Make OSX a11y work again.

Pretty major refactor of that code.

native/Avalonia.Native/src/OSX/AvnString.mm

@@ -160,7 +160,7 @@ NSString* GetNSStringAndRelease(IAvnString* s)
     {
         char* p;
         
-        if (s->Pointer((void**)&p) == S_OK)
+        if (s->Pointer((void**)&p) == S_OK && p != nullptr)
         {
             return [NSString stringWithUTF8String:p];
         }

native/Avalonia.Native/src/OSX/automation.h

@@ -1,16 +1,12 @@
 #import <Cocoa/Cocoa.h>
+#include "window.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
 class IAvnAutomationPeer;
 
-@interface AvnAutomationNode : NSAccessibilityElement
-- (AvnAutomationNode *)initWithPeer:(IAvnAutomationPeer *)peer;
+@interface AvnAccessibilityElement : NSAccessibilityElement
++ (AvnAccessibilityElement *) acquire:(IAvnAutomationPeer *) peer;
 @end
 
-struct INSAccessibilityHolder
-{
-    virtual NSObject* _Nonnull GetNSAccessibility () = 0;
-};
-
 NS_ASSUME_NONNULL_END

native/Avalonia.Native/src/OSX/automation.mm

@@ -1,66 +1,108 @@
-#import "automation.h"
 #include "common.h"
+#include "automation.h"
 #include "AvnString.h"
 #include "window.h"
 
-class AutomationNode : public ComSingleObject<IAvnAutomationNode, &IID_IAvnAutomationNode>,
-    public INSAccessibilityHolder
+@interface AvnAccessibilityElement (Events)
+- (void) raiseChildrenChanged;
+@end
+
+@interface AvnRootAccessibilityElement : AvnAccessibilityElement
+- (AvnView *) ownerView;
+- (AvnRootAccessibilityElement *) initWithPeer:(IAvnAutomationPeer *) peer owner:(AvnView*) owner;
+- (void) raiseFocusChanged;
+@end
+
+class AutomationNode : public ComSingleObject<IAvnAutomationNode, &IID_IAvnAutomationNode>
 {
-private:
-    NSAccessibilityElement* _node;
 public:
     FORWARD_IUNKNOWN()
 
-    AutomationNode(NSAccessibilityElement* node)
+    AutomationNode(AvnAccessibilityElement* owner)
     {
-        _node = node;
+        _owner = owner;
     }
-
-    AutomationNode(IAvnAutomationPeer* peer)
+    
+    AvnAccessibilityElement* GetOwner()
     {
-        _node = [[AvnAutomationNode alloc] initWithPeer: peer];
+        return _owner;
     }
     
-    virtual void ChildrenChanged() override
+    virtual void Dispose() override
     {
-        NSAccessibilityPostNotification(_node, NSAccessibilityLayoutChangedNotification);
     }
     
-    virtual void PropertyChanged(AvnAutomationProperty property) override
+    virtual void ChildrenChanged () override
     {
-        switch (property) {
-            case RangeValueProvider_Value:
-                NSAccessibilityPostNotification(_node, NSAccessibilityValueChangedNotification);
-                break;
-            default:
-                break;
-        }
+        [_owner raiseChildrenChanged];
     }
-
-    virtual void FocusChanged(IAvnAutomationPeer* peer) override
+    
+    virtual void PropertyChanged (AvnAutomationProperty property) override
     {
-        // Only implemented in top-level nodes, i.e. AvnWindow.
+        
     }
-
-    virtual NSObject* GetNSAccessibility() override
+    
+    virtual void FocusChanged () override
     {
-        return _node;
+        [(AvnRootAccessibilityElement*)_owner raiseFocusChanged];
     }
+    
+private:
+    AvnAccessibilityElement* _owner;
 };
 
-@implementation AvnAutomationNode
+@implementation AvnAccessibilityElement
 {
     IAvnAutomationPeer* _peer;
+    AutomationNode* _node;
     NSMutableArray* _children;
 }
 
