[path_provider] Fixed support for querying the root external storage directory

Author: gaaclarke

packages/path_provider/path_provider_android/android/src/main/java/io/flutter/plugins/pathprovider/Messages.java

@@ -1,7 +1,7 @@
 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-// Autogenerated from Pigeon (v3.1.5), do not edit directly.
+// Autogenerated from Pigeon (v3.2.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package io.flutter.plugins.pathprovider;
@@ -23,16 +23,17 @@
 public class Messages {
 
   public enum StorageDirectory {
-    music(0),
-    podcasts(1),
-    ringtones(2),
-    alarms(3),
-    notifications(4),
-    pictures(5),
-    movies(6),
-    downloads(7),
-    dcim(8),
-    documents(9);
+    root(0),
+    music(1),
+    podcasts(2),
+    ringtones(3),
+    alarms(4),
+    notifications(5),
+    pictures(6),
+    movies(7),
+    downloads(8),
+    dcim(9),
+    documents(10);
 
     private int index;
 

packages/path_provider/path_provider_android/android/src/main/java/io/flutter/plugins/pathprovider/PathProviderPlugin.java

@@ -125,6 +125,8 @@ private List<String> getPathProviderExternalCacheDirectories() {
 
   private String getStorageDirectoryString(@NonNull Messages.StorageDirectory directory) {
     switch (directory) {
+      case root:
+        return null;
       case music:
         return "music";
       case podcasts:

packages/path_provider/path_provider_android/lib/messages.g.dart

@@ -1,7 +1,7 @@
 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-// Autogenerated from Pigeon (v3.1.5), do not edit directly.
+// Autogenerated from Pigeon (v3.2.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name
 // @dart = 2.12
@@ -12,6 +12,7 @@ import 'package:flutter/foundation.dart' show WriteBuffer, ReadBuffer;
 import 'package:flutter/services.dart';
 
 enum StorageDirectory {
+  root,
   music,
   podcasts,
   ringtones,

packages/path_provider/path_provider_android/lib/path_provider_android.dart

@@ -5,8 +5,11 @@
 import 'package:path_provider_platform_interface/path_provider_platform_interface.dart';
 import 'messages.g.dart' as messages;
 
-messages.StorageDirectory _convertStorageDirectory(StorageDirectory directory) {
+messages.StorageDirectory _convertStorageDirectory(
+    StorageDirectory? directory) {
   switch (directory) {
+    case null:
+      return messages.StorageDirectory.root;
     case StorageDirectory.music:
       return messages.StorageDirectory.music;
     case StorageDirectory.podcasts:
@@ -73,10 +76,8 @@ class PathProviderAndroid extends PathProviderPlatform {
   Future<List<String>?> getExternalStoragePaths({
     StorageDirectory? type,
   }) async {
-    return type == null
-        ? <String>[]
-        : (await _api.getExternalStoragePaths(_convertStorageDirectory(type)))
-            .cast<String>();
+    return (await _api.getExternalStoragePaths(_convertStorageDirectory(type)))
+        .cast<String>();
   }
 
   @override

packages/path_provider/path_provider_android/pigeons/messages.dart

@@ -14,6 +14,7 @@ import 'package:pigeon/pigeon.dart';
   copyrightHeader: 'pigeons/copyright.txt',
 ))
 enum StorageDirectory {
+  root,
   music,
   podcasts,
   ringtones,