Use SAF for Android

lib/main.dart

@@ -1,5 +1,6 @@
 import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
+import 'package:saf/saf.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:sheetless/sheetview.dart';
 
@@ -33,6 +34,11 @@ class MyHomePage extends StatefulWidget {
 }
 
 class _MyHomePageState extends State<MyHomePage> {
+  @override
+  void initState() {
+    super.initState();
+  }
+
   Future<String?> getSavedSheetsPath() async {
     final prefs = await SharedPreferences.getInstance();
     return prefs.getString("sheets-path");
@@ -62,9 +68,31 @@ class _MyHomePageState extends State<MyHomePage> {
     return "No path selected";
   }
 
+  Future<String?> getSafPickedSheetsDirectory() async {
+    var pickedDirectories = await Saf.getPersistedPermissionDirectories();
+    if (pickedDirectories == null || pickedDirectories.isEmpty) {
+      return null;
+    }
+    return pickedDirectories.last;
+  }
+
   Future<List<Sheet>> acquireSheets() async {
-    var sheetsPath = await findAndSaveSheetsPath();
-    return loadSheetsSorted(sheetsPath);
+    String? sheetsDirectory = await getSafPickedSheetsDirectory();
+    if (sheetsDirectory == null || sheetsDirectory.isEmpty) {
+      Saf.getDynamicDirectoryPermission(grantWritePermission: false);
+      sheetsDirectory = await getSafPickedSheetsDirectory();
+      if (sheetsDirectory == null || sheetsDirectory.isEmpty) {
+        throw Exception("No Directory selected");
+      }
+    }
+
+    var sheetsDirectoryFiles = await Saf.getFilesPathFor(sheetsDirectory);
+    if (sheetsDirectoryFiles == null) {
+      Saf.releasePersistedPermissionFor(sheetsDirectory);
+      throw Exception(
+          "Permissions for directory no longer valid or Directory deleted. Please restart app.");
+    }
+    return loadSheetsSorted(sheetsDirectoryFiles);
   }
 
   @override

lib/sheet.dart

@@ -11,27 +11,34 @@ class Sheet {
   Sheet(this.author, this.name, this.path);
 }
 
-Future<List<Sheet>> loadSheetsSorted(String path) async {
-  var sheets = await _loadSheets(path);
+Future<List<Sheet>> loadSheetsSorted(List<String> sheetsDirectoryFiles) async {
+  var sheets = await _loadSheets(sheetsDirectoryFiles);
   sheets.sort((left, right) => left.name.compareTo(right.name));
   return sheets;
 }
 
-Future<List<Sheet>> _loadSheets(String path) async {
-  var dir = Directory(path);
-  if (!dir.existsSync()) {
-    throw Exception("Specified path '$path' does not exist");
-  }
+Future<List<Sheet>> _loadSheets(List<String> sheetsDirectoryFiles) async {
   final List<Sheet> sheets = List.empty(growable: true);
-  await for (final FileSystemEntity x in dir.list()) {
-    if (x is Directory) {
-      var authorName = p.basename(x.path);
-      await for (final FileSystemEntity a in x.list()) {
-        if (a is File) {
-          var sheetName = p.basenameWithoutExtension(a.path);
-          sheetName = sheetName.capitalize();
-          sheets.add(Sheet(authorName, sheetName, a.path));
+  var authorDirectories = sheetsDirectoryFiles
+      .map((e) => Directory(e))
+      .where((element) => element.existsSync());
+
+  for (Directory authorDirectory in authorDirectories) {
+    var authorName = p.basename(authorDirectory.path);
+    // Ignore hidden directories
+    if (authorName.startsWith(".")) {
+      continue;
+    }
+
+    await for (final FileSystemEntity sheetFile in authorDirectory.list()) {
+      if (sheetFile is File) {
+        var sheetName = p.basenameWithoutExtension(sheetFile.path);
+        // Ignore hidden files
+        if (sheetName.startsWith(".")) {
+          continue;
         }
+        sheetName = sheetName.capitalize();
+        sheets.add(Sheet(authorName, sheetName, sheetFile.path));
       }
     }
   }