Make CupertinoButton interactive by keyboard shortcuts (flutter#153126)

This should have been added with flutter#150721.

Author: victorsanni

packages/flutter/lib/src/cupertino/button.dart

@@ -6,6 +6,7 @@
 library;
 
 import 'package:flutter/foundation.dart';
+import 'package:flutter/semantics.dart';
 import 'package:flutter/widgets.dart';
 
 import 'colors.dart';
@@ -300,6 +301,13 @@ class _CupertinoButtonState extends State<CupertinoButton> with SingleTickerProv
     }
   }
 
+  void _handleTap([Intent? _]) {
+    if (widget.onPressed != null) {
+      widget.onPressed!();
+      context.findRenderObject()!.sendSemanticsEvent(const TapSemanticEvent());
+    }
+  }
+
   void _animate() {
     if (_animationController.isAnimating) {
       return;
@@ -321,6 +329,10 @@ class _CupertinoButtonState extends State<CupertinoButton> with SingleTickerProv
     });
   }
 
+  late final Map<Type, Action<Intent>> _actionMap = <Type, Action<Intent>>{
+    ActivateIntent: CallbackAction<ActivateIntent>(onInvoke: _handleTap),
+  };
+
   @override
   Widget build(BuildContext context) {
     final bool enabled = widget.enabled;
@@ -368,6 +380,7 @@ class _CupertinoButtonState extends State<CupertinoButton> with SingleTickerProv
     return MouseRegion(
       cursor: enabled && kIsWeb ? SystemMouseCursors.click : MouseCursor.defer,
       child: FocusableActionDetector(
+        actions: _actionMap,
         focusNode: widget.focusNode,
         autofocus: widget.autofocus,
         onFocusChange: widget.onFocusChange,

packages/flutter/test/cupertino/button_test.dart

@@ -7,6 +7,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/scheduler.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import '../widgets/semantics_tester.dart';
@@ -731,6 +732,41 @@ void main() {
       ),
     );
   });
+
+  testWidgets('Button can be activated by keyboard shortcuts', (WidgetTester tester) async {
+    tester.binding.focusManager.highlightStrategy = FocusHighlightStrategy.alwaysTraditional;
+    bool value = true;
+    await tester.pumpWidget(CupertinoApp(
+        home: Center(
+          child: StatefulBuilder(builder: (BuildContext context, StateSetter setState) {
+            return CupertinoButton(
+              onPressed: () {
+                setState(() {
+                  value = !value;
+                });
+              },
+              autofocus: true,
+              child: const Text('Tap me'),
+            );
+          }),
+        ),
+      ),
+    );
+    await tester.pump();
+    await tester.sendKeyEvent(LogicalKeyboardKey.enter);
+    await tester.pump();
+    // On web, buttons don't respond to the enter key.
+    expect(value, kIsWeb ? isTrue : isFalse);
+    await tester.sendKeyEvent(LogicalKeyboardKey.enter);
+    await tester.pump();
+    expect(value, isTrue);
+    await tester.sendKeyEvent(LogicalKeyboardKey.space);
+    await tester.pump();
+    expect(value, isFalse);
+    await tester.sendKeyEvent(LogicalKeyboardKey.space);
+    await tester.pump();
+    expect(value, isTrue);
+  });
 }
 
 Widget boilerplate({ required Widget child }) {