Maybe I missed something completly obvious but I tried to create an lazy list from the return of a flow but the State dosn't get updated Code in the 🧵 [SOLVED]

You’re repeatedly emitting the same list instance, and mutable state doesn’t notify changes if the same value is set multiple consecutive times. In general, you don’t want to emit mutable values in a flow, or store them in a mutable state.

doesn’t notify changes if the same value is set multiple consecutive times.

I thought the hashcode has to be diffrent? I now also tried it out with an Object and in my testings it only worked with 'primitiv' types (tested with List, Array, DataObject, Int and String)

You could instead of using flow use a

mutableStateListOf<>()

which will keep track of changes.

fun main() {
    val itemList = mutableStateListOf<RowData>()
    val fetchData = flow<Unit> {
        for (n in 0 until 20) {
            val toAdd = RowData(n, "Hi", n.toDouble(), n, n.toDouble())
            itemList.add(toAdd)
            delay(50)
        }
    }

    Window("Test", IntSize(600, 400)) {
        MaterialTheme {
            println("recomposed")

            LaunchedEffect(Unit) {
                fetchData.collect()
            }

            val state = LazyListState(0, 0)
            LazyRow(state = state, modifier = Modifier.fillMaxSize()) {
                items(itemList) {
                    Row(
                        horizontalArrangement = Arrangement.SpaceAround,
                        verticalAlignment = Alignment.CenterVertically,
                        modifier = Modifier.fillParentMaxWidth(),
                    ) {
                        Text(it.data1.toString())
                        Text(it.data2)
                        Text(it.data3.toString())
                        Text(it.data4.toString())
                    }
                }
            }
        }
    }
}

Doesn't work either 😬 Even if I make it inline wihout using a flow to dispatch the updates

fun main() {
    Window("Test", IntSize(600, 400)) {
        MaterialTheme {
            println("recomposed")

            val itemList = mutableStateListOf<RowData>()
            LaunchedEffect(Unit) {
                for (n in 0 until 20) {
                    val toAdd = RowData(n, "Hi", n.toDouble(), n, n.toDouble())
                    itemList.add(toAdd)
                    delay(50)
                }
            }

            val state = LazyListState(0, 0)
            LazyRow(state = state, modifier = Modifier.fillMaxSize()) {
                items(itemList) {
                    Row(
                        horizontalArrangement = Arrangement.SpaceAround,
                        verticalAlignment = Alignment.CenterVertically,
                        modifier = Modifier.fillParentMaxWidth(),
                    ) {
                        Text(it.data1.toString())
                        Text(it.data2)
                        Text(it.data3.toString())
                        Text(it.data4.toString())
                    }
                }
            }
        }
    }
}

Can you try to fetch the items using

LaunchedEffect(..) {
   withContext(<http://Dispatchers.IO|Dispatchers.IO>) {
      ....
   }
}

I do. Nothing changed by using another Dispatcher

It should work. I used it this way many times.

strange 🤔

But it work also with LazyRow but you have to scroll 😄

Yes because of 😂

Modifier.fillParentMaxWidth()

Ok yes i see.

nice to know thanks 👍 But I try to stay multiplattform as good as possible with my application The goal was to do a list that shows the item as fast as it got loaded