-- (AvnAutomationNode *)initWithPeer:(IAvnAutomationPeer *)peer
++ (AvnAccessibilityElement *)acquire:(IAvnAutomationPeer *)peer
+{
+    if (peer == nullptr)
+        return nil;
+    
+    auto instance = peer->GetNode();
+    
+    if (instance != nullptr)
+        return dynamic_cast<AutomationNode*>(instance)->GetOwner();
+    
+    if (peer->IsRootProvider())
+    {
+        auto window = peer->RootProvider_GetWindow();
+        auto holder = dynamic_cast<INSWindowHolder*>(window);
+        auto view = holder->GetNSView();
+        return [[AvnRootAccessibilityElement alloc] initWithPeer:peer owner:view];
+    }
+    else
+    {
+        return [[AvnAccessibilityElement alloc] initWithPeer:peer];
+    }
+}
+
+- (AvnAccessibilityElement *)initWithPeer:(IAvnAutomationPeer *)peer
 {
     self = [super init];
     _peer = peer;
+    _node = new AutomationNode(self);
+    _peer->SetNode(_node);
     return self;
 }
 
+- (NSString *)description
+{
+    return [NSString stringWithFormat:@"%@ '%@' (%p)",
+        GetNSStringAndRelease(_peer->GetClassName()),
+        GetNSStringAndRelease(_peer->GetName()),
+        _peer];
+}
+
+- (IAvnAutomationPeer *)peer
+{
+    return _peer;
+}
+
 - (BOOL)isAccessibilityElement
 {
     return _peer->IsControlElement();
@@ -96,7 +138,7 @@ public:
         case AutomationToolBar: return NSAccessibilityToolbarRole;
         case AutomationToolTip: return NSAccessibilityPopoverRole;
         case AutomationTree: return NSAccessibilityOutlineRole;
-        case AutomationTreeItem: return NSAccessibilityOutlineRowSubrole;
+        case AutomationTreeItem: return NSAccessibilityCellRole;
         case AutomationCustom: return NSAccessibilityUnknownRole;
         case AutomationGroup: return NSAccessibilityGroupRole;
         case AutomationThumb: return NSAccessibilityHandleRole;
@@ -110,8 +152,10 @@ public:
         case AutomationHeaderItem:  return NSAccessibilityButtonRole;
         case AutomationTable: return NSAccessibilityTableRole;
         case AutomationTitleBar: return NSAccessibilityGroupRole;
-        case AutomationSeparator: return NSAccessibilityUnknownRole;
-        default: return NSAccessibilityUnknownRole;
+        // Treat unknown roles as generic group container items. Returning
+        // NSAccessibilityUnknownRole is also possible but makes the screen
+       // reader focus on the item instead of passing focus to child items.
+        default: return NSAccessibilityGroupRole;
     }
 }
 
@@ -177,6 +221,15 @@ public:
     return [super accessibilityMaxValue];
 }
 
+- (BOOL)isAccessibilityEnabled
+{
+    return _peer->IsEnabled();
+}
+
+- (BOOL)isAccessibilityFocused
+{
+    return _peer->HasKeyboardFocus();
+}
 
 - (NSArray *)accessibilityChildren
 {
@@ -195,52 +248,55 @@ public:
                 
                 if (childPeers->Get(i, &child) == S_OK)
                 {
-                    NSObject* element = ::GetAccessibilityElement(child->GetNode());
+                    auto element = [AvnAccessibilityElement acquire:child];
                     [_children addObject:element];
                 }
             }
         }
     }
-    
+
     return _children;
 }
 
 - (NSRect)accessibilityFrame
 {
-    auto view = [self getAvnView];
-    auto window = [self getAvnWindow];
+    id topLevel = [self accessibilityTopLevelUIElement];
+    auto result = NSZeroRect;
 
-    if (view != nullptr)
+    if ([topLevel isKindOfClass:[AvnRootAccessibilityElement class]])
     {
-        auto bounds = ToNSRect(_peer->GetBoundingRectangle());
-        auto windowBounds = [view convertRect:bounds toView:nil];
-        auto screenBounds = [window convertRectToScreen:windowBounds];
-        return screenBounds;
+        auto root = (AvnRootAccessibilityElement*)topLevel;
+        auto view = [root ownerView];
+        
+        if (view)
+        {
+            auto window = [view window];
+            auto bounds = ToNSRect(_peer->GetBoundingRectangle());
+            auto windowBounds = [view convertRect:bounds toView:nil];
+            auto screenBounds = [window convertRectToScreen:windowBounds];
+            result = screenBounds;
+        }
     }
-    
-    return NSRect();
+
+    return result;
 }
 
