Timeline: add autoscroll on new messages

features/messages/src/main/java/io/element/android/x/features/messages/MessagesScreen.kt

@@ -224,6 +224,7 @@ fun TimelineItems(
     onReachedLoadMore: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
+    Box(modifier = modifier.fillMaxWidth()) {
         LazyColumn(
             modifier = modifier.fillMaxWidth(),
             state = lazyListState,
@@ -248,6 +249,8 @@ fun TimelineItems(
                 }
             }
         }
+        MessagesScrollHelper(lazyListState = lazyListState, timelineItems = timelineItems)
+    }
 }
 
 private fun MessagesTimelineItemState.key(): String {
@@ -455,6 +458,22 @@ fun MessageEventBubble(
     )
 }
 
+@Composable
+internal fun MessagesScrollHelper(
+    lazyListState: LazyListState,
+    timelineItems: List<MessagesTimelineItemState>,
+) {
+    val coroutineScope = rememberCoroutineScope()
+    val firstVisibleItemIndex by remember { derivedStateOf { lazyListState.firstVisibleItemIndex } }
+    LaunchedEffect(timelineItems, firstVisibleItemIndex) {
+        if (!lazyListState.isScrollInProgress &&
+            firstVisibleItemIndex < 2
+        ) coroutineScope.launch {
+            lazyListState.animateScrollToItem(0)
+        }
+    }
+}
+
 @Composable
 internal fun MessagesLoadingMoreIndicator(onReachedLoadMore: () -> Unit) {
     Box(