SelectionArea on iOS should toggle the context menu when tapping on the previous selection (#132851)

https://github.com/flutter/flutter/assets/948037/210fdee4-d922-422b-a257-4ee586a3814f

Related: https://github.com/flutter/flutter/issues/129583

packages/flutter/lib/src/widgets/selectable_region.dart

@@ -341,7 +341,20 @@ class SelectableRegionState extends State<SelectableRegion> with TextSelectionDe
     _gestureRecognizers[TapGestureRecognizer] = GestureRecognizerFactoryWithHandlers<TapGestureRecognizer>(
           () => TapGestureRecognizer(debugOwner: this),
           (TapGestureRecognizer instance) {
-        instance.onTap = _clearSelection;
+        instance.onTapUp = (TapUpDetails details) {
+          if (defaultTargetPlatform == TargetPlatform.iOS && _positionIsOnActiveSelection(globalPosition: details.globalPosition)) {
+            // On iOS when the tap occurs on the previous selection, instead of
+            // moving the selection, the context menu will be toggled.
+            final bool toolbarIsVisible = _selectionOverlay?.toolbarIsVisible ?? false;
+            if (toolbarIsVisible) {
+              hideToolbar(false);
+            } else {
+              _showToolbar(location: details.globalPosition);
+            }
+          } else {
+            _clearSelection();
+          }
+        };
         instance.onSecondaryTapDown = _handleRightClickDown;
       },
     );

packages/flutter/test/widgets/selectable_region_test.dart

@@ -886,6 +886,78 @@ void main() {
       await gesture.up();
     });
 
+    testWidgets(
+      'single tap on the previous selection toggles the toolbar on iOS',
+      (WidgetTester tester) async {
+        Set<ContextMenuButtonType> buttonTypes = <ContextMenuButtonType>{};
+        final UniqueKey toolbarKey = UniqueKey();
+        await tester.pumpWidget(
+          MaterialApp(
+            home: SelectableRegion(
+              focusNode: FocusNode(),
+              selectionControls: materialTextSelectionHandleControls,
+              contextMenuBuilder: (
+                BuildContext context,
+                SelectableRegionState selectableRegionState,
+              ) {
+                buttonTypes = selectableRegionState.contextMenuButtonItems
+                  .map((ContextMenuButtonItem buttonItem) => buttonItem.type)
+                  .toSet();
+                return SizedBox.shrink(key: toolbarKey);
+              },
+              child: const Column(
+                children: <Widget>[
+                  Text('How are you?'),
+                  Text('Good, and you?'),
+                  Text('Fine, thank you.'),
+                ],
+              ),
+            ),
+          ),
+        );
+
+        expect(buttonTypes.isEmpty, true);
+        expect(find.byKey(toolbarKey), findsNothing);
+
+        final RenderParagraph paragraph = tester.renderObject<RenderParagraph>(find.descendant(of: find.text('How are you?'), matching: find.byType(RichText)));
+        final TestGesture gesture = await tester.startGesture(textOffsetToPosition(paragraph, 2));
+        addTearDown(gesture.removePointer);
+        await tester.pump(const Duration(milliseconds: 500));
+        await gesture.up();
+        await tester.pumpAndSettle();
+        expect(paragraph.selections[0], const TextSelection(baseOffset: 0, extentOffset: 3));
+        expect(buttonTypes, contains(ContextMenuButtonType.copy));
+        expect(buttonTypes, contains(ContextMenuButtonType.selectAll));
+        expect(find.byKey(toolbarKey), findsOneWidget);
+
+        await gesture.down(textOffsetToPosition(paragraph, 2));
+        await tester.pump();
+        await gesture.up();
+        await tester.pumpAndSettle();
+        expect(paragraph.selections[0], const TextSelection(baseOffset: 0, extentOffset: 3));
+        expect(buttonTypes, contains(ContextMenuButtonType.copy));
+        expect(buttonTypes, contains(ContextMenuButtonType.selectAll));
+        expect(find.byKey(toolbarKey), findsNothing);
+
+        await gesture.down(textOffsetToPosition(paragraph, 2));
+        await tester.pump();
+        await gesture.up();
+        await tester.pumpAndSettle();
+        expect(paragraph.selections[0], const TextSelection(baseOffset: 0, extentOffset: 3));
+        expect(buttonTypes, contains(ContextMenuButtonType.copy));
+        expect(buttonTypes, contains(ContextMenuButtonType.selectAll));
+        expect(find.byKey(toolbarKey), findsOneWidget);
+
+        // Clear selection.
+        await tester.tapAt(textOffsetToPosition(paragraph, 9));
+        await tester.pump();
+        expect(paragraph.selections.isEmpty, true);
+        expect(find.byKey(toolbarKey), findsNothing);
+      },
+      variant: TargetPlatformVariant.only(TargetPlatform.iOS),
+      skip: kIsWeb, // [intended] Web uses its native context menu.
+    );
+
     testWidgets(
       'right-click mouse can select word at position on Apple platforms',
       (WidgetTester tester) async {