[Focus] Add run key command to dump the focus tree (#123473)

[Focus] Add run key command to dump the focus tree

Author: loic-sharma

dev/integration_tests/flutter_gallery/test/smoke_test.dart

@@ -81,6 +81,7 @@ Future<void> smokeDemo(WidgetTester tester, GalleryDemo demo) async {
   verifyToStringOutput('debugDumpApp', routeName, WidgetsBinding.instance.rootElement!.toStringDeep());
   verifyToStringOutput('debugDumpRenderTree', routeName, RendererBinding.instance.renderView.toStringDeep());
   verifyToStringOutput('debugDumpLayerTree', routeName, RendererBinding.instance.renderView.debugLayer?.toStringDeep() ?? '');
+  verifyToStringOutput('debugDumpFocusTree', routeName, WidgetsBinding.instance.focusManager.toStringDeep());
 
   // Scroll the demo around a bit more.
   await tester.flingFrom(const Offset(400.0, 300.0), const Offset(0.0, 400.0), 1000.0);

packages/flutter/lib/src/rendering/service_extensions.dart

@@ -68,7 +68,6 @@ enum RenderingServiceExtensions {
   ///   registered.
   debugDumpLayerTree,
 
-
   /// Name of service extension that, when called, will toggle whether all
   /// clipping effects from the layer tree will be ignored.
   ///

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

@@ -386,6 +386,16 @@ mixin WidgetsBinding on BindingBase, ServicesBinding, SchedulerBinding, GestureB
         },
       );
 
+      registerServiceExtension(
+        name: WidgetsServiceExtensions.debugDumpFocusTree.name,
+        callback: (Map<String, String> parameters) async {
+          final String data = focusManager.toStringDeep();
+          return <String, Object>{
+            'data': data,
+          };
+        },
+      );
+
       if (!kIsWeb) {
         registerBoolServiceExtension(
           name: WidgetsServiceExtensions.showPerformanceOverlay.name,

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

@@ -20,6 +20,15 @@ enum WidgetsServiceExtensions {
   ///   registered.
   debugDumpApp,
 
+  /// Name of service extension that, when called, will output a string
+  /// representation of the focus tree to the console.
+  ///
+  /// See also:
+  ///
+  /// * [WidgetsBinding.initServiceExtensions], where the service extension is
+  ///   registered.
+  debugDumpFocusTree,
+
   /// Name of service extension that, when called, will overlay a performance
   /// graph on top of this app.
   ///

packages/flutter/test/foundation/service_extensions_test.dart

@@ -177,7 +177,7 @@ void main() {
     // framework, excluding any that are for the widget inspector
     // (see widget_inspector_test.dart for tests of the ext.flutter.inspector
     // service extensions).
-    const int serviceExtensionCount = 37;
+    const int serviceExtensionCount = 38;
 
     expect(binding.extensions.length, serviceExtensionCount + widgetInspectorExtensionCount - disabledExtensions);
 
@@ -218,6 +218,19 @@ void main() {
     });
   });
 
+  test('Service extensions - debugDumpFocusTree', () async {
+    final Map<String, dynamic> result = await binding.testExtension(WidgetsServiceExtensions.debugDumpFocusTree.name, <String, String>{});
+
+    expect(result, <String, dynamic>{
+      'data': matches(
+        r'^'
+        r'FocusManager#[0-9a-f]{5}\n'
+        r' └─rootScope: FocusScopeNode#[0-9a-f]{5}\(Root Focus Scope\)\n'
+        r'$',
+      ),
+    });
+  });
+
   test('Service extensions - debugDumpRenderTree', () async {
     await binding.doFrame();
     final Map<String, dynamic> result = await binding.testExtension(RenderingServiceExtensions.debugDumpRenderTree.name, <String, String>{});

packages/flutter_tools/lib/src/base/command_help.dart

@@ -97,6 +97,12 @@ class CommandHelp {
     'Detach (terminate "flutter run" but leave application running).',
   );
 
+  late final CommandHelpOption f = _makeOption(
+    'f',
+    'Dump focus tree to the console.',
+    'debugDumpFocusTree',
+  );
+
   late final CommandHelpOption g = _makeOption(
     'g',
     'Run source code generators.'

