Why we must pass a param of "label" into TextField?Could it has a default value(null)?

What is the easiest way to convert a

androidx.compose.ui.graphics.Color

to a

ColorInt

?

I just tried to use

rememberCoroutineScope { Dispatchers.Default }

. When trying to build it leads to

e: org.jetbrains.kotlin.codegen.CompilationException: Back-end (JVM) Internal error: Couldn't transform method node:...

(full stack trace in thread). When using

rememberCoroutineScope()

without a custom context, everything works fine. Is this a known issue? Running

AS 4.2 Canary 9

and

1.0.0-alpha02

.

I need to provide in-app dark and light theme feature. Currently, I am changing theme using

isSystemInDarkTheme

but how to change theme using user input ?

is there a way to animate/create transition for

Composable

s getting "disposed". When changing state in compose it is usually done this way:

Surface(color = selectorExpandedColor, elevation = 3.dp) {
        when (currentSelector) {
            InputSelector.EMOJI -> EmojiSelector(onTextAdded, focusRequester)
            <http://InputSelector.DM|InputSelector.DM> -> NotAvailablePopup(onCloseRequested)
            InputSelector.PICTURE -> FunctionalityNotAvailablePanel()
            InputSelector.MAP -> FunctionalityNotAvailablePanel()
            InputSelector.PHONE -> FunctionalityNotAvailablePanel()
            else -> { throw NotImplementedError() }
        }
    }

(Note: Code above is taken from

JetChat

) But doing so, creates a jarring experience where contents just pops-out and pops-in in an instant. Is it possible to trigger/create transition or animation when changing states (animate composable out and then animate composable coming in)? Is there any guide for this out there?

LazyColumn

doesn't consider the contentPadding to show items https://issuetracker.google.com/issues/167913500 I've reported this bug almost a month ago but I mistakenly believed it was due to the translucent

TopAppBar

Hey. What is a RecomposeScope mentioned in the following paragraph (Sorry it sounds like a TOEFL question! lol)?

MutableState: A mutable value holder where reads to the value property during the execution of a Composable function, the current RecomposeScope will be subscribed to changes of that value. When the value property is written to and changed, a recomposition of any subscribed RecomposeScopes will be scheduled. If value is written to with the same value, no recompositions will be scheduled.

Hi I have been investigating Jetpack Compose couple of days. In Flutter and SwiftUI it is possible to have a shadow with different colors. But I could not find how I can achieve it in Jetpack Compose.

Will Compose support multiplatform? Any info on that?

What's the easiest way to create the equivalent of a grid layout recycler view currently? (not staggered) Thought of having a lazy list of column, where each line would be a row having n elements, but feels hacky

Is this a common known issue or I'm the only one having it - Interactive Preview is not working in AS 4.2 Canary 9 / Jetpack Compose

1.0.0-alpha02

/ Android Tools

4.2.0-alpha09

. AS goes into "Interactive mode", but when I start interacting, nothing happens (I have the simple demo with a button that shows the number of times it has been clicked. It was working in AS Canary 8 / Compose Alpha 1

Adding

clickable

modifier inside

LazyColumnFor

makes the scrolling jaggy. My first thought was that ripple effect has something to do with the lag, but, as I changed the indicator to

null

the problem is still there. here is link to my code in a thread related to this issue: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1599482698133100?thread_ts=1597241706.045300&cid=CJLTWPH7S

Alright I think I have a more complex bug today. I have an expandable Card (representing Articles). When collapsed, the Card contains the author and sources. When expanded, it also contains a longer description. The user can save the article by long pressing on the article (Obviously there will be a button for it, just to simplify the following sample code). A state representing the saving result will be displayed in the extended layout. So the user extends the article (by clicking on the card), the user long presses (on the card), and state might show up (uses

Random.nextInt(0, 3)

for testing purposes) As you can see in the screenshots below (1 -> 2), when having the content in the "extendedContent" changed, the card doesnt expand more to fit the contents. Now, when the Card is collapsed and expanded again (3), it resizes and looks how it should. However, if now the message disappears, it is again not resizing, meaning we have a lot of empty space (4)

Is there a solution for remembering UI State through app navigation? For example, i have a Tab Navigation/Pager with dynamic number of pages. Each page is a scrollable list containing items. When i navigate to a "sub-view" (would have been a fragment before), i'd like to remember scroll state, so when the user goes back, the list maintains it's scroll position. Remember does not work here because the component is removed from tree. Also i can't pull remember up the tree, because its not a static number of pages/lists.

