From 1246b9e376a8aafc52907664b41f1bdd4274e72a Mon Sep 17 00:00:00 2001
From: Stanislav Dmitrenko <7953703+avently@users.noreply.github.com>
Date: Mon, 12 Dec 2022 18:34:26 +0300
Subject: [PATCH] android: Chat auto-scrolling behaviour (#1556)

Co-authored-by: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>
---
 .../main/java/chat/simplex/app/views/chat/ChatView.kt  | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/apps/android/app/src/main/java/chat/simplex/app/views/chat/ChatView.kt b/apps/android/app/src/main/java/chat/simplex/app/views/chat/ChatView.kt
index 0c8d8ec749..0b3a55b140 100644
--- a/apps/android/app/src/main/java/chat/simplex/app/views/chat/ChatView.kt
+++ b/apps/android/app/src/main/java/chat/simplex/app/views/chat/ChatView.kt
@@ -617,17 +617,21 @@ private fun ScrollToBottom(chatId: ChatId, listState: LazyListState, chatItems:
     // Don't autoscroll next time until it will be needed
     shouldAutoScroll = false to chatId
   }
+  val scrollDistance = with(LocalDensity.current) { -39.dp.toPx() }
   /*
   * Since we use key with each item in LazyColumn, LazyColumn will not autoscroll to bottom item. We need to do it ourselves.
-  * When the first visible item (from bottom) is fully visible we can autoscroll to 0 item
+  * When the first visible item (from bottom) is visible (even partially) we can autoscroll to 0 item. Or just scrollBy small distance otherwise
   * */
   LaunchedEffect(Unit) {
     snapshotFlow { chatItems.lastOrNull()?.id }
       .distinctUntilChanged()
-      .filter { listState.firstVisibleItemIndex == 0 && listState.firstVisibleItemScrollOffset == 0 }
       .filter { listState.layoutInfo.visibleItemsInfo.firstOrNull()?.key != it }
       .collect {
-        listState.animateScrollToItem(0)
+        if (listState.firstVisibleItemIndex == 0) {
+          listState.animateScrollToItem(0)
+        } else {
+          listState.animateScrollBy(scrollDistance)
+        }
       }
   }
 }