I wrote this time displaying FLUTTER app, How can I improve it?

Question

I'm developing a clock widget in Flutter that displays the current time. I want to provide two methods for updating the time asynchronously: one using a continuous stream of time updates, and the other using a timer that updates the time at regular intervals.

Code Explanation:

clock() Method:

1. This method returns a continuous stream of time updates asynchronously.
2. It uses a while loop to continuously update the current time using DateTime.now() and formats it using DateFormat.
3. The time is yielded as a String and printed to the console.
4. It includes a delay using Future.delayed() to control the update frequency

timer() Method:

• This method returns a stream of time updates asynchronously using a timer.
• It initializes the current time and formats it.
• Inside a while loop, it checks if the current time differs from the last recorded time. If so, it updates the time and yields it. Otherwise, it repeats the same time for a maximum of 5 iterations.
• This method also includes a delay using Future.delayed().

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

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

  @override
  State<Clock> createState() => _ClockState();
}

class _ClockState extends State<Clock> {

  //first methode, returns time as String
  Stream<String> clock() async* {

    DateTime time;
    String current;
    while (true) {
      time = DateTime.now();
      current = DateFormat('hh : mm : ss').format(time);
      yield current;
      print(current);
      await Future.delayed(
        Duration(milliseconds: 100),
      );
    }
  }
  
   //seconde one
  Stream<String> timer() async* {
    DateTime time = DateTime.now();
    String current = DateFormat('hh : mm : ss').format(time);

    while (true) {
      if (current != DateFormat('hh : mm : ss').format(DateTime.now())) {
        current = DateFormat('hh : mm : ss').format(DateTime.now());
        yield current;
        print(current);
        await Future.delayed(
        Duration(milliseconds: 200),
      );
      } else {
        yield current;
        //this command repeats 5 time maximum
        print(current);
        await Future.delayed(
        Duration(milliseconds: 200),
      );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: StreamBuilder(
          stream: timer(),
          builder: (BuildContext context, AsyncSnapshot snapshot) {
            if (snapshot.hasData) {
              return Container(
                height: 350,
                width: 350,
                decoration: BoxDecoration(
                    border: Border.all(
                      color: Colors.blue,
                      width: 4,
                    ),
                    shape: BoxShape.circle),
                child: Center(
                  child: Text(
                    '${snapshot.data}',
                    style: TextStyle(
                      fontSize: 30,
                      fontWeight: FontWeight.w500,
                    ),
                  ),
                ),
              );
            } else {
              return Text('waiting...');
            }
          },
        ),
      ),
    );
  }
}

both methods rely on while loops where print statement in clock() repeats 10 times maximum and 5 times maximum in timer methode