Preliminary implementation of UIA for A11y on Windows

ci/licenses_golden/licenses_flutter

@@ -3277,6 +3277,7 @@ FILE: ../../../flutter/shell/platform/windows/windows_proc_table.cc
 FILE: ../../../flutter/shell/platform/windows/windows_proc_table.h
 FILE: ../../../flutter/shell/platform/windows/windows_registry.cc
 FILE: ../../../flutter/shell/platform/windows/windows_registry.h
+FILE: ../../../flutter/shell/platform/windows/windowsx_shim.h
 FILE: ../../../flutter/shell/profiling/sampling_profiler.cc
 FILE: ../../../flutter/shell/profiling/sampling_profiler.h
 FILE: ../../../flutter/shell/profiling/sampling_profiler_unittest.cc

shell/platform/windows/BUILD.gn

@@ -111,6 +111,7 @@ source_set("flutter_windows_source") {
     "windows_proc_table.h",
     "windows_registry.cc",
     "windows_registry.h",
+    "windowsx_shim.h",
   ]
 
   libs = [

shell/platform/windows/accessibility_bridge_windows.cc

@@ -31,53 +31,67 @@ void AccessibilityBridgeWindows::OnAccessibilityEvent(
 
   switch (event_type) {
     case ui::AXEventGenerator::Event::ALERT:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_SYSTEM_ALERT);
+      DispatchWinAccessibilityEvent(win_delegate, ax::mojom::Event::kAlert);
       break;
     case ui::AXEventGenerator::Event::CHECKED_STATE_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_VALUECHANGE);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kValueChanged);
       break;
     case ui::AXEventGenerator::Event::CHILDREN_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_REORDER);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kChildrenChanged);
+      break;
+    case ui::AXEventGenerator::Event::DOCUMENT_SELECTION_CHANGED:
+      DispatchWinAccessibilityEvent(
+          win_delegate, ax::mojom::Event::kDocumentSelectionChanged);
       break;
     case ui::AXEventGenerator::Event::FOCUS_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_FOCUS);
+      DispatchWinAccessibilityEvent(win_delegate, ax::mojom::Event::kFocus);
       SetFocus(win_delegate);
       break;
     case ui::AXEventGenerator::Event::IGNORED_CHANGED:
       if (ax_node->IsIgnored()) {
-        DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_HIDE);
+        DispatchWinAccessibilityEvent(win_delegate, ax::mojom::Event::kHide);
       }
       break;
     case ui::AXEventGenerator::Event::IMAGE_ANNOTATION_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_NAMECHANGE);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kTextChanged);
       break;
     case ui::AXEventGenerator::Event::LIVE_REGION_CHANGED:
       DispatchWinAccessibilityEvent(win_delegate,
-                                    EVENT_OBJECT_LIVEREGIONCHANGED);
+                                    ax::mojom::Event::kLiveRegionChanged);
       break;
     case ui::AXEventGenerator::Event::NAME_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_NAMECHANGE);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kTextChanged);
       break;
     case ui::AXEventGenerator::Event::SCROLL_HORIZONTAL_POSITION_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_SYSTEM_SCROLLINGEND);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kScrollPositionChanged);
       break;
     case ui::AXEventGenerator::Event::SCROLL_VERTICAL_POSITION_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_SYSTEM_SCROLLINGEND);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kScrollPositionChanged);
       break;
     case ui::AXEventGenerator::Event::SELECTED_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_VALUECHANGE);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kValueChanged);
       break;
     case ui::AXEventGenerator::Event::SELECTED_CHILDREN_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_SELECTIONWITHIN);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kSelectedChildrenChanged);
       break;
     case ui::AXEventGenerator::Event::SUBTREE_CREATED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_SHOW);
+      DispatchWinAccessibilityEvent(win_delegate, ax::mojom::Event::kShow);
       break;
     case ui::AXEventGenerator::Event::VALUE_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_VALUECHANGE);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kValueChanged);
       break;
     case ui::AXEventGenerator::Event::WIN_IACCESSIBLE_STATE_CHANGED:
-      DispatchWinAccessibilityEvent(win_delegate, EVENT_OBJECT_STATECHANGE);
+      DispatchWinAccessibilityEvent(win_delegate,
+                                    ax::mojom::Event::kStateChanged);
       break;
     case ui::AXEventGenerator::Event::ACCESS_KEY_CHANGED:
     case ui::AXEventGenerator::Event::ACTIVE_DESCENDANT_CHANGED:
@@ -90,7 +104,6 @@ void AccessibilityBridgeWindows::OnAccessibilityEvent(
     case ui::AXEventGenerator::Event::CONTROLS_CHANGED:
     case ui::AXEventGenerator::Event::DESCRIBED_BY_CHANGED:
     case ui::AXEventGenerator::Event::DESCRIPTION_CHANGED:
-    case ui::AXEventGenerator::Event::DOCUMENT_SELECTION_CHANGED:
     case ui::AXEventGenerator::Event::DOCUMENT_TITLE_CHANGED:
     case ui::AXEventGenerator::Event::DROPEFFECT_CHANGED:
     case ui::AXEventGenerator::Event::ENABLED_CHANGED:
@@ -151,7 +164,7 @@ AccessibilityBridgeWindows::CreateFlutterPlatformNodeDelegate() {
 
