kotlinlang #compose

Anyone knows any open source app that uses compose and mapView? I know the crane sample app, but I need a sample that uses maps and bottomNavBar or something similar that save states. I have a problem retaining mapview state on fragment recreation.

3 replies · 2 participants

Nat Strangerweather

12/13/2021, 10:29 PM

Hi, I'm trying to pass a variable out of my LaunchedEffect so I can use it. I'm not sure how to accomplish that. Any ideas?

11 replies · 4 participants

Miguel Vargas

12/14/2021, 12:00 AM

AndroidViews inside a LazyColumn recompose and recreates the Views as I scroll. I tried using

remember

to save the AndroidView as follows but it’s still recreating the Views as I scroll up and down. Is there any way to make it more efficient?

@Composable
fun ViewInLazyColumn() {
    LazyColumn {
        items(100) { idx ->
            val context = LocalContext.current

            val view = remember { MyView(context, idx.toString()) }
            AndroidView(factory = { view }) } } }

class MyView(context: Context, value: String) : TextView(context) {
    init {
        // View keeps getting recreated
        println("init MyView $value") 
        text = value } }

5 replies · 2 participants

Libor Bicanovsky

12/14/2021, 12:35 AM

Fyi, if anyone is using code similar to this:

condition?.let {
 //some composable
} ?: //other composable

In 1.1.0-beta04 this will not work correctly and the second condition will never be evaluated/displayed. It works correctly in previous versions (such as 1.0.5). Just wanted to mention it since it caught us out!

4 replies · 3 participants

mattinger

12/14/2021, 2:23 AM

Anyone know if there’s any easy way to get a robolectric test to wait for a coroutine launched by a “rememberCoroutineScope” scope?

10 replies · 3 participants

12/14/2021, 6:50 AM

Hello 👋 I'm experimenting a bit with compose navigation and was wondering if I could get some insight on something before I try "reinventing the wheel" or doing hacky workarounds. Will reply in thread with more detail

14 replies · 4 participants

Tgo1014

12/14/2021, 8:39 AM

Is there a way to set the default font family or I’ve to override in all “styles” (body1, h1, etc)?

11 replies · 5 participants

Ankit Shah

12/14/2021, 11:18 AM

Hello everyone, I have a question related to the navigation in jetpack compose, I do have a page with formfields in jetpack compose and filled some data in those. Now once I navigate to other page and if I go back I loose all the form data. I want to preserve the data when I go back. how can I achieve it using navcontroller?

1 reply · 2 participants

Brian G

12/14/2021, 3:08 PM

Any word on scroll indicators in Jetpack Compose? I don't see them on the roadmap either. Is Compose never going to have scroll indicators built-in?

☝️🏽 2

4 replies · 3 participants

PHondogo

12/14/2021, 3:25 PM

Hello! Compose application crashes with

java.lang.NoSuchMethodError: No static method infiniteRepeatable-9IiC70o$default(Landroidx/compose/animation/core/DurationBasedAnimationSpec;Landroidx/compose/animation/core/RepeatMode;JILjava/lang/Object;)Landroidx/compose/animation/core/InfiniteRepeatableSpec; in class Landroidx/compose/animation/core/AnimationSpecKt; or its super classes (declaration of 'androidx.compose.animation.core.AnimationSpecKt'

7 replies · 2 participants

mattinger

12/14/2021, 5:07 PM

So, i’m trying to use the accompanist permissions. The issue i’m running into is that i’m doing my checking when a particular button is clicked. As such, PermissionsRequired isn’t a great solution for me. Instead, i’ve built a composable that’s turned on and off with a flag. I’m not 100% happy with this, but wondering if there’s a better way. See thread for that function

3 replies · 1 participant

Brian Donovan

12/14/2021, 5:10 PM

Hi all, I’m trying to make my screen scrollable but having no luck. This is an image of the code and emulator

1 reply · 1 participant

Lucien Guimaraes

12/14/2021, 6:52 PM

About AnnotatedString API to have multiple styles for a text, how to achieve it with a string resource? Let's say I have the following one:

<string name="news_count_title">{{count}} {{text}}</string>

. I would like

count

and

text

to have different styles. How to properly achieve it in Compose?

