Add basic integration tests for NativeControlHost and improve its automation/a11y support.

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

@@ -60,7 +60,7 @@ @implementation AvnAccessibilityElement
     NSMutableArray* _children;
 }
 
-+ (AvnAccessibilityElement *)acquire:(IAvnAutomationPeer *)peer
++ (NSAccessibilityElement *)acquire:(IAvnAutomationPeer *)peer
 {
     if (peer == nullptr)
         return nil;
@@ -70,7 +70,12 @@ + (AvnAccessibilityElement *)acquire:(IAvnAutomationPeer *)peer
     if (instance != nullptr)
         return dynamic_cast<AutomationNode*>(instance)->GetOwner();
 
-    if (peer->IsRootProvider())
+    if (peer->IsInteropPeer())
+    {
+        auto view = (__bridge NSAccessibilityElement*)peer->InteropPeer_GetNativeControlHandle();
+        return view;
+    }
+    else if (peer->IsRootProvider())
     {
         auto window = peer->RootProvider_GetWindow();
 

samples/IntegrationTestApp/Embedding/INativeControlFactory.cs

@@ -0,0 +1,9 @@
+using System;
+using Avalonia.Platform;
+
+namespace IntegrationTestApp.Embedding;
+
+internal interface INativeControlFactory
+{
+    IPlatformHandle CreateControl(IPlatformHandle parent, Func<IPlatformHandle> createDefault);
+}

samples/IntegrationTestApp/Embedding/MacHelper.cs

@@ -0,0 +1,16 @@
+using MonoMac.AppKit;
+
+namespace IntegrationTestApp.Embedding;
+
+internal class MacHelper
+{
+    private static bool s_isInitialized;
+
+    public static void EnsureInitialized()
+    {
+        if (s_isInitialized)
+            return;
+        s_isInitialized = true;
+        NSApplication.Init();
+    }
+}

samples/IntegrationTestApp/Embedding/MacOSTextBoxFactory.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Text;
+using Avalonia.Platform;
+using MonoMac.AppKit;
+using MonoMac.WebKit;
+
+namespace IntegrationTestApp.Embedding;
+
+internal class MacOSTextBoxFactory : INativeControlFactory
+{
+    public IPlatformHandle CreateControl(IPlatformHandle parent, Func<IPlatformHandle> createDefault)
+    {
+        MacHelper.EnsureInitialized();
+
+        var textView = new NSTextView();
+        textView.TextStorage.Append(new("Native text box"));
+
+        return new MacOSViewHandle(textView);
+    }
+}

samples/IntegrationTestApp/Embedding/MacOSViewHandle.cs

@@ -0,0 +1,19 @@
+using System;
+using Avalonia.Controls.Platform;
+using MonoMac.AppKit;
+
+namespace IntegrationTestApp.Embedding;
+
+internal class MacOSViewHandle(NSView view) : INativeControlHostDestroyableControlHandle
+{
+    private NSView? _view = view;
+
+    public IntPtr Handle => _view?.Handle ?? IntPtr.Zero;
+    public string HandleDescriptor => "NSView";
+
+    public void Destroy()
+    {
+        _view?.Dispose();
+        _view = null;
+    }
+}

samples/IntegrationTestApp/Embedding/NativeTextBox.cs

@@ -0,0 +1,20 @@
+using Avalonia.Controls;
+using Avalonia.Platform;
+
+namespace IntegrationTestApp.Embedding;
+
+internal class NativeTextBox : NativeControlHost
+{
+    public static INativeControlFactory? Factory { get; set; }
+
+    protected override IPlatformHandle CreateNativeControlCore(IPlatformHandle parent)
+    {
+        return Factory?.CreateControl(parent, () => base.CreateNativeControlCore(parent))
+            ?? base.CreateNativeControlCore(parent); 
+    }
+
+    protected override void DestroyNativeControlCore(IPlatformHandle control)
+    {
+        base.DestroyNativeControlCore(control);
+    }
+}

