kotlinlang #compose

is there any reason that a mutable state flow wouldnt cause a composable function to reload its state when the value of the state flow has changed? I'm running into an issue where I'm changing the value of a mutable state flow but the composable function that collects it as state is not receiving the update or doing a rerender

Deepak Gahlot

03/15/2021, 3:49 AM

Hello, I'm using ActivityResults

val registerTakeFile = registerForActivityResult(
    ActivityResultContracts.OpenDocument()

and after updating to implementation "androidx.activity:activity-compose:1.3.0-alpha04" i'm getting an error

Can only use lower 16 bits for requestCode

Samir Basnet

03/15/2021, 6:34 AM

Any idea how to add that vertical dash before text without extra composable?

Samir Basnet

03/15/2021, 7:26 AM

Currently to shift focus to next textfield we have to write the logic manually, i was trying to create my own styled CustomStyledTextField composable to reuse it as form screen ,contains a lot of them but due to this focus logic being manual i find it hard to make resusable textfield . Is there an easy way or am i missing something?

Utkarsh Tiwari

03/15/2021, 11:19 AM

I created a custom Popup to appear around the button that triggers it’s visibility. However, for the buttons at the buttom of the activity, the popup overlays the Android Navigation Bar. Also the elevation keeps increasing (apparent from the increasing shadow range) on moving down the screen. Does anyone know how to avoid it from covering the Navigation bar at the bottom and fix the elevation issue?

Daniele B

03/15/2021, 1:37 PM

I having doubts about the Compose Navigation and Deep Linking. This is a simple master/detail app navigation. As you can see, I am loading the detail data, when clicking on a master list item. It works. But this wouldn’t work when deep linking to the detail screen, as it would show the DetailView without having loaded the data. Ideally, I would like to associate somehow the

model.loadDetailData(it)

call to the

composable("detail/{item}")

, but I can’t find a Compose API to do that. If I include the call inside the

composable

block, above

DetailView

, such call gets executed at each recomposition, creating a never-ending loop.

@Composable
fun Navigation(model: KMPViewModel) {
  val appState by model.stateFlow.collectAsState()
  val navController = rememberNavController()

  NavHost(navController, startDestination = "master") {
    composable("master") {
      MasterView(masterState = appState.masterState,
        onListItemClick = {
          navController.navigate("detail/$it")
          model.loadDetailData(it)
        }
      )
    }
    composable("detail/{item}") {
      DetailView(detailState = appState.detailState)
    }
  }

}

what is the right way to make it work with deep linking?

julioromano

03/15/2021, 1:54 PM

Weird scrolling issue when using
AndroidView
in
sheetContent
of a
BottomSheetScaffold
Please see the example code and video showing the bug in the thread.

✅ 1

Rick Regan

03/15/2021, 2:07 PM

I have a

Text

that gets recomposed even though its value is not based on mutable state. In particular, this happens when I include it in another composable that has a

Slider

with its own mutable state, and it doesn't happen when I put it in a separate composable (see thread for code). I know we're not supposed to depend on when recomposition happens or doesn't happen; I'm just trying to understand how Compose works (and avoid bugs that are hidden until code is refactored :) )

escodro

03/15/2021, 2:39 PM

Hello, everyone! 😊 Im having some questions about my implementation. Could you help me please? Basically I’m trying to create a new

State

wrapping the default

ModalBottomSheetState

and one

State

I created to handle which content should be shown for the user. The implementation is on the comments and I need help to understand if I’m correctly saving the

State

in order to use

rememberSaveable

with it. (It is working as expected, but I’m a little afraid of my “inner remember” inside the

Saver

😬) Thanks a lot in advance! ❤️

Denis

03/15/2021, 2:52 PM

Is it a known problem with theming in

beta02

? My app can switch from light to dark, but not back. And I can't understand what happened with it. It worked before beta02. https://kotlinlang.slack.com/archives/CJLTWPH7S/p1615651080120600

Zach Klippenstein (he/him) [MOD]

03/15/2021, 2:56 PM

New compose-backstack release is out: https://twitter.com/zachklipp/status/1371475164836196352?s=20

🎉 8

🔥 5

Daniel Candeias

03/15/2021, 4:30 PM

How can I have custom bullet point (color and size customisable), followed by multiline text, with bullet point aligned to first line? Something like this 👇 • This is a very long text which does not fit in one line

✅ 1

Shawn Tucker

03/15/2021, 5:24 PM

Is there a way to lock DrawerState open in compose?

oday

03/15/2021, 7:37 PM

I’m not sure how to refactor this code into the new SideEffect API’s which replace onCommit/onDispose as of alpha11

