Add childrenForSemantics to delegate

boxy/CHANGELOG.md

@@ -1,3 +1,6 @@
+## [2.3.0]
+* Added `BoxyDelegate.childrenForSemantics` for customizing the semantics order, thanks Albert221 for the PR!
+
 ## [2.2.2]
 * Fixed bug in CustomBoxy that prevented multiple Slivers from being used
 

boxy/example/ios/.gitignore

@@ -22,6 +22,7 @@ Flutter/app.flx
 Flutter/app.zip
 Flutter/flutter_assets/
 Flutter/flutter_export_environment.sh
+Flutter/ephemeral
 ServiceDefinitions.json
 Runner/GeneratedPluginRegistrant.*
 

boxy/lib/src/boxy/custom_boxy_base.dart

@@ -236,11 +236,11 @@ mixin RenderBoxyMixin<
 
   @override
   void visitChildrenForSemantics(RenderObjectVisitor visitor) {
-    for (final child in childHandleMap.values) {
-      if (!child._ignore) {
+    wrapPhase(BoxyDelegatePhase.semantics, () {
+      for (final child in delegate.childrenForSemantics) {
         visitor(child.render);
       }
-    }
+    });
   }
 
   @override
@@ -293,6 +293,9 @@ enum BoxyDelegatePhase {
 
   /// The boxy is currently being hit test.
   hitTest,
+
+  /// The boxy is currently being visited for semantics.
+  semantics,
 }
 
 /// Cache for [Layer] objects, used by [BoxyLayerContext] methods.
@@ -963,6 +966,20 @@ abstract class BaseBoxyDelegate<LayoutData extends Object,
     return out;
   }
 
+  /// An iterable of children to be visited for semantics, in paint order,
+  /// skipping children that are not semantically relevant.
+  ///
+  /// Override this to customize the semantics traversal order.
+  /// By default, returns [children] in paint order, filtering out
+  /// ignored children.
+  Iterable<ChildHandleType> get childrenForSemantics sync* {
+    for (final child in children) {
+      if (!child._ignore) {
+        yield child;
+      }
+    }
+  }
+
   /// The most recent constraints given to this boxy by its parent.
   Constraints get constraints;
 

boxy/pubspec.yaml

@@ -1,6 +1,6 @@
 name: boxy
 description: Overcome limitations of built-in layouts, advanced flex, custom multi-child layouts, slivers, and more!
-version: 2.2.2
+version: 2.3.0
 homepage: https://github.com/pingbird/boxy
 documentation: https://boxy.wiki
 

