Move Flutter widgets to packages directory

packages/flutter_widgets/lib/src/message_search_bloc.dart

@@ -0,0 +1,113 @@
+import 'package:flutter/material.dart';
+import 'package:rxdart/rxdart.dart';
+import 'package:stream_chat/stream_chat.dart';
+
+import 'stream_chat.dart';
+
+/// Widget dedicated to the management of a message list with pagination
+class MessageSearchBloc extends StatefulWidget {
+  /// The widget child
+  final Widget child;
+
+  /// Instantiate a new MessageSearchBloc
+  const MessageSearchBloc({
+    Key key,
+    @required this.child,
+  }) : super(key: key);
+
+  @override
+  MessageSearchBlocState createState() => MessageSearchBlocState();
+
+  /// Use this method to get the current [MessageSearchBlocState] instance
+  static MessageSearchBlocState of(BuildContext context) {
+    MessageSearchBlocState state;
+
+    state = context.findAncestorStateOfType<MessageSearchBlocState>();
+
+    if (state == null) {
+      throw Exception('You must have a MessageSearchBloc widget as ancestor');
+    }
+
+    return state;
+  }
+}
+
+/// The current state of the [MessageSearchBloc]
+class MessageSearchBlocState extends State<MessageSearchBloc>
+    with AutomaticKeepAliveClientMixin {
+  /// The current messages list
+  List<GetMessageResponse> get messageResponses => _messageResponses.value;
+
+  /// The current messages list as a stream
+  Stream<List<GetMessageResponse>> get messagesStream =>
+      _messageResponses.stream;
+
+  final BehaviorSubject<List<GetMessageResponse>> _messageResponses =
+      BehaviorSubject();
+
+  final BehaviorSubject<bool> _queryMessagesLoadingController =
+      BehaviorSubject.seeded(false);
+
+  /// The stream notifying the state of queryUsers call
+  Stream<bool> get queryMessagesLoading =>
+      _queryMessagesLoadingController.stream;
+
+  /// Calls [Client.search] updating [queryMessagesLoading] stream
+  Future<void> search({
+    Map<String, dynamic> filter,
+    Map<String, dynamic> messageFilter,
+    List<SortOption> sort,
+    String query,
+    PaginationParams pagination,
+  }) async {
+    final client = StreamChat.of(context).client;
+
+    if (client.state?.user == null ||
+        _queryMessagesLoadingController.value == true) {
+      return;
+    }
+    _queryMessagesLoadingController.add(true);
+    try {
+      final clear = pagination == null ||
+          pagination.offset == null ||
+          pagination.offset == 0;
+
+      final oldMessages = List<GetMessageResponse>.from(messageResponses ?? []);
+
+      final messageResponse = await client.search(
+        filter,
+        sort,
+        query,
+        pagination,
+        messageFilters: messageFilter,
+      );
+
+      if (clear) {
+        _messageResponses.add(messageResponse.results);
+      } else {
+        final temp = oldMessages + messageResponse.results;
+        _messageResponses.add(temp);
+      }
+
+      _queryMessagesLoadingController.add(false);
+    } catch (err, stackTrace) {
+      _queryMessagesLoadingController.addError(err, stackTrace);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    super.build(context);
+    return widget.child;
+  }
+
+  @override
+  void dispose() {
+    _messageResponses.close();
+    _queryMessagesLoadingController.close();
+    super.dispose();
+  }
+
+  @override
+  bool get wantKeepAlive => true;
+}