Flutter DirectoryListing

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android">

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>

    <application
        android:requestLegacyExternalStorage="true"
        android:label="directorylisting"
        android:name="${applicationName}"
        android:icon="@mipmap/ic_launcher">
        <activity
            android:name=".MainActivity"
            android:exported="true"
            android:launchMode="singleTop"
            android:taskAffinity=""
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <!-- Specifies an Android theme to apply to this Activity as soon as
                 the Android process has started. This theme is visible to the user
                 while the Flutter UI initializes. After that, this theme continues
                 to determine the Window background behind the Flutter UI. -->
            <meta-data
              android:name="io.flutter.embedding.android.NormalTheme"
              android:resource="@style/NormalTheme"
              />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
    </application>
    <!-- Required to query activities that can process text, see:
         https://developer.android.com/training/package-visibility and
         https://developer.android.com/reference/android/content/Intent#ACTION_PROCESS_TEXT.

         In particular, this is used by the Flutter engine in io.flutter.plugin.text.ProcessTextPlugin. -->
    <queries>
        <intent>
            <action android:name="android.intent.action.PROCESS_TEXT"/>
            <data android:mimeType="text/plain"/>
        </intent>
    </queries>
</manifest>

main.dart

import 'package:flutter/material.dart';

import 'dart:io';

import 'package:permission_handler/permission_handler.dart';

void main() {
  runApp(const MyApp());
}

class FileSystemItem {
  final String path;
  final bool isFolder;
  final String title;
  final List<FileSystemItem>? children;

  FileSystemItem({
    required this.path,
    required this.isFolder,
    required this.title,
    this.children,
  });
}

Future<List<FileSystemItem>> getDirectoryStructure(String dirPath) async {
  final dir = Directory(dirPath);
  if (!await dir.exists()) {
    return [];
  }
  return _getStructure(dir);
}

Future<List<FileSystemItem>> _getStructure(Directory dir) async {
  final List<FileSystemItem> structure = [];
  final List<FileSystemEntity> entities = dir.listSync();
  for (var entity in entities) {
    if (entity.path.contains("Android")) {
      continue;
    }
    final isFolder = entity is Directory;
    final path = entity.path;
    final title = path.split('/').last;

    structure.add(FileSystemItem(
      path: path,
      isFolder: isFolder,
      title: title,
      children: isFolder ? await _getStructure(Directory(path)) : null,
    ));
  }
  return structure;
}

class FileExplorerScreen extends StatelessWidget {
  final String path;

  FileExplorerScreen({required this.path});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(path.split('/').last)),
      body: FutureBuilder<List<FileSystemItem>>(
        future: getDirectoryStructure(path),
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return Center(child: CircularProgressIndicator());
          }
          if (!snapshot.hasData || snapshot.data!.isEmpty) {
            return Center(child: Text("No files found"));
          }
          return ListView.builder(
            itemCount: snapshot.data!.length,
            itemBuilder: (context, index) {
              final item = snapshot.data![index];
              return ListTile(
                leading: Icon(
                    item.isFolder ? Icons.folder : Icons.insert_drive_file),
                title: Text(item.title),
                onTap: item.isFolder
                    ? () {
                        Navigator.push(
                          context,
                          MaterialPageRoute(
                            builder: (context) =>
                                FileExplorerScreen(path: item.path),
                          ),
                        );
                      }
                    : () {
                  SnackBar snackBar = SnackBar(
                    content: Text("File: ${item.title}"),
                  );
                  ScaffoldMessenger.of(context).showSnackBar(snackBar);
                },
              );
            },
          );
        },
      ),
    );
  }
}

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  bool isStoragePermissionGranted = false;

  Future<void> requestStoragePermission() async {
    if (Platform.isAndroid) {
      if (await Permission.storage.request().isGranted) {
        setState(() {
          isStoragePermissionGranted = true;
        });
      } else if (await Permission.manageExternalStorage.request().isGranted) {
        setState(() {
          isStoragePermissionGranted = true;
        });
      } else {
        setState(() {
          isStoragePermissionGranted = false;
        });
      }
    } else {
      setState(() {
        isStoragePermissionGranted = true;
      });
    }
  }

  @override
  void initState() {
    super.initState();
    requestStoragePermission();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: isStoragePermissionGranted
          ? FileExplorerScreen(path: "/storage/emulated/0/")
          : Scaffold(
              body: Center(
                child: ElevatedButton(
                  onPressed: requestStoragePermission,
                  child: Text("Grant Storage Permission"),
                ),
              ),
            ),
    );
  }
}