mohemm-flutter-app/lib/home/home_screen.dart

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:queuing_system/core/base/app_scaffold_widget.dart';
import 'package:queuing_system/core/config/config.dart';
import 'package:queuing_system/core/config/size_config.dart';
import 'package:queuing_system/header/app_header.dart';
import 'package:queuing_system/home/que_item_list.dart';
import 'package:queuing_system/utils/signalR_utils.dart';
import 'package:queuing_system/utils/utils.dart';
import 'package:queuing_system/widget/data_display/app_texts_widget.dart';
import 'first_column.dart';

class MyHomePage extends StatefulWidget {
  String title = "MyHomePage";
  bool have0Patient = true;
  bool have1Patient = false;
  bool have2Patient = false;
  bool have3Patient = false;
  bool haveListOfPatient = false;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  Timer _timer;
  int remainingTime = 30;

  @override
  void dispose() {
    _timer.cancel();
    super.dispose();
  }

  startTimer() {
    Timer.periodic(const Duration(seconds: 1), (timer) {
      if (remainingTime == 0) {
        setState(() {
          remainingTime = 30;
        });
      } else {
        setState(() {
          remainingTime--;
          if (remainingTime > 25) {

            /// for 0 patinet
            widget.have0Patient = true;
            widget.have1Patient = false;
            widget.have2Patient = false;
            widget.have3Patient = false;
            widget.haveListOfPatient = false;
          } else if (remainingTime > 20) {
            /// for 1 patinet

            widget.have0Patient = false;
            widget.have1Patient = true;
            widget.have2Patient = false;
            widget.have3Patient = false;
            widget.haveListOfPatient = false;
          } else if (remainingTime > 15) {

            /// for 2 patinet

            widget.have0Patient = false;
            widget.have1Patient = false;
            widget.have2Patient = true;
            widget.have3Patient = false;
            widget.haveListOfPatient = false;
          } else if (remainingTime > 10) {
            /// for 3 only patinet
            widget.have0Patient = false;
            widget.have1Patient = false;
            widget.have2Patient = false;
            widget.have3Patient = true;
            widget.haveListOfPatient = false;
          } else {
            /// for 3+ only patinet

            widget.have0Patient = false;
            widget.have1Patient = false;
            widget.have2Patient = false;
            widget.have3Patient = true;
            widget.haveListOfPatient = true;
          }
        });
      }
    });
  }

  @override
  void initState() {
    startTimer();
    SignalRHelper signalRHelper = new SignalRHelper();
    if (!signalRHelper.getConnectionState()) signalRHelper.startSignalRConnection();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {


    return AppScaffold(
      appBar: AppHeader(),
      body: Column(
        children: [
          SizedBox(
              height: SizeConfig.getHeightMultiplier() *
                  (widget.haveListOfPatient
                      ? 2
                      : widget.have1Patient || widget.have0Patient
                          ? 20
                          : 10)),
          widget.have0Patient
              ? Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    Center(
                      child: AppText("Awaiting Patients Arrival",
                          fontFamily: 'Poppins-SemiBold.ttf',
                          letterSpacing: -1.56,
                          fontSize: SizeConfig.getWidthMultiplier() * 9),
                    ),
                  ],
                )
              : widget.haveListOfPatient
                  ? Row(
                      children: [
                        FirstColumn(
                          have3Patient: widget.have3Patient,
                          have2Patient: widget.have2Patient,
                        ),
                        const SizedBox(
                          width: 40,
                        ),
                        if (widget.haveListOfPatient)
                          Container(
                            width: 10,
                            height: SizeConfig.getHeightMultiplier() * 40,
                            color: AppGlobal.appLightGreyColor,
                          ),
                        if (widget.haveListOfPatient)
                          const SizedBox(
                            width: 40,
                          ),
                        if (widget.haveListOfPatient) const QueItemList()
                      ],
                    )
                  : FirstColumn(
                      have3Patient: widget.have3Patient,
                      have2Patient: widget.have2Patient,
                    ),
        ],
      ),
      bottomSheet: Container(
        color: Colors.transparent,
        height: Utils.getHeight(),
        width: double.infinity,
        child: Row(
          children: [
            Padding(
              padding: const EdgeInsets.only(top: 30, left: 30),
              child: AppText(
                "Powered By",
                letterSpacing: -1.56,
                fontSize: SizeConfig.getWidthMultiplier() * 2.6,
                fontFamily: 'Poppins-Medium.ttf',
              ),
            ),
            Padding(
              padding: const EdgeInsets.only(top: 40, left: 18),
              child: Image.asset(
                "assets/images/cloud_logo.png",
                height: SizeConfig.getHeightMultiplier() * 6,
              ),
            ),
          ],
        ),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}