 - (id)accessibilityParent
 {
     auto parentPeer = _peer->GetParent();
-    
-    if (parentPeer != nullptr)
-    {
-        return GetAccessibilityElement(parentPeer);
-    }
-    
-    return [NSApplication sharedApplication];
+    return parentPeer ? [AvnAccessibilityElement acquire:parentPeer] : [NSApplication sharedApplication];
 }
 
 - (id)accessibilityTopLevelUIElement
 {
-    return GetAccessibilityElement([self getRootNode]);
+    auto rootPeer = _peer->GetRootPeer();
+    return [AvnAccessibilityElement acquire:rootPeer];
 }
 
 - (id)accessibilityWindow
 {
-    return [self accessibilityTopLevelUIElement];
+    id topLevel = [self accessibilityTopLevelUIElement];
+    return [topLevel isKindOfClass:[NSWindow class]] ? topLevel : nil;
 }
 
 - (BOOL)isAccessibilityExpanded
@@ -326,58 +382,68 @@ public:
     return [super isAccessibilitySelectorAllowed:selector];
 }
 
-- (IAvnAutomationNode*)getRootNode
+- (void)raiseChildrenChanged
 {
-    auto rootPeer = _peer->GetRootPeer();
-    return rootPeer != nullptr ? rootPeer->GetNode() : nullptr;
+    NSAccessibilityPostNotification(self, NSAccessibilityLayoutChangedNotification);
 }
 
-- (IAvnWindowBase*)getWindow
+- (void)raisePropertyChanged
 {
-    auto rootNode = [self getRootNode];
+}
 
-    if (rootNode != nullptr)
-    {
-        IAvnWindowBase* window;
-        if (rootNode->QueryInterface(&IID_IAvnWindow, (void**)&window) == S_OK)
-        {
-            return window;
-        }
-    }
-    
-    return nullptr;
+- (void)setAccessibilityFocused:(BOOL)accessibilityFocused
+{
+    if (accessibilityFocused)
+        _peer->SetFocus();
 }
 
-- (AvnWindow*) getAvnWindow
+@end
+
+@implementation AvnRootAccessibilityElement
 {
-    auto window = [self getWindow];
-    return window != nullptr ? dynamic_cast<INSWindowHolder*>(window)->GetNSWindow() : nullptr;
+    AvnView* _owner;
 }
 
-- (AvnView*) getAvnView
+- (AvnRootAccessibilityElement *)initWithPeer:(IAvnAutomationPeer *)peer owner:(AvnView *)owner
 {
-    auto window = [self getWindow];
-    return window != nullptr ? dynamic_cast<INSWindowHolder*>(window)->GetNSView() : nullptr;
+    self = [super initWithPeer:peer];
+    _owner = owner;
+    return self;
 }
 
-@end
+- (AvnView *)ownerView
+{
+    return _owner;
+}
 
-extern IAvnAutomationNode* CreateAutomationNode(IAvnAutomationPeer* peer)
+- (id)accessibilityFocusedUIElement
 {
-    @autoreleasepool
-    {
-        return new AutomationNode(peer);
-    }
+    auto focusedPeer = [self peer]->RootProvider_GetFocus();
+    return [AvnAccessibilityElement acquire:focusedPeer];
 }
 
-extern NSObject* GetAccessibilityElement(IAvnAutomationPeer* peer)
+- (id)accessibilityHitTest:(NSPoint)point
 {
-    auto node = peer != nullptr ? peer->GetNode() : nullptr;
-    return GetAccessibilityElement(node);
+    auto clientPoint = [[_owner window] convertPointFromScreen:point];
+    auto localPoint = [_owner translateLocalPoint:ToAvnPoint(clientPoint)];
+    auto hit = [self peer]->RootProvider_GetPeerFromPoint(localPoint);
+    return [AvnAccessibilityElement acquire:hit];
 }
 
