stream_chat_flutter_core 10.2.0

stream_chat_flutter_core: ^10.2.0 copied to clipboard

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:stream_chat_flutter_core/stream_chat_flutter_core.dart';

Future<void> main() async {
  /// Create a new instance of [StreamChatClient] passing the apikey obtained
  /// from your project dashboard.
  final client = StreamChatClient('b67pax5b2wdq');

  /// Set the current user. In a production scenario, this should be done using
  /// a backend to generate a user token using our server SDK.
  /// Please see the following for more information:
  /// https://getstream.io/chat/docs/ios_user_setup_and_tokens/
  await client.connectUser(
    User(
      id: 'cool-shadow-7',
      image:
          'https://getstream.io/random_png/?id=cool-shadow-7&amp;name=Cool+shadow',
    ),
    '''eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VyX2lkIjoiY29vbC1zaGFkb3ctNyJ9.gkOlCRb1qgy4joHPaxFwPOdXcGvSPvp6QY0S4mpRkVo''',
  );

  runApp(StreamExample(client: client));
}

/// Example application using Stream Chat core widgets.
/// Stream Chat Core is a set of Flutter wrappers which provide basic
/// functionality for building Flutter applications using Stream.
///
/// If you'd prefer using pre-made UI widgets for your app, please see our other
/// package, `stream_chat_flutter`.
class StreamExample extends StatelessWidget {
  /// Minimal example using Stream's core Flutter package.
  ///
  /// If you'd prefer using pre-made UI widgets for your app, please see our
  /// other package, `stream_chat_flutter`.
  const StreamExample({Key? key, required this.client}) : super(key: key);

  /// Instance of Stream Client.
  /// Stream's [StreamChatClient] can be used to connect to our servers and
  /// set the default user for the application. Performing these actions
  /// trigger a websocket connection allowing for real-time updates.
  final StreamChatClient client;

  @override
  Widget build(BuildContext context) => MaterialApp(
    title: 'Stream Chat Core Example',
    home: HomeScreen(),
    builder: (context, child) => StreamChatCore(client: client, child: child!),
  );
}

/// Basic layout displaying a list of [Channel]s the user is a part of.
/// This is implemented using a [StreamChannelListController].
///
/// [StreamChannelListController] is a controller that lets you manage a list of
/// channels.
class HomeScreen extends StatefulWidget {
  /// Builds a basic layout displaying a list of [Channel]s the user is a
  /// part of.
  const HomeScreen({Key? key}) : super(key: key);

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  /// Controller used for loading more data and controlling pagination in
  /// [StreamChannelListController].
  late final channelListController = StreamChannelListController(
    client: StreamChatCore.of(context).client,
    filter: Filter.and([
      Filter.equal('type', 'messaging'),
      Filter.in_('members', [StreamChatCore.of(context).currentUser!.id]),
    ]),
  );

  @override
  void initState() {
    channelListController.doInitialLoad();
    super.initState();
  }

  @override
  void dispose() {
    channelListController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(title: const Text('Channels')),
    body: PagedValueListenableBuilder<int, Channel>(
      valueListenable: channelListController,
      builder: (context, value, child) {
        return value.when(
          (channels, nextPageKey, error) => LazyLoadScrollView(
            onEndOfPage: () async {
              if (nextPageKey != null) {
                channelListController.loadMore(nextPageKey);
              }
            },
            child: ListView.builder(
              /// We're using the channels length when there are no more
              /// pages to load and there are no errors with pagination.
              /// In case we need to show a loading indicator or and error
              /// tile we're increasing the count by 1.
              itemCount: (nextPageKey != null || error != null)
                  ? channels.length + 1
                  : channels.length,
              itemBuilder: (BuildContext context, int index) {
                if (index == channels.length) {
                  if (error != null) {
                    return TextButton(
                      onPressed: () {
                        channelListController.retry();
                      },
                      child: Text(error.message),
                    );
                  }
                  return CircularProgressIndicator();
                }

                final _item = channels[index];
                return ListTile(
                  title: Text(_item.name ?? ''),
                  subtitle: StreamBuilder<Message?>(
                    stream: _item.state!.lastMessageStream,
                    initialData: _item.state!.lastMessage,
                    builder: (context, snapshot) {
                      if (snapshot.hasData) {
                        return Text(snapshot.data!.text!);
                      }

                      return const SizedBox();
                    },
                  ),
                  onTap: () {
                    /// Display a list of messages when the user taps on
                    /// an item. We can use [StreamChannel] to wrap our
                    /// [MessageScreen] screen with the selected channel.
                    ///
                    /// This allows us to use a built-in inherited widget
                    /// for accessing our `channel` later on.
                    Navigator.of(context).push(
                      MaterialPageRoute(
                        builder: (context) => StreamChannel(
                          channel: _item,
                          child: const MessageScreen(),
                        ),
                      ),
                    );
                  },
                );
              },
            ),
          ),
          loading: () => const Center(
            child: SizedBox(
              height: 100,
              width: 100,
              child: CircularProgressIndicator(),
            ),
          ),
          error: (e) => Center(
            child: Text(
              'Oh no, something went wrong. '
              'Please check your config. $e',
            ),
          ),
        );
      },
    ),
  );
}

