jump scrollview on new messages

2020-12-03 10:49:41 +01:00
parent 759fe5510e
commit 4373888ae6
1 changed files with 17 additions and 0 deletions
@@ -164,6 +164,7 @@ class _MessageListViewState extends State<MessageListView> {
  Function _onThreadTap;
  bool _showScrollToBottom = false;
  ItemPositionsListener _itemPositionListener;
+  int messageListLength;

  @override
  Widget build(BuildContext context) {
@@ -203,6 +204,22 @@ class _MessageListViewState extends State<MessageListView> {
            );
          }

+          final newMessagesListLength = messages.length;
+
+          if (_itemPositionListener.itemPositions.value?.isNotEmpty == true &&
+              messageListLength != null) {
+            final first = _itemPositionListener.itemPositions.value.first;
+            final diff = newMessagesListLength - messageListLength;
+            if (diff > 0) {
+              _scrollController.jumpTo(
+                index: first.index + diff,
+                alignment: first.itemLeadingEdge,
+              );
+            }
+          }
+
+          messageListLength = newMessagesListLength;
+
          return Stack(
            alignment: Alignment.center,
            children: [