flutter_chatgpt_api 1.0.0

Flutter/Dart API around ChatGPT.

example/lib/main.dart

import 'package:example/session_token.dart';
import 'package:flutter/material.dart';
import 'package:flutter_chatgpt_api/flutter_chatgpt_api.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: 'Flutter ChatGPT API Example by justecdev',
      home: ChatPage(),
      debugShowCheckedModeBanner: false,
    );
  }
}

const backgroundColor = Color(0xff343541);
const botBackgroundColor = Color(0xff444654);

class ChatPage extends StatefulWidget {
  const ChatPage({super.key});

  @override
  State<ChatPage> createState() => _ChatPageState();
}

class _ChatPageState extends State<ChatPage> {
  final _textController = TextEditingController();
  final _scrollController = ScrollController();
  final List<ChatMessage> _messages = [];
  late ChatGPTApi _api;

  String? _parentMessageId;
  String? _conversationId;
  late bool isLoading;

  @override
  void initState() {
    super.initState();
    _api = ChatGPTApi(sessionToken: SESSION_TOKEN);
    isLoading = false;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        toolbarHeight: 100,
        title: const Padding(
          padding: EdgeInsets.all(8.0),
          child: Text(
            'Flutter ChatGPT API Example @coskuncay',
            maxLines: 2,
            textAlign: TextAlign.center,
          ),
        ),
        backgroundColor: botBackgroundColor,
      ),
      backgroundColor: backgroundColor,
      body: SafeArea(
        child: Column(
          children: [
            Expanded(
              child: _buildList(),
            ),
            Visibility(
              visible: isLoading,
              child: const Padding(
                padding: EdgeInsets.all(8.0),
                child: CircularProgressIndicator(
                  color: Colors.white,
                ),
              ),
            ),
            Padding(
              padding: const EdgeInsets.all(8.0),
              child: Row(
                children: [
                  _buildInput(),
                  _buildSubmit(),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildSubmit() {
    return Visibility(
      visible: !isLoading,
      child: Container(
        color: botBackgroundColor,
        child: IconButton(
          icon: const Icon(
            Icons.send_rounded,
            color: Color.fromRGBO(142, 142, 160, 1),
          ),
          onPressed: () async {
            setState(
              () {
                _messages.add(
                  ChatMessage(
                    text: _textController.text,
                    chatMessageType: ChatMessageType.user,
                  ),
                );
                isLoading = true;
              },
            );
            // Save the input and clearing the text field.
            var input = _textController.text;
            _textController.clear();

            // Needs a delay or the scroll won't always work.
            Future.delayed(const Duration(milliseconds: 50))
                .then((_) => _scrollDown());

            // Send the message to the API, use conversationId and parentMessageId
            // to keep the thread context.
            var newMessage = await _api.sendMessage(
              input,
              conversationId: _conversationId,
              parentMessageId: _parentMessageId,
            );
            setState(() {
              _conversationId = newMessage.conversationId;
              _parentMessageId = newMessage.messageId;
              isLoading = false;
              _messages.add(
                ChatMessage(
                  text: newMessage.message,
                  chatMessageType: ChatMessageType.bot,
                ),
              );
            });
            _textController.clear();
            // Needs a delay or the scroll won't always work.
            Future.delayed(const Duration(milliseconds: 50))
                .then((_) => _scrollDown());
          },
        ),
      ),
    );
  }

  Expanded _buildInput() {
    return Expanded(
      child: TextField(
        textCapitalization: TextCapitalization.sentences,
        style: const TextStyle(color: Colors.white),
        controller: _textController,
        decoration: const InputDecoration(
          fillColor: botBackgroundColor,
          filled: true,
          border: InputBorder.none,
          focusedBorder: InputBorder.none,
          enabledBorder: InputBorder.none,
          errorBorder: InputBorder.none,
          disabledBorder: InputBorder.none,
        ),
      ),
    );
  }

  ListView _buildList() {
    return ListView.builder(
      controller: _scrollController,
      itemCount: _messages.length,
      itemBuilder: (context, index) {
        var message = _messages[index];
        return ChatMessageWidget(
          text: message.text,
          chatMessageType: message.chatMessageType,
        );
      },
    );
  }

  void _scrollDown() {
    _scrollController.animateTo(
      _scrollController.position.maxScrollExtent,
      duration: const Duration(milliseconds: 300),
      curve: Curves.easeOut,
    );
  }
}

class ChatMessageWidget extends StatelessWidget {
  const ChatMessageWidget(
      {super.key, required this.text, required this.chatMessageType});

  final String text;
  final ChatMessageType chatMessageType;

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: const EdgeInsets.symmetric(vertical: 10.0),
      padding: const EdgeInsets.all(16),
      color: chatMessageType == ChatMessageType.bot
          ? botBackgroundColor
          : backgroundColor,
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          chatMessageType == ChatMessageType.bot
              ? Container(
                  margin: const EdgeInsets.only(right: 16.0),
                  child: CircleAvatar(
                    backgroundColor: const Color.fromRGBO(16, 163, 127, 1),
                    child: Image.asset(
                      'assets/bot.png',
                      color: Colors.white,
                      scale: 1.5,
                    ),
                  ),
                )
              : Container(
                  margin: const EdgeInsets.only(right: 16.0),
                  child: const CircleAvatar(
                    child: Icon(
                      Icons.person,
                    ),
                  ),
                ),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: <Widget>[
                Container(
                  padding: const EdgeInsets.all(8.0),
                  decoration: const BoxDecoration(
                    borderRadius: BorderRadius.all(Radius.circular(8.0)),
                  ),
                  child: Text(
                    text,
                    style: Theme.of(context)
                        .textTheme
                        .bodyLarge
                        ?.copyWith(color: Colors.white),
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}