samples/IntegrationTestApp/Embedding/Win32TextBoxFactory.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Text;
+using Avalonia.Platform;
+
+namespace IntegrationTestApp.Embedding;
+
+internal class Win32TextBoxFactory : INativeControlFactory
+{
+    public IPlatformHandle CreateControl(IPlatformHandle parent, Func<IPlatformHandle> createDefault)
+    {
+        var handle = WinApi.CreateWindowEx(0, "EDIT",
+            @"Native text box",
+            (uint)(WinApi.WindowStyles.WS_CHILD | WinApi.WindowStyles.WS_VISIBLE | WinApi.WindowStyles.WS_BORDER), 
+            0, 0, 1, 1, 
+            parent.Handle,
+            IntPtr.Zero, 
+            WinApi.GetModuleHandle(null), 
+            IntPtr.Zero);
+        return new Win32WindowControlHandle(handle, "HWND");
+    }
+}

samples/IntegrationTestApp/Embedding/Win32WindowControlHandle.cs

@@ -0,0 +1,11 @@
+using System;
+using Avalonia.Controls.Platform;
+using Avalonia.Platform;
+
+namespace IntegrationTestApp.Embedding;
+
+internal class Win32WindowControlHandle : PlatformHandle, INativeControlHostDestroyableControlHandle
+{
+    public Win32WindowControlHandle(IntPtr handle, string descriptor) : base(handle, descriptor) { }
+    public void Destroy() => WinApi.DestroyWindow(Handle);
+}

samples/IntegrationTestApp/Embedding/WinApi.cs

@@ -0,0 +1,82 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace IntegrationTestApp.Embedding;
+
+internal class WinApi
+{
+    [Flags]
+    public enum WindowStyles : uint
+    {
+        WS_BORDER = 0x800000,
+        WS_CAPTION = 0xc00000,
+        WS_CHILD = 0x40000000,
+        WS_CLIPCHILDREN = 0x2000000,
+        WS_CLIPSIBLINGS = 0x4000000,
+        WS_DISABLED = 0x8000000,
+        WS_DLGFRAME = 0x400000,
+        WS_GROUP = 0x20000,
+        WS_HSCROLL = 0x100000,
+        WS_MAXIMIZE = 0x1000000,
+        WS_MAXIMIZEBOX = 0x10000,
+        WS_MINIMIZE = 0x20000000,
+        WS_MINIMIZEBOX = 0x20000,
+        WS_OVERLAPPED = 0x0,
+        WS_OVERLAPPEDWINDOW = WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_THICKFRAME | WS_MINIMIZEBOX | WS_MAXIMIZEBOX,
+        WS_POPUP = 0x80000000u,
+        WS_POPUPWINDOW = WS_POPUP | WS_BORDER | WS_SYSMENU,
+        WS_SYSMENU = 0x80000,
+        WS_TABSTOP = 0x10000,
+        WS_THICKFRAME = 0x40000,
+        WS_VISIBLE = 0x10000000,
+        WS_VSCROLL = 0x200000,
+        WS_EX_DLGMODALFRAME = 0x00000001,
+        WS_EX_NOPARENTNOTIFY = 0x00000004,
+        WS_EX_NOREDIRECTIONBITMAP = 0x00200000,
+        WS_EX_TOPMOST = 0x00000008,
+        WS_EX_ACCEPTFILES = 0x00000010,
+        WS_EX_TRANSPARENT = 0x00000020,
+        WS_EX_MDICHILD = 0x00000040,
+        WS_EX_TOOLWINDOW = 0x00000080,
+        WS_EX_WINDOWEDGE = 0x00000100,
+        WS_EX_CLIENTEDGE = 0x00000200,
+        WS_EX_CONTEXTHELP = 0x00000400,
+        WS_EX_RIGHT = 0x00001000,
+        WS_EX_LEFT = 0x00000000,
+        WS_EX_RTLREADING = 0x00002000,
+        WS_EX_LTRREADING = 0x00000000,
+        WS_EX_LEFTSCROLLBAR = 0x00004000,
+        WS_EX_RIGHTSCROLLBAR = 0x00000000,
+        WS_EX_CONTROLPARENT = 0x00010000,
+        WS_EX_STATICEDGE = 0x00020000,
+        WS_EX_APPWINDOW = 0x00040000,
+        WS_EX_OVERLAPPEDWINDOW = WS_EX_WINDOWEDGE | WS_EX_CLIENTEDGE,
+        WS_EX_PALETTEWINDOW = WS_EX_WINDOWEDGE | WS_EX_TOOLWINDOW | WS_EX_TOPMOST,
+        WS_EX_LAYERED = 0x00080000,
+        WS_EX_NOINHERITLAYOUT = 0x00100000,
+        WS_EX_LAYOUTRTL = 0x00400000,
+        WS_EX_COMPOSITED = 0x02000000,
+        WS_EX_NOACTIVATE = 0x08000000
+    }
+
+    [DllImport("user32.dll", SetLastError = true)]
+    public static extern bool DestroyWindow(IntPtr hwnd);
+
+    [DllImport("kernel32.dll")]
+    public static extern IntPtr GetModuleHandle(string? lpModuleName);
+
+    [DllImport("user32.dll", SetLastError = true)]
+    public static extern IntPtr CreateWindowEx(
+        int dwExStyle,
+        string lpClassName,
+        string lpWindowName,
+        uint dwStyle,
+        int x,
+        int y,
+        int nWidth,
+        int nHeight,
+        IntPtr hWndParent,
+        IntPtr hMenu,
+        IntPtr hInstance,
+        IntPtr lpParam);
+}

