modal bottom sheet barrier label (#126431)

Adds barrierLabel as optional param in showModalBottomSheet

Fixes #83180

packages/flutter/lib/src/material/bottom_sheet.dart

@@ -1152,6 +1152,9 @@ class _BottomSheetSuspendedCurve extends ParametricCurve<double> {
 /// Returns a `Future` that resolves to the value (if any) that was passed to
 /// [Navigator.pop] when the modal bottom sheet was closed.
 ///
+/// The 'barrierLabel' parameter can be used to set a custom barrierlabel.
+/// Will default to modalBarrierDismissLabel of context if not set.
+///
 /// {@tool dartpad}
 /// This example demonstrates how to use [showModalBottomSheet] to display a
 /// bottom sheet that obscures the content behind it when a user taps a button.
@@ -1184,6 +1187,7 @@ Future<T?> showModalBottomSheet<T>({
   required BuildContext context,
   required WidgetBuilder builder,
   Color? backgroundColor,
+  String? barrierLabel,
   double? elevation,
   ShapeBorder? shape,
   Clip? clipBehavior,
@@ -1208,7 +1212,7 @@ Future<T?> showModalBottomSheet<T>({
     builder: builder,
     capturedThemes: InheritedTheme.capture(from: context, to: navigator.context),
     isScrollControlled: isScrollControlled,
-    barrierLabel: localizations.scrimLabel,
+    barrierLabel: barrierLabel ?? localizations.scrimLabel,
     barrierOnTapHint: localizations.scrimOnTapHint(localizations.bottomSheetLabel),
     backgroundColor: backgroundColor,
     elevation: elevation,

packages/flutter/test/material/bottom_sheet_test.dart

@@ -1999,6 +1999,58 @@ void main() {
     });
 
   });
+
+  group('showModalBottomSheet modalBarrierDismissLabel', () {
+    testWidgets('Verify that modalBarrierDismissLabel is used if provided',
+        (WidgetTester tester) async {
+      final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();
+      const String customLabel = 'custom label';
+      await tester.pumpWidget(MaterialApp(
+        home: Scaffold(
+          key: scaffoldKey,
+          body: const Center(child: Text('body')),
+        ),
+      ));
+
+      showModalBottomSheet<void>(
+        barrierLabel: 'custom label',
+        context: scaffoldKey.currentContext!,
+        builder: (BuildContext context) {
+          return const Text('BottomSheet');
+        },
+      );
+      await tester.pump();
+      await tester.pump(const Duration(seconds: 1));
+
+      final ModalBarrier modalBarrier =
+          tester.widget(find.byType(ModalBarrier).last);
+      expect(modalBarrier.semanticsLabel, customLabel);
+    });
+
+    testWidgets('Verify that modalBarrierDismissLabel from context is used if barrierLabel is not provided',
+        (WidgetTester tester) async {
+      final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();
+      await tester.pumpWidget(MaterialApp(
+        home: Scaffold(
+          key: scaffoldKey,
+          body: const Center(child: Text('body')),
+        ),
+      ));
+
+      showModalBottomSheet<void>(
+        context: scaffoldKey.currentContext!,
+        builder: (BuildContext context) {
+          return const Text('BottomSheet');
+        },
+      );
+      await tester.pump();
+      await tester.pump(const Duration(seconds: 1));
+
+      final ModalBarrier modalBarrier =
+          tester.widget(find.byType(ModalBarrier).last);
+      expect(modalBarrier.semanticsLabel, MaterialLocalizations.of(scaffoldKey.currentContext!).scrimLabel);
+    });
+  });
 }
 
 class _TestPage extends StatelessWidget {