set app_dir via ffi

flutter_hbb/android/app/src/main/AndroidManifest.xml

@@ -43,5 +43,6 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
-    </application>
+      </application>
+      <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 </manifest>

flutter_hbb/lib/main.dart

@@ -1,20 +1,28 @@
+import 'package:ffi/ffi.dart';
 import 'package:flutter/material.dart';
-import 'dart:io' show Platform;
+import 'package:path_provider/path_provider.dart';
+import 'dart:io';
 import 'dart:ffi';
+import 'dart:async';
 
 void main() {
-  final dylib = Platform.isAndroid ? DynamicLibrary.open('librustdesk.so') : DynamicLibrary.process();
-  final initialize = dylib.lookupFunction<Void Function(), void Function()>('initialize');
-  initialize();
   // final connect = dylib.lookupFunction<Void Function(Pointer<Utf8>), void Function(Pointer<Utf8>)>('connect');
   // connect(Utf8.toUtf8('test'));
   runApp(MyApp());
 }
 
+Future<Null> initialzeFFI() async {
+  final dylib = Platform.isAndroid ? DynamicLibrary.open('librustdesk.so') : DynamicLibrary.process();
+  String dir = (await getApplicationDocumentsDirectory()).path;
+  final initialize = dylib.lookupFunction<Void Function(Pointer<Utf8>), void Function(Pointer<Utf8>)>('initialize');
+  initialize(Utf8.toUtf8(dir));
+}
+
 class MyApp extends StatelessWidget {
   // This widget is the root of your application.
   @override
   Widget build(BuildContext context) {
+    initialzeFFI();
     return MaterialApp(
       title: 'Flutter Demo',
       theme: ThemeData(

flutter_hbb/pubspec.lock

@@ -64,6 +64,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.1.3"
+  file:
+    dependency: transitive
+    description:
+      name: file
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "5.2.1"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -74,6 +81,13 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  intl:
+    dependency: transitive
+    description:
+      name: intl
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.16.1"
   matcher:
     dependency: transitive
     description:
@@ -95,6 +109,62 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.8.0-nullsafety.1"
+  path_provider:
+    dependency: "direct main"
+    description:
+      name: path_provider
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.6.24"
+  path_provider_linux:
+    dependency: transitive
+    description:
+      name: path_provider_linux
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.0.1+2"
+  path_provider_macos:
+    dependency: transitive
+    description:
+      name: path_provider_macos
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.0.4+6"
+  path_provider_platform_interface:
+    dependency: transitive
+    description:
+      name: path_provider_platform_interface
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.4"
+  path_provider_windows:
+    dependency: transitive
+    description:
+      name: path_provider_windows
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.0.4+3"
+  platform:
+    dependency: transitive
+    description:
+      name: platform
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.2.1"
+  plugin_platform_interface:
+    dependency: transitive
+    description:
+      name: plugin_platform_interface
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.3"
+  process:
+    dependency: transitive
+    description:
+      name: process
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "3.0.13"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -156,5 +226,20 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.1.0-nullsafety.3"
+  win32:
+    dependency: transitive
+    description:
+      name: win32
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.7.3"
+  xdg_directories:
+    dependency: transitive
+    description:
+      name: xdg_directories
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.1.2"
 sdks:
   dart: ">=2.10.0-110 <2.11.0"
+  flutter: ">=1.12.13+hotfix.5 <2.0.0"

flutter_hbb/pubspec.yaml

@@ -29,6 +29,7 @@ dependencies:
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.0
   ffi: ^0.1.3
+  path_provider: ^1.6.24
 
 dev_dependencies:
   flutter_test: