fix(android): save files to SD card on Android 10 or lower (localsend…

…#1162)

app/assets/CHANGELOG.md

@@ -4,6 +4,7 @@
 - feat: use fix button width for all buttons in the selection row (only noticeable in Russian) (@Tienisto)
 - fix: picking many files should not freeze the UI (@Tienisto)
 - fix: do not create a new session for the same IP when sharing via link (@MisterChangRay)
+- fix(android): save files to SD card on Android 10 or older (@Tienisto)
 - i18n: add Danish (@Limfjorden)
 
 ## 1.13.1 (2023-12-08)

app/lib/model/state/server/receive_session_state.dart

@@ -19,6 +19,7 @@ class ReceiveSessionState with ReceiveSessionStateMappable {
   final int? startTime;
   final int? endTime;
   final String destinationDirectory;
+  final String cacheDirectory;
   final bool saveToGallery;
   final StreamController<Map<String, String>?>? responseHandler;
 
@@ -31,6 +32,7 @@ class ReceiveSessionState with ReceiveSessionStateMappable {
     required this.startTime,
     required this.endTime,
     required this.destinationDirectory,
+    required this.cacheDirectory,
     required this.saveToGallery,
     required this.responseHandler,
   });

app/lib/model/state/server/receive_session_state.mapper.dart

@@ -38,6 +38,8 @@ class ReceiveSessionStateMapper extends ClassMapperBase<ReceiveSessionState> {
   static const Field<ReceiveSessionState, int> _f$endTime = Field('endTime', _$endTime);
   static String _$destinationDirectory(ReceiveSessionState v) => v.destinationDirectory;
   static const Field<ReceiveSessionState, String> _f$destinationDirectory = Field('destinationDirectory', _$destinationDirectory);
+  static String _$cacheDirectory(ReceiveSessionState v) => v.cacheDirectory;
+  static const Field<ReceiveSessionState, String> _f$cacheDirectory = Field('cacheDirectory', _$cacheDirectory);
   static bool _$saveToGallery(ReceiveSessionState v) => v.saveToGallery;
   static const Field<ReceiveSessionState, bool> _f$saveToGallery = Field('saveToGallery', _$saveToGallery);
   static StreamController<Map<String, String>?>? _$responseHandler(ReceiveSessionState v) => v.responseHandler;
@@ -53,6 +55,7 @@ class ReceiveSessionStateMapper extends ClassMapperBase<ReceiveSessionState> {
     #startTime: _f$startTime,
     #endTime: _f$endTime,
     #destinationDirectory: _f$destinationDirectory,
+    #cacheDirectory: _f$cacheDirectory,
     #saveToGallery: _f$saveToGallery,
     #responseHandler: _f$responseHandler,
   };
@@ -67,6 +70,7 @@ class ReceiveSessionStateMapper extends ClassMapperBase<ReceiveSessionState> {
         startTime: data.dec(_f$startTime),
         endTime: data.dec(_f$endTime),
         destinationDirectory: data.dec(_f$destinationDirectory),
+        cacheDirectory: data.dec(_f$cacheDirectory),
         saveToGallery: data.dec(_f$saveToGallery),
         responseHandler: data.dec(_f$responseHandler));
   }
@@ -128,6 +132,7 @@ abstract class ReceiveSessionStateCopyWith<$R, $In extends ReceiveSessionState,
       int? startTime,
       int? endTime,
       String? destinationDirectory,
+      String? cacheDirectory,
       bool? saveToGallery,
       StreamController<Map<String, String>?>? responseHandler});
   ReceiveSessionStateCopyWith<$R2, $In, $Out2> $chain<$R2, $Out2>(Then<$Out2, $R2> t);
@@ -154,6 +159,7 @@ class _ReceiveSessionStateCopyWithImpl<$R, $Out> extends ClassCopyWithBase<$R, R
           Object? startTime = $none,
           Object? endTime = $none,
           String? destinationDirectory,
+          String? cacheDirectory,
           bool? saveToGallery,
           Object? responseHandler = $none}) =>
       $apply(FieldCopyWithData({
@@ -165,6 +171,7 @@ class _ReceiveSessionStateCopyWithImpl<$R, $Out> extends ClassCopyWithBase<$R, R
         if (startTime != $none) #startTime: startTime,
         if (endTime != $none) #endTime: endTime,
         if (destinationDirectory != null) #destinationDirectory: destinationDirectory,
+        if (cacheDirectory != null) #cacheDirectory: cacheDirectory,
         if (saveToGallery != null) #saveToGallery: saveToGallery,
         if (responseHandler != $none) #responseHandler: responseHandler
       }));
@@ -178,6 +185,7 @@ class _ReceiveSessionStateCopyWithImpl<$R, $Out> extends ClassCopyWithBase<$R, R
       startTime: data.get(#startTime, or: $value.startTime),
       endTime: data.get(#endTime, or: $value.endTime),
       destinationDirectory: data.get(#destinationDirectory, or: $value.destinationDirectory),
+      cacheDirectory: data.get(#cacheDirectory, or: $value.cacheDirectory),
       saveToGallery: data.get(#saveToGallery, or: $value.saveToGallery),
       responseHandler: data.get(#responseHandler, or: $value.responseHandler));
 

