#132 fixed magnifier controller widget update

lib/widgets/common/magnifier/controller/controller_delegate.dart

@@ -31,9 +31,16 @@ mixin MagnifierControllerDelegate on State<MagnifierCore> {
 
   final List<StreamSubscription> _subscriptions = [];
 
-  void startListeners() {
+  void registerDelegate(MagnifierCore widget) {
-    _subscriptions.add(controller.stateStream.listen(_onMagnifierStateChange));
+    _subscriptions.add(widget.controller.stateStream.listen(_onMagnifierStateChange));
-    _subscriptions.add(controller.scaleStateChangeStream.listen(_onScaleStateChange));
+    _subscriptions.add(widget.controller.scaleStateChangeStream.listen(_onScaleStateChange));
+  }
+
+  void unregisterDelegate(MagnifierCore oldWidget) {
+    _animateScale = null;
+    _subscriptions
+      ..forEach((sub) => sub.cancel())
+      ..clear();
   }
 
   void _onScaleStateChange(ScaleStateChange scaleStateChange) {
@@ -181,14 +188,6 @@ mixin MagnifierControllerDelegate on State<MagnifierCore> {
 
     return Offset(finalX, finalY);
   }
-
-  @override
-  void dispose() {
-    _animateScale = null;
-    _subscriptions.forEach((sub) => sub.cancel());
-    _subscriptions.clear();
-    super.dispose();
-  }
 }
 
 /// Simple class to store a min and a max value

lib/widgets/common/magnifier/core/core.dart

@@ -12,30 +12,25 @@ import 'package:flutter/widgets.dart';
 /// Internal widget in which controls all animations lifecycle, core responses
 /// to user gestures, updates to the controller state and mounts the entire Layout
 class MagnifierCore extends StatefulWidget {
+  final MagnifierController controller;
+  final ScaleStateCycle scaleStateCycle;
+  final bool applyScale;
+  final double panInertia;
+  final MagnifierTapCallback? onTap;
+  final Widget child;
+
   const MagnifierCore({
     Key? key,
-    required this.child,
-    required this.onTap,
     required this.controller,
     required this.scaleStateCycle,
     required this.applyScale,
     this.panInertia = .2,
+    required this.onTap,
+    required this.child,
   }) : super(key: key);
 
-  final Widget child;
-
-  final MagnifierController controller;
-  final ScaleStateCycle scaleStateCycle;
-
-  final MagnifierTapCallback? onTap;
-
-  final bool applyScale;
-  final double panInertia;
-
   @override
-  State<StatefulWidget> createState() {
+  State<StatefulWidget> createState() => _MagnifierCoreState();
-    return _MagnifierCoreState();
-  }
 }
 
 class _MagnifierCoreState extends State<MagnifierCore> with TickerProviderStateMixin, MagnifierControllerDelegate, CornerHitDetector {
@@ -52,6 +47,45 @@ class _MagnifierCoreState extends State<MagnifierCore> with TickerProviderStateM
 
   ScaleBoundaries? cachedScaleBoundaries;
 
+  @override
+  void initState() {
+    super.initState();
+    _scaleAnimationController = AnimationController(vsync: this)
+      ..addListener(handleScaleAnimation)
+      ..addStatusListener(onAnimationStatus);
+    _positionAnimationController = AnimationController(vsync: this)..addListener(handlePositionAnimate);
+    _registerWidget(widget);
+  }
+
+  @override
+  void didUpdateWidget(covariant MagnifierCore oldWidget) {
+    super.didUpdateWidget(oldWidget);
+
+    if (oldWidget.controller != widget.controller) {
+      _unregisterWidget(oldWidget);
+      _registerWidget(widget);
+    }
+  }
+
+  @override
+  void dispose() {
+    _unregisterWidget(widget);
+    _scaleAnimationController.dispose();
+    _positionAnimationController.dispose();
+    super.dispose();
+  }
+
+  void _registerWidget(MagnifierCore widget) {
+    registerDelegate(widget);
+    cachedScaleBoundaries = widget.controller.scaleBoundaries;
+    setScaleStateUpdateAnimation(animateOnScaleStateUpdate);
+  }
+
+  void _unregisterWidget(MagnifierCore oldWidget) {
+    unregisterDelegate(oldWidget);
+    cachedScaleBoundaries = null;
+  }
+
   void handleScaleAnimation() {
     setScale(_scaleAnimation.value, ChangeSource.animation);
   }
@@ -202,33 +236,11 @@ class _MagnifierCoreState extends State<MagnifierCore> with TickerProviderStateM
     }
   }
 
-  @override
-  void initState() {
-    super.initState();
-    _scaleAnimationController = AnimationController(vsync: this)..addListener(handleScaleAnimation);
-    _scaleAnimationController.addStatusListener(onAnimationStatus);
-
-    _positionAnimationController = AnimationController(vsync: this)..addListener(handlePositionAnimate);
-
-    startListeners();
-    setScaleStateUpdateAnimation(animateOnScaleStateUpdate);
-
-    cachedScaleBoundaries = widget.controller.scaleBoundaries;
-  }
-
   void animateOnScaleStateUpdate(double? prevScale, double? nextScale, Offset nextPosition) {
     animateScale(prevScale, nextScale);
     animatePosition(controller.position, nextPosition);
   }
 
-  @override
-  void dispose() {
-    _scaleAnimationController.removeStatusListener(onAnimationStatus);
-    _scaleAnimationController.dispose();
-    _positionAnimationController.dispose();
-    super.dispose();
-  }
-
   @override
   Widget build(BuildContext context) {
     // Check if we need a recalc on the scale

lib/widgets/common/magnifier/magnifier.dart

@@ -66,8 +66,8 @@ class Magnifier extends StatelessWidget {
         return MagnifierCore(
           controller: controller,
           scaleStateCycle: scaleStateCycle,
-          onTap: onTap,
           applyScale: applyScale,
+          onTap: onTap,
           child: child,
         );
       },

lib/widgets/viewer/visual/entry_page_view.dart

@@ -62,7 +62,7 @@ class _EntryPageViewState extends State<EntryPageView> {
   @override
   void initState() {
     super.initState();
-    _registerWidget();
+    _registerWidget(widget);
   }
 
   @override
@@ -70,19 +70,20 @@ class _EntryPageViewState extends State<EntryPageView> {
     super.didUpdateWidget(oldWidget);
 
     if (oldWidget.pageEntry != widget.pageEntry) {
-      _unregisterWidget();
+      _unregisterWidget(oldWidget);
-      _registerWidget();
+      _registerWidget(widget);
     }
   }
 
   @override
   void dispose() {
-    _unregisterWidget();
+    _unregisterWidget(widget);
     widget.onDisposed?.call();
     super.dispose();
   }
 
-  void _registerWidget() {
+  void _registerWidget(EntryPageView widget) {
+    final entry = widget.pageEntry;
     _viewStateNotifier = context.read<ViewStateConductor>().getOrCreateController(entry);
     _magnifierController = MagnifierController();
     _subscriptions.add(_magnifierController.stateStream.listen(_onViewStateChanged));
@@ -94,7 +95,7 @@ class _EntryPageViewState extends State<EntryPageView> {
     }
   }
 
-  void _unregisterWidget() {
+  void _unregisterWidget(EntryPageView oldWidget) {
     _videoCoverStream?.removeListener(_videoCoverStreamListener);
     _videoCoverStream = null;
     _videoCoverInfoNotifier.value = null;