-extern NSObject* GetAccessibilityElement(IAvnAutomationNode* node)
+- (id)accessibilityParent
 {
-    auto holder = dynamic_cast<INSAccessibilityHolder*>(node);
-    return holder != nullptr ? holder->GetNSAccessibility() : nil;
+    return _owner;
 }
+
+- (void)raiseFocusChanged
+{
+    id focused = [self accessibilityFocusedUIElement];
+    NSAccessibilityPostNotification(focused, NSAccessibilityFocusedUIElementChangedNotification);
+}
+
+- (void)accessibilityPerformAction:(NSAccessibilityActionName)action
+{
+    [_owner accessibilityPerformAction:action];
+}
+
+@end

native/Avalonia.Native/src/OSX/common.h

@@ -31,9 +31,6 @@ extern IAvnMenu* GetAppMenu ();
 extern NSMenuItem* GetAppMenuItem ();
 extern void SetAutoGenerateDefaultAppMenuItems (bool enabled);
 extern bool GetAutoGenerateDefaultAppMenuItems ();
-extern IAvnAutomationNode* CreateAutomationNode(IAvnAutomationPeer* peer);
-extern NSObject* GetAccessibilityElement(IAvnAutomationPeer* peer);
-extern NSObject* GetAccessibilityElement(IAvnAutomationNode* node);
 
 extern void InitializeAvnApp(IAvnApplicationEvents* events);
 extern NSApplicationActivationPolicy AvnDesiredActivationPolicy;

native/Avalonia.Native/src/OSX/main.mm

@@ -347,13 +347,7 @@ public:
             return S_OK;
         }
     }
-    
-    virtual HRESULT CreateAutomationNode (IAvnAutomationPeer* peer, IAvnAutomationNode** ppv) override
-    {
-        *ppv = ::CreateAutomationNode(peer);
-        return S_OK;
-    }
-    
+        
     virtual HRESULT SetAppMenu (IAvnMenu* appMenu) override
     {
         START_COM_CALL;

native/Avalonia.Native/src/OSX/window.mm

@@ -10,9 +10,7 @@
 
 class WindowBaseImpl : public virtual ComObject,
     public virtual IAvnWindowBase,
-    public virtual IAvnAutomationNode,
-    public INSWindowHolder,
-    public INSAccessibilityHolder
+    public INSWindowHolder
 {
 private:
     NSCursor* cursor;
@@ -21,7 +19,6 @@ public:
     FORWARD_IUNKNOWN()
     BEGIN_INTERFACE_MAP()
     INTERFACE_MAP_ENTRY(IAvnWindowBase, IID_IAvnWindowBase)
-    INTERFACE_MAP_ENTRY(IAvnAutomationNode, IID_IAvnAutomationNode)
     END_INTERFACE_MAP()
 
     virtual ~WindowBaseImpl()
@@ -131,11 +128,6 @@ public:
         return View;
     }
 
-    virtual NSObject* GetNSAccessibility() override
-    {
-        return Window;
-    }
-    
     virtual HRESULT Show(bool activate, bool isDialog) override
     {
         START_COM_CALL;
@@ -603,25 +595,6 @@ public:
         return S_OK;
     }
 
-    virtual void ChildrenChanged() override
-    {
-        NSAccessibilityPostNotification(Window, NSAccessibilityLayoutChangedNotification);
-    }
-
-    virtual void PropertyChanged(AvnAutomationProperty property) override
-    {
-    }
-    
-    virtual void FocusChanged(IAvnAutomationPeer* peer) override
-    {
-        auto element = GetAccessibilityElement(peer);
-        
-        if (element != nullptr)
-        {
-            NSAccessibilityPostNotification(element, NSAccessibilityFocusedUIElementChangedNotification);
-        }
-    }
-    
     virtual bool IsDialog()
     {
         return false;
@@ -1432,6 +1405,7 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     AvnPixelSize _lastPixelSize;
     NSObject<IRenderTarget>* _renderTarget;
     AvnPlatformResizeReason _resizeReason;
+    AvnAccessibilityElement* _accessibilityChild;
 }
 
 - (void)onClosed
@@ -2055,6 +2029,37 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     _resizeReason = reason;
 }
 
+- (AvnAccessibilityElement *) accessibilityChild
+{
+    if (_accessibilityChild == nil)
+    {
+        auto peer = _parent->BaseEvents->GetAutomationPeer();
+        
+        if (peer == nil)
+            return nil;
+
+        _accessibilityChild = [AvnAccessibilityElement acquire:peer];
+    }
+    
+    return _accessibilityChild;
+}
+
+- (NSArray *)accessibilityChildren
+{
+    auto child = [self accessibilityChild];
+    return NSAccessibilityUnignoredChildrenForOnlyChild(child);
+}
+
+- (id)accessibilityHitTest:(NSPoint)point
+{
+    return [[self accessibilityChild] accessibilityHitTest:point];
+}
+
+- (id)accessibilityFocusedUIElement
+{
+    return [[self accessibilityChild] accessibilityFocusedUIElement];
+}
+
 @end
 
