hash-wallet/lib/utils/date_picker.dart

import 'dart:io';
import 'package:hash_wallet/main.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

Future<DateTime?> getDate(
    {required BuildContext context,
    required DateTime initialDate,
    required DateTime firstDate,
    required DateTime lastDate}) {
  if (Platform.isIOS) {
    return _buildCupertinoDataPicker(context, initialDate, firstDate, lastDate);
  }

  return _buildMaterialDataPicker(context, initialDate, firstDate, lastDate);
}

Future<DateTime?> _buildMaterialDataPicker(
    BuildContext context, DateTime initialDate, DateTime firstDate, DateTime lastDate) async {
  return await showDatePicker(
      context: context,
      initialDate: initialDate,
      firstDate: firstDate,
      lastDate: lastDate,
      helpText: '');
}

Future<DateTime?> _buildCupertinoDataPicker(
    BuildContext context, DateTime initialDate, DateTime firstDate, DateTime lastDate) async {
  DateTime? date;
  await showModalBottomSheet<void>(
      context: navigatorKey.currentState!.context,
      builder: (_) {
        return Container(
          height: MediaQuery.of(context).size.height / 3,
          child: CupertinoDatePicker(
            mode: CupertinoDatePickerMode.date,
            onDateTimeChanged: (picked) => date = picked,
            initialDateTime: initialDate,
            minimumDate: firstDate,
            maximumDate: lastDate,
          ),
        );
      });
  return date;
}