 void AccessibilityBridgeWindows::DispatchWinAccessibilityEvent(
     std::shared_ptr<FlutterPlatformNodeDelegateWindows> node_delegate,
-    DWORD event_type) {
+    ax::mojom::Event event_type) {
   node_delegate->DispatchWinAccessibilityEvent(event_type);
 }
 
@@ -160,4 +173,18 @@ void AccessibilityBridgeWindows::SetFocus(
   node_delegate->SetFocus();
 }
 
+gfx::NativeViewAccessible
+AccessibilityBridgeWindows::GetChildOfAXFragmentRoot() {
+  return view_->GetNativeViewAccessible();
+}
+
+gfx::NativeViewAccessible
+AccessibilityBridgeWindows::GetParentOfAXFragmentRoot() {
+  return nullptr;
+}
+
+bool AccessibilityBridgeWindows::IsAXFragmentRootAControlElement() {
+  return true;
+}
+
 }  // namespace flutter

shell/platform/windows/accessibility_bridge_windows.h

@@ -6,13 +6,12 @@
 #define FLUTTER_SHELL_PLATFORM_WINDOWS_ACCESSIBILITY_BRIDGE_WINDOWS_H_
 
 #include "flutter/shell/platform/common/accessibility_bridge.h"
-
-#include "flutter/shell/platform/windows/flutter_windows_engine.h"
-#include "flutter/shell/platform/windows/flutter_windows_view.h"
+#include "flutter/third_party/accessibility/ax/platform/ax_fragment_root_delegate_win.h"
 
 namespace flutter {
 
 class FlutterWindowsEngine;
+class FlutterWindowsView;
 class FlutterPlatformNodeDelegateWindows;
 
 // The Win32 implementation of AccessibilityBridge.
@@ -24,7 +23,8 @@ class FlutterPlatformNodeDelegateWindows;
 ///
 /// AccessibilityBridgeWindows must be created as a shared_ptr, since some
 /// methods acquires its weak_ptr.
-class AccessibilityBridgeWindows : public AccessibilityBridge {
+class AccessibilityBridgeWindows : public AccessibilityBridge,
+                                   public ui::AXFragmentRootDelegateWin {
  public:
   AccessibilityBridgeWindows(FlutterWindowsEngine* engine,
                              FlutterWindowsView* view);
@@ -41,7 +41,7 @@ class AccessibilityBridgeWindows : public AccessibilityBridge {
   // This is a virtual method for the convenience of unit tests.
   virtual void DispatchWinAccessibilityEvent(
       std::shared_ptr<FlutterPlatformNodeDelegateWindows> node_delegate,
-      DWORD event_type);
+      ax::mojom::Event event_type);
 
   // Sets the accessibility focus to the accessibility node associated with the
   // specified semantics node.
@@ -50,6 +50,15 @@ class AccessibilityBridgeWindows : public AccessibilityBridge {
   virtual void SetFocus(
       std::shared_ptr<FlutterPlatformNodeDelegateWindows> node_delegate);
 
+  // |AXFragmentRootDelegateWin|
+  gfx::NativeViewAccessible GetChildOfAXFragmentRoot() override;
+
+  // |AXFragmentRootDelegateWin|
+  gfx::NativeViewAccessible GetParentOfAXFragmentRoot() override;
+
+  // |AXFragmentRootDelegateWin|
+  bool IsAXFragmentRootAControlElement() override;
+
  protected:
   // |AccessibilityBridge|
   void OnAccessibilityEvent(

shell/platform/windows/accessibility_bridge_windows_unittests.cc

@@ -29,7 +29,7 @@ namespace {
 // A structure representing a Win32 MSAA event targeting a specified node.
 struct MsaaEvent {
   std::shared_ptr<FlutterPlatformNodeDelegateWindows> node_delegate;
-  DWORD event_type;
+  ax::mojom::Event event_type;
 };
 
