From 04ca2c6eebaf5be6d5da4c73041ce13d95fb14cb Mon Sep 17 00:00:00 2001
From: Salvatore Giordano <salvatoregiordanoo@gmail.com>
Date: Tue, 26 Oct 2021 12:50:40 +0200
Subject: [PATCH] fix(ui): fix scroll to bottom logic

---
 .../src/positioned_list.dart                  |  5 ++++-
 .../src/scrollable_positioned_list.dart       |  8 --------
 .../lib/src/message_list_view.dart            | 19 +++++++++++++++----
 3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/packages/stream_chat_flutter/lib/scrollable_positioned_list/src/positioned_list.dart b/packages/stream_chat_flutter/lib/scrollable_positioned_list/src/positioned_list.dart
index 081d67e0..7cd4cf16 100644
--- a/packages/stream_chat_flutter/lib/scrollable_positioned_list/src/positioned_list.dart
+++ b/packages/stream_chat_flutter/lib/scrollable_positioned_list/src/positioned_list.dart
@@ -325,9 +325,12 @@ class _PositionedListState extends State<PositionedList> {
         for (final element in registeredElements.value!) {
           final box = element.renderObject as RenderBox;
           viewport ??= RenderAbstractViewport.of(box) as RenderViewport?;
+          if (viewport == null) {
+            continue;
+          }
           final key = element.widget.key as IndexedKey;
           if (widget.scrollDirection == Axis.vertical) {
-            final reveal = viewport!.getOffsetToReveal(box, 0).offset;
+            final reveal = viewport.getOffsetToReveal(box, 0).offset;
             if (!reveal.isFinite) continue;
             final itemOffset = reveal -
                 viewport.offset.pixels +
diff --git a/packages/stream_chat_flutter/lib/scrollable_positioned_list/src/scrollable_positioned_list.dart b/packages/stream_chat_flutter/lib/scrollable_positioned_list/src/scrollable_positioned_list.dart
index 388e5979..765a90a0 100644
--- a/packages/stream_chat_flutter/lib/scrollable_positioned_list/src/scrollable_positioned_list.dart
+++ b/packages/stream_chat_flutter/lib/scrollable_positioned_list/src/scrollable_positioned_list.dart
@@ -325,14 +325,6 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
         secondary.target = widget.itemCount - 1;
       }
     }
-
-    if (widget.initialScrollIndex != oldWidget.initialScrollIndex ||
-        widget.initialAlignment != oldWidget.initialAlignment) {
-      _jumpTo(
-        index: widget.initialScrollIndex,
-        alignment: widget.initialAlignment,
-      );
-    }
   }
 
   @override
diff --git a/packages/stream_chat_flutter/lib/src/message_list_view.dart b/packages/stream_chat_flutter/lib/src/message_list_view.dart
index 3760747d..6798c432 100644
--- a/packages/stream_chat_flutter/lib/src/message_list_view.dart
+++ b/packages/stream_chat_flutter/lib/src/message_list_view.dart
@@ -465,6 +465,9 @@ class _MessageListViewState extends State<MessageListView> {
                   _inBetweenList = true;
                 },
                 child: ScrollablePositionedList.separated(
+                  key: (initialIndex != 0 && initialAlignment != 0)
+                      ? ValueKey('$initialIndex-$initialAlignment')
+                      : null,
                   itemPositionsListener: _itemPositionListener,
                   initialScrollIndex: initialIndex,
                   initialAlignment: initialAlignment,
@@ -795,13 +798,19 @@ class _MessageListViewState extends State<MessageListView> {
               children: [
                 FloatingActionButton(
                   backgroundColor: _streamTheme.colorTheme.barsBg,
-                  onPressed: () {
+                  onPressed: () async {
                     if (unreadCount > 0) {
                       streamChannel!.channel.markRead();
                     }
                     if (!_upToDate) {
                       _bottomPaginationActive = false;
-                      streamChannel!.reloadChannel();
+                      initialAlignment = 0;
+                      initialIndex = 0;
+                      await streamChannel!.reloadChannel();
+
+                      WidgetsBinding.instance?.addPostFrameCallback((_) {
+                        _scrollController!.jumpTo(index: 0);
+                      });
                     } else {
                       _showScrollToBottom.value = false;
                       _scrollController!.scrollTo(
@@ -1057,8 +1066,10 @@ class _MessageListViewState extends State<MessageListView> {
         final scrollToIndex = () {
           final index = messages.indexWhere((m) => m.id == quotedMessageId);
           _scrollController?.scrollTo(
-            index: index,
-            duration: const Duration(milliseconds: 350),
+            index: index + 2, // +2 to account for loader and footer
+            duration: const Duration(seconds: 1),
+            curve: Curves.easeInOut,
+            alignment: 0.1,
           );
         };
         if (messages.map((e) => e.id).contains(quotedMessageId)) {