import 'package:flutter/material.dart'; class Item { bool isFolder; Uri uri; String name; Item(this.isFolder, this.uri, this.name); } class Folder { List items; Uri self; Uri parent; Folder(this.items, this.self, this.parent); } abstract class DataProvider { final List validSuffix = [".jpg", ".jpeg", ".png"]; void connect(); Future listOfFiles({Uri? uri}); ImageProvider getImageProvider(Uri uri); }