Hey o/ I was trying to implement a slowly moving background for a project using compose. I started using the canvas, paths and bezier curves for that. With that approach I’m having trouble making the waves, well… wavy… Then a colleague suggested using animated vector resources. It works more or less… I can use it and animate between paths to achieve the waves… but… using the

animatedVectorResource

and the

AnimatedImageVector

’s

painterFor

, it seems that all I can control is the direction of the animation with

atEnd

. Is there a way to get more control over the animated vector animation? I’d like to be able to loop the animated vector’s animation infinitely. Ideally with multiple steps to the animation (to improve the waviness of my background)

Hey everyone, I'm getting a weird bug with LazyRow... for some reason, when I scroll through 4 cards, the next cards are EMPTY! When I scroll back, the old cards are also empty... What am I doing wrong?

@Composable
fun HeaderCards(users: List<User>) {
    LazyRow(
        contentPadding = PaddingValues(horizontal = 10.dp),
        modifier = Modifier
            .fillMaxWidth(),
    ) {
        items(users) { user ->
            HeaderCard(user)
        }
    }
}

I'm struggling to draw a Painter to a Bitmap. The confusing thing is that the docs for painter say

In addition to providing the ability to draw into a specified bounded area,

Painter

provides a few high level mechanisms that consumers can use to configure how the content is drawn.

However, the entire public api is just the property

intrinsicSize

and the extension function

DrawScope.draw

. Confusingly

draw

doesn't take the painter as an argument, so I'm not sure how it could work. This is as far as I got:

val painter = painterResource(R.drawable.marker)
    val size = painter.intrinsicSize
    val image = ImageBitmap(size.width.roundToInt(), size.height.roundToInt())
    val canvas = Canvas(image)
    CanvasDrawScope().draw(LocalDensity.current, LocalLayoutDirection.current, canvas, size) {
    }

Any Compose folks want a method sample trace to see a pathological case of scroll delay in LazyColumn?

I need to have a composable and an android view collaboratively detect pointer events in a view. I want the composable to get access to the events first, and decide if it wants to exclusively handle them or if it wants the view to see them as well. Because I need to switch which composable renders above the android view without recreating the android view, (I think) I need them to be siblings.

Box(Modifier.fillMaxSize()) {
        AndroidView(/* ... */)
        
        when (foo) {
           is Bar -> Box(Modifier.fillMaxSize().pointerInput(key) { /* ... */ }
           is Buzz -> Box(Modifier.fillMaxSize().pointerInput(key) { /* ... */ }
           / * ... */
        }
}

The problem is both

Modifier.pointerInteropFilter

(even returning false) and

Modifier.pointerInput

(even with an empty block) prevent the view from seeing any pointer events.

Does Compose have a concept to explicitly ask for a recomposition? I am currently using some dummy state for that but that looks awkward.

how to Localization my app in compose without string XML file

How to modify padding inside TextField ?! The default text padding is very tiny I want to modify it without give more height to the whole TextField Is any one have an idea how to do it ?!

Does the automatic saved state population of navigation arguments only work with HiltViewModel or is it also populated when using Koin for instance? Or do I need to use hiltNavGraphViewModel? (as shown here: )

I had a piece of code that behaved in a way that I cannot understand:

//causes infinite recomposition
    val playerUiStateWrong by player.observeState()
        .map { PlayerUIState(it, sound) }
        .collectAsState(PlayerUIState(null, null))

    //works fine
    val playerState by player.observeState().collectAsState(PlayerState.Stopped)
    val playerUiState = PlayerUIState(playerState, sound)

I thought they would both do the same thing, but the first one, whenever I use

playerUiStateWrong

as a parameter in a modifier, causes infinite recompositions, whereas the second one works fine.

Can somebody help, need help in gesture part of jetpack compose https://stackoverflow.com/questions/67752131/long-press-gesture-in-jetpack-compose

Went into the beta and tried to make a new project with an empty Compose view. That didn’t work. So I did upgrade to beta 3 from Canary and cannot make a new one here either.

✅ [RESOLVED] What does it means? 🤔

I'd like to use the Palette API to generate the dominant color from a remote Image inside a ViewModel. I am a bit confused as to how to retrieve the Bitmap when using an image loading library such as Coil that's included into Accompanist. Anyone got ideas? FWIW, this is what my image loader code looks like right now

Since there's not a compose exposed dropdown menu yet I built one myself (there's a WIP patch somewhere, but it uses a lot of compose internals so it's hard to copy). I'm happy with how it looks, but not with the complexity of the code. Is there a way to avoid needing subcomposeLayout but get the same result? Thanks! https://gist.github.com/danielzfranklin/a54260971aa51b2e2c4140c741f7650b

✅ [RESOLVED] Anybody who can help me with Koin and Navigation Compose? Android Team said in a video that its possible to extract the passed in navigation arguments from the saved state handle. They used Hilt in their video, but i want to use Koin. This is how I am currently trying to achieve it, but the ID that I am passing to screen is null regardless.

Hi, is there any example of how can i use Navigation Compose 2.4.0-alpha01 new method currentBackStackEntryAsFlow(), I noticed @cb Tivi project is using this approach do we still need OnDestinationChangedListener or we can achieve the same with currentBackStackEntryAsFlow()?

