
    }

I am on a multi module project, and I have added the option to both build.gradle files.

Is there any way to do something like

notifyItemMoved()

from RecyclerView with Compose

AdapterList

?

Is there a trick to using composable function references?

@Preview
@Composable
fun ListifyLambda() {
  AdapterList(data = listOf("foo", "bar", "goo")) {
    ListItem(it)
  }
}

@Preview
@Composable
fun ListifyFnRef() {
  AdapterList(data = listOf("foo", "bar", "goo"), itemCallback = ::ListItem)
}

@Composable
fun ListItem(item: String) {
  Text(item)
}

Here,

ListifyLambda()

and

ListifyFnRef()

seem like they should be equivalent.

ListifyLambda()

compiles and runs without issue.

ListifyFnRef()

fails to compile, with:

Type mismatch: inferred type is KFunction1<String, Unit> but (String) -> Unit was expected

(

dev13

and AS 4.2 C1) It doesn't seem like the Kotlin itself is flawed. Function references that match the function type should be usable, and

ListItem()

seems to match the

itemCallback

. If you try swapping compatible lambda expressions and function references outside of composables, it works as expected. I have run into this a few times and just wrote it off as being glitchy prerelease stuff, but https://stackoverflow.com/q/62362663/115145 spurred me to try to get to the bottom of this. Are we doing something wrong, or is this a bug/limitation of something (e.g., Kotlin compiler plugin)?

Hey guys, could someone tell me, how to draw a dotted or dashed

Border

?

@kenkyee isn't the state stuff actually going against unidirectional data flow? Since events are not upstreamed to the data source and instead handled inside the component.

interface LayoutModifier : Modifier.Element {
    fun MeasureScope.measure(
        measurable: Measurable,
        constraints: Constraints,
        layoutDirection: LayoutDirection
    ): MeasureScope.MeasureResult

How exactly LayoutModifier works? instead of list of measurables for each child, there is only one measurable. and I've playing with it, when I tried

placeable.place(50.ipx, 50.ipx)

it applied for all children. I think there is some thing I misunderstood about it.

Spent some time this weekend hacking on my text formatting experiment project and finally implemented support for links and stuff. My general goal here is to get a feel for what a sort of Compose-based markup DSL for creating fancy text (roughly on the same level of flexibility as Markdown) could be like, while keeping formatting details consistent and centralized. It’s super rough, and there are some gross hacks here, and no tests, but the API turned out kinda nice. https://github.com/zach-klippenstein/compose-richtext/pull/3

Used the weekend to learn some React and I obviously had to make it about Jetpack Compose somehow. So I created this tool that makes recommendations for the right Compose API to use based on what you use today with the current Android UI Toolkit. Very IFTTT-eque if you will! You can find it here - https://jetpackcompose.app/. More details and demo here - https://twitter.com/vinaygaba/status/1272378671974645760

👋 I have 2 questions about animating things : 1️⃣ How to animate a Composable height from “wrap-content” to 0dp ? We could use the animate api to update scaleY from 1 to 0 but in a Column, the view would just be like “invisible” and not “gone” right ? I mean, elements after the resized one will not go up as the scaleY is changed 2️⃣ How to animate a Composable height update if its child height changes

Did someone notice that onClick callback of

DropdownMenuItem

is not fired?? I'm on dev13. Is it a bug or did I miss something?

Am I the only one frequently getting this error? I just re-run and it disappears, but it’s annoying as I have to build twice.

> A failure occurred while executing org.jetbrains.kotlin.gradle.internal.KaptExecution
   > java.lang.reflect.InvocationTargetException (no error message)

Is there a resource out there to understand how the layout, measurable, placeable, etc stuff work ? I find these things hard to reason about right now

What are good resources to understand how Compose helps separate UI and business logic? I feel like most examples use mutable local state, instead of state that is updated externally to the composable

Hi everyone I'm making a Compose-MVVM application and trying to implement network requests and make UI react to responses. And now I'm struggling on how to do it properly So here's my pseudo-code

@Composable
fun SampleScreen() {
    SampleScreenBody(viewModel = SampleViewModel())
}

@Composable
fun SampleScreenBody(viewModel: SampleViewModel) {
    Button(onClick = {
        viewModel.doSmth("Parameter") { response ->
            if (response == "Success") {
                //TODO: this is where I want to, for ex, move to another screen
                //or show a dialog.
                //How?
            }
        }
    }) {
        Text("Text")
    }
}

Which version of android studio should we use going forward for jetpack compose 4.1 Beta 1 or 4.2 Canary 1? Which versions of compose will work on 4.1 vs 4.2 (I am currently on dev11)?

Is it possible to scroll the

AdapterList

to the top? I can’t find any way to get access to scrollable modifier

Why can a measurable only be measured once? Isn’t it possible that a measurable in a layout might need to be measured more than once with different constraints? Or is this discouraged?

I’m having an issue with Vector Images overlap during recomposition.

val savedIcon = state { post.saved.icon }
Image(
            modifier = Modifier.weight(1f) + Modifier.clickable(onClick = {
                post.toggleSave()
                savedIcon.value = post.saved.icon
            }),
            asset = vectorResource(id = savedIcon.value)
        )

On toggle, the icon resource should swap. It works the first time (outline to solid) but on the second time the outline shows on top (shown in the pictures below). Any reason why this is happening?

Building MVI with Kotlin StateFlow.

val intentChannel = Channel<Intent>()
val state: StateFlow<ChannelState>
// Setup Ambient
val CurrAppState = ambientOf<ChannelState> { ChannelState.Edit }

In a Composable want to use the Ambient

@Composable
fun Foo(appState: StateFlow<ChannelState>){
   val currState by appState.collectAsState(initial = ChannelState.NotEdit)
   CurrAppState.provides(currState)

Passing

currState

down the tree everything works perferct but if use

CurrAppState.current

get the wrong state. Think I am doing something dumb. Thanks for the help.

@andylamax What is your build.gradle(Module:..

Is this a known issue?

Currently we can show classic Android views with

AndroidView()

composable. I'm curious if there will be a way to show `Fragment`s in composables? Maybe it's already possible (I haven't tried yet). Maybe we can wrap fragment within a

FrameLayout

or something? The reason why I'm asking is that we're thinking of moving our app navigation to be within composables. All our screens are

Fragment

s at the moment and ideally we would like to avoid converting each fragment to a custom view (before we can convert each of them to be composables)

Hi I'm new to Jetpack Compose, I wonder if there is anybody that found a way to handle navigation backstack with the hardware button? And now while we are at it, is the navigation lib going to be connected with Jetpack Compose later on? For now I am using the method from the sample:

object NavStatus {
    var currentScreen by mutableStateOf<Screen>(Screen.Home)
}

fun navigateTo(destination: Screen) {
    NavStatus.currentScreen = destination
}

This is fine if you specify onclicks in the UI. However the hardware button closes the app. Usually you would handle an onKeyListener in your fragments or onBackPress in an activity. I could imagine that you could keep an array of recent navigated screens and just pop one using the onbackpress listener in the MainActivity.

Hey! I’m trying to add Compose to an existing project, and I get this compilation error:

java.lang.IllegalStateException: new updateScope not found in result type of endRestartGroup

This happens as soon as I add the first @Composable annotated fun to the code (even if it’s completely empty). Any idea what I’m doing wrong?