8 replies · 4 participants

Colton Idle

12/14/2021, 9:01 PM

What's the default size for

Text

? I clicked into a Text and I see

fontSize: TextUnit = TextUnit.Unspecified,

3 replies · 2 participants

Colton Idle

12/14/2021, 9:13 PM

I have this Box that stretches/scales on the Y axis. My problem is that the contents within the box are clipped unless I add padding even though I have clip=false.

Box(
      modifier.fillMaxWidth().graphicsLayer {
        scaleY = 1000f
        clip = false
      },

Is there a way to prevent this clipping? I thought compose didn't clip by default? Even if it did, I thought clipToBounds() would allow me to pass in "false" but it does not.

13 replies · 3 participants

jeff

12/14/2021, 10:43 PM

Hoping someone can help me understand this recomposition behavior:

class Helper {
  val string = "string"
}

@Composable
fun RecompRepro(mutableState: MutableState<String>, helper: Helper) {
  LogCompositions(msg = "Root")
  Column(Modifier.height(100.dp)) {
    Text(mutableState.value)
    CustomComposableText(helper = helper)
  }
}

@Composable
fun CustomComposableText(helper: Helper) {
  LogCompositions(msg = "CustomComposableText")
  Text(helper.string)
}

if I change the value of mutableState 3 times, "Root" is printed 3 times and "CustomComposableText" is printed 1 time. That is as expected. But if I change

val string

var string

Helper

, then all of a sudden CustomComposableText is printed 3 times. Why?

10 replies · 2 participants

bbade_

12/15/2021, 12:20 AM

Question about MaterialTheme and overriding a color in a segment of code. If i had a layout

Column
  Button1
  *OddUi*
  Button3

Lets say i wanted to override

primary

and

onPrimary

when rendering the OddUi content. What’s the best way of doing this? MaterialTheme’s colors are

mutableStateOf

, so do i write

Button1()
MaterialTheme.primary = somethingElse
MaterialTheme.Colors.onPrimary = somethingElse
OddUi()
// restore the two colors
Button2

This feels odd or would i write

Button1()
CompositionLocalProvider(LocalColors provides MaterialTheme.colors.copy(primary = ..., onPrimary = ...) {
   OddUi()
}
Button2

With this though, localColors is internal, so i can’t override it, right? Is there a third option?

11 replies · 4 participants

Colton Idle

12/15/2021, 3:05 AM

I have a bottomSheet that I hide() on an event lambda i.e.

val successEvent = {
  scope.launch {
    bottomSheetState.hide()
  }
}

This works greats except that if the user happens to be touching the bottom sheet while I call hide(), then it won't actually hide. Is there another way to force the sheet to hide if I really need it to hide, or am I out of luck/file a feature request?

2 replies · 2 participants

nilTheDev

12/15/2021, 6:43 AM

I am trying to create a sudoku game. All the cells of the sudoku board are

boxes

- nested in

rows

and

columns

- with some border around them. However, in some of the

boxes

the border appears to be thicker than others. Anybody knows why this is happening? In the code, the thickness of the border of all the

boxes

are same.

11 replies · 3 participants

PHondogo

12/15/2021, 7:06 AM

Hello! Have anyone faced with

java.lang.NoClassDefFoundError: Failed resolution of: Landroidx/compose/animation/core/StartOffset;

when calling

InfiniteRepeatableSpec(
                animation = tween(200, easing = LinearEasing),
                repeatMode = RepeatMode.Restart,
                initialStartOffset = StartOffset(0)
            )

3 replies · 3 participants

jean

12/15/2021, 9:11 AM

I had an issue a few month ago with image loaded with coil inside a lazy list https://kotlinlang.slack.com/archives/CJLTWPH7S/p1619166350451300. I just updated my project to use

"io.coil-kt:coil-compose:1.4.0"

instead of

accompanist

and I’m back at the same problem. Images are not loading when I set them from the

items

block of the

LazyListScope

block. Do I need to change anything?

Image(
    painter = rememberImagePainter(url),
    contentDescription = stringResource(id = R.string.description),
    contentScale = ContentScale.Crop,
    modifier = Modifier
        .width(150.dp)
        .height(267.dp),
)

5 replies · 2 participants

Guilherme Delgado

12/15/2021, 10:39 AM

I’ve a formulary app with a lot of different input types (text, radio, check, signature, etc...) I can zoom in/out and drag the form around. I’ve notice performance issues (lots of lag when zooming and panning) when doing this:

inputs.forEach {
   TextFieldWrapper(
       id = ...,
       text = ...,
       onTextChanged = { my callback implementation }
   )
   ...
}

More in thread.

