fixed an issue that would cause the application to freeze if encryption takes a while

Author: SrS2225a

lib/services/file_upload.dart

@@ -19,6 +19,7 @@ import 'dart:async';
 import 'database.dart';
 
 typedef OnUploadProgressCallback = void Function(int sentBytes, int totalBytes);
+typedef IsEncryptingCallback = void Function(bool isEncrypting);
 
 class CustomFtpUploadResult {
   final bool success;
@@ -107,6 +108,7 @@ class FileService {
   static Future<String?> fileUploadMultiPart({
     required File file,
     required OnUploadProgressCallback setOnUploadProgress,
+    required IsEncryptingCallback setOnEncrypting,
     required BuildContext context,
   }) async {
     // Fetch selected uploader
@@ -125,7 +127,7 @@ class FileService {
     if(uploader != null) {
       try {
         String mimeType = lookupMimeType(file.path) ?? 'application/octet-stream';
-        FormData formData = await _buildFormData(uploader, file, mimeType);
+        FormData formData = await _buildFormData(uploader, file, mimeType, setOnEncrypting);
         Map<String, String> headers = await _getHeaders(uploader);
 
         return await _uploadFile(
@@ -159,6 +161,7 @@ class FileService {
         final encryptedStream = encryptPgpStream(
           file.openRead(),
           networkUploader.pgpPublicKey,
+            setOnEncrypting
         );
 
         final encryptedSize = networkUploader.pgpPublicKey != null
@@ -233,9 +236,9 @@ class FileService {
     };
   }
 
-  static Future<FormData> _buildFormData(Share uploader, File file, String mimeType) async {
+  static Future<FormData> _buildFormData(Share uploader, File file, String mimeType, IsEncryptingCallback setOnEncrypting) async {
     Uint8List bytes = await file.readAsBytes();
-    bytes = await encryptPgpBytes(bytes, uploader.pgpPublicKey);
+    bytes = await encryptPgpBytes(bytes, uploader.pgpPublicKey,  setOnEncrypting);
 
     final filename =  uploader.pgpPublicKey != null
         ? "${file.path.split("/").last}.asc"

lib/services/pgp_service.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:file_picker/file_picker.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:dart_pg/dart_pg.dart';
 
@@ -116,34 +117,58 @@ Future<void> _offerPrivateKeyExport(BuildContext context, String privateKey, Str
 Future<Uint8List> encryptPgpBytes(
     Uint8List data,
     String? armoredPublicKey,
+    void Function(bool isEncrypting) isEncrypting
     ) async {
   if (armoredPublicKey == null || armoredPublicKey.isEmpty) {
     return data;
   }
 
-  final publicKey = OpenPGP.readPublicKey(armoredPublicKey);
-  final encrypted = OpenPGP.encryptBinaryData(data, encryptionKeys: [publicKey]);
-  final armored = encrypted.armor();
-  return Uint8List.fromList(utf8.encode(armored));
+  // Offload to background isolate
+  isEncrypting.call(true);
+  final result = await compute(_encryptPgpBytesIsolate, {
+    'data': data,
+    'publicKey': armoredPublicKey,
+  });
+  isEncrypting.call(false);
+  return result;
 }
 
 Stream<List<int>> encryptPgpStream(
     Stream<List<int>> data,
     String? armoredPublicKey,
+    void Function(bool isEncrypting) isEncrypting
     ) async* {
   if (armoredPublicKey == null || armoredPublicKey.isEmpty) {
     yield* data;
     return;
   }
 
+  // Collect all chunks into a single Uint8List
   final buffer = BytesBuilder();
   await for (final chunk in data) {
     buffer.add(chunk);
   }
+  final bytes = buffer.toBytes();
+
+  // Offload encryption to a background isolate
+  isEncrypting.call(true);
+  final Uint8List encryptedBytes = await compute(_encryptPgpBytesIsolate, {
+    'data': bytes,
+    'publicKey': armoredPublicKey,
+  });
+  isEncrypting.call(false);
+
+  // Yield the encrypted data as a single chunk
+  yield encryptedBytes;
+}
+
+Future<Uint8List> _encryptPgpBytesIsolate(Map<String, dynamic> args) async {
+  final Uint8List data = args['data'];
+  final String armoredPublicKey = args['publicKey'];
 
   final publicKey = OpenPGP.readPublicKey(armoredPublicKey);
-  final encrypted = OpenPGP.encryptBinaryData(buffer.toBytes(), encryptionKeys: [publicKey]);
+  final encrypted = OpenPGP.encryptBinaryData(data, encryptionKeys: [publicKey]);
   final armored = encrypted.armor();
-  yield* Stream.fromIterable([utf8.encode(armored)]);
-  return;
+
+  return Uint8List.fromList(utf8.encode(armored));
 }

lib/views/components/add_uploader_simple.dart

@@ -222,7 +222,7 @@ class SimpleViewState extends State<SimpleView> {
                               onPressed: () async {
                                 final result =  await FilePicker.platform.pickFiles(
                                     type: FileType.custom,
-                                    allowedExtensions: ['asc', 'pgp', 'txt']
+                                    allowedExtensions: ['asc', 'pgp', 'txt', 'key']
                                 );
                                 final key = await importPgpKeyFromFile(result, context);
                                 _pgpKeyController.text = key!.trim();

lib/views/home_page.dart

@@ -33,6 +33,7 @@ class _HomePageState extends State<HomePage> with TickerProviderStateMixin {
   String _fileName = "";
   double _progressPercentValue = 0;
   bool _hasBeenPressed = false;
+  bool _isEncrypting = false;
   final List<String> _uploadedUrls = [];
 
   void _setUploadProgress(int sentBytes, int totalBytes) {
@@ -98,6 +99,11 @@ class _HomePageState extends State<HomePage> with TickerProviderStateMixin {
               file: uploadFile,
               setOnUploadProgress: _setUploadProgress,
               context: context,
+              setOnEncrypting: (isEncrypting) {
+                setState(() {
+                  _isEncrypting = isEncrypting;
+                });
+              },
             );
 
             if (value[i].type == SharedMediaType.TEXT && await uploadFile.exists()) {
@@ -236,6 +242,11 @@ class _HomePageState extends State<HomePage> with TickerProviderStateMixin {
                             file: file,
                             setOnUploadProgress: _setUploadProgress,
                             context: context,
+                            setOnEncrypting: (isEncrypting) {
+                              setState(() {
+                                _isEncrypting = isEncrypting;
+                              });
+                            }
                           );
 
                           if (url != null) {
@@ -271,7 +282,7 @@ class _HomePageState extends State<HomePage> with TickerProviderStateMixin {
                       textStyle: const TextStyle(fontSize: 20),
                     ),
                     child: _hasBeenPressed
-                        ? Text(AppLocalizations.of(context)!.uploading)
+                        ? Text(_isEncrypting ? "Encrypting...": AppLocalizations.of(context)!.uploading)
                         : Text(AppLocalizations.of(context)!.choose_files),
                   ),
                   progressColor: Colors.green[400],