kotlinlang #compose

Hi, for navigation I am using the library called Voyager, because its simple and fits my requirements very well. But I am not sure at how I would go about setting a new root screen with it. My application starts with a login screen, and then that should be replaced with a different screen once the user finishes logging in. I have a found a few functions like Navigator.popAll() but that only pops until the current root composable, so I am not sure how to go about this.

😍 1

✅ 1

Arun Joseph

01/11/2022, 4:30 PM

Is accompanyst permission lib is a goto choice if the permission request to be done in presentation layer?

Vsevolod Kaganovych

01/11/2022, 4:39 PM

Does anyone know how to use

TextFieldValue

TextField

with

AnnotatedString

? Example: I have a

ViewModel

from where I observe state. When text changes, I update my state and create a new

AnnotatedString

like this

val nokString = getNokString(amount = state.nokAmount)

the

getNokString()

looks like this

@Composable
private fun getNokString(amount: String): AnnotatedString {
    return buildAnnotatedString {
        withStyle(
            style = SpanStyle(
                fontFamily = MaterialTheme.typography.subtitle1.fontFamily,
                fontSize = 40.sp
            )
        ) {
            append(amount.ifEmpty { "0" })
        }
        append(" ")
        withStyle(
            style = SpanStyle(
                fontFamily = MaterialTheme.typography.subtitle1.fontFamily,
                fontSize = 14.sp
            )
        ) {
            append("NOK")
        }
    }
}

But when I assign a new value to

TextField

TextField(value = TextFieldValue(nokString),
          onValueChange = {
                 actioner.invoke(SendAction.OnNokChanged(it.text))
          })

The behaviour is unexpected: it appends the new result to the previous one. And I'm not sure how to handle this situation. Any ideas? Thanks in advance.

alorma

01/11/2022, 4:47 PM

Hi all! Is there a (out of the box) way to obtain the Hex value (as #aaxxyyzz) from a given

Color

Colton Idle

01/11/2022, 6:28 PM

If I have a Container composable that takes a list of other composables to display, and can display that list in a Row, is there any way to add a modifier to each composable, even though I don't know what each composable is?

fun SomeContainer(
    content: List<@Composable () -> Unit>)
  Row(
         Modifier.horizontalScroll(rememberScrollState()).height(IntrinsicSize.Min),
        ) {
            content.forEach {
                it(Modifier.fillMaxHeight()) <----- Anyway to get something like this
            }
        }

Wrapping it in a box for example doesn't help me, because although the box will get the modifier, the composable inside the box will not draw to fill max height.

mattinger

01/11/2022, 7:03 PM

So we have a MainActivity that’s mainly xml. But we’re starting to use compose for certain parts of it, and some of the things in there need to popup things like bottom sheet dialog. I was trying to write a declarative bridge that would do this, but i’m having trouble with the Preview annotation. I’m assuming we’re using FragmentActivity (because we always extend that in some indirect way). However Preview uses PreviewActivity which directly extends ComponentActivity. As a result, i can’t get access to the supportFragmentManager in order to show the dialog. Any suggestions? (code in thread)

Andy Himberger

01/12/2022, 3:28 AM

I am seeing some problems if a LiveData is updated in quick succession from a coroutine with postValue, that the compose observers are not always updated with the final value. If I insert a delay everything does work, its also odd because I am using the same Composable twice in my tree and one of them updates and the other doesn't, all of this seems more likely to happen (keeping old state) when the children are more expensive to update. It feels like if you have 2 updates, and the 2nd update comes in before the first one has completed recomposition, that first one when it ends is saving its state as if it did consume the update. (More in reply)

🤔 1

Deepak Gahlot

01/12/2022, 6:46 AM

Hi All,

yschimke

01/12/2022, 10:00 AM

Is there an easy way to disable events for the top layer of Box. I essentially want a debug only overlay, that doesn't stop the events being handled in the normal UI below.

Box {
  Content()
  Overlay(modifier = Modifier.ignoreTouchEvents())
}

Marco Righini

01/12/2022, 11:31 AM

Hi everyone, we are using a remote build machine. At the end of the remote compilation we are syncing back the apk from the remote build machine to the local machine. Compose previews are not working when building remotely (previews are empty) but working when building locally. The suspect is that we need to sync back not only the apk but other generated build files related to previews too. What are the build files that are compiled for showing the previews in Android Studio?