 
@@ -2466,75 +2471,6 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     }
 }
 
-- (BOOL)isAccessibilityElement
-{
-    [self getAutomationPeer];
-    return YES;
-}
-
-- (NSString *)accessibilityIdentifier
-{
-    auto peer = [self getAutomationPeer];
-    return GetNSStringAndRelease(peer->GetAutomationId());
-}
-
-- (NSArray *)accessibilityChildren
-{
-    auto peer = [self getAutomationPeer];
-    
-    if (_automationChildren == nullptr)
-    {
-        _automationChildren = (NSMutableArray*)[super accessibilityChildren];
-
-        auto childPeers = peer->GetChildren();
-        auto childCount = childPeers != nullptr ? childPeers->GetCount() : 0;
-
-        if (childCount > 0)
-        {
-            for (int i = 0; i < childCount; ++i)
-            {
-                IAvnAutomationPeer* child;
-                
-                if (childPeers->Get(i, &child) == S_OK)
-                {
-                    auto element = GetAccessibilityElement(child);
-                    [_automationChildren addObject:element];
-                }
-            }
-        }
-    }
-    
-    return _automationChildren;
-}
-
-- (id)accessibilityHitTest:(NSPoint)point
-{
-    point = [self convertPointFromScreen:point];
-    auto p = [_parent->View translateLocalPoint:ToAvnPoint(point)];
-    auto peer = [self getAutomationPeer];
-    auto hit = peer->RootProvider_GetPeerFromPoint(p);
-    return GetAccessibilityElement(hit);
-}
-
-- (id)accessibilityFocusedUIElement
-{
-    auto peer = [self getAutomationPeer];
-    
-    if (peer->IsRootProvider())
-    {
-        return GetAccessibilityElement(peer->RootProvider_GetFocus());
-    }
-    
-    return [super accessibilityFocusedUIElement];
-}
-
-- (IAvnAutomationPeer*) getAutomationPeer
-{
-    if (_automationPeer == nullptr)
-        _automationPeer = _parent->BaseEvents->AutomationStarted(_parent);
-    return _automationPeer;
-}
-
 @end
 
 class PopupImpl : public virtual WindowBaseImpl, public IAvnPopup

src/Avalonia.Native/AutomationNode.cs

@@ -1,40 +0,0 @@
-using Avalonia.Automation;
-using Avalonia.Automation.Peers;
-using Avalonia.Native.Interop;
-
-#nullable enable
-
-namespace Avalonia.Native
-{
-    internal class AutomationNode
-    {
-        public AutomationNode(IAvnAutomationNode native)
-        {
-            Native = native;
-        }
-
-        public IAvnAutomationNode Native { get; }
-
-        public void ChildrenChanged() => Native.ChildrenChanged();
-
-        public void PropertyChanged(AutomationProperty property, object? oldValue, object? newValue)
-        {
-            AvnAutomationProperty p;
-
-            if (property == AutomationElementIdentifiers.BoundingRectangleProperty)
-                p = AvnAutomationProperty.AutomationPeer_BoundingRectangle;
-            else if (property == AutomationElementIdentifiers.ClassNameProperty)
-                p = AvnAutomationProperty.AutomationPeer_ClassName;
-            else if (property == AutomationElementIdentifiers.NameProperty)
-                p = AvnAutomationProperty.AutomationPeer_Name;
-            else if (property == RangeValuePatternIdentifiers.ValueProperty)
-                p = AvnAutomationProperty.RangeValueProvider_Value;
-            else
-                return;
-            
-            Native.PropertyChanged(p);
-        }
-
-        public void FocusChanged(AutomationPeer? focus) => Native.FocusChanged(AvnAutomationPeer.Wrap(focus));
-    }
-}

src/Avalonia.Native/Avalonia.Native.csproj

@@ -16,6 +16,10 @@
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
   </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="..\Avalonia.Base\Metadata\NullableAttributes.cs" Link="NullableAttributes.cs" />
+  </ItemGroup>
   
