LazyColumn Scroll Delay in HorizontalPager - Jetpack Compose

Question

I'm encountering an issue while using Jetpack Compose. Specifically, when I have a LazyColumn inside a HorizontalPager, there is a noticeable scroll delay in the LazyColumn after the page changes. I've tried solutions like using a scrollable Column instead of LazyColumn at the outer level, but the problem persists.

Here's a simplified version of my code:

Column(modifier = Modifier.fillMaxSize()) {

    LazyColumn(
        modifier = Modifier
            .fillMaxSize(),
        state = listState,
        contentPadding = PaddingValues(
            top = rootPadding.calculateTopPadding() + dimen_2,
            bottom = rootPadding.calculateBottomPadding()
        ),
        verticalArrangement = Arrangement.spacedBy(dimen_16),
    ) {

        items(
            
            RenderWidget(
                position = index,
                widgetData = widgetData,
                isItemVisible = isItemVisible,
                iHomeCallback = iHomeCallback,
                onWishlist = onWishlist
            )
        }
    }

And RenderWidget code looks like this :-

fun RenderWidget(
     position: Int,
     widgetData: HomeWidgetModel?,
     isItemVisible: Boolean,
     iHomeCallback: IHomeCallback,
     onWishlist: ((ZProduct) -> Unit)? = null) {
     LogUtils.d("renderwidget: ${widgetData?.widget?.widgetName}")
     CardWithBackgroundImage() {
         HorizontalPager(
             modifier = modifier,
             pageCount = loopingCount,
             state = pagerState,
             pageSpacing = pageSpacing,
             contentPadding = contentPadding,
             userScrollEnabled = moreThanOneItem
         ) { index ->
             key(index) {
                 val page = pageMapper(index)
                 pageContent(page)
             }
         }
     }
 }

Has anyone faced a similar problem, and if so, could you please share insights or potential workarounds?

Answer 1

it seems like you are experiencing a scroll delay issue in LazyColumn when it is placed inside a HorizontalPager in Jetpack Compose. This is a common challenge when dealing with nested scrolling components.

One possible workaround is to use the nestedScroll modifier for the LazyColumn to improve the scrolling behavior. Here's how you can modify your LazyColumn code:

Column(modifier = Modifier.fillMaxSize()) {
    LazyColumn(
        modifier = Modifier
            .fillMaxSize()
            .nestedScroll(rememberNestedScrollConnection()),
        state = listState,
        contentPadding = PaddingValues(
            top = rootPadding.calculateTopPadding() + dimen_2,
            bottom = rootPadding.calculateBottomPadding()
        ),
        verticalArrangement = Arrangement.spacedBy(dimen_16),
    ) {
        items(
            RenderWidget(
                position = index,
                widgetData = widgetData,
                isItemVisible = isItemVisible,
                iHomeCallback = iHomeCallback,
                onWishlist = onWishlist
            )
        )
    }
}

Additionally, you can try adjusting the nestedScroll modifier on the outer Column and the userScrollEnabled parameter in the HorizontalPager to fine-tune the scrolling behavior.

If the issue persists, you might want to check for any performance bottlenecks in your RenderWidget and ensure that it is optimized for smooth rendering.

If these suggestions do not resolve the problem, consider checking the official Jetpack Compose documentation and GitHub repository for any known issues or updates that might address this behavior.