8 replies · 2 participants

loloof64

12/15/2021, 10:53 AM

Hi ! Is it possible to know which item of a LazyColumn has been clicked ? More in 🧵

9 replies · 4 participants

loloof64

12/15/2021, 11:02 AM

Can I get the output of

println()

call from an interactive

@Preview

in Android Studio ?

🇳🇴 3

1 reply · 1 participant

Hachemi Hamadi

12/15/2021, 11:30 AM

Hello, I am facing weird issue on some devices (Xiaomi mainly). Here is the output of the error stack :

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.cardshop.app.compose, PID: 12745
    java.lang.IllegalStateException: measure() may not be called multiple times on the same Measurable
        at androidx.compose.ui.node.OuterMeasurablePlaceable.remeasure-BRTryo0(OuterMeasurablePlaceable.kt:86)
        at androidx.compose.ui.node.OuterMeasurablePlaceable.measure-BRTryo0(OuterMeasurablePlaceable.kt:71)
        at androidx.compose.ui.node.LayoutNode.measure-BRTryo0(LayoutNode.kt:1293)
        at androidx.compose.foundation.layout.RowColumnImplKt$rowColumnMeasurePolicy$1.measure-3p2s80s(RowColumnImpl.kt:89)
        at androidx.compose.ui.node.InnerPlaceable.measure-BRTryo0(InnerPlaceable.kt:51)
        at androidx.compose.foundation.ScrollingLayoutModifier.measure-3p2s80s(Scroll.kt:342)
        at androidx.compose.ui.node.ModifiedLayoutNode.measure-BRTryo0(ModifiedLayoutNode.kt:39)
        at androidx.compose.ui.node.DelegatingLayoutNodeWrapper.measure-BRTryo0(DelegatingLayoutNodeWrapper.kt:131)
        at androidx.compose.ui.node.DelegatingLayoutNodeWrapper.measure-BRTryo0(DelegatingLayoutNodeWrapper.kt:131)
        at androidx.compose.ui.node.DelegatingLayoutNodeWrapper.measure-BRTryo0(DelegatingLayoutNodeWrapper.kt:131)
        at androidx.compose.ui.node.DelegatingLayoutNodeWrapper.measure-BRTryo0(DelegatingLayoutNodeWrapper.kt:131)
        at androidx.compose.ui.node.DelegatingLayoutNodeWrapper.measure-BRTryo0(DelegatingLayoutNodeWrapper.kt:131)
        at androidx.compose.ui.node.DelegatingLayoutNodeWrapper.measure-BRTryo0(DelegatingLayoutNodeWrapper.kt:131)
        at androidx.compose.ui.graphics.SimpleGraphicsLayerModifier.measure-3p2s80s(GraphicsLayerModifier.kt:306)
        at androidx.compose.ui.node.ModifiedLayoutNode.measure-BRTryo0(ModifiedLayoutNode.kt:39)
        at androidx.compose.ui.node.DelegatingLayoutNodeWrapper.measure-BRTryo0(DelegatingLayoutNodeWrapper.kt:131)
        at androidx.compose.foundation.layout.PaddingModifier.measure-3p2s80s(Padding.kt:364)
        at androidx.compose.ui.node.ModifiedLayoutNode.measure-BRTryo0(ModifiedLayoutNode.kt:39)
        at androidx.compose.foundation.layout.FillModifier.measure-3p2s80s(Size.kt:658)
        at androidx.compose.ui.node.ModifiedLayoutNode.measure-BRTryo0(ModifiedLayoutNode.kt:39)
        at androidx.compose.ui.node.OuterMeasurablePlaceable$remeasure$3.invoke(OuterMeasurablePlaceable.kt:100)
        at androidx.compose.ui.node.OuterMeasurablePlaceable$remeasure$3.invoke(OuterMeasurablePlaceable.kt:99)
        at androidx.compose.runtime.snapshots.SnapshotStateObserver.observeReads(SnapshotStateObserver.kt:126)
        at androidx.compose.ui.node.OwnerSnapshotObserver.observeReads$ui_release(OwnerSnapshotObserver.kt:88)
        at androidx.compose.ui.node.OwnerSnapshotObserver.observeMeasureSnapshotReads$ui_release(OwnerSnapshotObserver.kt:76)
        at androidx.compose.ui.node.OuterMeasurablePlaceable.remeasure-BRTryo0(OuterMeasurablePlaceable.kt:99)
        at androidx.compose.ui.node.LayoutNode.remeasure-_Sx5XlM$ui_release(LayoutNode.kt:1302)
        at androidx.compose.ui.node.LayoutNode.remeasure-_Sx5XlM$ui_release$default(LayoutNode.kt:1298)
        at androidx.compose.ui.node.LayoutNode.onBeforeLayoutChildren(LayoutNode.kt:1080)
        at androidx.compose.ui.node.LayoutNode.layoutChildren$ui_release(LayoutNode.kt:961)
        at androidx.compose.ui.node.LayoutNode.onNodePlaced$ui_release(LayoutNode.kt:954)
        at androidx.compose.ui.node.InnerPlaceable.placeAt-f8xVGno(InnerPlaceable.kt:125)
        at androidx.compose.ui.layout.Placeable.access$placeAt-f8xVGno(Placeable.kt:31)
        at androidx.compose.ui.layout.Placeable$PlacementScope.place-70tqf50(Placeable.kt:370)
        at androidx.compose.ui.layout.Placeable$PlacementScope.place-70tqf50$default(Placeable.kt:203)
        at androidx.compose.ui.node.DelegatingLayoutNodeWrapper$measure$1$1.placeChildren(DelegatingLayoutNodeWrapper.kt:138)
        at androidx.compose.ui.node.DelegatingLayoutNodeWrapper.placeAt-f8xVGno(DelegatingLayoutNodeWrapper.kt:126)
        at androidx.compose.ui.layout.Placeable.access$placeAt-f8xVGno(Placeable.kt:31)
        at androidx.compose.ui.layout.Placeable$PlacementScope.place-70tqf50(Placeable.kt:370)

