Looking at

compose-navigation

, it seems like the api is quite akward to use. It requires predefining routes with Strings, and then specifying those Strings again when you want to navigate to those routes. And then passing parameters into the routes is a whole world of complication. What will you do when you need to pass real objects? Serialization? Why not a solution that looks like this, in the way Flutter did it?

onClick = { navigate { TheOtherComposable(obj1, obj2) } }

is there any Date/Time picker for compose?

The app should not search immediately when the text changes, but only after an interval.

var result by remember { mutableStateOf(emptyList<String>()) }
val (query, changeQuery) = remember { mutableStateOf("") }
LaunchedEffect(subject = query) {
    delay(300L)
    stations = getResultFromWebServer(query)
}
BasicTextField(value = query, onValueChange = changeQuery)

Is this the correct way to do it?

Hey, I want to access

MaterialTheme.colors.background

inside my

transitionDefinition

but I as this function is not marked with

@Composable

I am getting this error

@Composable invocations can only happen from the context of a @Composable function

Is the

transitionDefinition

function made non-composable on purpose? How can I make access these values inside

transitionDefinition

? My use case is to have different values for light and dark theme. Something like this…

private val SomeTransitionDefinition = transitionDefinition<SomeState> {
    state(SomeState.State1) {
        this[backgroundColor] = if (MaterialTheme.colors.isLight) MaterialTheme.colors.primary else MaterialTheme.colors.secondary
    }
}

Hi! Sorry I have a dumb question but can’t seem to figure it out. I created a reuseable listing component for pagination here

fun <T> VerticalListingComponent(
    itemList: List<T>,
    loading: Boolean,
    loadNextPage: () -> Unit
)

and am calling it through this

VerticalListingComponent(
    itemList = itemListingState.listings,
    loading = itemListingState.loading,
    {}
)

When I update the itemListingState the VerticalListingComponent seems to be consuming and displaying the new itemList properly, but it seems to be ignoring the loading boolean that I’m passing (I have a loading indicator that shows when loading = true). Does anyone know what I’m doing wrong?

Is there an existing implementation of a modifier/component to reorder the elements of a LazyColumn with a drag handle?

Hi, is there a jetpack compose component that loads images from a url like picasso?

Is there a way to get an undecorated TextField in compose?

Hello. Has anyone has an sample multi-module project with enabled Compose in some module? I'm trying to migrate some feature to Compose and project can't build at all. As I know, compose has a conflict with kapt and kotlin-android-extensions, but I don't have this one in project.

anyone came across this error before in compose?

I'm exploring the navigation library with compose, I get that the navigation is string based, so any arguments I want to pass to the composable must be inserted in the route string. I have 2 screens. In the first screen the user creates a

SearchRequest

to pass to the second screen that uses it to fetch the items from a web server.

data class SearchRequest(
    val departFrom: String,
    val arriveAt: String,
    val departureTime: Time, // data class with day, month and year
    val departureDate: Date // data class with minute and hour
)

What's the best way to translate this object to a route without parcelizing it?

I have a WebComponent Composable that's implemented with the legacy view interop:

AndroidView(viewBlock = { webView })

. This will load most webpages, but it fails to load resource intensive iFrames such as an interactive elections map graphic. I added the hardware acceleration tag to the app's Manifest, but still no luck. A log shows that the Fragment's rootview is hardware accelerated, but the Composable's AndroidView is not. The docs state that hardware acceleration is only possible through the Manifest's application or activity tags, or programmatically through the Window. I'm wondering if AndroidView doesn't support this yet if it isn't attached to the Activity or Window under the hood. Has anyone else encountered difficulty with hardware acceleration with AndroidView interop? Code snippet in the thread.

I'm struggling to implement a rather simple behaviour (automatic navigation without user interaction) using the recommended Architecture pattern where only a ViewModel is passed to a Composable and some navigation block to trigger on a user interaction. I've tried to pass a route as a State to the Composable (which triggers navigation when not null) in order to treat it as simple data in the ViewModel but I'm then stuck because when the user hits Back it navigate him back to the most recent screen automatically. I think I would need some kind of transient state which is restored to null when processed by the Composable view but I really don't know how to do it... Any input/help would be very very appreciated 🙏

Is there anyway to Stroke and Fill a path at the same time using jetpack compose. from the source codes I can only see

Fill

and

Stroke

but i need something like

StrokeAndFill

Hello) I try to add Compose into existing project, copy paste all necessary dependencies from sample project but during compilation receive very interesting error 😄 Gradle build tools: 4.2.0-alpha16

e: androidx.compose.compiler.plugins.kotlin.IncompatibleComposeRuntimeVersionException: You are using an outdated version of Compose Runtime that is not compatible with the version of the Compose Compiler plugin you have installed. The compose compiler plugin you are using (version 1.0.0-alpha07) expects a minimum runtime version of 1.0.0-alpha07.

