Gallery/lib/main.dart

import 'dart:io';
import 'dart:ui';

import 'package:flutter/material.dart';
import 'package:permission_handler/permission_handler.dart';

import 'home_page.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  if (Platform.isAndroid) {
    if (await Permission.storage.request().isGranted) {
      runApp(const MyApp());
    }
  } else {
    runApp(const MyApp());
  }
}

class AppScrollBehavior extends MaterialScrollBehavior {
  @override
  Set<PointerDeviceKind> get dragDevices => {
        PointerDeviceKind.touch,
        PointerDeviceKind.mouse,
      };
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      scrollBehavior: AppScrollBehavior(),
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Gallery'),
    );
  }
}