refactor(neon): unify file dialog capabilities

Signed-off-by: Christian Badelt <cbadelt@cb.dedyn.io>
Signed-off-by: Nikolas Rimikis <leptopoda@users.noreply.github.com>

packages/neon/neon/lib/src/platform/android.dart

@@ -31,6 +31,9 @@ class AndroidNeonPlatform implements NeonPlatform {
   @override
   bool get canUseSharing => true;
 
+  @override
+  bool get shouldUseFileDialog => true;
+
   @override
   Future<String> get userAccessibleAppDataPath async {
     if (!await Permission.storage.request().isGranted) {

packages/neon/neon/lib/src/platform/linux.dart

@@ -31,6 +31,9 @@ class LinuxNeonPlatform implements NeonPlatform {
   @override
   bool get canUseSharing => false;
 
+  @override
+  bool get shouldUseFileDialog => false;
+
   @override
   String get userAccessibleAppDataPath => p.join(Platform.environment['HOME']!, 'Neon');
 

packages/neon/neon/lib/src/platform/platform.dart

@@ -59,6 +59,11 @@ abstract interface class NeonPlatform {
 
   abstract final bool canUseSharing;
 
+  /// Whether this platform should use file dialog.
+  ///
+  /// This is needed to compensate lacking support of `https://pub.dev/packages/file_picker`.
+  abstract final bool shouldUseFileDialog;
+
   FutureOr<String> get userAccessibleAppDataPath;
 
   FutureOr<void> init();

packages/neon/neon/lib/src/utils/save_file.dart

@@ -3,9 +3,10 @@ import 'dart:typed_data';
 
 import 'package:file_picker/file_picker.dart';
 import 'package:flutter_file_dialog/flutter_file_dialog.dart';
+import 'package:neon/src/platform/platform.dart';
 
 Future<String?> saveFileWithPickDialog(final String fileName, final Uint8List data) async {
-  if (Platform.isAndroid || Platform.isIOS) {
+  if (NeonPlatform.instance.shouldUseFileDialog) {
     // TODO: https://github.com/nextcloud/neon/issues/8
     return FlutterFileDialog.saveFile(
       params: SaveFileDialogParams(