screensaver: fixed autopilot when device orientation changes

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 
 ## <a id="unreleased"></a>[Unreleased]
 
+### Fixed
+
+- screensaver stopping when device orientation changes
+
 ## <a id="v1.6.12"></a>[v1.6.12] - 2022-08-27
 
 ### Added

lib/widgets/viewer/screen_saver_page.dart

@@ -29,7 +29,7 @@ class ScreenSaverPage extends StatefulWidget {
   State<ScreenSaverPage> createState() => _ScreenSaverPageState();
 }
 
-class _ScreenSaverPageState extends State<ScreenSaverPage> {
+class _ScreenSaverPageState extends State<ScreenSaverPage> with WidgetsBindingObserver {
   late final ViewerController _viewerController;
   CollectionLens? _slideshowCollection;
 
@@ -47,24 +47,24 @@ class _ScreenSaverPageState extends State<ScreenSaverPage> {
     );
     source.stateNotifier.addListener(_onSourceStateChanged);
     _initSlideshowCollection();
-  }
+    WidgetsBinding.instance.addObserver(this);
-
-  void _onSourceStateChanged() {
-    if (_slideshowCollection == null) {
-      _initSlideshowCollection();
-      if (_slideshowCollection != null) {
-        setState(() {});
-      }
-    }
   }
 
   @override
   void dispose() {
     source.stateNotifier.removeListener(_onSourceStateChanged);
     _viewerController.dispose();
+    WidgetsBinding.instance.removeObserver(this);
     super.dispose();
   }
 
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    if (state == AppLifecycleState.resumed) {
+      _viewerController.autopilot = true;
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     Widget child;
@@ -102,6 +102,15 @@ class _ScreenSaverPageState extends State<ScreenSaverPage> {
     );
   }
 
+  void _onSourceStateChanged() {
+    if (_slideshowCollection == null) {
+      _initSlideshowCollection();
+      if (_slideshowCollection != null) {
+        setState(() {});
+      }
+    }
+  }
+
   void _initSlideshowCollection() {
     if (source.stateNotifier.value != SourceState.ready || _slideshowCollection != null) return;