I have a problem with Accompanist image loading crashing my app, error in thread

Does Compose have a concept like Flutter’s Provider classes? It would be nice to provide and instance of a class at a high level and easily retrieve it at a lower level

How would you go for finger "hover" detection? I have a grid of boxes and I want the user to hold their finger and drag onto the boxes, all the boxes that have been touched by the finger should be notified.

How do you mock

rememberLauncherForActivityResult

in Compose? With

registerForActivityResult

you could send in a

registry

parameter to prevent the real implementation from being called in UI-tests. However this is missing for the Compose equivalent.

is it possible to expand composable as much as possible, without using constraint layout. For example:

Column(
        modifier = Modifier.fillMaxHeight(),
        verticalArrangement = Arrangement.SpaceBetween
    ) {
        // How to expand this composable height as much as possible...
        Text(text = "long text over multiple lines", modifier = Modifier.fillMaxHeight())
        // ...without loosing sight of this one?
        Text(text = "long text over multiple lines")
    }

Does studio has support for Gradle's new version catalog feature introduced in 7.0 or I should stick with

ext {}

to define my dependencies so that studio can show a lint warning if there are any new version of library available?

If I have

val state = remember { ... }

and then below this line I have

Column { Box { Column { Component(state) } } }

, does it make any difference (performance or memory-wise) to have this state closer to its usage, i.e. should I put it in the innermost lambda rather than have it outside? I mean in this case none of intermediate composable lambdas need this state and this is known to stay like this. But having it "outside" is sometimes better for organizational purposes.

Does anyone know how to draw gradient line in compose? I see only end color

Has anyone else encountered this bug? If I use a Button with a Text(text = stringResources(...)), the text will be aligned to the bottom of the button (second image). However, if I use a string directly, everything works just fine (first image / 🧵 with the code and more info) (happening on both

beta-09

and

rc01

)

Hello, everyone! 👋 I’m having some issues with Instrumented Tests. Could you help me please? Basically my MainActivity contains a

LocalBackPressedDispatcher

to handle back presses. The code is similar to:

setContent {
    AlkaaTheme {
        CompositionLocalProvider(LocalBackPressedDispatcher provides onBackPressedDispatcher) {
            NavGraph()
        }
    }
}

But now my tests are failing with

No Back Dispatcher provided

but I’m not finding a way to provide it.

composeTestRule.setContent {
    AlkaaTheme {
        CompositionLocalProvider(
            LocalBackPressedDispatcher provides onBackPressedDispatcher //unresolved reference
        ) {
            NavGraph()
        }
    }
}

I tried with both

createComposeRule()

and

createEmptyComposeRule()

. Thanks a lot!

I just published Integrating Exoplayer in Jetpack Compose https://link.medium.com/RkCJIHkQFhb . Once more let us see the beauty of Compose

Can I request if a Composable like my ImageView is visible or has disappeared? I have a image gallery grid with 1000+ photos and if my ImageView is visible I launch a coroutine so set and fetch a thumbnail to display. But if the user scrolls quickly trough the gallery I want to cancel the request for loading the thumbnail as it's not needed. I use

rememberCoroutineScope()

but it looks like that "isActive" in the loading job still returns "true" even if it's not more on screen. To test that I have put into a delay of 1000ms. Is there something like "onDisappeared" that I can use to cancel my job? Or can I have that coroutineScope cancel the job automatic if it's no longer visible?

Why is

Modifier.swipeable()

in Material? This doesn’t feel like a behavior that is Material-specific, and some of the internal bits make it difficult to recreate swipeable components such as

ModalBottomSheet

in non-Material design systems

I wonder, how efficient this code is (🧵). Is this less efficient than just using composable lambda instead of AlertAction? Will AlertAction constructor (basically a function) allocate new ComposableLambda each time icon changes? If so, is it worse than slot api based impl? Intention is to solve this

What is "good practice" for defining dimensions in Compose? i.e. as plain "magic numbers" like `40.dp`/`12.sp` etc inside Composables, or extracting as constants in separate Kt file, or keeping them in XML?

I have an onClick listener right now and it's drawing a ripple with straight edges. How can I turn it into a circular ripple?

Is it possible to add contentPadding to HorizontalPager from Accompagnist ? Like it's done for LazyRow

Is there any way to define the width of an element after it had been measured in a custom layout?

Layout(content = {
   Composable1()
   Composable2()
   ComposableWhoseSizeDependsOnOtherComposables()
} { measurables, constraints ->
 // I measure all the elements and get the width i'd like the last element to be
 layout(width, height) {
   // I place placables for composable 1 and 2
   //
   // How can i make composable 3's width depend on the measurements I had made on 1 and 2?
 }
}

Does anyone know how can I scroll to the top when clicking BottomNavBar item again?

Should apps that define their own non-Material design system be using the new profile rules to create ART profiles for key theming Composables (e.g equivalents of

MaterialTheme

)? If so, do profile rules work in a library module (i.e. modules that are not packaged as AARs)? The release notes specifically say “Libraries can define these rules which will be packaged in AAR artifacts”, which seems to indicate perhaps not.

On Android 9 I have a strange artefact where

Column(modifier = Modifier.alpha(0.9f)) { Surface(elevation = 16.dp) }

is drawing drastically different shadow + gets clipped — compared to

alpha(1f)

. None of this happens on other SDK versions. Is this some known/reported bug?

Has anyone tried to use

animateColorAsState

to targetColor then back to initialColor with colors that have alpha? I'm running into seemingly a bug? with using alpha colors. It will animate to the desired color, then go back to almost initialColor but with some of the targetColor applied as alpha then back to targetColor and finally it will go to the initialColor again with no alpha.

What would be the correct way to center your LazyVerticalGrid? As you can see on the right there's more spacing due to how adaptive cells work.

Hello! I have been trying to make a color picker for Jetpack Compose (Desktop) because I couldn't find any.

Good Day everyone , I was finally able to release an app built purely on jetpack compose, please take a look. https://play.google.com/store/apps/details?id=com.rocketlabs.rockmal It's based around the myanimelist.net api and hence helps its users to track their anime list

Is it possible to limit a

LazyVerticalGrid

to specific number of rows or do I have to manually calculate how many items I need to pass to it in order to make it stay on the number of rows I want to show?

I’ve an idea. What if every composable function returns virtual custom Unit void in order to restrict composable function content types. We could convert these custom units to void at compile time. For example: We have a composable function which accepts only Text composable

@Cooposable

fun RenderSomeUI(modifier: Modifier, content: @Composable () -> TextUnit){

}

Is there an analog to TextLayout in compose? I’m trying to figure out the width of some text for animation purposes

I've heard that compose in release mode enables a lot of optimizations and feels more snappy. I wonder what does "release mode" mean here? I have a "custom" build type which has "debuggable = true; minifyEnabled = true", so I guess R8 does run. But app still feels not very snappy on older devices (especially around

LazyColumn

). Will setting

debuggable = false

improve things? Or maybe something else?