back_to_switch.diff

diff --git a/lib/web_ui/lib/src/engine/semantics/label_and_value.dart b/lib/web_ui/lib/src/engine/semantics/label_and_value.dart
index 843c4dedda..f5e1bc7780 100644
--- a/lib/web_ui/lib/src/engine/semantics/label_and_value.dart
+++ b/lib/web_ui/lib/src/engine/semantics/label_and_value.dart
@@ -27,7 +27,7 @@ enum LabelRepresentation {
   /// role) JAWS on Windows. However, this role is still the most common, as it
   /// applies to all container nodes, and many ARIA roles (e.g. checkboxes,
   /// radios, scrollables, sliders).
-  ariaLabel(AriaLabelRepresentation),
+  ariaLabel,

   /// Represents the label as a [DomText] node.
   ///
@@ -37,7 +37,7 @@ enum LabelRepresentation {
   ///
   /// This representation is compatible with most web crawlers, and it is the
   /// best option for certain ARIA roles, such as buttons, links, and headings.
-  domText(DomTextRepresentation),
+  domText,

   /// Represents the label as a sized span.
   ///
@@ -45,17 +45,23 @@ enum LabelRepresentation {
   /// need to be laid out to compute the right size. It is compatible with most
   /// web crawlers, and it is the best options for certain ARIA roles, such as
   /// the implicit "generic" role used for plain text (not headings).
-  sizedSpan(SizedSpanRepresentation);
-
-  const LabelRepresentation(this.implementation);
-
-  /// The type used to implement this representation.
-  final Type implementation;
+  sizedSpan;
+
+  /// Creates the behavior for this label representation.
+  LabelRepresentationBehavior createBehavior(PrimaryRoleManager owner) {
+    return switch (this) {
+      LabelRepresentation.ariaLabel => AriaLabelRepresentation._(owner),
+      LabelRepresentation.domText => DomTextRepresentation._(owner),
+      LabelRepresentation.sizedSpan => SizedSpanRepresentation._(owner),
+    };
+  }
 }

 /// Provides a DOM behavior for a [LabelRepresentation].
 abstract final class LabelRepresentationBehavior {
-  LabelRepresentationBehavior(this.owner);
+  LabelRepresentationBehavior(this.kind, this.owner);
+
+  final LabelRepresentation kind;

   /// The role manager that this label representation is attached to.
   final PrimaryRoleManager owner;
@@ -103,7 +109,7 @@ abstract final class LabelRepresentationBehavior {
 ///
 ///     <flt-semantics aria-label="Hello, World!"></flt-semantics>
 final class AriaLabelRepresentation extends LabelRepresentationBehavior {
-  AriaLabelRepresentation._(super.owner);
+  AriaLabelRepresentation._(PrimaryRoleManager owner) : super(LabelRepresentation.ariaLabel, owner);

   String? _previousLabel;

@@ -137,7 +143,7 @@ final class AriaLabelRepresentation extends LabelRepresentationBehavior {
 /// no ARIA role set, or the role does not size the element, then the
 /// [SizedSpanRepresentation] representation can be used.
 final class DomTextRepresentation extends LabelRepresentationBehavior {
-  DomTextRepresentation._(super.owner);
+  DomTextRepresentation._(PrimaryRoleManager owner) : super(LabelRepresentation.domText, owner);

   DomText? _domText;
   String? _previousLabel;
@@ -200,7 +206,7 @@ typedef _Measurement = ({
 /// Text scaling is used to control the size of the screen reader focus ring.
 /// This is used for plain text nodes (e.g. paragraphs of text).
 final class SizedSpanRepresentation extends LabelRepresentationBehavior {
-  SizedSpanRepresentation._(super.owner) {
+  SizedSpanRepresentation._(PrimaryRoleManager owner) : super(LabelRepresentation.sizedSpan, owner) {
     _domText.style
       // `inline-block` is needed for two reasons:
       // - It supports measuring the true size of the text. Pure `block` would
@@ -423,13 +429,9 @@ class LabelAndValue extends RoleManager {
       : preferredRepresentation;

     LabelRepresentationBehavior? representation = _representation;
-    if (representation == null || representation.runtimeType != effectiveRepresentation.implementation) {
+    if (representation == null || representation.kind != effectiveRepresentation) {
       representation?.cleanUp();
-      _representation = representation = switch (effectiveRepresentation) {
-        LabelRepresentation.ariaLabel => AriaLabelRepresentation._(owner),
-        LabelRepresentation.domText => DomTextRepresentation._(owner),
-        LabelRepresentation.sizedSpan => SizedSpanRepresentation._(owner),
-      };
+      _representation = representation = effectiveRepresentation.createBehavior(owner);
     }
     return representation;
   }