#603 fixed switching to PiP when going home with gesture navigation

CHANGELOG.md

@@ -15,6 +15,7 @@ All notable changes to this project will be documented in this file.
 
 ### Fixed
 
+- Video: switching to PiP when going home with gesture navigation
 - Viewer: multi-page context update when removing burst entries
 - prevent editing item when Exif editing changes mime type
 - parsing videos with skippable boxes in `meta` box

lib/widgets/aves_app.dart

@@ -61,6 +61,11 @@ class AvesApp extends StatefulWidget {
   static final List<Locale> supportedLocales = AppLocalizations.supportedLocales.where((v) => !_unsupportedLocales.contains(v)).toList();
   static final ValueNotifier<EdgeInsets> cutoutInsetsNotifier = ValueNotifier(EdgeInsets.zero);
 
+  // children widgets registering as `WidgetsBinding` observers and implementing `didChangeAppLifecycleState`
+  // do not receive events fast enough for time sensitive actions (like PiP when leaving by gesture to home)
+  // so we use this notifier to propagate events as soon as received by the top widget `AvesApp`
+  static final ValueNotifier<AppLifecycleState> lifecycleStateNotifier = ValueNotifier(AppLifecycleState.detached);
+
   // do not monitor all `ModalRoute`s, which would include popup menus,
   // so that we can react to fullscreen `PageRoute`s only
   static final RouteObserver<PageRoute> pageRouteObserver = RouteObserver<PageRoute>();
@@ -364,6 +369,7 @@ class _AvesAppState extends State<AvesApp> with WidgetsBindingObserver {
   @override
   void didChangeAppLifecycleState(AppLifecycleState state) {
     reportService.log('Lifecycle ${state.name}');
+    AvesApp.lifecycleStateNotifier.value = state;
     switch (state) {
       case AppLifecycleState.inactive:
         switch (_appModeNotifier.value) {

lib/widgets/viewer/entry_viewer_stack.dart

@@ -62,7 +62,7 @@ class EntryViewerStack extends StatefulWidget {
   State<EntryViewerStack> createState() => _EntryViewerStackState();
 }
 
-class _EntryViewerStackState extends State<EntryViewerStack> with EntryViewControllerMixin, FeedbackMixin, SingleTickerProviderStateMixin, WidgetsBindingObserver {
+class _EntryViewerStackState extends State<EntryViewerStack> with EntryViewControllerMixin, FeedbackMixin, SingleTickerProviderStateMixin {
   final Floating _floating = Floating();
   late int _currentEntryIndex;
   late ValueNotifier<int> _currentVerticalPage;
@@ -155,7 +155,7 @@ class _EntryViewerStackState extends State<EntryViewerStack> with EntryViewContr
     );
     initEntryControllers(entry);
     _registerWidget(widget);
-    WidgetsBinding.instance.addObserver(this);
+    AvesApp.lifecycleStateNotifier.addListener(_onAppLifecycleStateChanged);
     WidgetsBinding.instance.addPostFrameCallback((_) => _initOverlay());
   }
 
@@ -178,7 +178,7 @@ class _EntryViewerStackState extends State<EntryViewerStack> with EntryViewContr
     _verticalPager.dispose();
     _heroInfoNotifier.dispose();
     _stopOverlayHidingTimer();
-    WidgetsBinding.instance.removeObserver(this);
+    AvesApp.lifecycleStateNotifier.removeListener(_onAppLifecycleStateChanged);
     _unregisterWidget(widget);
     super.dispose();
   }
@@ -191,33 +191,6 @@ class _EntryViewerStackState extends State<EntryViewerStack> with EntryViewContr
     widget.collection?.removeListener(_onCollectionChanged);
   }
 
-  @override
-  void didChangeAppLifecycleState(AppLifecycleState state) {
-    switch (state) {
-      case AppLifecycleState.inactive:
-        _onAppInactive();
-        break;
-      case AppLifecycleState.paused:
-      case AppLifecycleState.detached:
-        pauseVideoControllers();
-        break;
-      case AppLifecycleState.resumed:
-        availability.onResume();
-        break;
-    }
-  }
-
-  Future<void> _onAppInactive() async {
-    viewerController.autopilot = false;
-    bool enabledPip = false;
-    if (settings.videoBackgroundMode == VideoBackgroundMode.pip) {
-      enabledPip |= await _enablePictureInPicture();
-    }
-    if (!enabledPip) {
-      await pauseVideoControllers();
-    }
-  }
-
   @override
   Widget build(BuildContext context) {
     final viewStateConductor = context.read<ViewStateConductor>();
@@ -292,6 +265,36 @@ class _EntryViewerStackState extends State<EntryViewerStack> with EntryViewContr
     );
   }
 
+  void _onAppLifecycleStateChanged() {
+    switch (AvesApp.lifecycleStateNotifier.value) {
+      case AppLifecycleState.inactive:
+        _onAppInactive();
+        break;
+      case AppLifecycleState.paused:
+      case AppLifecycleState.detached:
+        pauseVideoControllers();
+        break;
+      case AppLifecycleState.resumed:
+        availability.onResume();
+        break;
+    }
+  }
+
+  Future<void> _onAppInactive() async {
+    final playingController = context.read<VideoConductor>().getPlayingController();
+    viewerController.autopilot = false;
+    bool enabledPip = false;
+    if (settings.videoBackgroundMode == VideoBackgroundMode.pip) {
+      enabledPip |= await _enablePictureInPicture();
+    }
+    if (enabledPip) {
+      // ensure playback, in case lifecycle paused/resumed events happened when switching to PiP
+      await playingController?.play();
+    } else {
+      await pauseVideoControllers();
+    }
+  }
+
   Widget _decorateOverlay(Widget overlay) {
     return ValueListenableBuilder<double>(
       valueListenable: _overlayAnimationController,