2-3.Userinterface, timer(start and pause) and data format

import 'package:flutter/material.dart';
import 'package:toonflix/screens/home_screen.dart';

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

class App extends StatelessWidget {
  const App({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        textTheme: const TextTheme(
          displayLarge: TextStyle(
            color: Color(0xFF232B55),
          ),
        ),
        cardColor: const Color(0xFFF4EDDB),
      ),
      home: const HomeScreen(),
    );
  }
}

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

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

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  static const twentyFiveMinutes = 1500;
  int totalSeconds = twentyFiveMinutes;
  bool isRunning = false;
  int totalPomodoros = 0;
  late Timer timer;

  void onTick(Timer timer) {
    if (totalSeconds == 0) {
      setState(() {
        totalPomodoros = totalPomodoros + 1;
        isRunning = false;
        totalSeconds = twentyFiveMinutes;
      });
      timer.cancel();
    } else {}
    setState(() {
      totalSeconds = totalSeconds - 1;
    });
  }

  void onStartPressed() {
    timer = Timer.periodic(const Duration(seconds: 1), onTick);
    setState(() {
      isRunning = true;
    });
  }

  void onPausePressed() {
    timer.cancel();
    setState(() {
      isRunning = false;
    });
  }

  String format(int seconds) {
    var duration = Duration(seconds: seconds);
    print(duration.toString());
    print(duration.toString().split('.'));
    print(duration.toString().split('.').first);
    print(duration.toString().split('.').first.substring(2, 7));
    return duration.toString().split('.').first.substring(2, 7);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Theme.of(context).colorScheme.background,
      body: Column(
        children: [
          Flexible(
            flex: 1, // ratio of box size
            child: Container(
              alignment: Alignment.bottomCenter,
              child: Text(
                format(totalSeconds),
                style: TextStyle(
                    color: Theme.of(context).cardColor,
                    fontSize: 90,
                    fontWeight: FontWeight.w600),
              ),
            ),
          ),
          Flexible(
            flex: 3,
            child: Center(
              child: IconButton(
                iconSize: 120,
                color: Theme.of(context).cardColor,
                onPressed: isRunning ? onPausePressed : onStartPressed,
                icon: Icon(
                  isRunning
                      ? Icons.pause_circle_outline
                      : Icons.play_circle_outline,
                ),
              ),
            ),
          ),
          Flexible(
            flex: 1,
            child: Row(
              children: [
                Expanded(
                  child: Container(
                    decoration: BoxDecoration(
                      color: Theme.of(context).cardColor,
                      borderRadius: BorderRadius.circular(50),
                    ),
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        Text(
                          'Pomodors',
                          style: TextStyle(
                            fontSize: 20,
                            fontWeight: FontWeight.w600,
                            color:
                                Theme.of(context).textTheme.displayLarge!.color,
                          ),
                        ),
                        Text(
                          '$totalPomodoros',
                          style: TextStyle(
                            fontSize: 60,
                            fontWeight: FontWeight.w600,
                            color:
                                Theme.of(context).textTheme.displayLarge!.color,
                          ),
                        ),
                      ],
                    ),
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

Userinterface

 

timer(start and pause) 

---------------------
class _HomeScreenState extends State<HomeScreen> {
  int totalSeconds = 1500;  //hereherehereherehereherehere
  late Timer timer;  //hereherehereherehereherehere

  void onTick(Timer timer) {  //hereherehereherehereherehere
    setState(() {
      totalSeconds = totalSeconds - 1;  //hereherehereherehereherehere
    });
  }
---------------------
          Flexible(
            flex: 3,
            child: Center(
              child: IconButton(
                iconSize: 120,
                color: Theme.of(context).cardColor,
                onPressed: onStartPressed, //hereherehereherehereherehere
                icon: const Icon(
                  Icons.play_circle_outline,
                ),
              ),
            ),
          ),

 

data format

----------

  void onStartPressed() {
    timer = Timer.periodic(const Duration(seconds: 1), onTick);
    setState(() {
      isRunning = true;
    });
  }

  void onPausePressed() {
    timer.cancel();
    setState(() {
      isRunning = false;
    });
  }
  
  
----------


          Flexible(
            flex: 3,
            child: Center(
              child: IconButton(
                iconSize: 120,
                color: Theme.of(context).cardColor,
                
                
                
                onPressed: isRunning ? onPausePressed : onStartPressed,
                icon: Icon(
                  isRunning
                      ? Icons.pause_circle_outline
                      : Icons.play_circle_outline,
                ),
              ),
            ),
          ),

 

 

--------------
class _HomeScreenState extends State<HomeScreen> {
  static const twentyFiveMinutes = 1500;
  int totalSeconds = twentyFiveMinutes;
  bool isRunning = false;
  int totalPomodoros = 0;
  late Timer timer;
--------------



--------------
  void onTick(Timer timer) {
    if (totalSeconds == 0) {
      setState(() {
        totalPomodoros = totalPomodoros + 1;
        isRunning = false;
        totalSeconds = twentyFiveMinutes;
      });
      timer.cancel();
    } else {}
    setState(() {
      totalSeconds = totalSeconds - 1;
    });
  }
--------------


  
  
  --------------

  String format(int seconds) {
    var duration = Duration(seconds: seconds);
    print(duration.toString());
    print(duration.toString().split('.'));
    print(duration.toString().split('.').first);
    print(duration.toString().split('.').first.substring(2, 7));
    return duration.toString().split('.').first.substring(2, 7);
  }
  
  --------------