Smooth scrolling of LazyColumn in desktop compose - android-jetpack-compose

Question

I made LazyColumn with vertical scroll bar and it's work good, but when i scroll mouse, column just jumping(not smooth), but when I scroll vert. bar, it's smooth
#ExperimentalFoundationApi
#OptIn(ExperimentalMaterial3Api::class, ExperimentalComposeUiApi::class)
#Composable
fun App() {
Box(modifier = Modifier.fillMaxSize().padding(10.dp)
) {
val animatedpr = remember { androidx.compose.animation.core.Animatable(initialValue = 0.8f) }
val stateVertical = rememberLazyListState(0)
LaunchedEffect(Unit){animatedpr.animateTo(targetValue = 1f, animationSpec = tween(300, easing = LinearEasing))}
LazyColumn(modifier = Modifier.fillMaxSize(), horizontalAlignment = Alignment.CenterHorizontally, state = stateVertical) {
items(1100) {
OutlinedCard(modifier = Modifier.size(500.dp, 100.dp).padding(20.dp).animateItemPlacement().graphicsLayer(scaleY = animatedpr.value, scaleX = animatedpr.value)) {
}
}
}
VerticalScrollbar(
modifier = Modifier.align(Alignment.CenterEnd).fillMaxHeight(),
adapter = rememberScrollbarAdapter(
scrollState = stateVertical
)
)
}
}

Answer 1

better sollution
if(it.changes.first().scrollDelta.y == 1.0f){
scope.launch { stateVertical.animateScrollBy(200.0f) }
}
else{
scope.launch {
scope.launch { stateVertical.animateScrollBy(-200.0f) }
}
}

Answer 2

The problem is that you use a single scroll state for two different scroll views. This is causing the jumping while recomposing.

Answer 3

I fixed it by adding "scrollhandler"(onPointerEvent(PointerEventType.Scroll))
val scope = rememberCoroutineScope() // coroutine for scroling(idk, i know coroutines very bad)
val stateVertical = rememberLazyListState(0)
.....
LazyColumn(modifier = Modifier.fillMaxSize().onPointerEvent(PointerEventType.Scroll){
var currentItem = stateVertical.layoutInfo.visibleItemsInfo[0].index
val itemsToScrolling = stateVertical.layoutInfo.visibleItemsInfo.size/2 // how many items we scrolling
if(it.changes.first().scrollDelta.y == 1.0f){ // scroll down
scope.launch { stateVertical.animateScrollToItem(currentItem+itemsToScrolling) }
}
else{ // scroll up
if(currentItem < itemsToScrolling){currentItem = itemsToScrolling} // because we cannot animate to negative number
scope.launch { stateVertical.animateScrollToItem(currentItem-itemsToScrolling) }
}
}, state = stateVertical){
*items*
}