refactor(perf): Enhance state management and theme usage in form and navigation components

Author: bdlukaa

lib/src/controls/flyouts/menu_bar.dart

@@ -1,5 +1,6 @@
 import 'package:fluent_ui/fluent_ui.dart';
 import 'package:flutter/foundation.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:flutter/services.dart';
 
 /// Represents a top-level menu in a [MenuBar] control.
@@ -168,10 +169,11 @@ class MenuBarState extends State<MenuBar> {
       //
       // Even though the duration is zero, it is necessary to wait for the
       // transition to finish before showing the next flyout. Otherwise, the
-      // flyout will fail to show due to [_locked]. This has a similar effect
-      // to moving this task to the next frame or using a [Future.microtask].
-      await Future<void>.delayed(Duration.zero);
-      setState(() {});
+      // flyout will fail to show due to [_locked]. Use SchedulerBinding for
+      // frame-aligned updates instead of arbitrary delay.
+      SchedulerBinding.instance.addPostFrameCallback((_) {
+        if (mounted) setState(() {});
+      });
     }
   }
 

lib/src/controls/form/combo_box.dart

@@ -1246,7 +1246,7 @@ class ComboBoxState<T> extends State<ComboBox<T>> {
     }
   }
 
-  TextStyle? get _textStyle =>
+  TextStyle? _textStyle(BuildContext context) =>
       widget.style ?? FluentTheme.of(context).typography.body;
 
   /// Opens the combo box popup.
@@ -1279,7 +1279,7 @@ class ComboBoxState<T> extends State<ComboBox<T>> {
         from: context,
         to: navigator.context,
       ),
-      style: _textStyle!,
+      style: _textStyle(context)!,
       barrierLabel: FluentLocalizations.of(context).modalBarrierDismissLabel,
       popupColor: widget.popupColor,
     );
@@ -1327,6 +1327,7 @@ class ComboBoxState<T> extends State<ComboBox<T>> {
     assert(debugCheckHasDirectionality(context));
 
     final theme = FluentTheme.of(context);
+    final textStyle = _textStyle(context)!;
 
     // The width of the button and the menu are defined by the widest
     // item and the width of the placeholder.
@@ -1350,7 +1351,7 @@ class ComboBoxState<T> extends State<ComboBox<T>> {
       placeholderIndex = items.length;
       items.add(
         DefaultTextStyle.merge(
-          style: _textStyle!.copyWith(
+          style: textStyle.copyWith(
             color: theme.resources.textFillColorDisabled,
           ),
           child: IgnorePointer(child: displayedHint),
@@ -1382,8 +1383,8 @@ class ComboBoxState<T> extends State<ComboBox<T>> {
       builder: (context) {
         return DefaultTextStyle.merge(
           style: isEnabled
-              ? _textStyle!
-              : _textStyle!.copyWith(
+              ? textStyle
+              : textStyle.copyWith(
                   color: theme.resources.textFillColorDisabled,
                 ),
           child: Container(

lib/src/controls/form/number_box.dart

@@ -565,7 +565,6 @@ class NumberBoxState<T extends num> extends State<NumberBox<T>> {
 
     if (_textBoxKey.currentContext != null) {
       Overlay.of(context).insert(_entry!);
-      if (mounted) setState(() {});
     }
   }
 
@@ -827,6 +826,7 @@ class _NumberBoxCompactOverlay extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasFluentTheme(context));
+    final theme = FluentTheme.of(context);
 
     return Padding(
       padding: const EdgeInsetsDirectional.only(start: 10),
@@ -840,10 +840,10 @@ class _NumberBoxCompactOverlay extends StatelessWidget {
             height: kNumberBoxOverlayHeight,
             width: kNumberBoxOverlayWidth,
             decoration: BoxDecoration(
-              color: FluentTheme.of(context).menuColor,
+              color: theme.menuColor,
               border: Border.all(
                 width: 0.25,
-                color: FluentTheme.of(context).inactiveBackgroundColor,
+                color: theme.inactiveBackgroundColor,
               ),
             ),
             child: Column(

lib/src/controls/inputs/dropdown_button.dart

@@ -182,6 +182,7 @@ class DropDownButton extends StatefulWidget {
           return FadeTransition(opacity: animation, child: child);
         }
 
+        final animationCurve = FluentTheme.of(context).animationCurve;
         switch (placement) {
           case FlyoutPlacementMode.bottomCenter:
           case FlyoutPlacementMode.bottomLeft:
@@ -194,10 +195,7 @@ class DropDownButton extends StatefulWidget {
                       begin: const Offset(0, -1),
                       end: Offset.zero,
                     ).animate(
-                      CurvedAnimation(
-                        parent: animation,
-                        curve: FluentTheme.of(context).animationCurve,
-                      ),
+                      CurvedAnimation(parent: animation, curve: animationCurve),
                     ),
                 child: child,
               ),
@@ -213,10 +211,7 @@ class DropDownButton extends StatefulWidget {
                       begin: const Offset(0, 1),
                       end: Offset.zero,
                     ).animate(
-                      CurvedAnimation(
-                        parent: animation,
-                        curve: FluentTheme.of(context).animationCurve,
-                      ),
+                      CurvedAnimation(parent: animation, curve: animationCurve),
                     ),
                 child: child,
               ),

lib/src/controls/navigation/navigation_view/indicators.dart

@@ -58,9 +58,8 @@ class NavigationIndicatorState<T extends NavigationIndicator> extends State<T> {
       );
       if (offsets != localOffsets) {
         offsets = localOffsets;
+        if (mounted) setState(() {});
       }
-
-      if (mounted) setState(() {});
     });
   }