@Composable
internal fun Handler(
    enabled: Boolean = true,
    onBackPressed: () -> Unit
) {
    val dispatcher =
        (AmbientBackPressedDispatcher.current ?: return).onBackPressedDispatcher

    val handler = remember { ComposableBackHandler(enabled) }

    onCommit(dispatcher) {
        dispatcher.addCallback(handler)

        onDispose { handler.remove() }
    }
    onCommit(enabled) {
        handler.isEnabled = enabled
        handler.onBackPressed = onBackPressed
    }
}

the

onCommit

and

onDispose

methods are now unresolved, not sure what to replace them with or how

Dylan

03/15/2021, 8:09 PM

What's the best way to know the scroll direction of a LazyColumn? I'm currently using a LazyListState, and by keeping a reference of the last value of

firstVisibleItemScrollOffset

from LazyListState, I can compare it to the current value so if

lastOffset

is lower than

firstVisibleItemScrollOffset

, that means the user is scrolling down, however if

lastOffset

is higher than

firstVisibleItemScrollOffset

, that means the user is scrolling up. At least that's the result I was hoping for but unfortunately

firstVisibleItemScrollOffset

is often equal to

lastOffset

. So what is the best way to know the scroll direction of a LazyColumn? 🤔 (What I would like to achieve is similar to what we used to do with the XML Toolbar View using app:layout_scrollFlags)

Tim Malseed

03/16/2021, 2:02 AM

Hey all, I've got a bit of a code design problem, to do with holding observable state in a ViewModel, to be consumed by Composable functions..

Klaas Kabini

03/16/2021, 3:55 AM

Can someone explain to me how does nested navigation work in compose

Nathan Castlehow

03/16/2021, 4:30 AM

Hi, I have some values that are provided to my view model as a

MutableStateFlow

. I then want to “proxy” these through my view model to the view and expose them as something that the view can bind to. I want to avoid exposing them to the view as flows and then calling

collectAsState

inside the view as i want to keep most things inside the view model.

Jason Ankers

03/16/2021, 5:06 AM

Followup question to a discussion a while back: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1614609620302500?thread_ts=1614345603.389700&cid=CJLTWPH7S What would be the best way to collect a cold data source like this (scoped to the composable), but also keep a reference to it in the viewmodel? The viewmodel needs to keep a reference because we keep a bunch of

derivedStateOf

business logic inside it

Rafs

03/16/2021, 8:06 AM

How do I draw behind the status bar like this?

Deepak Gahlot

03/16/2021, 8:45 AM

Is there a way we can remove this default padding before the Text Cursor in Jetpack Compose

julioromano

03/16/2021, 8:50 AM

Has anyone affected by https://issuetracker.google.com/issues/182387688 found a workaround? It seems to me this pretty much makes

AndroidView

useless in 99% of its use cases.

✅ 1

😞 2

🇳🇴 1

fabio.carballo

03/16/2021, 9:05 AM

how could one anchor one view to be displayed on other? for example, anchoring a snackbar above a FAB?

:thank-you: 1

Geert

03/16/2021, 9:33 AM

2021-03-16 10:31:43.170 21227-21227/? E/AndroidRuntime: FATAL EXCEPTION: main
    Process: app.medxpert.medxpert, PID: 21227
    java.lang.ArrayIndexOutOfBoundsException: length=0; index=-5
        at androidx.compose.runtime.SlotTableKt.key(SlotTable.kt:2531)
        at androidx.compose.runtime.SlotTableKt.access$key(SlotTable.kt:1)
        at androidx.compose.runtime.SlotReader.groupKey(SlotTable.kt:619)
        at androidx.compose.runtime.ComposerImpl.end(Composer.kt:2065)
        at androidx.compose.runtime.ComposerImpl.endGroup$runtime_release(Composer.kt:1462)
        at androidx.compose.runtime.ComposerImpl.endRoot(Composer.kt:1147)
        at androidx.compose.runtime.ComposerImpl.composeContent$runtime_release(Composer.kt:2602)
        at androidx.compose.runtime.CompositionImpl.composeContent(Composition.kt:348)

:thread-please: 9

Geert

03/16/2021, 9:33 AM

I have this error when I download the App from the Google Play Store, but not when I start it from Android Studio. Can someone explain me what is wrong? I don’t understand it. I think it has something to do with LazyColumns. Since they are used where it crashes. It occurs on beta01 and beta02… I am not using any Dialogs like the other examples with this error.

Hatice Sarp

03/16/2021, 11:05 AM

I upload the file with workmanager. I want to observe the workmanager progress and show file upload progress in ui. I also update the progress variable with the high order function. The problem is my screen is constantly recomposed. I see that the progress suddenly reaches 100. In the following example in WorkManager codelab, it is done with viewbinding(https://developer.android.com/codelabs/android-adv-workmanager#4) How can I update progress bar on ui according to the progress of worker in workmanager ?

Arun

03/16/2021, 11:54 AM

Do we have to implement the error text ourselves or does

OutlinedTextField

include it somewhere?

Mjahangiry75

03/16/2021, 1:24 PM

I am using a

WebView

inside an

AndroidView

and it's so heavy, while it works smoothly in traditional way see the code in thread

oday

03/16/2021, 2:30 PM

also why does this happen? it seems ultra straightforward and should work ..