add paginationLimit to message list core and ui package

packages/stream_chat_flutter_core/lib/src/message_list_core.dart

@@ -71,6 +71,7 @@ class MessageListCore extends StatefulWidget {
     this.parentMessage,
     this.messageListController,
     this.messageFilter,
+    this.paginationLimit = 20,
   }) : super(key: key);
 
   /// A [MessageListController] allows pagination.
@@ -86,6 +87,9 @@ class MessageListCore extends StatefulWidget {
   /// Function used to build an empty widget
   final WidgetBuilder emptyBuilder;
 
+  /// Limit used to paginate messages
+  final int paginationLimit;
+
   /// Callback triggered when an error occurs while performing the given
   /// request.
   ///
@@ -163,13 +167,20 @@ class MessageListCoreState extends State<MessageListCore> {
   /// Fetches more messages with updated pagination and updates the widget.
   ///
   /// Optionally pass the fetch direction, defaults to [QueryDirection.top]
+  /// Optionally pass a limit, defaults to 20
   Future<void> paginateData({
     QueryDirection direction = QueryDirection.top,
   }) {
     if (!_isThreadConversation) {
-      return _streamChannel!.queryMessages(direction: direction);
+      return _streamChannel!.queryMessages(
+        direction: direction,
+        limit: widget.paginationLimit,
+      );
     } else {
-      return _streamChannel!.getReplies(widget.parentMessage!.id);
+      return _streamChannel!.getReplies(
+        widget.parentMessage!.id,
+        limit: widget.paginationLimit,
+      );
     }
   }
 
@@ -179,7 +190,10 @@ class MessageListCoreState extends State<MessageListCore> {
 
     if (newStreamChannel != _streamChannel) {
       if (_streamChannel == null /*only first time*/ && _isThreadConversation) {
-        newStreamChannel.getReplies(widget.parentMessage!.id);
+        newStreamChannel.getReplies(
+          widget.parentMessage!.id,
+          limit: widget.paginationLimit,
+        );
       }
       _streamChannel = newStreamChannel;
     }
@@ -197,7 +211,10 @@ class MessageListCoreState extends State<MessageListCore> {
 
     if (widget.parentMessage?.id != widget.parentMessage?.id) {
       if (_isThreadConversation) {
-        _streamChannel!.getReplies(widget.parentMessage!.id);
+        _streamChannel!.getReplies(
+          widget.parentMessage!.id,
+          limit: widget.paginationLimit,
+        );
       }
     }
   }

packages/stream_chat_flutter_core/lib/src/stream_channel.dart

@@ -147,9 +147,18 @@ class StreamChannelState extends State<StreamChannel> {
   }
 
   /// Calls [channel.query] updating [queryMessage] stream
-  Future<void> queryMessages({QueryDirection? direction = QueryDirection.top}) {
-    if (direction == QueryDirection.top) return _queryTopMessages();
-    return _queryBottomMessages();
+  Future<void> queryMessages({
+    QueryDirection? direction = QueryDirection.top,
+    int limit = 20,
+  }) {
+    if (direction == QueryDirection.top) {
+      return _queryTopMessages(
+        limit: limit,
+      );
+    }
+    return _queryBottomMessages(
+      limit: limit,
+    );
   }
 
   /// Calls [channel.getReplies] updating [queryMessage] stream