WearNavScaffold broken after compose 1.0.0-rc01

[yschimke]

https://user-images.githubusercontent.com/231923/174258979-52f8811b-50ef-4f0a-a948-63bc7edc67f1.mov

[yschimke]

the difference appears to be that we don't receive state updates from scrollState.centerItemIndex and scrollState.centerItemScrollOffset the first time we display them. However if you navigate away and then back the updates are fired.

If I put some logging into Modifier.fadeAwayScalingLazyList state, I don't see state fired events, but a simple launched effect polling every 2 seconds does show the right values. And they both see the same list state instance.

@ExperimentalHorologistComposeLayoutApi
public fun Modifier.fadeAwayScalingLazyList(
    initialIndex: Int = 1,
    initialOffset: Int = 0,
    scrollStateFn: () -> ScalingLazyListState,
): Modifier =
    composed {
        val scrollState = remember { scrollStateFn() }

        val centerItemIndex = scrollState.centerItemIndex
        val centerItemScrollOffset = scrollState.centerItemScrollOffset

        LaunchedEffect(Unit) {
            while (true) {
                delay(2.seconds)
                println("Manual: ${scrollState.centerItemScrollOffset} ${scrollState.centerItemIndex} $scrollState")
            }
        }

        SideEffect {
            println("State: $centerItemScrollOffset $centerItemIndex $scrollState")
        }

[luizgrp]

Is this workaround still required given this issue has been fixed?

[yschimke]

Let me check. Thanks!

[yschimke]

I think that code is still an improvement, specifically this should cut down on recomposes.

        val isInitial by remember(scrollState) {
            derivedStateOf { scrollState.centerItemIndex == initialIndex }
        }