boxy/test/boxy_semantics_test.dart

@@ -0,0 +1,224 @@
+import 'package:boxy/boxy.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'common.dart';
+
+/// A simple delegate that lays out children in a column.
+class SimpleDelegate extends BoxyDelegate {
+  @override
+  Size layout() {
+    double y = 0;
+    double maxWidth = 0;
+    for (final child in children) {
+      final size = child.layout(constraints);
+      child.position(Offset(0, y));
+      y += size.height;
+      if (size.width > maxWidth) {
+        maxWidth = size.width;
+      }
+    }
+    return Size(maxWidth, y);
+  }
+}
+
+/// A delegate that reverses the children order for paint/hit-test.
+class ReversedChildrenDelegate extends BoxyDelegate {
+  @override
+  Size layout() {
+    double y = 0;
+    double maxWidth = 0;
+    for (final child in children) {
+      final size = child.layout(constraints);
+      child.position(Offset(0, y));
+      y += size.height;
+      if (size.width > maxWidth) {
+        maxWidth = size.width;
+      }
+    }
+    return Size(maxWidth, y);
+  }
+
+  @override
+  List<BoxyChild> get children => super.children.reversed.toList();
+}
+
+/// A delegate that provides custom semantics order independent of children.
+class CustomSemanticsDelegate extends BoxyDelegate {
+  @override
+  Size layout() {
+    double y = 0;
+    double maxWidth = 0;
+    for (final child in children) {
+      final size = child.layout(constraints);
+      child.position(Offset(0, y));
+      y += size.height;
+      if (size.width > maxWidth) {
+        maxWidth = size.width;
+      }
+    }
+    return Size(maxWidth, y);
+  }
+
+  @override
+  Iterable<BoxyChild> get childrenForSemantics sync* {
+    // Return only the second child for semantics
+    final allChildren = super.children;
+    if (allChildren.length > 1) {
+      yield allChildren[1];
+    }
+  }
+}
+
+/// Collects children visited by visitChildrenForSemantics.
+List<RenderObject> getSemanticsChildren(RenderObject renderObject) {
+  final children = <RenderObject>[];
+  renderObject.visitChildrenForSemantics(children.add);
+  return children;
+}
+
+void main() {
+  testWidgets(
+    'Default childrenForSemantics returns children in paint order',
+    (tester) async {
+      await tester.pumpWidget(
+        TestFrame(
+          child: CustomBoxy(
+            key: const GlobalObjectKey(#boxy),
+            delegate: SimpleDelegate(),
+            children: const [
+              BoxyId(
+                id: #first,
+                child: SizedBox(
+                  key: GlobalObjectKey(#first),
+                  width: 100,
+                  height: 50,
+                ),
+              ),
+              BoxyId(
+                id: #second,
+                child: SizedBox(
+                  key: GlobalObjectKey(#second),
+                  width: 100,
+                  height: 50,
+                ),
+              ),
+              BoxyId(
+                id: #third,
+                child: SizedBox(
+                  key: GlobalObjectKey(#third),
+                  width: 100,
+                  height: 50,
+                ),
+              ),
+            ],
+          ),
+        ),
+      );
+
+      final boxyRender = keyBox(#boxy);
+      final semanticsChildren = getSemanticsChildren(boxyRender);
+
+      expect(semanticsChildren.length, 3);
+      expect(semanticsChildren[0], keyBox(#first));
+      expect(semanticsChildren[1], keyBox(#second));
+      expect(semanticsChildren[2], keyBox(#third));
+    },
+  );
+
+  testWidgets(
+    'Overriding children affects childrenForSemantics',
+    (tester) async {
+      await tester.pumpWidget(
+        TestFrame(
+          child: CustomBoxy(
+            key: const GlobalObjectKey(#boxy),
+            delegate: ReversedChildrenDelegate(),
+            children: const [
+              BoxyId(
+                id: #first,
+                child: SizedBox(
+                  key: GlobalObjectKey(#first),
+                  width: 100,
+                  height: 50,
+                ),
+              ),
+              BoxyId(
+                id: #second,
+                child: SizedBox(
+                  key: GlobalObjectKey(#second),
+                  width: 100,
+                  height: 50,
+                ),
+              ),
+              BoxyId(
+                id: #third,
+                child: SizedBox(
+                  key: GlobalObjectKey(#third),
+                  width: 100,
+                  height: 50,
+                ),
+              ),
+            ],
+          ),
+        ),
+      );
+
+      final boxyRender = keyBox(#boxy);
+      final semanticsChildren = getSemanticsChildren(boxyRender);
+
+      // Semantics should follow the reversed children order
+      expect(semanticsChildren.length, 3);
+      expect(semanticsChildren[0], keyBox(#third));
+      expect(semanticsChildren[1], keyBox(#second));
+      expect(semanticsChildren[2], keyBox(#first));
+    },
+  );
+
+  testWidgets(
+    'Overriding childrenForSemantics customizes semantics order',
+    (tester) async {
+      await tester.pumpWidget(
+        TestFrame(
+          child: CustomBoxy(
+            key: const GlobalObjectKey(#boxy),
+            delegate: CustomSemanticsDelegate(),
+            children: const [
+              BoxyId(
+                id: #first,
+                child: SizedBox(
+                  key: GlobalObjectKey(#first),
+                  width: 100,
+                  height: 50,
+                ),
+              ),
+              BoxyId(
+                id: #second,
+                child: SizedBox(
+                  key: GlobalObjectKey(#second),
+                  width: 100,
+                  height: 50,
+                ),
+              ),
+              BoxyId(
+                id: #third,
+                child: SizedBox(
+                  key: GlobalObjectKey(#third),
+                  width: 100,
+                  height: 50,
+                ),
+              ),
+            ],
+          ),
+        ),
+      );
+
+      final boxyRender = keyBox(#boxy);
+      final semanticsChildren = getSemanticsChildren(boxyRender);
+
+      // Only the second child should be in semantics
+      expect(semanticsChildren.length, 1);
+      expect(semanticsChildren[0], keyBox(#second));
+    },
+  );
+}