Jaime

01/12/2022, 3:18 PM

hi everyone, do you know any way or best practice to make the compose views responsive for all devices, I am doing with constraintlayout as in xml but it doesn’t work very well on small devices

Marcin Wisniowski

01/12/2022, 3:25 PM

How can I put a bigger composable in a smaller parent (both with fixed sizes), so that it's clipped? (like would happen by default with Views) My child composable just resizes itself to fit into the parent, which I don't want. I tried using

requiredWidth()

but that centers it inside the parent (it overflows to both sides), where I want it left-aligned and clipped on the right.

✅ 1

Stylianos Gakis

01/12/2022, 5:02 PM

A question about

derivedStateOf

for when we want to calculate some result using composable’s parameters vs using local mutableState objects. More in thread 🧵

myanmarking

01/12/2022, 5:46 PM

Having something like this:

fun someComposable(enabled: Boolean){

var valueField by remember{

mutableStateOf(..)

val errorInternal: Boolean = remember(enabled, valueField) {

derivedStateOf(valueField && enabled)

I need a state that depends on another state and a variable. derivedStateOf is for state only. This works but is this the correct approach?

Colton Idle

01/12/2022, 7:17 PM

Compose Version 1.2.0-alpha01 out today 🎉 Notable changes (in my opinion): • kotlin 1.6.10 (even though we technically had this last release) • New parameter

userScrollEnabled

was added to

LazyColumn

LazyRow

, and

LazyVerticalGrid

in order to allow users to temporarily or permanently disable the user initiated scroll via touch gestures or accessibility actions. Scrolling programmatically via the methods on the state will still be allowed. (I7eae9, b/201150093) • Added Wear OS device ids to Preview devices list (I93232) • Fixes

TextField

cursor handle not hiding when scrolled out of view. (I14552, b/208883748) •

ModalBottomSheetState

now has a

isSkipHalfExpanded

flag. It can be either set through the constructor or updated later on by setting `ModalBottomSheetState`'s

isSkipHalfExpanded

property to

true

. Updating `isSkipHalfExpanded`'s value causes a recomposition of the sheet. (I18b86, b/186669820) Edit: Can we get a slackbot that posts releases and release notes? lol

🎉 8

🙌 3

👀 8

Bojie Jiang

01/12/2022, 8:01 PM

I found app background mix up when turning to dark theme as below, we can see Text background layers overlapping. Is there an easy to debug this issue? Thanks!

brabo-hi

01/12/2022, 8:05 PM

Hi all, when inside a compose component, how could we listen to the activity event

override fun onNewIntent(intent: Intent?) {}

Colton Idle

01/12/2022, 8:43 PM

Out of curiosity. if I just wanted to "watch" what updates are going into compose, would I just broswe this list for the most recent changes to get excited about? https://android-review.googlesource.com/q/project:platform%252Fframeworks%252Fsupport+branch:androidx-main or is there a better set of params to view what CLs are created?

Simon Stahl

01/13/2022, 12:29 AM

Hi everyone. I was wondering what a good solution for the

Flow operator functions should not be invoked within composition

warning is Say I have following method in my VM:

@Composable
fun getValue() =
    flowOf(1, 2, 3)
        .map { it.toString() } // warning here
        .collectAsState(initial = "")

The naive solution is to just split the method up

fun getValueFlow() =
    flowOf(1, 2, 3)
        .map { it.toString() }

@Composable
fun getValue() =
    getValueFlow()
        .collectAsState(initial = "")

But that is not really a functional change and if there is an issue with flow operations, then we would still have it. What would be a real fix for this warning?

Cristian Rosa

01/13/2022, 3:21 AM

Does anybody know if there is any issue with androidx.compose.material3
v1.0.0-alpha02
and setting (according material 3 specification) right color on TextButton

TextButton(
    onClick = onConfirm,
    enabled = onConfirmEnable,
    colors = ButtonDefaults.textButtonColors(
        contentColor = MaterialTheme.colorScheme.primary,
        disabledContentColor = Color.Red,
        containerColor = Color.Transparent,
        disabledContainerColor = Color.Transparent,
    )

Doing by this che color always have primary color even when it’s disable…..I know those “transparent” look ugly, they were just for test it quicker! 😄

FunkyMuse

01/13/2022, 8:35 AM

hey guys, is there something like

afterTextChanged

for TextInputField in compose?

