flutter/examples/api/lib/material/date_picker/show_date_picker.0.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Template: dev/snippets/config/templates/stateful_widget_restoration_material.tmpl
//
// Comment lines marked with "▼▼▼" and "▲▲▲" are used for authoring
// of samples, and may be ignored if you are just exploring the sample.

// Flutter code sample for showDatePicker
//
//***************************************************************************
//* ▼▼▼▼▼▼▼▼ description ▼▼▼▼▼▼▼▼ (do not modify or remove section marker)

// This sample demonstrates how to create a restorable Material date picker.
// This is accomplished by enabling state restoration by specifying
// [MaterialApp.restorationScopeId] and using [Navigator.restorablePush] to
// push [DatePickerDialog] when the button is tapped.

//* ▲▲▲▲▲▲▲▲ description ▲▲▲▲▲▲▲▲ (do not modify or remove section marker)
//***************************************************************************

import 'package:flutter/material.dart';

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

/// This is the main application widget.
class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      restorationScopeId: 'app',
      title: _title,
      home: MyStatefulWidget(restorationId: 'main'),
    );
  }
}

/// This is the stateful widget that the main application instantiates.
class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget({Key? key, this.restorationId}) : super(key: key);

  final String? restorationId;

  @override
  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}

/// This is the private State class that goes with MyStatefulWidget.
/// RestorationProperty objects can be used because of RestorationMixin.
class _MyStatefulWidgetState extends State<MyStatefulWidget>
    with RestorationMixin {
  // In this example, the restoration ID for the mixin is passed in through
  // the [StatefulWidget]'s constructor.
  @override
  String? get restorationId => widget.restorationId;

//********************************************************************
//* ▼▼▼▼▼▼▼▼ code ▼▼▼▼▼▼▼▼ (do not modify or remove section marker)

  final RestorableDateTime _selectedDate =
      RestorableDateTime(DateTime(2021, 7, 25));
  late final RestorableRouteFuture<DateTime?> _restorableDatePickerRouteFuture =
      RestorableRouteFuture<DateTime?>(
    onComplete: _selectDate,
    onPresent: (NavigatorState navigator, Object? arguments) {
      return navigator.restorablePush(
        _datePickerRoute,
        arguments: _selectedDate.value.millisecondsSinceEpoch,
      );
    },
  );

  static Route<DateTime> _datePickerRoute(
    BuildContext context,
    Object? arguments,
  ) {
    return DialogRoute<DateTime>(
      context: context,
      builder: (BuildContext context) {
        return DatePickerDialog(
          restorationId: 'date_picker_dialog',
          initialEntryMode: DatePickerEntryMode.calendarOnly,
          initialDate: DateTime.fromMillisecondsSinceEpoch(arguments! as int),
          firstDate: DateTime(2021, 1, 1),
          lastDate: DateTime(2022, 1, 1),
        );
      },
    );
  }

  @override
  void restoreState(RestorationBucket? oldBucket, bool initialRestore) {
    registerForRestoration(_selectedDate, 'selected_date');
    registerForRestoration(
        _restorableDatePickerRouteFuture, 'date_picker_route_future');
  }

  void _selectDate(DateTime? newSelectedDate) {
    if (newSelectedDate != null) {
      setState(() {
        _selectedDate.value = newSelectedDate;
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(
          content: Text(
              'Selected: ${_selectedDate.value.day}/${_selectedDate.value.month}/${_selectedDate.value.year}'),
        ));
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: OutlinedButton(
          onPressed: () {
            _restorableDatePickerRouteFuture.present();
          },
          child: const Text('Open Date Picker'),
        ),
      ),
    );
  }

//* ▲▲▲▲▲▲▲▲ code ▲▲▲▲▲▲▲▲ (do not modify or remove section marker)
//********************************************************************

}