@Arkadii Ivanov has covered a pure compose navigation example by using

Decompose

in one of his recent blog posts. I was interested in decompose and had a look into this example but I can't figure out how it's restoring the scroll position of the

LazyColumn

when moving from the details screen back to the list screen. I'm looking for hours but I can't find the responsible piece of code. Can some please have a look and give me a hint? https://github.com/arkivanov/ComposeNavigatorExample

I am having two `Text()`composable in a

column

, can I control the vertical spacing between them, is there a way

I’m trying to create a Kotlin Multiplatform Compose app and having all kinds of build problems. Is there an example I can start with? Not sure if it is due to the latest alpha

https://twitter.com/AndroidDev/status/1363207926580711430?s=19 Does this language have a name? Is it Koxml? 😀

would it be possible that passing instances whose source code is in java confuse the composition? even when those parameters are wrapped with a kotlin class? I have a setup which includes an AndroidView where it is very easy reproduce that java and kotlin classes behave differently.

This message was deleted.

Im animating my sine curve indefinetly horizontaly, any better ideas how to do it ?

LaunchedEffect(key1 = Unit, block = {
    while (isActive) {
        delay(50)
        horizontalAnimation.value = horizontalAnimation.value + 2.dp
    }
})

Is it expected Behavior to recompose the items of LazyColumn on each scroll event ? I was try to log the composition count

LazyColumn(
    state = scrollState,
    modifier = Modifier.fillMaxSize()
) {
    item {
        LogCompositions("CompetitionDetailsScreenNew header")
         //Some item
     }
}

Is this a good channel for Skija / Skiko questions? Is there a more specific one? Should there be one? 🙂

I have

LazyVerticalGrid

with

itemsIndexed

over a property which is

mutableStateListOf

. Everything is working fine when I add items, but when I remove items via

remove

or

clear

on that list I get an exception trying to access non-existing items. It’s a call from inside the

itemsIndexed

, looks like it didn’t notice collection has changed. Is it a known issue or am I doing something wrong?

Well as much exited as i am for jetpack compose i am still worried about the Preview in Android Studio. It is in no way what i would consider usable . Takes forever just to show a simple Text composable . Can't imagine how slow it would be when need to preview complex composables. If we take current xml preview speed as 10 then compose preview is around 3. It's like no matter how productive jetpack compose is Android Studio drags it down

I still kinda lost in implementing a grid which would have fixed size of cells (like, square), and will fit as much cells on a single row as possible, and then go to next row. Lazy, scrollable, etc just like

LazyVerticalGrid

. I would prefer to have

GridCells

variant like

FixedSize(32.dp, 40.dp)

out of the box, but there is none. Can anyone give me a clue, please?

Has everyone set the Kotlin plugin channel to early access preview? When I updated to Compose alpha12 I had to do that (I think). My Android Studio is now a disaster. Autocomplete fails, or the suggestion popup disappears immediately so it's unusable. Some files can't open, or hang on "Loading..." or "Analyzing..." while pegging CPU. I can't get work done.

I have a sealed class

CanvasElement

and two subclasses

CanvasElement.Text

and

CanvasElement.Image

. Then I have a list like

val elements = mutableStateListOf<CanvasElement>()

. How can I recompose my composables when I change an element in my list to the same element but a different property which is only present in

CanvasElement.Text

and

CanvasElement.Image

and not in

CanvasElement

. Something like this:

sealed class CanvasElement(open val id: String, open val position: Offset) {
    data class Text(val size: Float, override val position: Offset, open val id: String): CanvasElement(id, position)
    data class Image(val size: IntSize, override val position: Offset, open val id: String): CanvasElement(id, position)
}

val elements = mutableStateListOf<CanvasElement>()

fun modifyElement(id: String, newElement) {
    // find index of id
    ...
    elements[index] = newElement
}

Then if I modify one of my text elements by changing its size, I want my Text composable to recompose:

modifyElement((myElement as CanvasElement.Text).copy(size = newSize))

@Composable
fun Element(element: CanvasElement) {
    when(element) {
        is CanvasElement.Text -> Text("text", size = element.size) // does not recompose when size changes
        is CanvasElement.Image -> ... // does not recompose when size changes
    }
}

But the recomposition isn't happening and the text size stays the same. Is it not possible? Do I have to keep separate lists for

CanvasElement.Text

and

CanvasElement.Image

?