Hey guys. I'm sorry I'm still pretty new to Compose. I want to achieve this type of behavior. could anyone point me in the right direction? Should I use the Swipeable modifier? Thank you in advance

Are there APIs for image convolutions in Compose (on

ImageBitmap

)? In general, there doesn't seem to be a way, maybe by design, to get access to the underlying pixel information for direct manipulation.

AndroidImageAsset

and

DesktopImageAsset

go through a somewhat of a contortion to expose the underlying pixel information to the

ImageBitmap

, but I don't see any way to get those pixels afterwards.

In the

Jetchat

app, if you click on any of the chat messages prior to engaging message input, and then try to type a message, the input field won't trigger the keyboard to show up. Is this a known issue and are there any workarounds for it? I experience pretty much the same behavior in my project when I first click outside an input field and then on it, it seems to obtain the focus but the soft keyboard doesn't appear.

I’m trying to

remember

a state on each item of a hoisted list. The idea is that an item’s state is remembered even if the list has been updated. Is it possible right now?

@Composable
fun Component(list: List<T>) {
  list.forEach { item ->
    // something like this but this won't work
    // this should stay as false if (someCondition) for the unchanged iteems even if the list is updated
    val rememberedFlag = remember(item) { mutableStateOf(true) }

    if (someCondition) rememberedFlag.value = false
  }
}

Edit: ^Actually works apparently

After filing https://github.com/JetBrains/compose-jb/issues/108 I took a look at the implementation of

ImageAsset

as

AndroidImageAsset

and how it's painted in

AndroidCanvas.drawImage

- where it is explicitly checked to be an

AndroidImageAsset

. So even though

Canvas.drawImage

accepts

ImageAsset

, it's going to accept a very specific implementation of that interface - one on Android and one on desktop. Is there a way to create an

ImageAsset

at runtime dynamically? Not from a resource, not from a file, but by populating each pixel individually as an int array, and then "wrapping" that array as an implementation of

ImageAsset

that is platform agnostic?

There are examples of creating an empty

ImageAsset

and drawing on it - such as

ImageAssetSample

, but it's a chicken-and-egg problem. In order to be able to draw a dynamic "bitmap" onto it, such a bitmap would first need to already exist.

What is wrong with this animation? It is supposed to change size to 100.dp when clicked but does nothing.

val size1 = animate(300.dp)
val size2 = animate(100.dp)

var aSize by mutableStateOf(size1)
Image(vectorResource(id = R.drawable.video), modifier = Modifier.size(aSize).clickable(onClick = { aSize = size2 }).background(Color.Red))

I haven’t used compose navigation yet, but for those who are, does it prevent accidentally navigating to multiple destinations at a time? For example, a button that navigates to another screen is clicked multiple times, or multiple buttons navigating to different destinations are clicked at the same time. In pre-Compose multiple Activity approach this problem doesn’t happen as the input is blocked when you start an activity immediately on click. Wondering if I need to debounce all my navigation clicks.

Is this correct?

A MutableState only lasts in a single composition and it is lost in the next composition unless we remember it with

remember

.

Sorry if this question already been asked, but is it possible to run latest compose alpha with AGP 4.1.1? decided to upgrade from alpha03 to alpha07 but gradle can’t resolve compose-compiler-1.0.0-alpha07 =(

savedInstanceState

doesn't work in a NavHost. This sample will always print '1'. Am I doing something wrong?

NavHost(navController, startDestination = "search") {
    composable("search") {
        var counter by savedInstanceState { 0 }
        counter += 1
        Log.d("counter", counter.toString())
    }
}

So I am going over a few YouTube tutorials on YouTube. The issue is that Compose is in Alpha and changing. Where can I find what is the most up to date info on component properties? I noticed that on

OutlinedButton

we can no longer set

backgroundColor

or

contentColor

and I am no sure of how to do this. I also noticed that

verticalGravity

is gone, but it has been replaced with

verticalAlignment

. While that was slightly obvious using auto-completion, I can't find the color properties. Or how I might navigate how to find these changed properties in the future. It seems

colors

is something I have to look at, but I am not sure how to execute this in code yet

How to give Line Spacing for Text view in Compose ?

I’m trying to enable Compose only on one module of my application, but to do that I need to use the latest version of the Android Gradle plugin. I tried with this:

buildscript {
    configurations.all {
        resolutionStrategy { force 'com.android.tools.build:gradle:4.2.0-alpha16' }
    }
}

but didn’t work 😞 Do you know a solution to enable Compose on a single module?