ChatUI #

A flexible, Chat UI package for Flutter. Build modern chat experiences with infinite scrolling, message grouping, reactions, attachments, link previews, and a fully themable interface.

• Widgets: ChatInterface, ChatBubble, input composer
• State: ChatController to add/update messages, scroll control, input visibility
• Models: ChatMessage, ChatUser, ChatAttachment, ChatReaction, ChatMessageStatus, ChatMessageType
• Paging: Built on infinite_scroll_pagination for smooth, reverse list loading
• Theming: ChatTheme and ChatUiConfig for deep customization
• Utilities: Markdown input, image/file picker helpers, debouncer, downloader

Features #

• Plug-and-play ChatInterface widget
• Infinite scroll with reverse list and date headers
• Message composer with markdown, emoji-ready, and send/attach hooks
• Attachments: images, documents, and custom via ChatController
• Message statuses: pending/sent/delivered/seen (icons included)
• Reactions and reply support in the message model
• Jump to bottom FAB with viewport-aware visibility
• Theming: presets (light/dark) and granular overrides; auto-derive from Material theme

Early release ⚠️ #

This is an early release of the package. It is still under development and may change significantly. So, please use it with caution.

Getting started #

1. Add dependency in your pubspec.yaml:

dependencies:
  chat_interface: ^0.0.1

2. Ensure required assets are available (already bundled when using the package):

• assets/images/PENDING.png, SENT.png, DELIVERED.png, SEEN.png
• assets/images/image.png (default wallpaper)

3. Initialize the package once in main():

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

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  initializeChatInterface();
  runApp(const MyApp());
}

If you forget to initialize, the UI will show a helpful error with instructions.

Usage #

Minimal example #

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

class MyChatPage extends StatefulWidget {
  const MyChatPage({super.key});
  @override
  State<MyChatPage> createState() => _MyChatPageState();
}

class _MyChatPageState extends State<MyChatPage> {
  late final PagingController<int, ChatMessage> paging;
  late final ChatController controller;
  final currentUser = ChatUser(id: 'u1', name: 'You');

  @override
  void initState() {
    super.initState();
    paging = PagingController<int, ChatMessage>(
      getNextPageKey: (state) => null, // provide your paging key logic
      fetchPage: (pageKey) => <ChatMessage>[], // fetch messages here
    );

    controller = ChatController(
      scrollController: ScrollController(),
      otherUsers: const [],
      currentUser: currentUser,
      pagingController: paging,
      focusNode: FocusNode(),
    );

    // Optionally handle callbacks
    controller.onMessageAdded = (msg) async {
      // Call your API to send message
    };
  }

  @override
  void dispose() {
    paging.dispose();
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Chat')),
      body: ChatInterface(controller: controller),
    );
  }
}

Sending messages #

• Programmatically add a text message:

await controller.addMessage(
  ChatMessage(
    id: DateTime.now().millisecondsSinceEpoch.toString(),
    message: 'Hello world',
    type: ChatMessageType.chat,
    senderId: controller.currentUser.id,
    roomId: 'room-1',
    chatStatus: ChatMessageStatus.pending,
    createdAt: DateTime.now(),
    updatedAt: DateTime.now(),
  ),
);

• Update an existing message:

await controller.updateMessage(
  message.copyWith(
    message: 'Edited message',
    editedAt: DateTime.now(),
  ),
);

Attachments #

Use built-ins or your own picker:

// Use default helpers
await controller.pickAndSendImageFromGallery();
await controller.pickAndSendImageFromCamera();
await controller.pickAndSendFile();

// Or send your own attachment object
await controller.sendAttachmentMessage(
  ChatAttachment(
    fileName: 'report.pdf',
    fileSize: 1024 * 120,
    mimeType: 'application/pdf',
    // file / bytes source per your flow
  ),
);

Paging and scrolling #

• Provide PagingController<int, ChatMessage> with your fetchPage logic
• The list is reverse: true; newest at bottom
• Call controller.scrollToLastMessage() to jump to bottom

Theming #

Quick presets or full control via ChatTheme and ChatUiConfig.

ChatInterface(
  controller: controller,
  config: ChatUiConfig(
    theme: ChatTheme.fromMaterialTheme(Theme.of(context)),
  ),
)

See advanced options and examples in THEME_CUSTOMIZATION.md.

API surface #

• Initialize: initializeChatInterface({bool isDebug = true})
• Widget: ChatInterface(controller: ..., config: ChatUiConfig(...))
• Controller: ChatController
  • addMessage, updateMessage, scrollToLastMessage
  • pickAndSendImageFromGallery, pickAndSendImageFromCamera, pickAndSendFile
  • sendAttachmentMessage
  • toggleInputField, showInputField
  • otherUsers, currentUser, messages
• Models: ChatMessage, ChatUser, ChatAttachment, ChatReaction, ChatReplyMessage
• Enums: ChatMessageStatus, ChatMessageType

Example app #

A runnable sample is available under example/. It demonstrates Supabase initialization, Riverpod-driven controller creation, paging setup, theming, and the core ChatInterface widget.

Example (Supabase + Riverpod) #

Key excerpts from the example app to mirror the setup.

