Regarding this change: https://android-review.googlesource.com/c/platform/frameworks/support/+/1435797 is there a specific reason to let the drawing order affect the zOrder instead of an expliciet (and optional) zIndex parameter to the place* methods? When code in a custom layout is re-ordered (for whatever reason) this potentially breaks the layout. Or am I missing something here?

A question popped into my mind recently: how deep does the view hierarchy of Composables have to be to notice any performance hit?

Hey folks, I wanted to play with animations in Compose. And I found that there are several ways to do it. But I couldn't find good comparisons and reasoning behind those. It got me confused and curious. That's why I put together different methods and prepared a talk on creating animations in Compose. I gave it at droidcon EMEA today. Just wanted to share it with you. Here are the slides and demo repository. Slides: https://slides.com/wajahatkarim/composeanimations Github: https://github.com/wajahatkarim3/droidcon2020

I have a Card + Switch. How do I handle the state so it toggles on onClick of the Card, and I can use an onCheckedChange correctly?

Has anyone worked out a way to run an infinite animation with a specified delay between value changes? I'm using

repeatable

with

AnimationConstants.Infinite

and

animatedFloat

. I'm basically trying to force a canvas redraw every 300ms

Hello, I made this tinder like cards, hope you like it! Sorry for the spaghetti code, aiming to make it more clear and less buggy https://github.com/davideC00/CardStack

I'm trying to use

savedInstanceState

with

MutableState

val themeColor by savedInstanceState(user) { mutableStateOf(Color.Blue) }

but I'm getting this error:

java.lang.IllegalArgumentException: Please use savedInstanceState() if you want to save a MutableState

What am I doing wrong here?

I have a simple toggle that increment or decrements based on clicking + or -. The preview interaction doesn’t do anything but if I run it on device it works fine. Is there something that I’m missing in this example to make it work in the preview?

@Preview
@Composable
fun Counter() {
    var count by remember { mutableStateOf(0) }
    Row {
        Image(vectorResource(R.drawable.ic_remove), Modifier.clickable { count-- })
        Text(text = count.toString(), modifier = Modifier.align(Alignment.CenterVertically))
        Image(vectorResource(R.drawable.ic_add), Modifier.clickable { count++ })
    }
}

Do we have a compose component for expandable search like in gmail and other apps something like https://stackoverflow.com/questions/29149268/how-to-implement-search-bar-like-gmail-app-in-android

today i realized that the preview does not show AlertDialog…..

Hi, any idea why android studio doesn't see the sources for jetpack androidx.compose.material library? AS 4.2 canary 13, compose 1.0.0-alpha04

Hello, I made a custom switch with a number of size parameters. I would like to reuse that composable, but smaller. Is there a way of assigning a scale to the composable, or do I have to pass each size parameter along with the other function params? Here is what the switch looks like:

@Composable
fun CustomToggle(
    color: Color, gradientColor: Color, selected: Boolean,
    onSelected: () -> Unit
) {

    val toggleAlign = animate(if (selected) 65.dp else 5.dp)

    Box() {
        Box(
            modifier = Modifier
                .height(40.dp)
                .width(100.dp)
                .clip(RoundedCornerShape(50))
                .background(HorizontalGradient(
                    0.0f to color,
                    0.5f to gradientColor,
                    1.0f to color,
                    startX = 0.0f,
                    endX = with(DensityAmbient.current) { 100.dp.toPx() }
                )
                ),
        ) {}
        Surface(
            modifier = Modifier.size(30.dp)
                .align(Alignment.CenterStart)
                .offset(toggleAlign)
                .clip(RoundedCornerShape(50))
                .toggleable(value = selected, onValueChange = { onSelected() }),
            color = Color.White,
            elevation = 7.dp
        ) {}
    }
}

I want to increase the progress of a

LinearProgressIndicator

over time. Like I want it to go from 0 to 100 in 3 seconds. How do I approach this?

onCommit

with input of some

SnapshotMutableState

doesn’t trigger its lambda when value changes.

onCommit

with

SnapshotMutableState::value

does. That’s more likely because

SnapshotMutableState

doesn’t implement and delegate

equals

to its

value

. Is this intentional behavior?

Hello everyone 👋 I’m trying to test my composables using androidTests, the tests passe correctly but all functions mentioned in the official doc are marked as