Hi folks. Please help. I have crash

java.lang.IllegalStateException: pending composition has not been applied

in this code. Where I’m wrong?

Hey everyone, is there a way to assign a weight sum to a Row, like there is with LinearLayouts? For example, I have this:

Row {
    columns.forEach {
        Card(Modifier.weight(1f))
    }
}

In my case the number of columns is dynamic, and the max number of columns is 3 And I get a row looking like this, when I have 3 columns: (each card has weight 1) [ ] [ ] [ ] And when there is only 1 column, I get this: (each card has weight 1) [ ] I wanted to get this: (each card has weight 1, weight sum is 3) [ ]

Please tell me how to add the addOnDestinationChangedListener correctly

How are people tracking selection state in

LazyColumn

? Something like this multi-column layout (which might be for tablets on Android, or for larger screens on desktop) where the middle column is a lazily loaded list of articles / emails / etc, and the right column is the full detail of the selected element.

How can we make a Box zoomable, I did try it images and it works fine. But i want to make a box zoomable (like it can grow and shrink depending on user gesture)

val scale = remember { mutableStateOf(1f) }

Box(modifier = Modifier
    .height(250.dp)
    .fillMaxWidth()
    .background(color = Color.White)
    .graphicsLayer(
        scaleX = maxOf(.5f, minOf(3f, scale.value)),
        scaleY = maxOf(.5f, minOf(3f, scale.value)),
    )
    .pointerInput(Unit) {
        detectTransformGestures { centroid, pan, zoom, rotation ->
            scale.value *= zoom
        }
    }
)

Hi, I am playing with Dialog and vertical scroll, when I click a button inside Dialog, it scrolls to top. How can I keep the scroll position intact on button click?

Hi everyone! 😄 I tried creating Neumorphism UI with Jetpack Compose. You can take a look at the lib/code here - https://github.com/CuriousNikhil/neumorphic-compose I’m learning this and probability of the code being correct/holding best practices may be less. 😅 I’ve a couple of questions. The idea is simple, I’ve created a custom modifier by extending the

DrawModifier

and I’m drawing the shadows using

contentDrawScope

provided by

DrawModifier

. 1. First of all, Is this a correct to extend the modifiers? 2. To render the shadows(GradientDrawable) smoothly, I’m using RenderScript (I know it’s going to be deprecated in the Android12. I’ll migrate.). I need

context

param to invoke renderscript api. Is it okay to pass

context

param in the Modifier?

I have a very peculiar use case for a

TextField

/ text input. I'm building an app for mobile phones that have hardware barcode scanners. When the user scans a barcode, the actual barcode is transmitted as a sequence of key events. In a

View

world I have an

EditText

that is focused, so when a user scans a barcode, its value is entered into the

EditText

and I can just do

editText.text.toString()

to get the value of the scanned barcode + the user sees what was scanned. As the user is expected to use the barcode scanner for input, the on-screen software keyboard must not be shown. This was easy to do with

EditText

. Now I wanted to replicate the same functionality in Compose using a

TextField

. Unfortunately, I can't find a way how to do that. If you specify

readOnly = true

, then the

CoreTextField

doesn't use the

TextInputService

and the TextField is not listening for any input key events. It seems that

readOnly

is suited for cases where we'll just display data, like a Calculator app. Then I went deeper into `CoreTextField`'s implementation and decided to try another approach. I created a composable that didn't use any

TextField

. Instead, I got a reference to the

LocalTextInputService.current

, created an

EditProcessor

instance and called

startInput()

like so:

@Composable
fun ScannerInput() {    
    val textInputService = LocalTextInputService.current
    var textFieldValue = remember { mutableStateOf(TextFieldValue()) }
    val editProcessor = EditProcessor()

    textInputService?.startInput(
        value = textFieldValue.value,
        imeOptions = ImeOptions.Default.copy(singleLine = true),
        onEditCommand = {
            val newValue = editProcessor.apply(it)
            Log.d("Scanner", "onEditCommand: $newValue")
        },
        onImeActionPerformed = {
            Log.e("Scanner", "onImeActionPerformed: $it")
        }
    )
}

The thing is that down into the implementation of

TextInputService

, it's making a call to

showSoftwareKeyboard()

and the keyboard is shown 😞 Any idea what else I could try, as this is a core part of my app and the requirement is strictly never to show the on-screen software keyboard 🤔

Hey. Maybe someone can help me. After the change to

compose 1.0.0-beta07

various items disappear when scrolling in

LazyColumn

. I could reproduce the problem in a minimal example by inserting a

Box

inside a

LazyColumn

between

AnimatedVisibility

and the actual

Card

(the same happens with e.g.

Column

). Example in my answer

Can we expect to have kotlin 1.5 support in beta08?

Anyone know how to use accompnist/coil +

Crossfade()

? The docs state that you CAN crossfade, but not exactly how? I also looked at Owl sample app but didn't see usage of crossfade either.

How to determine in which direction lazy list is being scrolled?

Is it possible to animate AppBar navigationIcon appearance? I mean not only of navigationIcon anim in-out, but navigation title slide. I mean exactly smooth swithing between next AppBar states