 // Accessibility bridge delegate that captures events dispatched to the OS.
@@ -43,7 +43,7 @@ class AccessibilityBridgeWindowsSpy : public AccessibilityBridgeWindows {
 
   void DispatchWinAccessibilityEvent(
       std::shared_ptr<FlutterPlatformNodeDelegateWindows> node_delegate,
-      DWORD event_type) override {
+      ax::mojom::Event event_type) override {
     dispatched_events_.push_back({node_delegate, event_type});
   }
 
@@ -76,7 +76,7 @@ class FlutterWindowsEngineSpy : public FlutterWindowsEngine {
       : FlutterWindowsEngine(project) {}
 
  protected:
-  virtual std::shared_ptr<AccessibilityBridge> CreateAccessibilityBridge(
+  virtual std::shared_ptr<AccessibilityBridgeWindows> CreateAccessibilityBridge(
       FlutterWindowsEngine* engine,
       FlutterWindowsView* view) override {
     return std::make_shared<AccessibilityBridgeWindowsSpy>(engine, view);
@@ -169,7 +169,7 @@ std::shared_ptr<AccessibilityBridgeWindowsSpy> GetAccessibilityBridgeSpy(
 
 void ExpectWinEventFromAXEvent(int32_t node_id,
                                ui::AXEventGenerator::Event ax_event,
-                               DWORD expected_event) {
+                               ax::mojom::Event expected_event) {
   auto window_binding_handler =
       std::make_unique<::testing::NiceMock<MockWindowBindingHandler>>();
   FlutterWindowsView view(std::move(window_binding_handler));
@@ -246,12 +246,12 @@ TEST(AccessibilityBridgeWindows, DispatchAccessibilityAction) {
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityEventAlert) {
   ExpectWinEventFromAXEvent(0, ui::AXEventGenerator::Event::ALERT,
-                            EVENT_SYSTEM_ALERT);
+                            ax::mojom::Event::kAlert);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityEventChildrenChanged) {
   ExpectWinEventFromAXEvent(0, ui::AXEventGenerator::Event::CHILDREN_CHANGED,
-                            EVENT_OBJECT_REORDER);
+                            ax::mojom::Event::kChildrenChanged);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityEventFocusChanged) {
@@ -270,7 +270,8 @@ TEST(AccessibilityBridgeWindows, OnAccessibilityEventFocusChanged) {
                                  ax::mojom::EventFrom::kNone,
                                  {}}});
   ASSERT_EQ(bridge->dispatched_events().size(), 1);
-  EXPECT_EQ(bridge->dispatched_events()[0].event_type, EVENT_OBJECT_FOCUS);
+  EXPECT_EQ(bridge->dispatched_events()[0].event_type,
+            ax::mojom::Event::kFocus);
 
   ASSERT_EQ(bridge->focused_nodes().size(), 1);
   EXPECT_EQ(bridge->focused_nodes()[0], 1);
@@ -279,62 +280,62 @@ TEST(AccessibilityBridgeWindows, OnAccessibilityEventFocusChanged) {
 TEST(AccessibilityBridgeWindows, OnAccessibilityEventIgnoredChanged) {
   // Static test nodes with no text, hint, or scrollability are ignored.
   ExpectWinEventFromAXEvent(4, ui::AXEventGenerator::Event::IGNORED_CHANGED,
-                            EVENT_OBJECT_HIDE);
+                            ax::mojom::Event::kHide);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityImageAnnotationChanged) {
   ExpectWinEventFromAXEvent(
       1, ui::AXEventGenerator::Event::IMAGE_ANNOTATION_CHANGED,
-      EVENT_OBJECT_NAMECHANGE);
+      ax::mojom::Event::kTextChanged);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityLiveRegionChanged) {
   ExpectWinEventFromAXEvent(1, ui::AXEventGenerator::Event::LIVE_REGION_CHANGED,
-                            EVENT_OBJECT_LIVEREGIONCHANGED);
+                            ax::mojom::Event::kLiveRegionChanged);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityNameChanged) {
   ExpectWinEventFromAXEvent(1, ui::AXEventGenerator::Event::NAME_CHANGED,
-                            EVENT_OBJECT_NAMECHANGE);
+                            ax::mojom::Event::kTextChanged);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityHScrollPosChanged) {
   ExpectWinEventFromAXEvent(
       1, ui::AXEventGenerator::Event::SCROLL_HORIZONTAL_POSITION_CHANGED,
-      EVENT_SYSTEM_SCROLLINGEND);
+      ax::mojom::Event::kScrollPositionChanged);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityVScrollPosChanged) {
   ExpectWinEventFromAXEvent(
       1, ui::AXEventGenerator::Event::SCROLL_VERTICAL_POSITION_CHANGED,
-      EVENT_SYSTEM_SCROLLINGEND);
+      ax::mojom::Event::kScrollPositionChanged);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilitySelectedChanged) {
   ExpectWinEventFromAXEvent(1, ui::AXEventGenerator::Event::SELECTED_CHANGED,
-                            EVENT_OBJECT_VALUECHANGE);
+                            ax::mojom::Event::kValueChanged);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilitySelectedChildrenChanged) {
   ExpectWinEventFromAXEvent(
       2, ui::AXEventGenerator::Event::SELECTED_CHILDREN_CHANGED,
-      EVENT_OBJECT_SELECTIONWITHIN);
+      ax::mojom::Event::kSelectedChildrenChanged);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilitySubtreeCreated) {
   ExpectWinEventFromAXEvent(0, ui::AXEventGenerator::Event::SUBTREE_CREATED,
-                            EVENT_OBJECT_SHOW);
+                            ax::mojom::Event::kShow);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityValueChanged) {
   ExpectWinEventFromAXEvent(1, ui::AXEventGenerator::Event::VALUE_CHANGED,
-                            EVENT_OBJECT_VALUECHANGE);
+                            ax::mojom::Event::kValueChanged);
 }
 
