tweaks

Signed-off-by: dom <githubaccount56556@proton.me>

lib/common/widgets/dynamic_sliver_appbar_medium.dart

@@ -43,10 +43,10 @@ class DynamicSliverAppBarMedium extends StatefulWidget {
     this.forceMaterialTransparency = false,
     this.clipBehavior,
     this.appBarClipper,
-    this.afterCalc,
+    this.onPerformLayout,
   });
 
-  final ValueChanged<double>? afterCalc;
+  final ValueChanged<double>? onPerformLayout;
   final Widget? flexibleSpace;
   final Widget? leading;
   final bool automaticallyImplyLeading;
@@ -93,7 +93,6 @@ class DynamicSliverAppBarMedium extends StatefulWidget {
 }
 
 class _DynamicSliverAppBarMediumState extends State<DynamicSliverAppBarMedium> {
-  final GlobalKey _key = GlobalKey();
   double? _height;
   double? _width;
   late double _topPadding;
@@ -112,18 +111,17 @@ class _DynamicSliverAppBarMediumState extends State<DynamicSliverAppBarMedium> {
   @override
   Widget build(BuildContext context) {
     if (_height == null) {
-      WidgetsBinding.instance.addPostFrameCallback((_) {
-        _height =
-            (_key.currentContext!.findRenderObject() as RenderBox).size.height;
-        widget.afterCalc?.call(_height!);
-        setState(() {});
-      });
       return SliverToBoxAdapter(
         child: OnlyLayoutWidget(
+          onPerformLayout: (Size size) {
+            if (!mounted) return;
+            _height = size.height;
+            widget.onPerformLayout?.call(_height!);
+            setState(() {});
+          },
           child: UnconstrainedBox(
             alignment: Alignment.topLeft,
             child: SizedBox(
-              key: _key,
               width: _width,
               child: widget.flexibleSpace,
             ),

lib/common/widgets/only_layout_widget.dart

@@ -1,17 +1,42 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart' show RenderProxyBox;
+import 'package:flutter/scheduler.dart';
+
+typedef LayoutCallback = void Function(Size size);
 
 class OnlyLayoutWidget extends SingleChildRenderObjectWidget {
   const OnlyLayoutWidget({
     super.key,
     super.child,
+    required this.onPerformLayout,
   });
 
+  final LayoutCallback onPerformLayout;
+
   @override
-  RenderObject createRenderObject(BuildContext context) => Layout();
+  RenderObject createRenderObject(BuildContext context) =>
+      Layout(onPerformLayout: onPerformLayout);
+
+  @override
+  void updateRenderObject(BuildContext context, Layout renderObject) {
+    super.updateRenderObject(context, renderObject);
+    renderObject.onPerformLayout = onPerformLayout;
+  }
 }
 
 class Layout extends RenderProxyBox {
+  Layout({required this.onPerformLayout});
+
+  LayoutCallback onPerformLayout;
+
+  @override
+  void performLayout() {
+    super.performLayout();
+    SchedulerBinding.instance.addPostFrameCallback((_) {
+      onPerformLayout(size);
+    });
+  }
+
   @override
   void paint(PaintingContext context, Offset offset) {}
 }

lib/common/widgets/self_sized_horizontal_list.dart

@@ -23,22 +23,17 @@ class SelfSizedHorizontalList extends StatefulWidget {
 }
 
 class _SelfSizedHorizontalListState extends State<SelfSizedHorizontalList> {
-  final _key = GlobalKey();
   double? _height;
 
   @override
   Widget build(BuildContext context) {
     if (_height == null) {
-      WidgetsBinding.instance.addPostFrameCallback(
+      return OnlyLayoutWidget(
-        (_) {
+        onPerformLayout: (Size size) {
-          _height = (_key.currentContext!.findRenderObject() as RenderBox)
+          if (!mounted) return;
-              .size
+          _height = size.height;
-              .height;
           setState(() {});
         },
-      );
-      return OnlyLayoutWidget(
-        key: _key,
         child: Padding(
           padding: widget.padding ?? .zero,
           child: widget.itemBuilder(context, 0),

lib/pages/dynamics_topic/view.dart

@@ -159,7 +159,7 @@ class _DynTopicPageState extends State<DynTopicPage> with DynMixin {
       Loading() => const SliverAppBar(),
       Success(:final response) when response != null => DynamicSliverAppBarMedium(
         pinned: true,
-        afterCalc: (value) =>
+        onPerformLayout: (value) =>
             _controller.appbarOffset = value - kToolbarHeight - padding.top,
         title: IgnorePointer(child: Text(response.topicItem!.name)),
         flexibleSpace: Container(