packages/flutter_tools/lib/src/resident_runner.dart

@@ -752,6 +752,22 @@ abstract class ResidentHandlers {
     return true;
   }
 
+  Future<bool> debugDumpFocusTree() async {
+    if (!supportsServiceProtocol || !isRunningDebug) {
+      return false;
+    }
+    for (final FlutterDevice? device in flutterDevices) {
+      final List<FlutterView> views = await device!.vmService!.getFlutterViews();
+      for (final FlutterView view in views) {
+        final String data = await device.vmService!.flutterDebugDumpFocusTree(
+          isolateId: view.uiIsolate!.id!,
+        );
+        logger.printStatus(data);
+      }
+    }
+    return true;
+  }
+
   /// Dump the application's current semantics tree to the terminal.
   ///
   /// If semantics are not enabled, nothing is returned.
@@ -1521,6 +1537,7 @@ abstract class ResidentRunner extends ResidentHandlers {
       commandHelp.t.print();
       if (isRunningDebug) {
         commandHelp.L.print();
+        commandHelp.f.print();
         commandHelp.S.print();
         commandHelp.U.print();
         commandHelp.i.print();
@@ -1706,6 +1723,8 @@ class TerminalHandler {
       case 'D':
         await residentRunner.detach();
         return true;
+      case 'f':
+        return residentRunner.debugDumpFocusTree();
       case 'g':
         await residentRunner.runSourceGenerators();
         return true;

packages/flutter_tools/lib/src/vmservice.dart

@@ -643,6 +643,16 @@ class FlutterVmService {
     return response?['data']?.toString() ?? '';
   }
 
+  Future<String> flutterDebugDumpFocusTree({
+    required String isolateId,
+  }) async {
+    final Map<String, Object?>? response = await invokeFlutterExtensionRpcRaw(
+      'ext.flutter.debugDumpFocusTree',
+      isolateId: isolateId,
+    );
+    return response?['data']?.toString() ?? '';
+  }
+
   Future<String> flutterDebugDumpSemanticsTreeInTraversalOrder({
     required String isolateId,
   }) async {

packages/flutter_tools/test/general.shard/base/command_help_test.dart

@@ -60,6 +60,7 @@ void _testMessageLength({
   expect(commandHelp.b.toString().length, lessThanOrEqualTo(expectedWidth));
   expect(commandHelp.c.toString().length, lessThanOrEqualTo(expectedWidth));
   expect(commandHelp.d.toString().length, lessThanOrEqualTo(expectedWidth));
+  expect(commandHelp.f.toString().length, lessThanOrEqualTo(expectedWidth));
   expect(commandHelp.g.toString().length, lessThanOrEqualTo(expectedWidth));
   expect(commandHelp.hWithDetails.toString().length, lessThanOrEqualTo(expectedWidth));
   expect(commandHelp.hWithoutDetails.toString().length, lessThanOrEqualTo(expectedWidth));
@@ -137,6 +138,7 @@ void main() {
         expect(commandHelp.U.toString(), endsWith('\x1B[90m(debugDumpSemantics)\x1B[39m\x1B[22m'));
         expect(commandHelp.a.toString(), endsWith('\x1B[90m(debugProfileWidgetBuilds)\x1B[39m\x1B[22m'));
         expect(commandHelp.b.toString(), endsWith('\x1B[90m(debugBrightnessOverride)\x1B[39m\x1B[22m'));
+        expect(commandHelp.f.toString(), endsWith('\x1B[90m(debugDumpFocusTree)\x1B[39m\x1B[22m'));
         expect(commandHelp.i.toString(), endsWith('\x1B[90m(WidgetsApp.showWidgetInspectorOverride)\x1B[39m\x1B[22m'));
         expect(commandHelp.o.toString(), endsWith('\x1B[90m(defaultTargetPlatform)\x1B[39m\x1B[22m'));
         expect(commandHelp.p.toString(), endsWith('\x1B[90m(debugPaintSizeEnabled)\x1B[39m\x1B[22m'));
@@ -193,6 +195,7 @@ void main() {
         expect(commandHelp.b.toString(), equals('\x1B[1mb\x1B[22m Toggle platform brightness (dark and light mode).        \x1B[90m(debugBrightnessOverride)\x1B[39m\x1B[22m'));
         expect(commandHelp.c.toString(), equals('\x1B[1mc\x1B[22m Clear the screen'));
         expect(commandHelp.d.toString(), equals('\x1B[1md\x1B[22m Detach (terminate "flutter run" but leave application running).'));
+        expect(commandHelp.f.toString(), equals('\x1B[1mf\x1B[22m Dump focus tree to the console.                               \x1B[90m(debugDumpFocusTree)\x1B[39m\x1B[22m'));
         expect(commandHelp.g.toString(), equals('\x1B[1mg\x1B[22m Run source code generators.'));
         expect(commandHelp.hWithDetails.toString(), equals('\x1B[1mh\x1B[22m Repeat this help message.'));
         expect(commandHelp.hWithoutDetails.toString(), equals('\x1B[1mh\x1B[22m List all available interactive commands.'));

packages/flutter_tools/test/general.shard/resident_runner_test.dart

@@ -1455,6 +1455,7 @@ flutter:
           commandHelp.w,
           commandHelp.t,
           commandHelp.L,
+          commandHelp.f,
           commandHelp.S,
           commandHelp.U,
           commandHelp.i,

packages/flutter_tools/test/general.shard/terminal_handler_test.dart

@@ -400,6 +400,52 @@ void main() {
       await terminalHandler.processTerminalInput('L');
     });
 