 TEST(AccessibilityBridgeWindows, OnAccessibilityStateChanged) {
   ExpectWinEventFromAXEvent(
       1, ui::AXEventGenerator::Event::WIN_IACCESSIBLE_STATE_CHANGED,
-      EVENT_OBJECT_STATECHANGE);
+      ax::mojom::Event::kStateChanged);
 }
 
 }  // namespace testing

shell/platform/windows/flutter_platform_node_delegate_windows.cc

@@ -10,6 +10,7 @@
 #include "flutter/shell/platform/windows/flutter_windows_view.h"
 #include "flutter/third_party/accessibility/ax/ax_clipping_behavior.h"
 #include "flutter/third_party/accessibility/ax/ax_coordinate_system.h"
+#include "flutter/third_party/accessibility/ax/platform/ax_fragment_root_win.h"
 
 namespace flutter {
 
@@ -90,14 +91,8 @@ gfx::Rect FlutterPlatformNodeDelegateWindows::GetBoundsRect(
 }
 
 void FlutterPlatformNodeDelegateWindows::DispatchWinAccessibilityEvent(
-    DWORD event_type) {
-  HWND hwnd = view_->GetPlatformWindow();
-  if (!hwnd) {
-    return;
-  }
-  assert(ax_platform_node_);
-  ::NotifyWinEvent(event_type, hwnd, OBJID_CLIENT,
-                   -ax_platform_node_->GetUniqueId());
+    ax::mojom::Event event_type) {
+  ax_platform_node_->NotifyAccessibilityEvent(event_type);
 }
 
 void FlutterPlatformNodeDelegateWindows::SetFocus() {
@@ -107,4 +102,9 @@ void FlutterPlatformNodeDelegateWindows::SetFocus() {
   GetNativeViewAccessible()->accSelect(SELFLAG_TAKEFOCUS, varchild);
 }
 
+gfx::AcceleratedWidget
+FlutterPlatformNodeDelegateWindows::GetTargetForNativeAccessibilityEvent() {
+  return view_->GetPlatformWindow();
+}
+
 }  // namespace flutter

shell/platform/windows/flutter_platform_node_delegate_windows.h

@@ -42,12 +42,15 @@ class FlutterPlatformNodeDelegateWindows : public FlutterPlatformNodeDelegate {
   // Dispatches a Windows accessibility event of the specified type, generated
   // by the accessibility node associated with this object. This is a
   // convenience wrapper around |NotifyWinEvent|.
-  virtual void DispatchWinAccessibilityEvent(DWORD event_type);
+  virtual void DispatchWinAccessibilityEvent(ax::mojom::Event event_type);
 
   // Sets the accessibility focus to the accessibility node associated with
   // this object.
   void SetFocus();
 
+  // | AXPlatformNodeDelegate |
+  gfx::AcceleratedWidget GetTargetForNativeAccessibilityEvent() override;
+
  private:
   ui::AXPlatformNode* ax_platform_node_;
   std::weak_ptr<AccessibilityBridge> bridge_;

shell/platform/windows/flutter_window.cc

@@ -303,4 +303,8 @@ AccessibilityRootNode* FlutterWindow::GetAccessibilityRootNode() {
   return accessibility_root_;
 }
 
+ui::AXFragmentRootDelegateWin* FlutterWindow::GetAxFragmentRootDelegate() {
+  return binding_handler_delegate_->GetAxFragmentRootDelegate();
+}
+
 }  // namespace flutter