   <ItemGroup>
     <ProjectReference Include="..\..\packages\Avalonia\Avalonia.csproj" />

src/Avalonia.Native/AvnAutomationPeer.cs

@@ -1,9 +1,12 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Runtime.CompilerServices;
 using Avalonia.Automation;
 using Avalonia.Automation.Peers;
 using Avalonia.Automation.Provider;
+using Avalonia.Controls;
 using Avalonia.Native.Interop;
 
 #nullable enable
@@ -12,11 +15,20 @@ namespace Avalonia.Native
 {
     internal class AvnAutomationPeer : CallbackBase, IAvnAutomationPeer
     {
+        private static readonly ConditionalWeakTable<AutomationPeer, AvnAutomationPeer> s_wrappers = new();
         private readonly AutomationPeer _inner;
 
-        public AvnAutomationPeer(AutomationPeer inner) => _inner = inner;
+        private AvnAutomationPeer(AutomationPeer inner)
+        {
+            _inner = inner;
+            _inner.ChildrenChanged += (_, _) => Node?.ChildrenChanged();
+            if (inner is WindowBaseAutomationPeer window)
+                window.FocusChanged += (_, _) => Node?.FocusChanged(); 
+        }
 
-        public IAvnAutomationNode Node => throw new NotImplementedException();
+        ~AvnAutomationPeer() => Node?.Dispose();
+        
+        public IAvnAutomationNode? Node { get; private set; }
         public IAvnString? AcceleratorKey => _inner.GetAcceleratorKey().ToAvnString();
         public IAvnString? AccessKey => _inner.GetAccessKey().ToAvnString();
         public AvnAutomationControlType AutomationControlType => (AvnAutomationControlType)_inner.GetAutomationControlType();
@@ -43,17 +55,31 @@ namespace Avalonia.Native
                 var peer = _inner;
                 var parent = peer.GetParent();
 
-                while (!(peer is IRootProvider) && parent is object)
+                while (peer is not IRootProvider && parent is not null)
                 {
                     peer = parent;
                     parent = peer.GetParent();
                 }
 
-                return new AvnAutomationPeer(peer);
+                return Wrap(peer);
             }
         }
 
+        public void SetNode(IAvnAutomationNode node)
+        {
+            if (Node is not null)
+                throw new InvalidOperationException("The AvnAutomationPeer already has a node.");
+            Node = node;
+        }
+        
         public int IsRootProvider() => (_inner is IRootProvider).AsComBool();
+
+        public IAvnWindowBase RootProvider_GetWindow()
+        {
+            var window = (WindowBase)((ControlAutomationPeer)_inner).Owner;
+            return ((WindowBaseImpl)window.PlatformImpl!).Native;
+        }
+        
         public IAvnAutomationPeer? RootProvider_GetFocus() => Wrap(((IRootProvider)_inner).GetFocus());
 
         public IAvnAutomationPeer? RootProvider_GetPeerFromPoint(AvnPoint point)
@@ -68,7 +94,7 @@ namespace Avalonia.Native
             {
                 var parent = result.GetParent();
 
-                if (parent is object)
+                if (parent is not null)
                     result = parent;
                 else
                     break;
@@ -108,9 +134,12 @@ namespace Avalonia.Native
         public int IsValueProvider() => (_inner is IValueProvider).AsComBool();
         public IAvnString ValueProvider_GetValue() => ((IValueProvider)_inner).Value.ToAvnString();
         public void ValueProvider_SetValue(string value) => ((IValueProvider)_inner).SetValue(value);
-        
-        public static AvnAutomationPeer? Wrap(AutomationPeer? peer) =>
-            peer != null ? new AvnAutomationPeer(peer) : null;
+
+        [return: NotNullIfNotNull("peer")]
+        public static AvnAutomationPeer? Wrap(AutomationPeer? peer)
+        {
+            return peer is null ? null : s_wrappers.GetValue(peer, x => new(peer));
+        }
     }
 
     internal class AvnAutomationPeerArray : CallbackBase, IAvnAutomationPeerArray
@@ -119,7 +148,7 @@ namespace Avalonia.Native
         
