Adding UIA accessibility support for PictureBox control (#3233)

src/System.Windows.Forms/src/PublicAPI.Unshipped.txt

@@ -5,3 +5,4 @@ System.Windows.Forms.ListViewGroup.TitleImageKey.get -> string!
 System.Windows.Forms.ListViewGroup.TitleImageKey.set -> void
 ~System.Windows.Forms.ListView.GroupImageList.get -> System.Windows.Forms.ImageList
 ~System.Windows.Forms.ListView.GroupImageList.set -> void
+~override System.Windows.Forms.PictureBox.CreateAccessibilityInstance() -> System.Windows.Forms.AccessibleObject

src/System.Windows.Forms/src/System/Windows/Forms/PictureBox.PictureBoxAccessibleObject.cs

@@ -0,0 +1,32 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using static Interop;
+
+namespace System.Windows.Forms
+{
+    public partial class PictureBox
+    {
+        internal class PictureBoxAccessibleObject : ControlAccessibleObject
+        {
+            public PictureBoxAccessibleObject(PictureBox owner) : base(owner)
+            {
+            }
+
+            internal override object? GetPropertyValue(UiaCore.UIA propertyID)
+                => propertyID switch
+                {
+                    UiaCore.UIA.NamePropertyId
+                        => Name,
+                    UiaCore.UIA.ControlTypePropertyId
+                        => UiaCore.UIA.PaneControlTypeId,
+                    UiaCore.UIA.AutomationIdPropertyId
+                        => Owner.Name,
+                    UiaCore.UIA.IsKeyboardFocusablePropertyId
+                        => true,
+                    _ => base.GetPropertyValue(propertyID)
+                };
+        }
+    }
+}

src/System.Windows.Forms/src/System/Windows/Forms/PictureBox.cs

@@ -27,7 +27,7 @@ namespace System.Windows.Forms
     [Docking(DockingBehavior.Ask)]
     [Designer("System.Windows.Forms.Design.PictureBoxDesigner, " + AssemblyRef.SystemDesign)]
     [SRDescription(nameof(SR.DescriptionPictureBox))]
-    public class PictureBox : Control, ISupportInitialize
+    public partial class PictureBox : Control, ISupportInitialize
     {
         /// <summary>
         ///  The type of border this control will have.
@@ -837,6 +837,8 @@ namespace System.Windows.Forms
             remove => Events.RemoveHandler(EVENT_SIZEMODECHANGED, value);
         }
 
+        internal override bool SupportsUiaProviders => true;
+
         [Browsable(false)]
         [EditorBrowsable(EditorBrowsableState.Never)]
         public new bool TabStop
@@ -969,6 +971,9 @@ namespace System.Windows.Forms
             }
         }
 
+        protected override AccessibleObject CreateAccessibilityInstance()
+            => new PictureBoxAccessibleObject(this);
+
         protected override void Dispose(bool disposing)
         {
             if (disposing)

src/System.Windows.Forms/tests/UnitTests/AccessibleObjects/PictureBox.PictureBoxAccessibleObjectTests.cs