Currently, I have created a compose-blur library to solve the same needs as https://issuetracker.google.com/issues/166927547. Now that I have finished the rendering of the static content, I am going to implement real-time blur, but I currently have some problem: 1. I want to know how to take screenshots of some widgets in compose, or their nodes, similar to the

findRenderObject().toImage()

in flutter, I really hope this exists, because the performance cost of cropping the widget area after using

PixelCopy

to screenshot the entire window view may be expensive. 2. I'm not sure if there is an api on compose that can monitor the changes of all components, similar to the native

View.doOnPreDraw

, if it does not exist, then I will try to refresh the blur by monitoring the changes of window view, but if it is invalid for compose, Then I may need to refresh every 100ms, which would be terrible!

I need to have a badge-like component that basically shows a number inside a circle. I’m trying to center number vertically inside a circle, but it always slightly higher than needed. If I add black background to the

Text

it has some space below the number. The text rectangle is centered, but not the text itself. How do I fix it?

Hello. On the old Transition API,

transition

s had

onStateChangeFinished

callback. Does anyone know if there's a similar callback on the new API?

Beginners question here: When do I use

ViewModel

and

LiveData

and when should I use

mutableStateOf

?

I've just started learning Compose (like an hour ago). I'm trying to create a google map view from the crane demo app (https://github.com/android/compose-samples/blob/23fef0091a7f952516fcbd489c84760892[…]ain/java/androidx/compose/samples/crane/details/MapViewUtils.kt) and I'm trying to take out the mapview section out of the code and put it into my app. I'm getting an import error for LocalContext and LocalLifecycleOwner.

import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.platform.LocalLifecycleOwner

Not getting much from google were these renamed possibly? Or do i need to add a dep somewhere

Is there a way to do some kind of absolute positioning? I’d like to draw content over other content conditionally, but I could use some tips on how to do so

Hi, I would like to know if there is an api in current compose that can capture the current composable as a bitmap 🤨? I need to capture the content of the widget separately to present some effects.I have seen that compose is rendered by a LayoutNode tree, so can we get a node content publicly? Although this is a bit against the principles of declarative programming... but it does require

Referencing my navController inside a

LazyColumn

seems to cause an infinite recompose loop. Anyone know why this might be happening?

I am confused about when to call

remember

. Should I wrap

remember

in all object initialization places?

Is it possible to use different Themes inside NavHost? I try to apply new theme in the

composable

but it doesn’t work

Is it just me or

Column(modifier = Modifier.fillMaxSize())

is overriding background set in

Colors(..., background = Color.Red, ...)

for the Material Theme. Not sure if it is strictly

Column

releated but if I remove it from the view hierarchy I am able to see

Color.Red

as the background.

Column

that I am removing has no background of its own. I fail to pinpoint if there is some material color that is taken by default for

Column

background. I have checked the source code and couldn't find any defaults taken f.e. from

colorPrimary

or else. Now I see it as a bug but maybe I got something wrong..

I am trying to put two text on the right side. Here is a code for it Click Here

How would you ideally represent an observable list of data, where each element also has a state that can be updated. In case a single element updates its state, the list state should ideally not be updated to avoid unnecessary recomposition, etc I suppose you can do better than a

mutableStateListOf<StateFlow<StateFulData>>()

or similar?

I am trying to follow the Android Developer’s guide on Navigating with Compose but it suggest to use

navController.navigate("yourDirection")

to navigate from a composable to another and my version of

navigate

don’t provide the right implementation. I am using

androidx.navigation:navigation-compose:1.0.0-alpha06

Is it possible to give a

TextDecoration

a separate colour from the text being decorated? TextDecoration