🧵 2

:thread-please: 2

5 replies · 3 participants

loloof64

12/15/2021, 12:09 PM

Reading at navigation documentation (https://developer.android.com/jetpack/compose/navigation#nav-with-args), I've seen that we can navigate with string argument. But is there a way to pass custom argument ? Or must I serialize/deserialize between my custom

class

and

String

? Or is even this last very bad practice ?

37 replies · 5 participants

Colton Idle

12/15/2021, 3:14 PM

This might be a dumb question, but what's the easiest way to consume release notes for compose updates. I know I can go to https://developer.android.com/jetpack/androidx/releases/compose-animation for example and then click through each artifact, but is there just like a general "release notes for compose 1.1.0-beta04" that includes all artifacts?

👀 1

3 replies · 3 participants

trevjones

12/15/2021, 3:35 PM

Back in the old days I could drop something like this into my custom test runner onStart

Espresso.setFailureHandler { error, viewMatcher ->
    val scan = Radiography.scan(viewStateRenderers = DefaultsIncludingPii)
    error.addSuppressed(RuntimeException("\n$scan"))
    error.addSuppressed(RuntimeException(idlingRegistryStatus))
    DefaultFailureHandler(targetContext).handle(error, viewMatcher)
}

Is there a good way to do similar with the compose rule + testing apis?

2 replies · 2 participants

Javier

12/15/2021, 3:44 PM

Is it possible to change the compositionLocal inside AppBar to avoid adding an alpha to the content?

➕ 1

5 replies · 3 participants

Billy Newman

12/15/2021, 3:54 PM

Hello all! Is it possible to get attributes, say for instance the background color, of composable that is passed as a parameter? See reply for example.

17 replies · 5 participants

Title

Billy Newman

12/15/2021, 3:54 PM

Hello all! Is it possible to get attributes, say for instance the background color, of composable that is passed as a parameter? See reply for example.

Something like this:

@Composable
fun Content(someComposable: (@Composable () -> Unit)? = null) {
  val background = someComposable?.background()  // This does not work
}

Kirill Grouchnikov

12/15/2021, 4:14 PM

There is no such thing. This

someComposable

is not a view / container / component in the traditional sense. It may emit one UI component, it may emit more than one, or it may not emit anything.

