chat message page

chat.dart

// show chat screen
import 'dart:developer';

import 'package:chat/consts.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';

class ChatPage extends StatelessWidget {
  ChatPage({Key? key, required this.roomId}) : super(key: key);

  final String roomId;
  final TextEditingController messageController = TextEditingController();

  sendMessage({required String message}) {
    if (message.trim().isNotEmpty) {
      // save message to firestore
      // chats/[ROOM-ID]/messages/[TIMESTAMP]/doc
      final timeStamp = DateTime.now().millisecondsSinceEpoch.toString();
      firestore.collection("chats").doc(roomId).collection("messages").doc(timeStamp).set({
        'content': message.trim(),
        'uid': auth.currentUser!.uid,
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Column(
        children: [
          // chat message
          Expanded(
            child: StreamBuilder(
              stream: firestore.collection("chats").doc(roomId).collection("messages").snapshots(),
              builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
                // has error
                if (snapshot.hasError) {
                  return Text("Error");
                }

                // has data
                log('${snapshot.data!.docs.length}');
                if (snapshot.hasData) {
                  final docs = snapshot.data!.docs;
                  return ListView.builder(
                    itemCount: docs.length,
                    itemBuilder: (context, index) {
                      return ListTile(
                        title: Text(docs[index]["content"]),
                      );
                    },
                  );
                }

                // loading
                return Center(child: CircularProgressIndicator());
              },
            ),
          ),

          // chat box
          Container(
            width: MediaQuery.of(context).size.width,
            height: 64,
            child: Row(
              children: [
                // text form field
                Container(
                  width: MediaQuery.of(context).size.width - 48,
                  height: 64,
                  child: TextFormField(
                    controller: messageController,
                    onFieldSubmitted: (newValue) {
                      // send message
                      log('${newValue}');
                      sendMessage(message: newValue);
                    },
                  ),
                ),

                // icon button
                IconButton(
                  onPressed: () {
                    // send message
                    log('${messageController.text}');
                    sendMessage(message: messageController.text);
                  },
                  icon: Icon(Icons.send),
                ),
              ],
            ),
          )
        ],
      ),
    );
  }
}