         public AvnAutomationPeerArray(IReadOnlyList<AutomationPeer> items)
         {
-            _items = items.Select(x => new AvnAutomationPeer(x)).ToArray();
+            _items = items.Select(x => AvnAutomationPeer.Wrap(x)).ToArray();
         }
         
         public uint Count => (uint)_items.Length;

src/Avalonia.Native/WindowImplBase.cs

@@ -62,7 +62,6 @@ namespace Avalonia.Native
         private GlPlatformSurface _glSurface;
         private NativeControlHostImpl _nativeControlHost;
         private IGlContext _glContext;
-        private AvnAutomationPeer _automationPeer;
 
         internal WindowBaseImpl(IAvaloniaNativeFactory factory, AvaloniaNativePlatformOptions opts,
             AvaloniaNativePlatformOpenGlInterface glFeature)
@@ -158,6 +157,11 @@ namespace Avalonia.Native
         public IMouseDevice MouseDevice => _mouse;
         public abstract IPopupImpl CreatePopup();
 
+        public AutomationPeer GetAutomationPeer()
+        {
+            return _inputRoot is Control c ? ControlAutomationPeer.CreatePeerForElement(c) : null;
+        }
+        
         protected unsafe class WindowBaseEvents : CallbackBase, IAvnWindowBaseEvents
         {
             private readonly WindowBaseImpl _parent;
@@ -262,6 +266,11 @@ namespace Avalonia.Native
                     return (AvnDragDropEffects)args.Effects;
                 }
             }
+
+            IAvnAutomationPeer IAvnWindowBaseEvents.AutomationPeer
+            {
+                get => AvnAutomationPeer.Wrap(_parent.GetAutomationPeer());
+            }
         }
        
         public void Activate()

src/Avalonia.Native/avn.idl

@@ -419,6 +419,7 @@ enum AvnPlatformResizeReason
 
 enum AvnAutomationControlType
 {
+    AutomationNone,
     AutomationButton,
     AutomationCalendar,
     AutomationCheckBox,
@@ -480,7 +481,6 @@ interface IAvaloniaNativeFactory : IUnknown
      HRESULT CreateMenuItem(IAvnMenuItem** ppv);
      HRESULT CreateMenuItemSeparator(IAvnMenuItem** ppv);
      HRESULT CreateTrayIcon(IAvnTrayIcon** ppv);
-     HRESULT CreateAutomationNode(IAvnAutomationPeer* peer, IAvnAutomationNode** ppv);
 }
 
 [uuid(233e094f-9b9f-44a3-9a6e-6948bbdd9fb1)]
@@ -570,6 +570,7 @@ interface IAvnWindowBaseEvents : IUnknown
      AvnDragDropEffects DragEvent(AvnDragEventType type, AvnPoint position,
                                          AvnInputModifiers modifiers, AvnDragDropEffects effects,
                                          IAvnClipboard* clipboard, [intptr]void* dataObjectHandle);
+     IAvnAutomationPeer* GetAutomationPeer();
 }
 
 [uuid(1ae178ee-1fcc-447f-b6dd-b7bb727f934c)]
@@ -811,6 +812,8 @@ interface IAvnApplicationEvents : IUnknown
 interface IAvnAutomationPeer : IUnknown
 {
      IAvnAutomationNode* GetNode();
+     void SetNode(IAvnAutomationNode* node);
+
      IAvnString* GetAcceleratorKey();
      IAvnString* GetAccessKey();
      AvnAutomationControlType GetAutomationControlType();
@@ -832,6 +835,7 @@ interface IAvnAutomationPeer : IUnknown
      IAvnAutomationPeer* GetRootPeer();
      
      bool IsRootProvider();
+     IAvnWindowBase* RootProvider_GetWindow();
      IAvnAutomationPeer* RootProvider_GetFocus();
      IAvnAutomationPeer* RootProvider_GetPeerFromPoint(AvnPoint point);
      
@@ -871,7 +875,8 @@ interface IAvnAutomationPeerArray : IUnknown
 [uuid(004dc40b-e435-49dc-bac5-6272ee35382a)]
 interface IAvnAutomationNode : IUnknown
 {
+    void Dispose();
     void ChildrenChanged();
     void PropertyChanged(AvnAutomationProperty property);
-    void FocusChanged(IAvnAutomationPeer* peer);
+    void FocusChanged();
 }