todotxt_reminder/lib/addReminder.dart

import 'package:flutter/material.dart';
import 'package:nextcloud_reminder/repeating_task.dart';

class AddTaskWidget extends StatefulWidget {
  const AddTaskWidget({super.key, this.restorationId, required this.onSave});

  final ValueChanged<RepeatingTask> onSave;
  final String? restorationId;

  @override
  State<StatefulWidget> createState() => _AddTaskWidgetState();
}

//TODO: make _repeat changeable.

class _AddTaskWidgetState extends State<AddTaskWidget> with RestorationMixin {
  final _formKey = GlobalKey<FormState>();
  final _titleController = TextEditingController();
  final int _repeat = 1;
  final RestorableDateTime _beginDate = RestorableDateTime(DateTime.now());

  @override
  void dispose() {
    _titleController.dispose();
    super.dispose();
  }

  @override
  String? get restorationId => widget.restorationId;

  late final RestorableRouteFuture<DateTime?> _restorableDatePickerRouteFuture =
      RestorableRouteFuture<DateTime?>(
    onComplete: _selectDate,
    onPresent: (NavigatorState navigator, Object? arguments) {
      return navigator.restorablePush(
        _datePickerRoute,
        arguments: _beginDate.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(2000),
          lastDate: DateTime(2100),
        );
      },
    );
  }

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

  void _selectDate(DateTime? newSelectedDate) {
    if (newSelectedDate != null) {
      setState(() {
        _beginDate.value = newSelectedDate;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Add new repeating Task')
      ),
      body: Form(
        key: _formKey,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            TextFormField(
              // The validator receives the text that the user has entered.
              validator: (value) {
                if (value == null || value.isEmpty) {
                  return 'Please enter a name';
                }
                return null;
              },
              controller: _titleController,
              decoration: const InputDecoration(
                labelText: "Taskname"
              ),
            ),
            Container(
              decoration: const BoxDecoration(),
              child: Row(
                children: [
                  Text("Begin: ", style: Theme.of(context).textTheme.labelLarge),
                  Expanded(
                      child: Text("${_beginDate.value.year}-${_beginDate.value.month.toString().padLeft(2,'0')}-${_beginDate.value.day.toString().padLeft(2,'0')}")
                  ),
                  IconButton(
                    onPressed: () => _restorableDatePickerRouteFuture.present(),
                    icon: Icon(Icons.date_range,
                      color: Theme.of(context).focusColor))
                ]
              )
            ),
            Padding(
              padding: const EdgeInsets.symmetric(vertical: 16.0),
              child: ElevatedButton(
                onPressed: () {
                  // Validate returns true if the form is valid, or false otherwise.
                  if (_formKey.currentState!.validate()) {
                    // If the form is valid, display a snackbar. In the real world,
                    // you'd often call a server or save the information in a database.
                    ScaffoldMessenger.of(context).showSnackBar(
                      const SnackBar(content: Text('Task added.')),
                    );
                    widget.onSave(RepeatingTask(
                        title: _titleController.text, begin: _beginDate.value, repeat: _repeat,));
                    Navigator.pop(context);
                  }
                },
                child: const Text('Submit'),
              ),
            ),
          ],
        ),
      )
    );
  }
}