IssueTracker

Jetpack Compose version: 1.2.0-beta01

Jetpack Compose component used: Box, Text, AnimationState,

Android Studio Build: 2021.1.1 Patch 2

Kotlin version: 1.6.21

Only reproducible on Android emulators with API 21 and 22.

The following code animates the Text alpha on each Button click. When alpha is animated from 1 to 0, Text blinks at the very end of the animation, when the value reaches 0. E.g. Text is fully visible again just for a moment, and then disappears completely.

Column {
    val text = remember { "SomeText".repeat(100) }
    var direction by remember { mutableStateOf(false) }
    val animationState = remember(direction) { AnimationState(initialValue = if (direction) 1F else 0F) }

    LaunchedEffect(animationState) {
        animationState.animateTo(
            targetValue = if (direction) 0F else 1F,
            animationSpec = tween(),
            sequentialAnimation = !animationState.isFinished,
        )
    }

    Box(modifier = Modifier
        .alpha(animationState.value)
        .requiredSize(300.dp)) {
        Text(text)
    }

    Button(onClick = { direction = !direction }) {
        Text("Click")
    }
}