app/lib/pages/receive_history_page.dart

@@ -5,7 +5,7 @@ import 'package:localsend_app/provider/receive_history_provider.dart';
 import 'package:localsend_app/provider/settings_provider.dart';
 import 'package:localsend_app/theme.dart';
 import 'package:localsend_app/util/file_size_helper.dart';
-import 'package:localsend_app/util/native/get_destination_directory.dart';
+import 'package:localsend_app/util/native/directories.dart';
 import 'package:localsend_app/util/native/open_file.dart';
 import 'package:localsend_app/util/native/open_folder.dart';
 import 'package:localsend_app/util/native/platform_check.dart';

app/lib/provider/network/server/controller/receive_controller.dart

@@ -1,6 +1,5 @@
 import 'dart:async';
 import 'dart:convert';
-import 'dart:io';
 
 import 'package:collection/collection.dart';
 import 'package:common/common.dart';
@@ -22,13 +21,11 @@ import 'package:localsend_app/provider/progress_provider.dart';
 import 'package:localsend_app/provider/receive_history_provider.dart';
 import 'package:localsend_app/provider/settings_provider.dart';
 import 'package:localsend_app/util/api_route_builder.dart';
-import 'package:localsend_app/util/file_path_helper.dart';
+import 'package:localsend_app/util/native/directories.dart';
 import 'package:localsend_app/util/native/file_saver.dart';
-import 'package:localsend_app/util/native/get_destination_directory.dart';
 import 'package:localsend_app/util/native/platform_check.dart';
 import 'package:localsend_app/util/native/tray_helper.dart';
 import 'package:logging/logging.dart';
-import 'package:path/path.dart' as p;
 import 'package:permission_handler/permission_handler.dart';
 import 'package:routerino/routerino.dart';
 import 'package:shelf/shelf.dart';
@@ -194,6 +191,7 @@ class ReceiveController {
 
     final settings = server.ref.read(settingsProvider);
     final destinationDir = settings.destination ?? await getDefaultDestinationDirectory();
+    final cacheDir = await getCacheDirectory();
     final sessionId = _uuid.v4();
 
     _logger.info('Session Id: $sessionId');
@@ -222,6 +220,7 @@ class ReceiveController {
           startTime: null,
           endTime: null,
           destinationDirectory: destinationDir,
+          cacheDirectory: cacheDir,
           saveToGallery: checkPlatformWithGallery() && settings.saveToGallery && dto.files.values.every((f) => !f.fileName.contains('/')),
           responseHandler: streamController,
         ),
@@ -391,21 +390,23 @@ class ReceiveController {
     );
 
     try {
-      final destinationPath = await _digestFilePathAndPrepareDirectory(
-        parentDirectory: receiveState.destinationDirectory,
+      final fileType = receivingFile.file.fileType;
+      final saveToGallery = receiveState.saveToGallery && (fileType == FileType.image || fileType == FileType.video);
+
+      final destinationPath = await digestFilePathAndPrepareDirectory(
+        parentDirectory: saveToGallery ? receiveState.cacheDirectory : receiveState.destinationDirectory,
         fileName: receivingFile.desiredName!,
       );
 
