Added automation peer for TokenizingTextBox

Author: jamesmcroft

Microsoft.Toolkit.Uwp.UI.Controls.Input/TokenizingTextBox/TokenizingTextBox.cs

@@ -2,15 +2,16 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Collections.ObjectModel;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.Toolkit.Uwp.Deferred;
+using Microsoft.Toolkit.Uwp.UI.Automation.Peers;
 using Microsoft.Toolkit.Uwp.UI.Helpers;
 using Windows.System;
 using Windows.UI.Core;
 using Windows.UI.Xaml;
+using Windows.UI.Xaml.Automation.Peers;
 using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Input;
 
@@ -486,6 +487,15 @@ protected void UpdateCurrentTextEdit(ITokenStringContainer edit)
             Text = edit.Text; // Update our text property.
         }
 
+        /// <summary>
+        /// Creates AutomationPeer (<see cref="UIElement.OnCreateAutomationPeer"/>)
+        /// </summary>
+        /// <returns>An automation peer for this <see cref="TokenizingTextBox"/>.</returns>
+        protected override AutomationPeer OnCreateAutomationPeer()
+        {
+            return new TokenizingTextBoxAutomationPeer(this);
+        }
+
         /// <summary>
         /// Remove the specified token from the list.
         /// </summary>

Microsoft.Toolkit.Uwp.UI.Controls.Input/TokenizingTextBox/TokenizingTextBoxAutomationPeer.cs

@@ -0,0 +1,116 @@
+// 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 System.Collections.Generic;
+using Microsoft.Toolkit.Uwp.UI.Controls;
+using Windows.UI.Xaml.Automation;
+using Windows.UI.Xaml.Automation.Peers;
+using Windows.UI.Xaml.Controls;
+
+namespace Microsoft.Toolkit.Uwp.UI.Automation.Peers
+{
+    /// <summary>
+    /// Defines a framework element automation peer for the <see cref="TokenizingTextBox"/> control.
+    /// </summary>
+    public class TokenizingTextBoxAutomationPeer : ListViewBaseAutomationPeer
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TokenizingTextBoxAutomationPeer"/> class.
+        /// </summary>
+        /// <param name="owner">
+        /// The <see cref="TokenizingTextBox" /> that is associated with this <see cref="T:Microsoft.Toolkit.Uwp.UI.Automation.Peers.TokenizingTextBoxAutomationPeer" />.
+        /// </param>
+        public TokenizingTextBoxAutomationPeer(TokenizingTextBox owner)
+            : base(owner)
+        {
+        }
+
+        private TokenizingTextBox OwningTokenizingTextBox
+        {
+            get
+            {
+                return Owner as TokenizingTextBox;
+            }
+        }
+
+        /// <summary>
+        /// Called by GetClassName that gets a human readable name that, in addition to AutomationControlType,
+        /// differentiates the control represented by this AutomationPeer.
+        /// </summary>
+        /// <returns>The string that contains the name.</returns>
+        protected override string GetClassNameCore()
+        {
+            return Owner.GetType().Name;
+        }
+
+        /// <summary>
+        /// Called by GetName.
+        /// </summary>
+        /// <returns>
+        /// Returns the first of these that is not null or empty:
+        /// - Value returned by the base implementation
+        /// - Name of the owning Carousel
+        /// - Carousel class name
+        /// </returns>
+        protected override string GetNameCore()
+        {
+            string name = this.OwningTokenizingTextBox.Name;
+            if (!string.IsNullOrEmpty(name))
+            {
+                return name;
+            }
+
+            name = AutomationProperties.GetName(this.OwningTokenizingTextBox);
+            if (!string.IsNullOrEmpty(name))
+            {
+                return name;
+            }
+
+            return base.GetNameCore();
+        }
+
+        /// <summary>
+        /// Gets the control pattern that is associated with the specified Windows.UI.Xaml.Automation.Peers.PatternInterface.
+        /// </summary>
+        /// <param name="patternInterface">A value from the Windows.UI.Xaml.Automation.Peers.PatternInterface enumeration.</param>
+        /// <returns>The object that supports the specified pattern, or null if unsupported.</returns>
+        protected override object GetPatternCore(PatternInterface patternInterface)
+        {
+            switch (patternInterface)
+            {
+                case PatternInterface.Selection:
+                    return this;
+            }
+
+            return base.GetPatternCore(patternInterface);
+        }
+
+        /// <summary>
+        /// Gets the collection of elements that are represented in the UI Automation tree as immediate
+        /// child elements of the automation peer.
+        /// </summary>
+        /// <returns>The children elements.</returns>
+        protected override IList<AutomationPeer> GetChildrenCore()
+        {
+            TokenizingTextBox owner = this.OwningTokenizingTextBox;
+
+            ItemCollection items = owner.Items;
+            if (items.Count <= 0)
+            {
+                return null;
+            }
+
+            List<AutomationPeer> peers = new List<AutomationPeer>(items.Count);
+            for (int i = 0; i < items.Count; i++)
+            {
+                if (owner.ContainerFromIndex(i) is TokenizingTextBoxItem element)
+                {
+                    peers.Add(FromElement(element) ?? CreatePeerForElement(element));
+                }
+            }
+
+            return peers;
+        }
+    }
+}