kotlinlang #compose

What is the proper way to get the height of the screen in Compose for something like this Linear Gradient? I have to specify the height, but what I really want is from the top of the view to the end of the view, which can change depending on the running device. What’s the right way to do this in compose?

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Column(
            Modifier
                .weight(1f)
                .fillMaxSize()
                .background(
                    VerticalGradient(
                        colors = listOf(
                            Color(125, 206, 250),
                            Color(82, 88, 245),
                        ),
                        startY = 0f,
                        endY = 100f
                    )
                )
        ) {
            SecondarySection()
        }

nitrog42

11/11/2020, 11:51 PM

Question, what is your average preview update time ? (like changing a string in the preview how much time does it take to update)

Bradleycorn

11/12/2020, 12:09 AM

Anyone using the

CoilImage

composable from the Accompanist library that @cb put together? I’m wondering what’s the best way to use a placeholder image resource when my composable is displayed via a

@Preview

? During preview the image state is

Empty

, so I thought about using the content composable and setting a placeholder image when image state is empty. That works. But, the placeholder image is also displayed briefly (before the actual image is loaded) when the app is run on a device, and I don’t want that.

👍 1

redrield

11/12/2020, 12:46 AM

What would i have to do to emulate the Active button look in compose?

Denis Sakhapov

11/12/2020, 3:22 AM

androidx.compose.runtime.stateFor

has been removed in

alpha07

. What is the replacement for that?

Sam

11/12/2020, 5:33 AM

Is there any way to utilize

WindowInsetsAnimation

within a Jetpack Compose project? This allows fine grain control and coordination of the keyboard animation (as described in this article). Most examples I've seen utilize

setWindowInsetsAnimationCallback

(like in this sample code) but I'm not sure how this would work in Compose?

👀 1

Daniel

11/12/2020, 8:41 AM

e: java.lang.NoSuchMethodError: 'org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl org.jetbrains.kotlin.parcelize.ParcelizeResolveExtension$Companion$createMethod$functionDescriptor$1.initialize(org.jetbrains.kotlin.descriptors.ReceiverParameterDescriptor, org.jetbrains.kotlin.descriptors.ReceiverParameterDescriptor, java.util.List, java.util.List, org.jetbrains.kotlin.types.KotlinType, org.jetbrains.kotlin.descriptors.Modality, org.jetbrains.kotlin.descriptors.DescriptorVisibility)'

Rafs

11/12/2020, 9:38 AM

Is there anyway of saving a composable to a

Bitmap

Just like what we do with

View.drawToBitmap()

Dieter Holz

11/12/2020, 9:58 AM

Since alpha07 MediaPlayer doesn’t play sounds anymore This worked before (in alpha06)

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private val soundPlayer by lazy { MediaPlayer.create(context, R.raw.transporter) }

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soundPlayer.start()

R.raw.transporter is a mp3-File Any hints?

Vivek Sharma

11/12/2020, 11:44 AM

Hey devs, I was trying compose navigation, and I added the

implementation "androidx.navigation:navigation-compose:1.0.0-alpha01"

and I didnt write any code in main activity except the code which is generated at build of new project and app didnt run Logcat showing :

java.lang.NoClassDefFoundError: Failed resolution of: Landroidx/compose/foundation/Background;

at androidx.compose.foundation.BackgroundKt.background-1xq40Q0(Background.kt:44)

at androidx.compose.material.SurfaceKt.Surface-biUpMIw(Surface.kt:101)

Grigorii Yurkov

11/12/2020, 12:48 PM

I am wondering, why

Color

has 3 properties named

red

green

blue

Color

can store non-RGB colors, for instance HSV. Isn't it confusing?

Daniele B

11/12/2020, 1:54 PM

After updating to alpha07, the text color on both topbar and bottombar became black (it was white). Is this a bug? I don’t think I have changed anything in my code.

Gifgroen

11/12/2020, 3:17 PM

Hey, if I were to have updated compose and get an error, what would be the best way to find out what changed? Aka where do I find the best changelog I can search for this? I get error ->

unresolv3d reference: InspectableParameter

Bryan Herbst

11/12/2020, 5:10 PM

Question/feedback on supporting non-Material design systems and future compatibility: Why are all of the components in

androidx.compose.material

named as though they are the the canonical implementation, when the messaging so far is that Material is an implementation of a specific design system?

Text

is a great example- it’s name alone ensures that it will be the first text Composable that most engineers reach for, but that presents two problems in my mind: • Today, any project with its own design system has the burden of ensuring its engineers use their design system’s text instead of the innocent and generic sounding

Text

• When a new Android-default design system inevitably comes along in the future, we have a similar problem- does the new design system create a

HoloText

, create its own Composable named

Text

, or does Material rename

Text

to something else? Contrast that with the Material Components library with

View

s, which explicitly labels the material-themed components e.g.

MaterialRadioButton

. There are some tricks under the hood to swap them in for framework components in some cases, but they still get a clear name in the library.

👍 1

👀 1

David Attias

11/12/2020, 5:31 PM

Hey guys, I have an issue that occurs randomly: the soft keyboard is not showing up when focusing a TextField. When this happens, I need to relaunch the app and it works the next launch most of the time. I get the following line in the logs.

