Will Compose solve also animations? Like moving widget from one position to another, or change scale, etc.

Hi all. the question might be a bit stupid, yet i want to ask it. 1)How does compose resolve layout? (each frame, build + cache, some kind of states), is it somehow relate to

onLayout

onMeasure

or so. Is it just a single view with 'draw' instructions genereated by compose? 2) Am i righre

+memo

- just cache for some kind of date to reuse and not to stere in memory twise,

+state

-some kind of 'model' that reatain state regardless activity state. And what is differences in those

Feedback on JetNews sample app: Many in-app composables use direct read access to global variables such as

posts

. This may work fine for simple app, but for complex app, the in-app widgets should be reusable and independent on some global state. Rather the data on which widget works should be passed as parameters. Even codelabs mention this: https://codelabs.developers.google.com/codelabs/jetpack-compose-basics/#4 I suggest that you keep actual

posts: List<Post>

as property of

MainActivity

(or its persisten state if needed), and pass this to widgets in parameters. Accessing global variables in widgets is antipattern by my opinion. I tried and it's easy achievable.

class MainActivity : AppCompatActivity() {
    private val posts: List<Post> = listOf(
        ...
    )

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
		// load or transform posts
        val posts = getPostsWithImagesLoaded(posts, resources)
        setContent {
            JetnewsApp(posts)
        }
    }
}

Same for

topics

and other globals.

Jetnews is mostly a showcase for widgets, not an example of how to architecture and app (see navigation for instance)

Won't we get some context into each composable function? Current

View

has

Context

which allows to load resources (strings, images), read configuration or even get

Application

object. Now I wonder if similar context may be there automatically, or we must pass it ourselves as paramater?

Compose seems legit to be crossplatform

In noble future when compose is released, activities, fragments, views will be annotated with

@Deprecated

?

Hello, does anyone have issue with kapt and compose? I cannot make it work within the same module but I can if kapt doesn't coexist in the same module with compose. I am getting

e: java.lang.IllegalStateException: Backend Internal error: Exception during code generation

What is the official name of these

@Composable

functions (or result that they create on UI tree)? Widget, node, component or else?

Components, composables, composable functions

How to understand

measurement

and

intrinsic measurement

?

Why is compose using framework dialogs and popup windows instead of replicate them with composable functions?

I'm trying to replicate flutters Listview widget but don't really know how to do it. Is it possible with the current apis? I already tried to only layout placeables that are in a specific range and it kind of works but is really slow. So i guess thats not the way to go.

Any idea when Compose will be production ready? I am starting a new project and first customer review is December 2020. Should I start it with Compose, or ...?

@Preview

annotation is not available in

android-x-master

repo, is it? Just synced, AS 4.0 is now bundled 👏🏼

I noticed that some questions are getting asked again and again at this channel and it is really hard to dig into numerous threads to find an answer without posting, so I decided to create a FAQ about jetpack compose. Feel free to contribute, if you think that I missed something important. Let’s make a good ground for others to start from https://github.com/Mishkun/jetpack-compose-faq

Am I the only one getting this?

Hi there, I'm currently doing a small pet project and trying out compose. For what I've seen so far, also including the JetNews app in google samples repo, it seems that the way of using Models is by putting them in some global scope and accessing them from the calling site + modifying with mutable states. Is this the intended behaviour? Or would it be possible to use a more direct functional/reactive approach of passing updated states from an upstream?

changed the approach as Leland suggested

I am getting this error when trying to import the Jetnews sample app. Does anyone know why?

What architecture is better to use with compose. I think MVP looks not bad

Can I use intelij with some version of Android plugin to compile Compose insisted of Android Studio?

Currently compose needs minSdk 21. Will the final released version support lower API levels?

Hello everybody, I'm trying to make a little PoC with Compose and I have encountered something I cannot explain. The code can be found here : https://github.com/bmonjoie/ComposeTipsCalculator/blob/master/app/src/main/java/be/xzan/composetipscalculator/MainActivity.kt As you can see, I have my

@Composable

functions as top level functions. but it brings a weird behavior. Before, those functions were part of

MainActivity

and the behavior was the one you can see in attachment. Meaning, when I would change a

TextField

, it would stay focused. If I move the function as top level functions, it adds a new line on top but keep it focused on the empty one. The only difference between the two are were the functions are. Can somebody explain ? PS : I have tried adding

@Pivotal

or

key(position) { ... }

around the

Entry

but it doesn't change anything.

Hi! Going through Compose Tutorial. Few things strike me (naming related): •

DrawImage

component name feels a bit weird when used in a declarative framework. It sounds like a command to be executed rather than something describing a component. Following this we should've had

DrawText

instead of

Text

, no? 🙂 •

Column(modifier = ...)

. Here

modifier

also feels like a name that is way too generic. I mean isn't each and every argument of

Column

component a modifier in some sense (it modifies its behavior/view)? I wish it would be more specific into what exactly it modifies

APIs aren't final yet :)

what about

.toDp()

are we going to get a

toDip()

? 😆 did anyone raise this at the time? 🙂

Is there any example of lists sticky headers and footers (horizontal and vertical), and multi-level sticky headers/footers (like one sticky header, plus a second one for a subset of the bigger data chunk for very long lists)?

I have to display a stream of data (at least 1000 items), every

add

to

ModelList

reloads the view, no? Because of that while the items are being loaded the app lags quite a lot, do I have to implement something like a pagination myself or is there a way to optimize such thing out of the box?