Flutter chat interface

import 'package:flutter/material.dart';

// Model for a chat message
class Message {
  final String senderName;
  final String content;
  final DateTime timestamp;

  Message({required this.senderName, required this.content, required this.timestamp});
}

void main() => runApp(ChatApp());

class ChatApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: ChatScreen(),
    );
  }
}

class ChatScreen extends StatefulWidget {
  @override
  _ChatScreenState createState() => _ChatScreenState();
}

class _ChatScreenState extends State<ChatScreen> {
  List<Message> _messages = []; // List to store chat messages
  TextEditingController _textController = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Group Chat'),
      ),
      body: Column(
        children: [
          Expanded(
            child: ListView.builder(
              reverse: true,
              itemCount: _messages.length,
              itemBuilder: (context, index) {
                Message message = _messages[index];
                bool isMe = message.senderName == 'Me'; // Replace 'Me' with the user's name
                return ChatBubble(
                  message: message.content,
                  senderName: message.senderName,
                  isMe: isMe,
                  time: message.timestamp,
                );
              },
            ),
          ),
          Container(
            padding: EdgeInsets.symmetric(horizontal: 8.0),
            child: Row(
              children: [
                Expanded(
                  child: TextField(
                    controller: _textController,
                    decoration: InputDecoration(hintText: 'Type a message...'),
                  ),
                ),
                IconButton(
                  icon: Icon(Icons.send),
                  onPressed: () {
                    _sendMessage();
                  },
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  // Function to send a new message
  void _sendMessage() {
    String text = _textController.text;
    if (text.trim().isNotEmpty) {
      // Replace 'Me' with the user's name
      Message newMessage = Message(senderName: 'Me', content: text, timestamp: DateTime.now());
      setState(() {
        _messages.insert(0, newMessage);
      });
      _textController.clear();
    }
  }
}

class ChatBubble extends StatelessWidget {
  final String message;
  final String senderName;
  final bool isMe;
  final DateTime time;

  ChatBubble({required this.message, required this.senderName, required this.isMe, required this.time});

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(8.0),
      child: Column(
        crossAxisAlignment: isMe ? CrossAxisAlignment.end : CrossAxisAlignment.start,
        children: [
          if (!isMe)
            Text(
              senderName,
              style: TextStyle(fontWeight: FontWeight.bold, color: Colors.grey[600]),
            ),
          Container(
            padding: EdgeInsets.symmetric(horizontal: 12.0, vertical: 8.0),
            decoration: BoxDecoration(
              color: isMe ? Colors.blue : Colors.grey[300],
              borderRadius: BorderRadius.circular(20.0),
            ),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  message,
                  style: TextStyle(color: isMe ? Colors.white : Colors.black),
                ),
                SizedBox(height: 4.0),
                Text(
                  time.toString(), // Format the timestamp as needed
                  style: TextStyle(fontSize: 12.0, color: Colors.grey),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}