Jetpack compoes lazycolumn skipping frames (lagging)

Question

Hi i'm trying to implement a lazycolumn of a list of posts, I tested it on the emulator api 21 and 29 and it looks kinda smooth on the api 29 it's a little bit laggy, when I tested it on a physical device it was lagging, It looks like it's skipping frames or something..

I tried to remove some views that uses imageVector to see if that was the problem and still the same problem.

This is my composable view:

@Composable
fun HomePostView(
    category: String,
    imagesUrl: List<String> = listOf(imageHolder),
    doctorProfileImage: String = imageUrl,
    title: String,
    subTitle: String
) {


    Card(
        shape = PostCardShape.large, modifier = Modifier
            .padding(horizontal = 3.dp)
            .fillMaxWidth()
    ) {

        Column {

            PostTopView(
                category = category,
                onOptionsClicked = { /*TODO option click*/ },
                onBookmarkClicked = {/*TODO bookmark click*/ })

            CoilImage(
                data = imagesUrl[0],
                fadeIn = true,
                contentDescription = "post_image",
                modifier = Modifier
                    .fillMaxWidth()
                    .requiredHeight(190.dp)
                    .padding(horizontal = contentPadding),
                contentScale = ContentScale.Crop
            )

            Spacer(modifier = Modifier.height(10.dp))

            PostDoctorContent(
                doctorProfileImage = doctorProfileImage,
                title = title,
                subTitle = subTitle
            )
            Spacer(modifier = Modifier.height(contentPadding))

            PostBottomView(likesCount = 293, commentsCount = 22)

            Spacer(modifier = Modifier.height(contentPadding))

        }


    }
    Spacer(modifier = Modifier.height(10.dp))


}


@Composable
private fun PostDoctorContent(doctorProfileImage: String, title: String, subTitle: String) {
    Row(
        modifier = Modifier
            .fillMaxWidth()
            .padding(horizontal = contentPadding)
    ) {

        CoilImage(data = doctorProfileImage,
            contentScale = ContentScale.Crop,
            contentDescription = null,
            fadeIn = true,
            modifier = Modifier
                .size(30.dp)
                .clip(CircleShape)
                .clickable {
                    /*Todo on doctor profile clicked*/
                })


        Column {
            Text(
                text = title, fontSize = 14.sp, maxLines = 1,
                overflow = TextOverflow.Ellipsis,
                modifier = Modifier.padding(horizontal = contentPadding)
            )

            Text(
                text = subTitle,
                fontSize = 11.sp,
                color = LightTextColor,
                maxLines = 2,
                overflow = TextOverflow.Ellipsis,
                modifier = Modifier.padding(horizontal = contentPadding)
            )
        }
    }


}

@Composable
private fun PostBottomView(likesCount: Long, commentsCount: Long) {
    Row(
        modifier = Modifier.padding(horizontal = contentPadding),
        verticalAlignment = Alignment.CenterVertically
    ) {

        Row(
            Modifier
                .clip(RoundedCornerShape(50))
                .clickable { /*Todo on like clicked*/ }
                .padding(5.dp),
            verticalAlignment = Alignment.CenterVertically
        ) {
            Icon(
                imageVector = ImageVector.vectorResource(id = R.drawable.ic_heart),
                contentDescription = "Like"
            )
            Spacer(modifier = Modifier.width(5.dp))
            Text(text = likesCount.toString(), fontSize = 9.sp)
        }
        Spacer(Modifier.width(20.dp))

        Row(
            Modifier
                .clip(RoundedCornerShape(50))
                .clickable { /*Todo on comment clicked*/ }
                .padding(5.dp),
            verticalAlignment = Alignment.CenterVertically
        ) {
            Icon(
                imageVector = ImageVector.vectorResource(id = R.drawable.ic_comment),
                contentDescription = "Comment"
            )
            Spacer(modifier = Modifier.width(5.dp))
            Text(text = commentsCount.toString(), fontSize = 9.sp)
        }


    }
}

@Composable
private fun PostTopView(
    category: String,
    onOptionsClicked: () -> Unit,
    onBookmarkClicked: () -> Unit
) {
    Row(
        modifier = Modifier.fillMaxWidth(),
        verticalAlignment = Alignment.CenterVertically,
        horizontalArrangement = Arrangement.SpaceBetween
    ) {

        Row(verticalAlignment = Alignment.CenterVertically) {
            IconButton(onClick = onOptionsClicked) {
                Icon(
                    imageVector = ImageVector.vectorResource(id = R.drawable.ic_threedots),
                    contentDescription = "Options",
                    tint = Color.Unspecified
                )
            }

            Text(text = category, fontSize = 16.sp, color = LightTextColor)

        }

        IconButton(onClick = onBookmarkClicked) {
            Icon(
                imageVector = ImageVector.vectorResource(id = R.drawable.ic_bookmark),
                contentDescription = "Bookmark"
            )
        }

    }
}

and the lazyColumn:

LazyColumn(contentPadding = paddingValues , state = state ) {
    item {
        Spacer(modifier = Modifier.height(10.dp))

        DoctorsList(
            viewModel.doctorListData.value,
            onCardClicked = {})
    }
    items(30) {  post ->
        HomePostView(
            category = "Public Health ",
            title = "Food Importance",
            subTitle = "you should eat every day it's healthy and important for you, and drink water every 2 hours and what you should do is you should run every day for an hour"
        )

    }
}

Note: I'm still not using a viewmodel i'm just testing the view with fake data

Answer 1

This may not work for anyone else but on an earlier version (1.0.0-beta01) I saw a very large improvement in performance when I switched

lazy(items) { item ->
    ...
}

to

items.forEach { item ->
    lazy {
        ...
    }
}

I have no idea why and I'm not sure if this is still the case in later versions but its worth checking. So for the example given in the question, that would mean changing

items(30) {
    ...
}

to

repeat(30) {
    item { 
        ...
    }
}