cpd_2022_zi/lib/pages/timer_page.dart

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:smoke_cess_app/widgets/timer_button.dart';

class StopWatchTimerPage extends StatefulWidget {
  @override
  _StopWatchTimerPageState createState() => _StopWatchTimerPageState();
}

class _StopWatchTimerPageState extends State<StopWatchTimerPage> {
  static const countdownDuration = Duration(minutes: 1);
  Duration duration = Duration();
  Timer? timer;

  bool countDown = true;

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    reset();
  }

  void reset() {
    if (countDown) {
      setState(() => duration = countdownDuration);
    } else {
      setState(() => duration = Duration());
    }
  }

  void startTimer() {
    timer = Timer.periodic(Duration(seconds: 1), (_) => addTime());
  }

  void addTime() {
    final addSeconds = countDown ? -1 : 1;
    setState(() {
      final seconds = duration.inSeconds + addSeconds;
      if (seconds < 0) {
        timer?.cancel();
      } else {
        duration = Duration(seconds: seconds);
      }
    });
  }

  void stopTimer({bool resets = true}) {
    if (resets) {
      reset();
    }
    setState(() => timer?.cancel());
  }

  @override
  Widget build(BuildContext context) => Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            buildTime(),
            SizedBox(
              height: 80,
            ),
            buildButtons()
          ],
        ),
      );

  Widget buildTime() {
    String twoDigits(int n) => n.toString().padLeft(2, '0');
    final minutes = twoDigits(duration.inMinutes.remainder(60));
    final seconds = twoDigits(duration.inSeconds.remainder(60));
    return Row(mainAxisAlignment: MainAxisAlignment.center, children: [
      SizedBox(
        width: 8,
      ),
      buildTimeCard(time: minutes, header: 'MINUTEN'),
      SizedBox(
        width: 8,
      ),
      buildTimeCard(time: seconds, header: 'SEKUNDEN'),
    ]);
  }

  Widget buildTimeCard({required String time, required String header}) =>
      Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Container(
            padding: EdgeInsets.all(8),
            decoration: BoxDecoration(
                color: Colors.white, borderRadius: BorderRadius.circular(20)),
            child: Text(
              time,
              style: TextStyle(
                  fontWeight: FontWeight.bold,
                  color: Colors.black,
                  fontSize: 50),
            ),
          ),
          SizedBox(
            height: 24,
          ),
          Text(header, style: TextStyle(color: Colors.black45)),
        ],
      );

  Widget buildButtons() {
    final isRunning = timer == null ? false : timer!.isActive;
    final isCompleted = duration.inSeconds == 0;
    return isRunning || isCompleted
        ? TimerButton(
            onClicked: stopTimer,
            icon: Icon(
              Icons.stop,
              size: 50,
              color: Colors.white,
            ),
            color: Colors.red)
        : TimerButton(
            onClicked: startTimer,
            icon: Icon(
              Icons.play_arrow,
              size: 50,
              color: Colors.white,
            ),
            color: Colors.green);
  }
}