Main entry (example/lib/main.dart):

import 'package:chat_interface/chat_interface.dart';
import 'package:flutter/material.dart';
import 'package:supabase_flutter/supabase_flutter.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Supabase.initialize(
    url: 'YOUR_SUPABASE_URL',
    anonKey: 'YOUR_SUPABASE_ANON_KEY',
  );
  initializeChatInterface();
  runApp(MaterialApp(home: ChatPage(roomId: 'room-1')));
}

class ChatPage extends HookConsumerWidget {
  final String roomId;
  const ChatPage({super.key, required this.roomId});
  // ... uses chatControllerXProvider to get a ChatController and renders ChatInterface
}

Using the ChatController from a Riverpod provider and passing it to ChatInterface:

// inside ChatPage build → snapshot.when(...)
return ChatInterface(
  controller: controller,
  config: ChatUiConfig(
    scaffold: ChatExtra.scaffoldConfig(context),
    theme: ChatExtra.chatTheme(context),
    customMessage: (controller, message, index) => CustomChatCard(
      controller: controller,
      message: message,
      index: index,
    ),
  ),
);

Provider that constructs ChatController (example/lib/provider.dart):

@riverpod
Future<ChatController?> chatControllerX(
  Ref ref, {
  required String roomId,
  required FocusNode focusNode,
  required ScrollController scrollController,
}) async {
  try {
    const pageSize = 100;
    final supabase = Supabase.instance.client;
    final currentUser = supabase.auth.currentUser;
    final roomCurrentUser = ChatUser(
      id: currentUser?.id ?? '',
      name: currentUser?.email ?? '',
    );
    if (currentUser == null) {
      return null;
    }
    final room = await supabase
        .from('rooms')
        .select('*')
        .eq('id', roomId)
        .single();
    final pagingController = PagingController<int, ChatMessage>(
      getNextPageKey: (state) {
        final keys = state.keys ?? [];
        final pages = state.pages;
        if (keys.isEmpty) return 0;
        if (pages != null && pages.last.length < pageSize) return null;
        return keys.last + 1;
      },
      fetchPage: (pageKey) async {
        final queries = supabase
            .from('messages')
            .select('*, sender:messages_room_member_fk(*)')
            .eq('room_id', roomId)
            .order('created_at', ascending: false)
            .range(pageKey, pageKey + pageSize - 1)
            .limit(pageSize);
        final data = await queries;
        if (data == null || data.isEmpty) {
          throw Exception('No data found');
        }
        return data.map((e) => ChatMessageMapper.fromMap(e)).toList();
      },
    );
    final controller = ChatController(
      scrollController: scrollController,
      currentUser: roomCurrentUser,
      otherUsers: const [],
      pagingController: pagingController,
      focusNode: focusNode,
    );
    controller.uuidGenerator = () => Uuid().v4();
    controller.onMessageAdded = (message) async {
      // call your api to send message
    };
    controller.onMarkAsSeen = (message) async {
      // call your api to mark message as seen
    };
    controller.setRoom(room);
    controller.onTapCamera = () async {
      // custom camera action
    };
    return controller;
  } catch (e) {
    return null;
  }
}

Optional theming and background helpers used in the example:

class ChatExtra {
  static ScaffoldConfig scaffoldConfig(BuildContext context) => ScaffoldConfig(
    background: Container(
      decoration: BoxDecoration(
        image: DecorationImage(
          image: CachedNetworkImageProvider(
            ImageWrapper(imageId: 'chat-background-1.png', bucketId: 'assets')
                    .toSupabaseUrl ??
                'https://web.whatsapp.com/img/bg-chat-tile-dark_a4be512e7195b6b733d9110b408f075d.png',
          ),
          fit: BoxFit.cover,
          colorFilter: ColorFilter.mode(
            context.colors.neutral100,
            BlendMode.exclusion,
          ),
          alignment: Alignment.center,
          opacity: 0.6,
          filterQuality: FilterQuality.high,
          isAntiAlias: true,
        ),
        color: context.colors.backgroundPrimary,
      ),
    ),
  );

  static ChatTheme chatTheme(BuildContext context) =>
      ChatTheme.fromMaterialTheme(context.theme).copyWith(
        inputTextStyle: context.bodyMedium.copyWith(
          color: context.colors.contentPrimary,
        ),
        receivedMessageTextStyle: context.bodyMedium.copyWith(
          color: context.colors.contentPrimary,
        ),
        timestampColor: context.colors.onSurfaceVariant,
        attachmentButtonColor: context.colors.borderInverseOpaque,
        sentMessageTextStyle: context.bodyMedium.copyWith(
          color: context.colors.contentInversePrimary,
        ),
      );
}

Note: The Supabase schema and authentication flow are out of scope for this package; the example assumes you already have rooms and messages tables and an authenticated user.

FAQ #

• I see an initialization error in the UI. Call initializeChatInterface() in main() before running the app.

• Do I have to use the built-in pickers? No. Use your own flow and call sendAttachmentMessage with a ChatAttachment.

• How do I customize the look? Use ChatTheme and ChatUiConfig, or start with ChatTheme.light() / ChatTheme.dark() and copyWith.

Contributing #

Issues and PRs are welcome. Please run format/lints and include screenshots/GIFs for UI changes.

License #

This project is available under the terms of the license in LICENSE.