Is there any issue/"initiative" to decompose TextField? Such simple thing as setting a background color seems quite impossible. (outline api doesn't provide bg color property, filled text field applies 0.12% transparency on the passed value...) All building blocks are internal/private 😞

When a composable function is invoked, the invocation might occur on a different thread from the caller. That means code that modifies variables in a composable lambda should be avoided–both because such code is not thread-safe, and because it is an impermissible side-effect of the composable lambda. -link

Parallel execution in Compose is very new to me. Could someone tell me please how I can modify variables if I am not allowed to do it in a Composable lamda? Also, what does thread-safety mean in the above paragraph?

How to set height to

fillMaxHeight

inside component where height is

wrapContentHeight

?

I’m facing a problem with

LazyColumnFor

. The problem is kind of hard to explain, so I included a video. depensing on the scroll position of Column recomposing with a subset list of items leads to empty list.

I’m not sure is I’m doing something wrong, but in my app the content in

scaffold

is drawn behind the

bottomBar

. is this the expected behaviour? The content:

Text(modifier = Modifier.verticalScroll(rememberScrollState()),text = <a Long content>)

BottomNavivation

composable (green accent) has a different ripple than

BottomNavigationView

(red accent) from Material Components for Android (which is the same effect showed in the material guidelines)

Hi. @romainguy said in a recent that Jetpack Compose has to catch up with 15 years of development. Does that mean that Android's classic way of using xml layouts has been in use since 2005? I ask because Android's public first public release seems to be 2008.

Hiya! Thank you for the codelabs/compose tutorials, they have been super helpful. I was wondering if there’s any tutorials/deeper dive on building custom Modifiers. Modifiers seem pretty core to compose components but besides digging into the source code there doesn’t seem to be much else on it (There was a custom text Modifier.layout in the layout tutorial).

Hi all, hope you all good, I have a question regarding @Model Annotation in Jetpack library. What does it mean and how can I use it in my JetPack Compose project. Which dependency contains it. Sorry for my bad English. Thanks

Hi all. I have a question related to nested scrolling inside draggable and swappable components. I have been investigating Crane App. The BottomUp Slider view contains list. Which causes the list to consume all scroll until it reaches to bottom. Then finally the slider scrolls. I was able to overcome this issue by disabling and enabling LazyColumnFor, but it is not smooth at all. I wonder if there is a better way to handle it?

Is there a modifier to scale a composable? kinda like how scalex and scaley work? I need something temporary (for animations)

How can I support RTL text in Compose e.g. inside a Text Composable?

I’m trying to use ViewModel + LiveData, as seen https://developer.android.com/jetpack/compose/interop#viewmodel however the code sample (in thread reply) always shows null

All children of the a compose app's material theme must follow the typography defined in that theme, mustn't they?

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            DraftNotebookTheme {
                Surface(color = MaterialTheme.colors.background) {
                    MyButton("Android")
                }
            }
        }
    }
}

@Composable
fun MyButton(label: String) {
    Button(onClick = {}) {
        Text(label)
    }
}

@Preview(showBackground = true)
@Composable
fun DefaultPreview() {
    DraftNotebookTheme {
        MyButton("سلام دنیا")
    }
}

When doing preview, the text shown on the button does not follow the font family I have set in the theme. Is this a bug?

Hi, based on codelabe on Modifiers ⬇️

Note : By convention, the modifier is specified as the first optional parameter of a function. This enables you to specify a modifier on a composable without having to name all parameters.

Is there a reason why the AppTopBar Modifier was not put as the first parameter in the compose material TopAppBar implementation ?

@Composable
fun TopAppBar(
    title: @Composable () -> Unit,
    modifier: Modifier = Modifier,
    navigationIcon: @Composable (() -> Unit)? = null,
    actions: @Composable RowScope.() -> Unit = {},
    backgroundColor: Color = MaterialTheme.colors.primarySurface,
    contentColor: Color = contentColorFor(backgroundColor),
    elevation: Dp = TopAppBarElevation
) {...}