+    testWithoutContext('f - debugDumpFocusTree', () async {
+      final TerminalHandler terminalHandler = setUpTerminalHandler(<FakeVmServiceRequest>[
+        listViews,
+        const FakeVmServiceRequest(
+          method: 'ext.flutter.debugDumpFocusTree',
+          args: <String, Object>{
+            'isolateId': '1',
+          },
+          jsonResponse: <String, Object>{
+            'data': 'FOCUS TREE',
+          }
+        ),
+      ]);
+      await terminalHandler.processTerminalInput('f');
+
+      expect(terminalHandler.logger.statusText, contains('FOCUS TREE'));
+    });
+
+    testWithoutContext('f - debugDumpLayerTree with web target', () async {
+      final TerminalHandler terminalHandler = setUpTerminalHandler(<FakeVmServiceRequest>[
+        listViews,
+        const FakeVmServiceRequest(
+          method: 'ext.flutter.debugDumpFocusTree',
+          args: <String, Object>{
+            'isolateId': '1',
+          },
+          jsonResponse: <String, Object>{
+            'data': 'FOCUS TREE',
+          }
+        ),
+      ], web: true);
+      await terminalHandler.processTerminalInput('f');
+
+      expect(terminalHandler.logger.statusText, contains('FOCUS TREE'));
+    });
+
+    testWithoutContext('f - debugDumpFocusTree with service protocol and profile mode is skipped', () async {
+      final TerminalHandler terminalHandler = setUpTerminalHandler(<FakeVmServiceRequest>[], buildMode: BuildMode.profile);
+      await terminalHandler.processTerminalInput('f');
+    });
+
+    testWithoutContext('f - debugDumpFocusTree without service protocol is skipped', () async {
+      final TerminalHandler terminalHandler = setUpTerminalHandler(<FakeVmServiceRequest>[], supportsServiceProtocol: false);
+      await terminalHandler.processTerminalInput('f');
+    });
+
     testWithoutContext('o,O - debugTogglePlatform', () async {
       final TerminalHandler terminalHandler = setUpTerminalHandler(<FakeVmServiceRequest>[
         // Request 1.

packages/flutter_tools/test/general.shard/vmservice_test.dart

@@ -447,6 +447,46 @@ void main() {
     expect(fakeVmServiceHost.hasRemainingExpectations, false);
   });
 
+  testWithoutContext('flutterDebugDumpFocusTree handles missing method', () async {
+    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(
+      requests: <VmServiceExpectation>[
+        const FakeVmServiceRequest(
+          method: 'ext.flutter.debugDumpFocusTree',
+          args: <String, Object>{
+            'isolateId': '1',
+          },
+          errorCode: RPCErrorCodes.kMethodNotFound,
+        ),
+      ]
+    );
+
+    expect(await fakeVmServiceHost.vmService.flutterDebugDumpFocusTree(
+      isolateId: '1',
+    ), '');
+    expect(fakeVmServiceHost.hasRemainingExpectations, false);
+  });
+
+  testWithoutContext('flutterDebugDumpFocusTree returns data', () async {
+    final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(
+      requests: <VmServiceExpectation>[
+        const FakeVmServiceRequest(
+          method: 'ext.flutter.debugDumpFocusTree',
+          args: <String, Object>{
+            'isolateId': '1',
+          },
+          jsonResponse: <String, Object> {
+            'data': 'Hello world',
+          },
+        ),
+      ]
+    );
+
+    expect(await fakeVmServiceHost.vmService.flutterDebugDumpFocusTree(
+      isolateId: '1',
+    ), 'Hello world');
+    expect(fakeVmServiceHost.hasRemainingExpectations, false);
+  });
+
   testWithoutContext('Framework service extension invocations return null if service disappears ', () async {
     final FakeVmServiceHost fakeVmServiceHost = FakeVmServiceHost(
       requests: <VmServiceExpectation>[

packages/flutter_tools/test/integration.shard/overall_experience_test.dart

@@ -604,6 +604,7 @@ void main() {
       'w Dump widget hierarchy to the console.                                               (debugDumpApp)',
       't Dump rendering tree to the console.                                          (debugDumpRenderTree)',
       'L Dump layer tree to the console.                                               (debugDumpLayerTree)',
+      'f Dump focus tree to the console.                                               (debugDumpFocusTree)',
       'S Dump accessibility tree in traversal order.                                   (debugDumpSemantics)',
       'U Dump accessibility tree in inverse hit test order.                            (debugDumpSemantics)',
       'i Toggle widget inspector.                                  (WidgetsApp.showWidgetInspectorOverride)',