Gallery/lib/data_provider/local_data_provider.dart

import 'dart:io';

import 'package:flutter/cupertino.dart';
import 'package:gallery/data_provider/data_provider.dart';

class LocalDataProvider extends DataProvider {
  final Future<Directory> initialPath;

  LocalDataProvider(this.initialPath);

  @override
  Future<void> connect() async {}

  @override
  Future<Folder> listOfFiles({Uri? uri}) async {
    final dir = uri != null ? Directory.fromUri(uri) : await initialPath;

    final list = dir.listSync();
    final List<Item> res = [];

    for (var val in list) {
      if (validSuffix.any((suff) => val.path.endsWith(suff))) {
        res.add(Item(false, val.uri, val.uri.pathSegments.last));
      } else if (await FileSystemEntity.isDirectory(val.path)) {
        res.add(
            Item(true, val.uri, val.uri.pathSegments.reversed.skip(1).first));
      }
    }

    res.sort(
      (a, b) => b.isFolder ? 1 : -1,
    );

    return Folder(res, dir.uri, dir.parent.uri);
  }

  @override
  ImageProvider getImageProvider(Uri uri) {
    return FileImage(File.fromUri(uri));
  }
}