       _logger.info('Saving ${receivingFile.file.fileName} to $destinationPath');
 
-      final fileType = receivingFile.file.fileType;
-      final saveToGallery = receiveState.saveToGallery && (fileType == FileType.image || fileType == FileType.video);
       await saveFile(
         destinationPath: destinationPath,
         name: receivingFile.desiredName!,
         saveToGallery: saveToGallery,
         isImage: fileType == FileType.image,
         stream: request.read(),
+        androidSdkInt: server.ref.read(deviceInfoProvider).androidSdkInt,
         onProgress: (savedBytes) {
           if (receivingFile.file.size != 0) {
             server.ref.notifier(progressProvider).setProgress(
@@ -688,23 +689,6 @@ void _cancelBySender(ServerUtils server) {
       ));
 }
 
-/// If there is a file with the same name, then it appends a number to its file name
-Future<String> _digestFilePathAndPrepareDirectory({required String parentDirectory, required String fileName}) async {
-  final actualFileName = p.basename(fileName);
-  final fileNameParts = p.split(fileName);
-  final dir = p.joinAll([parentDirectory, ...fileNameParts.take(fileNameParts.length - 1)]);
-
-  Directory(dir).createSync(recursive: true);
-
-  String destinationPath;
-  int counter = 1;
-  do {
-    destinationPath = counter == 1 ? p.join(dir, actualFileName) : p.join(dir, actualFileName.withCount(counter));
-    counter++;
-  } while (await File(destinationPath).exists());
-  return destinationPath;
-}
-
 extension on ReceiveSessionState {
   ReceiveSessionState fileFinished({
     required String fileId,

app/lib/util/native/get_destination_directory.dart → app/lib/util/native/directories.dart

@@ -33,3 +33,7 @@ Future<String> getDefaultDestinationDirectory() async {
       return downloadDir.path.replaceAll('\\', '/');
   }
 }
+
+Future<String> getCacheDirectory() async {
+  return (await path.getTemporaryDirectory()).path;
+}

app/lib/util/native/file_saver.dart

@@ -1,10 +1,16 @@
 import 'dart:io';
+import 'dart:typed_data';
 
 import 'package:gal/gal.dart';
+import 'package:localsend_app/util/file_path_helper.dart';
 import 'package:logging/logging.dart';
+import 'package:path/path.dart' as p;
+import 'package:saf_stream/saf_stream.dart';
 
 final _logger = Logger('FileSaver');
 
+final _saf = SafStream();
+
 /// Saves the data [stream] to the [destinationPath].
 /// [onProgress] will be called on every 100 ms.
 Future<void> saveFile({
@@ -13,14 +19,69 @@ Future<void> saveFile({
   required bool saveToGallery,
   required bool isImage,
   required Stream<List<int>> stream,
+  required int? androidSdkInt,
   required void Function(int savedBytes) onProgress,
 }) async {
+  if (!saveToGallery && androidSdkInt != null && androidSdkInt <= 29) {
+    final sdCardPath = getSdCardPath(destinationPath);
+    if (sdCardPath != null) {
+      // Use Android SAF to save the file to the SD card
+      final info = await _saf.startWriteStream(
+        Uri.parse('content://com.android.externalstorage.documents/tree/${sdCardPath.sdCardId}:${sdCardPath.path}'),
+        name,
+        isImage ? 'image/*' : '*/*',
+      );
+      final sessionID = info.session;
+      await _saveFile(
+        destinationPath: destinationPath,
+        saveToGallery: saveToGallery,
+        isImage: isImage,
+        stream: stream,
+        onProgress: onProgress,
+        write: null,
+        writeAsync: (data) async {
+          await _saf.writeChunk(sessionID, Uint8List.fromList(data));
+        },
+        close: () async {
+          await _saf.endWriteStream(sessionID);
+        },
+      );
+      return;
+    }
+  }
+
   final sink = File(destinationPath).openWrite();
+  await _saveFile(
+    destinationPath: destinationPath,
+    saveToGallery: saveToGallery,
+    isImage: isImage,
+    stream: stream,
+    onProgress: onProgress,
+    write: sink.add,
+    writeAsync: null,
+    close: sink.close,
+  );
+}
+
+Future<void> _saveFile({
+  required String destinationPath,
+  required bool saveToGallery,
+  required bool isImage,
+  required Stream<List<int>> stream,
+  required void Function(int savedBytes) onProgress,
+  required void Function(List<int> data)? write,
+  required Future<void> Function(List<int> data)? writeAsync,
+  required Future<void> Function() close,
+}) async {
   try {
     int savedBytes = 0;
     final stopwatch = Stopwatch()..start();
     await for (final event in stream) {
-      sink.add(event);
+      if (writeAsync != null) {
+        await writeAsync(event);
+      } else {
+        write!(event);
+      }
 
