Hello, I've had issues with alpha when updating f...

# compose

[bruno.aybar]

Hello,

I've had issues with alpha when updating from alpha02 to alpha03 .

alpha02 : animate alpha for a button, works fine
alpha03 : animate alpha for a button, main content animates correctly, but a weird border animation occurs

I made an small sample:

@Composable
fun Alpha(modifier: Modifier) {
    val animation = animatedFloat(initVal = 1f)
    onActive {
        animation.animateTo(0f, anim = repeatable(
            iterations = Infinite,
            repeatMode = RepeatMode.Reverse,
            animation = tween(1000))
        )
    }
    Button(
        onClick = { ... },
        modifier = modifier.drawOpacity(animation.value)
    ) {
        Text("test")
    }
}

@Preview(showBackground = true)
@Composable
fun AlphaPreview() {
    Stack(Modifier.fillMaxSize()) {
        Alpha(Modifier.gravity(Alignment.Center))
    }
}

And this is how it looks if I use alpha03 :

alpha03.mov

[bruno.aybar]

this is how it looks in alpha02 :

alpha02.mov

[Zach Klippenstein (he/him) [MOD]]

I noticed this with Scaffold and Crossfade too I think

[bruno.aybar]

I wonder if it's related to the device. I'm able to replicate in most devices (phones with Android 10-11), but I'm not seeing this issue in my tablet (Galaxy Tab S3 w/ Android 8 )

[Zach Klippenstein (he/him) [MOD]]

I saw it on an emulator running Android 10. Maybe an OS issue around rendering shadows?

[Konyaco]

have the same issue

[bruno.aybar]

How does it work for you folks if you run Interactive Preview? I've just run a quick test, and in my case, it is showing that shadow in both in alpha02 and alpha03 🤔

[Andrey Kulikov]

Thanks for reporting! I filed a bug about it: https://issuetracker.google.com/issues/169835769