D/InputMethodManager: showSoftInput - cancel : mServedView != view : DecorView@c9ce8f2[MainActivity]  view : androidx.compose.ui.platform.AndroidComposeView{800f9 VFED..... ........ 0,0-1080,2181}

grandstaish

11/12/2020, 5:38 PM

Is the concept of ‘assistive helper text’ coming to the material

TextField

composable? https://material.io/components/text-fields#anatomy. I realise we can just add text manually underneath the

TextField

component, but if it were built-in then you’d get the right text style, color, and positioning for free.

✅ 1

Zach Klippenstein (he/him) [MOD]

11/12/2020, 6:29 PM

@Leland Richardson [G] Does the new stability inference feature mean that the Stable/Immutable annotations can eventually be deprecated? Are there still cases that the inference misses that need to be explicitly annotated?

Slackbot

11/12/2020, 7:33 PM

This message was deleted.

Kirill Grouchnikov

11/12/2020, 9:58 PM

I have a case where I want to "tag" a certain subtree as a "logical" grouping of content. For example, in Office you have the ribbon "group", the footer "group", the taskpane "group". One option is to use an ambient to wrap that group, but it feels too heavyweight. And the other option is to use a modifier, but it looks like a modifier only gets "applied" to the specific composable. If I have another composable down the tree and I want to check which logical group it belongs to, there doesn't seem to be a way (by design?) to walk the modifiers of my parent chain. Should I go with ambients?

Sam

11/12/2020, 11:01 PM

why doesn't this compile:

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val countries by remember { listOf(Locale.getISOCountries().map { Locale("", it) }) }

with exception:

Type 'TypeVariable(T)' has no method 'getValue(Nothing?, KProperty<*>)' and thus it cannot serve as a delegate

Ian Sikes

11/12/2020, 11:09 PM

hey y'all 👋 I have a question about managing state in Jetpack Compose. Is there a way to perform some "cleanup" on a `remember`'d value before it is recomputed? I'm coming from React land where this is sort of thing is handled by

useEffect

. For example:

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val (session, setSession) = remember(sessionId) {
    mutableStateOf(Session(sessionId))
}

When the

sessionId

changes, a new

Session

is created. But I need to call

session.close()

beforehand. I can probably think of some hacky way to handle this but I'm trying to figure out what the "correct" Compose way is

Arkadii Ivanov

11/13/2020, 12:01 AM

Which approach is more idiomatic in Compose? 1 or 2?

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@Composable
fun foo1(dependency: () -> Dependency) {
    val x = remember { Bar(dependency()) }
}

@Composable
fun foo2(dependency: Dependency) {
    val x = remember { Bar(dependency) }
}

zoha131

11/13/2020, 12:26 AM

after upgrading to latest alpha-07 version I am unable to use CoilImage and getting this fatal error:

fkrauthan

11/13/2020, 1:04 AM

Does anyone have any must read articles/tutorials if I want to get started with android compose to build a brand new app?

Mehdi Haghgoo

11/13/2020, 4:55 AM

I cannot seem to understand these two lines in the state code lab. private var _todoItems = MutableLiveData(listOf<TodoItem>()) val todoItems: LiveData<List<TodoItem>> = _todoItems If todoItems is immutable val, then how is it constantly updated with _todoItems livedata?

Kshitij Patil

11/13/2020, 5:25 AM

I've a "Android Library" module for my common Composables. This module doesn't have any activity as I'm not defining any actual Screen here. How can I test the Composables in this module?

bharat to

11/13/2020, 7:43 AM

How to turnoff ripple effect that comes with

Modifier.clickable()

? for every

*Button

this behavior is common. I couldn't find any online resources to do this in compose.

Ashwani Singh

11/13/2020, 9:14 AM

Hi All, How to convert below code into compose:

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private fun subscribeObservers() {
    homePageViewModel.viewState.observe(this) { viewState ->
        if (viewState != null) {
            viewState.pageUILayoutList?.let { pageUILayoutList ->
                printLogD("HomePageFragment | pageUILayoutList", pageUILayoutList.toString())
            }

            viewState.allModulesForPage?.let { allModulesContent ->
                printLogD("HomePageFragment | allContents", "" + allModulesContent.toString())

            }
        }
    }
}

I used below code, but its not work

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val homePageViewModel = (ContextAmbient.current as DashboardActivity).homePageViewModel
onActive {
    homePageViewModel.setStateEvent(
        HomePageStateEvent.GetPageModuleEvent()
    )
    homePageViewModel.setStateEvent(
        HomePageStateEvent.GetContentEvent()
    )
}
val viewState: HomePageViewState by homePageViewModel.viewState.observeAsState(
    HomePageViewState()
)
var pageUIMap: HashMap<String, String>? = null
if (viewState.pageUILayoutList != null) {
  // But not getting any call here
}

🧵 1

Vivek Sharma

11/13/2020, 10:30 AM

I was using compose-navigation with bottom nav, I got a doubt (As docs stated one is

Profile Composable

and other is

FriendList Composable

, using as eg. and below as onClick code

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onClick = {
              // This is the equivalent to popUpTo the start destination
                 navController.popBackStack(navController.graph.startDestination, false)
                 if (currentRoute != screen.route) {
                            navController.navigate(screen.route)
                 }
          }

) Lets say So startDestination is

Profile

, then we clicked on

FriendList

bottom nav item, and then we clicked Profile, then FriendList When I press back, I never go back to FriendList, though I have visited it twice How does popBackStack works here, popping till Profile and not including Profile

Animesh Sahu

11/13/2020, 11:04 AM

Hi, how memory (state) management work with compose? How to dispose a object if it does not need to be alive (like View.GONE) 👀