       savedBytes += event.length;
       if (stopwatch.elapsedMilliseconds >= 100) {
@@ -29,7 +90,7 @@ Future<void> saveFile({
       }
     }
 
-    await sink.close();
+    await close();
 
     if (saveToGallery) {
       isImage ? await Gal.putImage(destinationPath) : await Gal.putVideo(destinationPath);
@@ -39,11 +100,48 @@ Future<void> saveFile({
     onProgress(savedBytes); // always emit final event
   } catch (_) {
     try {
-      await sink.close();
+      await close();
       await File(destinationPath).delete();
     } catch (e) {
       _logger.warning('Could not delete file', e);
     }
     rethrow;
   }
 }
+
+/// If there is a file with the same name, then it appends a number to its file name
+Future<String> digestFilePathAndPrepareDirectory({required String parentDirectory, required String fileName}) async {
+  final actualFileName = p.basename(fileName);
+  final fileNameParts = p.split(fileName);
+  final dir = p.joinAll([parentDirectory, ...fileNameParts.take(fileNameParts.length - 1)]);
+
+  Directory(dir).createSync(recursive: true);
+
+  String destinationPath;
+  int counter = 1;
+  do {
+    destinationPath = counter == 1 ? p.join(dir, actualFileName) : p.join(dir, actualFileName.withCount(counter));
+    counter++;
+  } while (await File(destinationPath).exists());
+  return destinationPath;
+}
+
+final _sdCardPathRegex = RegExp(r'^/storage/([A-Fa-f0-9]{4}-[A-Fa-f0-9]{4})/(.*)$');
+
+class SdCardPath {
+  final String sdCardId;
+  final String path;
+
+  SdCardPath(this.sdCardId, this.path);
+}
+
+/// Checks if the [path] is on the SD card and returns the SD card path.
+/// Returns `null` if the [path] is not on the SD card.
+/// Only works on Android.
+SdCardPath? getSdCardPath(String path) {
+  final match = _sdCardPathRegex.firstMatch(path);
+  if (match == null) {
+    return null;
+  }
+  return SdCardPath(match.group(1)!, match.group(2)!);
+}

app/pubspec.lock

@@ -1181,6 +1181,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.8.0"
+  saf_stream:
+    dependency: "direct main"
+    description:
+      name: saf_stream
+      sha256: "1db21cfa5914a5cf9a7c962b5d57fc8c07011561e365e7ff7f8013019cc3c0f3"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.4.0"
   screen_retriever:
     dependency: "direct main"
     description:

app/pubspec.yaml

@@ -48,6 +48,7 @@ dependencies:
   refena_flutter: 1.6.0
   refena_inspector_client: 1.2.0
   routerino: 0.8.0
+  saf_stream: 0.4.0 # Saving files to SD card for Android <11
   screen_retriever: 0.1.9
   share_handler: 0.0.19
   share_handler_ios: 0.0.12 # Keep iOS <14 support