HorizontalDatePickerWidget({
    required this.startDate,
    required this.endDate,
    required this.selectedDate,
    required this.widgetWidth,
    required this.datePickerController,
    this.dateItemComponentList = const <DateItem>[
      DateItem.Month,
      DateItem.Day,
      DateItem.WeekDay
    ],
    this.width = 60,
    this.height = 80,
    this.onValueSelected,
    this.normalColor = Colors.white,
    this.selectedColor = Colors.black,
    this.disabledColor = Colors.white,
    this.normalTextColor = Colors.black,
    this.selectedTextColor = Colors.white,
    this.disabledTextColor = const Color(0xFFBDBDBD),
    this.monthFontSize = 12,
    this.dayFontSize = 18,
    this.weekDayFontSize = 12,
  })

import 'package:flutter/material.dart';
import 'package:horizontal_center_date_picker/datepicker_controller.dart';
import 'package:horizontal_center_date_picker/horizontal_date_picker.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: TestPage(),
    );
  }
}

class TestPage extends StatefulWidget {
  @override
  _TestPageState createState() => _TestPageState();
}

class _TestPageState extends State<TestPage> {
  @override
  Widget build(BuildContext context) {
    var now = DateTime.now();
    DateTime startDate = now.subtract(Duration(days: 14));
    DateTime endDate = now.add(Duration(days: 7));
    print('startDate = $startDate ; endDate = $endDate');
    return Container(
      color: Colors.grey,
      alignment: Alignment.center,
      child: HorizontalDatePickerWidget(
        startDate: startDate,
        endDate: endDate,
        selectedDate: now,
        widgetWidth: MediaQuery.of(context).size.width,
        datePickerController: DatePickerController(),
        onValueSelected: (date) {
          print('selected = ${date.toIso8601String()}');
        },
      ),
    );
  }
}