@@ -0,0 +1,125 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Xunit;
+using static Interop.UiaCore;
+
+namespace System.Windows.Forms.Tests
+{
+    public class PictureBox_PictureBoxAccessibleObjectTests
+    {
+        [WinFormsFact]
+        public void PictureBoxAccessibleObject_Ctor_NullControl_ThrowsArgumentNullException()
+        {
+            Assert.Throws<ArgumentNullException>("ownerControl", () => new PictureBox.PictureBoxAccessibleObject(null));
+        }
+
+        [WinFormsFact]
+        public void PictureBoxAccessibleObject_Ctor_Default()
+        {
+            using var pictureBox = new PictureBox();
+            Assert.False(pictureBox.IsHandleCreated);
+            var pictureBoxAccessibleObject = new PictureBox.PictureBoxAccessibleObject(pictureBox);
+
+            Assert.NotNull(pictureBoxAccessibleObject.Owner);
+            // TODO: ControlAccessibleObject shouldn't force handle creation, tracked in https://github.com/dotnet/winforms/issues/3062
+            Assert.True(pictureBox.IsHandleCreated);
+        }
+
+        [WinFormsFact]
+        public void PictureBoxAccessibleObject_Description_ReturnsExpected()
+        {
+            using var pictureBox = new PictureBox
+            {
+                AccessibleDescription = "TestDescription",
+            };
+
+            Assert.False(pictureBox.IsHandleCreated);
+            var pictureBoxAccessibleObject = new PictureBox.PictureBoxAccessibleObject(pictureBox);
+
+            Assert.Equal("TestDescription", pictureBoxAccessibleObject.Description);
+            // TODO: ControlAccessibleObject shouldn't force handle creation, tracked in https://github.com/dotnet/winforms/issues/3062
+            Assert.True(pictureBox.IsHandleCreated);
+        }
+
+        [WinFormsFact]
+        public void PictureBoxAccessibleObject_Name_ReturnsExpected()
+        {
+            using var pictureBox = new PictureBox
+            {
+                AccessibleName = "TestName"
+            };
+
+            Assert.False(pictureBox.IsHandleCreated);
+            var pictureBoxAccessibleObject = new PictureBox.PictureBoxAccessibleObject(pictureBox);
+
+            Assert.Equal("TestName", pictureBoxAccessibleObject.Name);
+            // TODO: ControlAccessibleObject shouldn't force handle creation, tracked in https://github.com/dotnet/winforms/issues/3062
+            Assert.True(pictureBox.IsHandleCreated);
+        }
+
+        [WinFormsFact]
+        public void PictureBoxAccessibleObject_CustomRole_ReturnsExpected()
+        {
+            using var pictureBox = new PictureBox
+            {
+                AccessibleRole = AccessibleRole.PushButton
+            };
+
+            Assert.False(pictureBox.IsHandleCreated);
+            var pictureBoxAccessibleObject = new PictureBox.PictureBoxAccessibleObject(pictureBox);
+
+            Assert.Equal(AccessibleRole.PushButton, pictureBoxAccessibleObject.Role);
+            // TODO: ControlAccessibleObject shouldn't force handle creation, tracked in https://github.com/dotnet/winforms/issues/3062
+            Assert.True(pictureBox.IsHandleCreated);
+        }
+
+        [WinFormsFact]
+        public void PictureBoxAccessibleObject_DefaultRole_ReturnsExpected()
+        {
+            using var pictureBox = new PictureBox();
+            Assert.False(pictureBox.IsHandleCreated);
+            var pictureBoxAccessibleObject = new PictureBox.PictureBoxAccessibleObject(pictureBox);
+            Assert.Equal(AccessibleRole.Client, pictureBoxAccessibleObject.Role);
+
+            // TODO: ControlAccessibleObject shouldn't force handle creation, tracked in https://github.com/dotnet/winforms/issues/3062
+            Assert.True(pictureBox.IsHandleCreated);
+        }
+
+        [WinFormsTheory]
+        [InlineData((int)UIA.NamePropertyId, "TestName")]
+        [InlineData((int)UIA.ControlTypePropertyId, UIA.PaneControlTypeId)]
+        [InlineData((int)UIA.IsKeyboardFocusablePropertyId, true)]
+        [InlineData((int)UIA.AutomationIdPropertyId, "PictureBox1")]
+        public void PictureBoxAccessibleObject_GetPropertyValue_Invoke_ReturnsExpected(int propertyID, object expected)
+        {
+            using var pictureBox = new PictureBox
+            {
+                Name = "PictureBox1",
+                AccessibleName = "TestName"
+            };
+
+            Assert.False(pictureBox.IsHandleCreated);
+            var pictureBoxAccessibleObject = new PictureBox.PictureBoxAccessibleObject(pictureBox);
+            object value = pictureBoxAccessibleObject.GetPropertyValue((UIA)propertyID);
+
+            Assert.Equal(expected, value);
+            // TODO: ControlAccessibleObject shouldn't force handle creation, tracked in https://github.com/dotnet/winforms/issues/3062
+            Assert.True(pictureBox.IsHandleCreated);
+        }
+
+        [WinFormsFact]
+        public void PictureBoxAccessibleObject_IsPatternSupported_Invoke_ReturnsTrue_ForLegacyIAccessiblePatternId()
+        {
+            using var pictureBox = new PictureBox();
+            Assert.False(pictureBox.IsHandleCreated);
+            var pictureBoxAccessibleObject = new PictureBox.PictureBoxAccessibleObject(pictureBox);
+
+            Assert.True(pictureBoxAccessibleObject.IsPatternSupported(UIA.LegacyIAccessiblePatternId));
+            // TODO: ControlAccessibleObject shouldn't force handle creation, tracked in https://github.com/dotnet/winforms/issues/3062
+            Assert.True(pictureBox.IsHandleCreated);
+        }
+    }
+}
+