/// A list of messages sent in the current channel.
/// When a user taps on a channel in [HomeScreen], a navigator push
/// [MessageScreen] to display the list of messages in the selected channel.
///
/// This is implemented using [MessageListCore], a convenience builder with
/// callbacks for building UIs based on different api results.
class MessageScreen extends StatefulWidget {
  /// Build a MessageScreen
  const MessageScreen({Key? key}) : super(key: key);

  @override
  _MessageScreenState createState() => _MessageScreenState();
}

class _MessageScreenState extends State<MessageScreen> {
  final StreamMessageComposerController messageComposerController =
      StreamMessageComposerController();
  late final ScrollController _scrollController;
  final messageListController = MessageListController();

  @override
  void initState() {
    super.initState();
    _scrollController = ScrollController();
  }

  @override
  void dispose() {
    messageComposerController.dispose();
    _scrollController.dispose();
    super.dispose();
  }

  void _updateList() {
    _scrollController.animateTo(
      0,
      duration: const Duration(milliseconds: 200),
      curve: Curves.easeOut,
    );
  }

  @override
  Widget build(BuildContext context) {
    /// To access the current channel, we can use the `.of()` method on
    /// [StreamChannel] to fetch the closest instance.
    final channel = StreamChannel.of(context).channel;
    return Scaffold(
      appBar: AppBar(
        title: StreamBuilder<Iterable<User>>(
          initialData: channel.state?.typingEvents.keys,
          stream: channel.state?.typingEventsStream.map((it) => it.keys),
          builder: (context, snapshot) {
            if (snapshot.hasData && snapshot.data!.isNotEmpty) {
              return Text('${snapshot.data!.first.name} is typing...');
            }
            return const SizedBox();
          },
        ),
      ),
      body: SafeArea(
        child: Column(
          children: [
            Expanded(
              child: LazyLoadScrollView(
                onEndOfPage: () async {
                  messageListController.paginateData!();
                },
                child: MessageListCore(
                  messageListController: messageListController,
                  emptyBuilder: (BuildContext context) =>
                      const Center(child: Text('Nothing here yet')),
                  loadingBuilder: (BuildContext context) => const Center(
                    child: SizedBox(
                      height: 100,
                      width: 100,
                      child: CircularProgressIndicator(),
                    ),
                  ),
                  messageListBuilder:
                      (BuildContext context, List<Message> messages) =>
                          ListView.builder(
                            controller: _scrollController,
                            itemCount: messages.length,
                            reverse: true,
                            itemBuilder: (BuildContext context, int index) {
                              final item = messages[index];
                              final client = StreamChatCore.of(context).client;
                              if (item.user!.id == client.uid) {
                                return Align(
                                  alignment: Alignment.centerRight,
                                  child: Padding(
                                    padding: const EdgeInsets.all(8),
                                    child: Text(item.text!),
                                  ),
                                );
                              } else {
                                return Align(
                                  alignment: Alignment.centerLeft,
                                  child: Padding(
                                    padding: const EdgeInsets.all(8),
                                    child: Text(item.text!),
                                  ),
                                );
                              }
                            },
                          ),
                  errorBuilder: (BuildContext context, error) {
                    print(error.toString());
                    return const Center(
                      child: SizedBox(
                        height: 100,
                        width: 100,
                        child: Text(
                          'Oh no, an error occured. Please see logs.',
                        ),
                      ),
                    );
                  },
                ),
              ),
            ),
            Padding(
              padding: const EdgeInsets.all(8),
              child: Row(
                children: [
                  Expanded(
                    child: TextField(
                      controller: messageComposerController.textFieldController,
                      decoration: const InputDecoration(
                        hintText: 'Enter your message',
                      ),
                    ),
                  ),
                  Material(
                    type: MaterialType.circle,
                    color: Colors.blue,
                    clipBehavior: Clip.hardEdge,
                    child: InkWell(
                      onTap: () async {
                        if (messageComposerController.text.isNotEmpty) {
                          await channel.sendMessage(
                            messageComposerController.message,
                          );
                          messageComposerController.clear();
                          if (mounted) {
                            _updateList();
                          }
                        }
                      },
                      child: const Padding(
                        padding: EdgeInsets.all(8),
                        child: Center(
                          child: Icon(Icons.send, color: Colors.white),
                        ),
                      ),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

/// Extensions can be used to add functionality to the SDK. In the example
/// below, we add a simple extensions to the [StreamChatClient].
extension on StreamChatClient {
  /// Fetches the current user id.
  String get uid => state.currentUser!.id;
}