samples/IntegrationTestApp/IntegrationTestApp.csproj

@@ -4,6 +4,7 @@
     <TargetFramework>$(AvsCurrentTargetFramework)</TargetFramework>
     <Nullable>enable</Nullable>
     <NoWarn>$(NoWarn);AVP1012</NoWarn>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
   </PropertyGroup>
 
   <PropertyGroup>
@@ -12,13 +13,14 @@
     <NSHighResolutionCapable>true</NSHighResolutionCapable>
     <CFBundleShortVersionString>1.0.0</CFBundleShortVersionString>
   </PropertyGroup>
-  
+
   <ItemGroup>
     <AvaloniaResource Include="Assets\*" />
   </ItemGroup>
 
   <ItemGroup>
     <PackageReference Include="Dotnet.Bundle" Version="0.9.13" />
+    <PackageReference Include="MonoMac.NetStandard" Version="0.0.4" />
   </ItemGroup>
 
   <ItemGroup>

samples/IntegrationTestApp/MainWindow.axaml

@@ -3,6 +3,7 @@
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:integrationTestApp="using:IntegrationTestApp"
+        xmlns:embedding="using:IntegrationTestApp.Embedding"
         mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
         x:Class="IntegrationTestApp.MainWindow"
         Name="MainWindow"
@@ -94,6 +95,20 @@
         </StackPanel>
       </TabItem>
 
+      <TabItem Header="Embedding">
+        <StackPanel>
+          <embedding:NativeTextBox Name="NativeTextBox" Height="23"/>
+          <StackPanel Orientation="Horizontal">
+            <CheckBox Name="EmbeddingPopupOpenCheckBox">Open Popup</CheckBox>
+            <Popup IsOpen="{Binding #EmbeddingPopupOpenCheckBox.IsChecked}"
+                   PlacementTarget="EmbeddingPopupOpenCheckBox"
+                   Placement="Right">
+              <embedding:NativeTextBox Name="NativeTextBoxInPopup" Width="200" Height="23"/>
+            </Popup>
+          </StackPanel>
+        </StackPanel>
+      </TabItem>
+
       <TabItem Header="Gestures">
         <DockPanel>
           <DockPanel DockPanel.Dock="Top">

