disable volume handling when on Settings screen

lib/data/volume_events_service.dart

@@ -1,3 +1,5 @@
+import 'dart:io';
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 
@@ -10,8 +12,12 @@ class VolumeEventsService {
 
   const VolumeEventsService();
 
-  /// Returns current status of volume handling
+  /// If set to `false` we allow system to handle key events.
+  /// Returns current status of volume handling.
   Future<bool> setVolumeHandling(bool enableHandling) async {
+    if (!Platform.isAndroid) {
+      return false;
+    }
     return volumeHandlingChannel
         .invokeMethod<bool>("setVolumeHandling", enableHandling)
         .then((value) => value!);
@@ -22,6 +28,12 @@ class VolumeEventsService {
   /// KEYCODE_VOLUME_DOWN = 25;
   /// pressed
   Stream<int> volumeButtonsEventStream() {
-    return volumeEventsChannel.receiveBroadcastStream().cast<int>();
+    if (!Platform.isAndroid) {
+      return const Stream.empty();
+    }
+    return volumeEventsChannel
+        .receiveBroadcastStream()
+        .cast<int>()
+        .where((event) => event == 24 || event == 25);
   }
 }

lib/interactors/settings_interactor.dart

@@ -31,9 +31,16 @@ class SettingsInteractor {
     });
   }
 
+  Future<void> disableVolumeHandling() async {
+    await _volumeEventsService.setVolumeHandling(false);
+  }
+  Future<void> restoreVolumeHandling() async {
+    await _volumeEventsService
+        .setVolumeHandling(_userPreferencesService.volumeAction != VolumeAction.none);
+  }
+
   VolumeAction get volumeAction => _userPreferencesService.volumeAction;
   Future<void> setVolumeAction(VolumeAction value) async {
-    /// If user selects `VolumeAction.volume` we allow system to handle key events
     await _volumeEventsService.setVolumeHandling(value != VolumeAction.none);
     _userPreferencesService.volumeAction = value;
   }

lib/screens/metering/components/shared/volume_keys_notifier/notifier_volume_keys.dart

@@ -4,7 +4,7 @@ import 'package:flutter/material.dart';
 import 'package:lightmeter/data/models/volume_action.dart';
 import 'package:lightmeter/data/volume_events_service.dart';
 
-class VolumeKeysNotifier extends ChangeNotifier {
+class VolumeKeysNotifier extends ChangeNotifier with RouteAware {
   final VolumeEventsService volumeEventsService;
   late final StreamSubscription<VolumeKey> _volumeKeysSubscription;
   VolumeKey _value = VolumeKey.up;
@@ -13,7 +13,6 @@ class VolumeKeysNotifier extends ChangeNotifier {
     // TODO: add RouteObserver and disable overriden action if SettingScreen is opened
     _volumeKeysSubscription = volumeEventsService
         .volumeButtonsEventStream()
-        .where((event) => event == 24 || event == 25)
         .map((event) => event == 24 ? VolumeKey.up : VolumeKey.down)
         .listen((event) {
       value = event;

lib/screens/settings/screen_settings.dart

@@ -1,14 +1,33 @@
 import 'package:flutter/material.dart';
 import 'package:lightmeter/generated/l10n.dart';
+import 'package:lightmeter/interactors/settings_interactor.dart';
 import 'package:lightmeter/screens/settings/components/about/widget_settings_section_about.dart';
 import 'package:lightmeter/screens/settings/components/general/widget_settings_section_general.dart';
 import 'package:lightmeter/screens/settings/components/metering/widget_settings_section_metering.dart';
 import 'package:lightmeter/screens/settings/components/theme/widget_settings_section_theme.dart';
 import 'package:lightmeter/screens/shared/sliver_screen/screen_sliver.dart';
+import 'package:lightmeter/utils/inherited_generics.dart';
 
-class SettingsScreen extends StatelessWidget {
+class SettingsScreen extends StatefulWidget {
   const SettingsScreen({super.key});
 
+  @override
+  State<SettingsScreen> createState() => _SettingsScreenState();
+}
+
+class _SettingsScreenState extends State<SettingsScreen> {
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    context.get<SettingsInteractor>().disableVolumeHandling();
+  }
+
+  @override
+  void deactivate() {
+    context.get<SettingsInteractor>().restoreVolumeHandling();
+    super.deactivate();
+  }
+
   @override
   Widget build(BuildContext context) {
     return ScaffoldMessenger(

test/data/volume_events_service_test.dart

@@ -35,10 +35,4 @@ void main() {
 
     test('false', () async => expectLater(service.setVolumeHandling(false), completion(false)));
   });
-
-  group('volumeButtonsEventStream', () {
-    test('true', () async => expectLater(service.setVolumeHandling(true), completion(true)));
-
-    test('false', () async => expectLater(service.setVolumeHandling(false), completion(false)));
-  });
 }