Mirror ExpansionTile shape and collapsedShape

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A67XoQYsLVvoMtiKcXXUxY

Author: claude

CHANGELOG.md

@@ -41,7 +41,8 @@
   - `ListTileProperties.minTileHeight`, `titleAlignment` (new
     `ListTileTitleAlignmentC`)
   - `MaterialLoadingIndicatorProperties.strokeAlign`, `trackGap`
-  - `ExpansionTileProperties.showTrailingIcon`
+  - `ExpansionTileProperties.showTrailingIcon`, `shape`, `collapsedShape`,
+    `cornerRadius`
   - `TextMixin.softWrap`
 - Document the Flutter replacements for deprecated `cacheExtent`
   (`scrollCacheExtent`) and `Radio.groupValue` (`RadioGroup`).

lib/src/api/nodes/expansion_tile_node.dart

@@ -230,6 +230,17 @@ class ExpansionTileProperties extends CustomProperties with FieldsHolder {
   /// `ExpansionTile.showTrailingIcon`.
   bool showTrailingIcon;
 
+  /// Border shape of the tile when expanded. When set, it replaces the
+  /// dividers drawn by [showDividers]. Mirrors `ExpansionTile.shape`.
+  CShapeBorder? shape;
+
+  /// Border shape of the tile when collapsed. When set, it replaces the
+  /// dividers drawn by [showDividers]. Mirrors `ExpansionTile.collapsedShape`.
+  CShapeBorder? collapsedShape;
+
+  /// Corner radius applied to [shape] and [collapsedShape].
+  CornerRadius cornerRadius;
+
   /// Platform or null affinity defaults to trailing.
   ListTileControlAffinityC effectiveAffinity(
     ListTileControlAffinityC? affinity,
@@ -261,6 +272,9 @@ class ExpansionTileProperties extends CustomProperties with FieldsHolder {
     this.visualDensity = VisualDensityModel.standard,
     this.showDividers = true,
     this.showTrailingIcon = true,
+    this.shape,
+    this.collapsedShape,
+    this.cornerRadius = CornerRadius.zero,
   });
 
   /// Duplicates this [ExpansionTileProperties] instance with given data
@@ -282,6 +296,9 @@ class ExpansionTileProperties extends CustomProperties with FieldsHolder {
     VisualDensityModel? visualDensity,
     bool? showDividers,
     bool? showTrailingIcon,
+    CShapeBorder? shape,
+    CShapeBorder? collapsedShape,
+    CornerRadius? cornerRadius,
   }) {
     return ExpansionTileProperties(
       backgroundColor: backgroundColor ?? this.backgroundColor,
@@ -302,6 +319,9 @@ class ExpansionTileProperties extends CustomProperties with FieldsHolder {
       visualDensity: visualDensity ?? this.visualDensity,
       showDividers: showDividers ?? this.showDividers,
       showTrailingIcon: showTrailingIcon ?? this.showTrailingIcon,
+      shape: shape ?? this.shape,
+      collapsedShape: collapsedShape ?? this.collapsedShape,
+      cornerRadius: cornerRadius ?? this.cornerRadius,
     );
   }
 
@@ -406,6 +426,28 @@ class ExpansionTileProperties extends CustomProperties with FieldsHolder {
       () => showTrailingIcon,
       (value) => showTrailingIcon = value,
     ),
+    'shape': EnumFieldAccess<CShapeBorder?>(
+      'Shape',
+      'Border shape of the tile when expanded.',
+      () => shape,
+      (value) => shape = value,
+      defaultValue: () => null,
+      options: () => CShapeBorder.values,
+    ),
+    'collapsedShape': EnumFieldAccess<CShapeBorder?>(
+      'Collapsed Shape',
+      'Border shape of the tile when collapsed.',
+      () => collapsedShape,
+      (value) => collapsedShape = value,
+      defaultValue: () => null,
+      options: () => CShapeBorder.values,
+    ),
+    'cornerRadius': RadiusFieldAccess(
+      'Corner Radius',
+      'Corner radius applied to the shapes.',
+      () => cornerRadius,
+      (value) => cornerRadius = value,
+    ),
   };
 
   @override
@@ -426,6 +468,9 @@ class ExpansionTileProperties extends CustomProperties with FieldsHolder {
     visualDensity,
     showDividers,
     showTrailingIcon,
+    shape,
+    collapsedShape,
+    cornerRadius,
   ];
 
   @override

lib/src/api/nodes/expansion_tile_node.g.dart

@@ -226,6 +226,14 @@ void main() {
         ExpansionTileProperties(showTrailingIcon: false).toJson(),
       );
       expect(copy.showTrailingIcon, isFalse);
+      final shaped = ExpansionTileProperties.fromJson(
+        ExpansionTileProperties(
+          shape: CShapeBorder.roundedRectangle,
+          cornerRadius: CornerRadius.zero,
+        ).toJson(),
+      );
+      expect(shaped.shape, CShapeBorder.roundedRectangle);
+      expect(shaped.collapsedShape, isNull);
     });
 
     test('TextNode.softWrap', () {