Billy Newman

12/15/2021, 4:17 PM

Ok makes sense. Ideas on another to achieve what I am after? Looking into a custom scope for that composable. Still not 100% sure how to implement, but something like this:

interface CustomScope {
   
   @Stable
   fun Modifier.background(background: Color): Modifier

}

@Composable
fun Content(someComposable: (@Composable CustomScope.() -> Unit)? = null) {
...
}

Adam Powell

12/15/2021, 4:19 PM

what exactly is it that you're after? The compose way is generally to tell your children what to do and expect them to do it, not assemble your children and then query their state after the fact

it's highly unusual for a parent to ask a child about the nature of its background drawing and wanting to do that is a bit of an encapsulation break, like using reflection to inspect the private properties of an object

Billy Newman

12/15/2021, 4:43 PM

Sure, specifically I have a common composable for a draggable view. That draggable view has a “drag handle view” at the top. However that common view can also be customized with a header:

@Composable
fun CommonContent(header: (@Composable () -> Unit)? = null) {
  DragHandle()

  header?.invoke()
}

@Composable
fun CustomContent() {

  CommonContent() {
    // custom header
    Column(Modifier.background(Color.Blue)) { ... }
  }
}

I would like for the drag handle view to have the same background color as the custom header. And I don’t really want to duplicate code. IE in this case a drag handle is “common” and should always be present regardless of the custom header.

Casey Brooks

12/15/2021, 4:57 PM

Since your custom header is a child of

CommonContent

, you can use CompositionLocals to implicitly pass parameters down through the composition tree https://developer.android.com/jetpack/compose/compositionlocal

➕ 1

Chris Sinco [G]

12/15/2021, 5:04 PM

Adding to Casey’s suggestion, using colors from

MaterialTheme

MaterialTheme.colors.background

can be useful here because from the code POV you are using a semantic color key, but can use CompositionLocal to override in specific parts in the hierarchy if needed.

You could also consider a color parameter for DragHandle that defaults to something

Billy Newman

12/15/2021, 5:11 PM

Sure I can always pass more information in the CommonContent composable…

@Composable
fun CommonContent(
  header: (@Composable () -> Unit)? = null,
  headerColor: Color = Color.White
) {
  DragHandle(headerColor)

  header?.invoke()
}

But where does that end. Passing in every attribute the drag handle would have in common with the header component seems excessive.

Not sure I fully understand how to use CompositionLocals in this case. Not really sure I want to pass parameters “down”

Also @Adam Powell looking at implementations of customs scopes like Row and Column, they end up using:

interface ParentDataModifier : Modifier.Element {
    /**
     * Provides a parentData, given the [parentData] already provided through the modifier's chain.
     */
    fun Density.modifyParentData(parentData: Any?): Any?
}

To allow the child to modify something on the parent right? Seems like exactly what I am trying to do.

Chris Sinco [G]

12/15/2021, 5:17 PM

Not really sure I want to pass parameters “down”

Right, this is where CompositionLocals can be useful as it passes things down in the hierarchy, and it works particularly well for color overrides at certain parts of a UI hierarchy

Casey Brooks

12/15/2021, 5:20 PM

It would look something like this:

val LocalHeaderColor = compositionLocalOf { Color.Unspecified }

@Composable
fun CommonContent(
  header: (@Composable () -> Unit)? = null,
  headerColor: Color = Color.White
) {
    CompositionLocalProvider(LocalHeaderColor provides headerColor) {
        DragHandle()
        header?.invoke()
    }
}

The content of both

DragHandle

and the

header

lambda can then reference the configured header color with

LocalHeaderColor.current

, without having to pass it explicitly through function parameters

✔️ 1

Billy Newman

12/15/2021, 6:32 PM

Casey, thanks for the example, still new to compose. I will give this a go, I greatly appreciate the help!

Chris Sinco [G]

12/15/2021, 6:38 PM

+1 great example Casey!

:thank-you: 1

Adam Powell

12/15/2021, 6:45 PM

the ParentDataModifiers and scoped modifier factories are less about modifying something on the parent and more about the parent passing down the capability for child elements to annotate the layout nodes they emit in a particular way

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