Michael Bichlmeier

01/13/2022, 9:25 AM

Hey guys. Does anyone of you knows a compose image zoom library like this https://github.com/igreenwood/loupe ? Overall requirements for our view: • Show image in fullscreen • Image zoom in/out with pinch gesture • double tap for zoom in/out (by percent) • Pager for multiple images • Image description overlay • Swipe to dismiss I know we can implement things like the last two points quite simply by our own, but maybe there is already a library with all these features 😉

Ankit Shah

01/13/2022, 10:14 AM

Hello Everyone, I need to add a lazyVerticalGrid inside a scrollable column. How can I achieve it? for example:

Column(modifier = Modifier
    .padding(it)
    .fillMaxSize()
    .verticalScroll(scrollState)
){
Box(){
    Text("Sample Widget")
}
Box(){
    LazyVerticalGrid(cells = GridCells.Fixed(3)) {
                items(3) { index ->
                    val item = index
                    Text(text = "Item $item")
                }
            }
    }
}

xxfast

01/13/2022, 11:00 AM

Hi all, trying to use

androidx.compose.material3:material3:1.0.0-alpha03

, and i’m running into this when building the app

e: java.lang.IllegalArgumentException: Failed requirement.
	at androidx.compose.compiler.plugins.kotlin.lower.ComposableFunctionBodyTransformer.visitNormalComposableCall(ComposableFunctionBodyTransformer.kt:2660)

Full trace in the thread. I’m using kotlin-1.6.10

elye

01/13/2022, 12:43 PM

Is it possible to make a passed in variable (i.e. MutableState) still a delegate, so I can assign to the value directly (instead of using the

.value

)? More info on my question on https://stackoverflow.com/questions/70696585/can-we-still-use-the-variable-delegate-for-variable-pass-through-parameter

Ankit Shah

01/13/2022, 1:04 PM

https://kotlinlang.slack.com/archives/CJLTWPH7S/p1588253042070100 This is a 2 years old issue. I am stuck in the same. Does anyone have solution to this?

ste

01/13/2022, 1:30 PM

I'm getting a

ClassCastException

with the following minimal snippet:

var something by rememberSaveable { mutableStateOf(0) }
val value by rememberSaveable(something) { mutableStateOf("Hello") }
val somethingElse by rememberSaveable { mutableStateOf(false) } // !!!

println("value: $value") // !!!

Box(
    modifier = Modifier
        .fillMaxSize()
        .clickable { something += 1 }
)

However, after

something

is changed, it throws

java.lang.ClassCastException: java.lang.Boolean cannot be cast to java.lang.String

on configuration change. I know the example doesn't make sense, but is this a bug or whatsoever?

👀 1

K Merle

01/13/2022, 2:01 PM

How to prevent autoscroll on LazyColumn update if item index 0 is not visible?

Stylianos Gakis

01/13/2022, 3:07 PM

Question about Android Studio tooling for compose animations. More in thread 🧵

efemoney

01/13/2022, 4:31 PM

How can I require only a specific set of composable functions be called inside the scope of one of my slots. My use case is I have an “action bar” slot that can contain any number of

ActionItem(...)

composables up until a maximum number (eg based on available space, only 3

ActionItem(...)

s allowed). Is this enforceable at compile time? (eg something like coroutines’

@RestrictedSuspension

) 🤔 or can it only be implemented as a custom

Layout

(that maybe checks, at runtime, for a particular

parentData

type)?

Title

efemoney

01/13/2022, 4:31 PM

How can I require only a specific set of composable functions be called inside the scope of one of my slots. My use case is I have an “action bar” slot that can contain any number of

ActionItem(...)

composables up until a maximum number (eg based on available space, only 3

ActionItem(...)

s allowed). Is this enforceable at compile time? (eg something like coroutines’

@RestrictedSuspension

) 🤔 or can it only be implemented as a custom

Layout

(that maybe checks, at runtime, for a particular

parentData

type)?

Casey Brooks

01/13/2022, 5:34 PM

Requiring specific methods is kind-of against the philosophy of compose. A better solution is to use a "scope object" as the slot lambda's receiver to expose and encourage the correct APIs for that scope, while giving users the flexibility to do something different if they need to. This is done commonly throughout the Compose/Material stdlibs for reference (for example,

Column()

ColumnScope

Box()

BoxScope

, etc)

➕ 3

Alternatively, if it does truly need to be restricted, don't use a slot. Pass configuration parameters or a builder object to the function instead

➕ 1

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