deprecated

without mentioning alternatives ! Am I missing something ? 🤔

Hey guys, since i switched to alpha04, i got these crash

java.lang.IllegalStateException: Reading a state that was created after the snapshot was taken or in a snapshot that has not yet been applied
        at androidx.compose.runtime.snapshots.SnapshotKt.readError(Snapshot.kt:1525)
        at androidx.compose.runtime.snapshots.SnapshotKt.readable(Snapshot.kt:1521)
        at androidx.compose.runtime.snapshots.SnapshotKt.readable(Snapshot.kt:1512)
        at androidx.compose.runtime.SnapshotMutableState.getValue(MutableState.kt:294)
        at androidx.compose.foundation.text.TextFieldState.getHasFocus(CoreTextField.kt:537)
        at androidx.compose.foundation.text.CoreTextFieldKt$CoreTextField$4$focusObserver$1.invoke(CoreTextField.kt:198)
        at androidx.compose.foundation.text.CoreTextFieldKt$CoreTextField$4$focusObserver$1.invoke(Unknown Source:3)
        at androidx.compose.ui.node.ModifiedFocusObserverNode.propagateFocusStateChange(ModifiedFocusObserverNode.kt:32)
	....
	    at androidx.compose.runtime.Composer.recomposeToGroupEnd(Composer.kt:1560)
        at androidx.compose.runtime.Composer.skipToGroupEnd(Composer.kt:1784)
        at androidx.compose.ui.LayoutKt.WithConstraints(Layout.kt:532)
        at androidx.compose.material.DrawerKt.BottomDrawerLayout-rxTpieo(Drawer.kt:427)
        at de.charlex.xxx.ui.MyAppKt$MyAppContent$1.invoke(MyApp.kt:171)                       <----- Thats the first line in stacktrace where my sources are referenced.

Line MyApp.kt:171:

BottomDrawerLayout(

I was not able to find the reason. If i remove the BottomDrawerLayout, the app don't crash anymore. I tried another app, added a BottomDrawerLayout there and .... it worked fine... I think the reason for the crash is not the BottomDrawerLayout. Any ideas?

Is anyone aware of a "Tutorial" composable that highlights other composables with descriptions?

Did anyone hear anything about multiplatform compose at the online Kotlin event today?

Any schedule for a feature complete beta release?

I gave it a shot this weekend to implement a markdown renderer in Jetpack Compose. Thanks to

compose-richtext

and abundance of Markdown parsers, I was able to have a working prototype in 2 evenings. Hopefully I can share the code once it is more organized and readable.

Hello, I read the source code of

CircularProgressIndicator

to learn how to write a custom view.But I'm confused about the

Modifier.semantics

. I thought it's

SemanticsModifierCore

may store the properties of `CircularProgressIndicator`，but i did't see anything about

SemanticsModifierCore

in

CircularProgressIndicator

.So what does

Modifier.semantics

do for us?😢

Hey guys, i have a question. I tried to use an app-wide Scaffold with NavHost (from the navigation Snapshot Library) in its content. Each view should be able to edit the state of the bottomAppBar and the fab. (Show Fab, disable BottomDrawerLayout Gesture, hide BottomAppBar and so on) I tried the following, but i doesn't work. When i try to navigate to the LoginScreen, the changes in the bottomAppBarConfig and the fabConfig are triggering a complete redraw and the NavHost will also be recreated. Even before i try to navigate the hole tree recreates in a loop because of the config change for the first view How to do it correctly? I dont want to set the Scaffold per view because the app contains nearly 40 views...

Is

PasswordTextField

depcreated?

Hi all! I'm writing an app and adding screenshot tests for my components and I'm facing some issues with the RoundedCornerShape. When using a shape for the component background the rendering result is not the changes a little bit and this makes the screenshot test tool to report there is an error in the rendering. The shape I'm using is this

RoundedCornerShape(size = 16.dp)

The error reported by the screenshot testing shows a bunch of small different pixels making the tests fail. Red dots in the screenshot are the errors reported by the testing tool. Do you know if the rendering can vary depending on the build or any other param?

Hey guys, wanted your thoughts on implementing this UI with compose. • Text is 70% of width • Then image takes rest width and is slightly outside of the card. So, whats the best way to implement this? Stack/Box? Constraint Layout? etc.

So I have this code:

val emojiState = remember { mutableStateOf(EmojiState.HIDDEN) }
val definition = transitionDefinition<EmojiState> {
    state(EmojiState.HIDDEN) {
        this[emojiSize] = 0.dp
    }

    state(EmojiState.START) {
        this[emojiSize] = 20.dp
    }

    state(EmojiState.END) {
        this[emojiSize] = 50.dp
    }

    transition(fromState = EmojiState.START, toState = EmojiState.END) {
        interruptionHandling = InterruptionHandling.SNAP_TO_END
        emojiSize using tween(3000, easing = FastOutSlowInEasing)
    }
}

val transitionState = transition(
    definition = createEmojiTransition(),
    initState = emojiState.value,
    toState = if (emojiState.value == EmojiState.START) EmojiState.END else EmojiState.HIDDEN,
    onStateChangeFinished = {
        emojiState.value = it
    }
)

When I change

emojiState

to

HIDDEN

while the transition from

START

to

END

is going on, it looks like the transition isn't interrupted and still going on in the background. For example, I change the transition to

HIDDEN

1000 millis after starting the

START

to

END

transition, then after 2000 millis the

onStateChangeFinished

is run and it sets my state back to

END

. Is there some way I can interrupt the transition and prevent

onStateChangeFinished

to be called for interrupted transitions. Or maybe my logic is at fault here?

Hey guys! How can I save and restore a

LazyColumn

or

LazyRow

scroll position across process death?

Is it possible to add a Gradient Background to a Button? I tried adding a gradient to a Column and set the Column as the content of the button and set the button’s background color to Transparent, and I can see the gradient but for some reason I still have some paddings (even though they are set to 0).