samples/IntegrationTestApp/Program.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Linq;
 using Avalonia;
+using IntegrationTestApp.Embedding;
 
 namespace IntegrationTestApp
 {
@@ -31,6 +32,13 @@ public static void Main(string[] args)
         public static AppBuilder BuildAvaloniaApp()
             => AppBuilder.Configure<App>()
                 .UsePlatformDetect()
+                .AfterSetup(builder =>
+                {
+                    NativeTextBox.Factory = 
+                        OperatingSystem.IsWindows() ? new Win32TextBoxFactory() :
+                        OperatingSystem.IsMacOS() ? new MacOSTextBoxFactory() :
+                        null;
+                })
                 .LogToTrace();
     }
 }

samples/IntegrationTestApp/app.manifest

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <assemblyIdentity version="1.0.0.0" name="ControlCatalog.app"/>
+
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- A list of the Windows versions that this application has been tested on
+           and is designed to work with. Uncomment the appropriate elements
+           and Windows will automatically select the most compatible environment. -->
+
+      <!-- Windows Vista -->
+      <!--<supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}" />-->
+
+      <!-- Windows 7 -->
+      <!--<supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}" />-->
+
+      <!-- Windows 8 -->
+      <!--<supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}" />-->
+
+      <!-- Windows 8.1 -->
+      <!--<supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}" />-->
+
+      <!-- Windows 10 -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
+
+    </application>
+  </compatibility>
+</assembly>

src/Avalonia.Controls/Automation/Peers/InteropAutomationPeer.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using Avalonia.Automation.Peers;
+using Avalonia.Platform;
+
+namespace Avalonia.Controls.Automation.Peers;
+
+/// <summary>
+/// Represents the root of a native control automation tree hosted by a <see cref="NativeControlHost"/>.
+/// </summary>
+/// <remarks>
+/// This peer should be special-cased in the platform backend, as it represents a native control
+/// and hence none of the standard automation peer methods are applicable.
+/// </remarks>
+internal class InteropAutomationPeer : AutomationPeer
+{
+    private AutomationPeer? _parent;
+
+    public InteropAutomationPeer(IPlatformHandle nativeControlHandle) => NativeControlHandle = nativeControlHandle;
+    public IPlatformHandle NativeControlHandle { get; }
+
+    protected override void BringIntoViewCore() => throw new NotImplementedException();
+    protected override string? GetAcceleratorKeyCore() => throw new NotImplementedException();
+    protected override string? GetAccessKeyCore() => throw new NotImplementedException();
+    protected override AutomationControlType GetAutomationControlTypeCore() => throw new NotImplementedException();
+    protected override string? GetAutomationIdCore() => throw new NotImplementedException();
+    protected override Rect GetBoundingRectangleCore() => throw new NotImplementedException();
+    protected override string GetClassNameCore() => throw new NotImplementedException();
+    protected override AutomationPeer? GetLabeledByCore() => throw new NotImplementedException();
+    protected override string? GetNameCore() => throw new NotImplementedException();
+    protected override IReadOnlyList<AutomationPeer> GetOrCreateChildrenCore() => throw new NotImplementedException();
+    protected override AutomationPeer? GetParentCore() => _parent;
+    protected override bool HasKeyboardFocusCore() => throw new NotImplementedException();
+    protected override bool IsContentElementCore() => throw new NotImplementedException();
+    protected override bool IsControlElementCore() => throw new NotImplementedException();
+    protected override bool IsEnabledCore() => throw new NotImplementedException();
+    protected override bool IsKeyboardFocusableCore() => throw new NotImplementedException();
+    protected override void SetFocusCore() => throw new NotImplementedException();
+    protected override bool ShowContextMenuCore() => throw new NotImplementedException();
+
+    protected internal override bool TrySetParent(AutomationPeer? parent)
+    {
+        _parent = parent;
+        return true;
+    }
+}