Merge pull request #3518 from windows-toolkit/jamesmcroft/3517-bladeview-automation

Added automation peers for BladeView and BladeItem controls

Author: michael-hawker

Microsoft.Toolkit.Uwp.UI.Controls/BladeView/BladeItem.Properties.cs

@@ -39,6 +39,8 @@ public partial class BladeItem
         /// </summary>
         public static readonly DependencyProperty CloseButtonForegroundProperty = DependencyProperty.Register(nameof(CloseButtonForeground), typeof(Brush), typeof(BladeItem), new PropertyMetadata(new SolidColorBrush(Colors.Black)));
 
+        private WeakReference<BladeView> _parentBladeView;
+
         /// <summary>
         /// Gets or sets the foreground color of the close button
         /// </summary>
@@ -84,6 +86,16 @@ public bool IsOpen
             set { SetValue(IsOpenProperty, value); }
         }
 
+        internal BladeView ParentBladeView
+        {
+            get
+            {
+                this._parentBladeView.TryGetTarget(out var bladeView);
+                return bladeView;
+            }
+            set => this._parentBladeView = new WeakReference<BladeView>(value);
+        }
+
         private static void IsOpenChangedCallback(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
         {
             BladeItem bladeItem = (BladeItem)dependencyObject;

Microsoft.Toolkit.Uwp.UI.Controls/BladeView/BladeItem.cs

@@ -4,8 +4,10 @@
 
 using System;
 using Microsoft.Toolkit.Uwp.Extensions;
+using Microsoft.Toolkit.Uwp.UI.Automation.Peers;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Automation;
+using Windows.UI.Xaml.Automation.Peers;
 using Windows.UI.Xaml.Controls;
 
 namespace Microsoft.Toolkit.Uwp.UI.Controls
@@ -92,6 +94,15 @@ protected override void OnCollapsed(EventArgs args)
             }
         }
 
+        /// <summary>
+        /// Creates AutomationPeer (<see cref="UIElement.OnCreateAutomationPeer"/>)
+        /// </summary>
+        /// <returns>An automation peer for this <see cref="BladeItem"/>.</returns>
+        protected override AutomationPeer OnCreateAutomationPeer()
+        {
+            return new BladeItemAutomationPeer(this);
+        }
+
         private void OnSizeChanged(object sender, SizeChangedEventArgs sizeChangedEventArgs)
         {
             if (IsExpanded)

Microsoft.Toolkit.Uwp.UI.Controls/BladeView/BladeItemAutomationPeer.cs

@@ -0,0 +1,163 @@
+// 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 Microsoft.Toolkit.Uwp.UI.Controls;
+using Microsoft.Toolkit.Uwp.UI.Extensions;
+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="BladeItem"/>.
+    /// </summary>
+    public class BladeItemAutomationPeer : FrameworkElementAutomationPeer
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BladeItemAutomationPeer"/> class.
+        /// </summary>
+        /// <param name="owner">
+        /// The <see cref="BladeItem" /> that is associated with this <see cref="T:Windows.UI.Xaml.Automation.Peers.BladeItemAutomationPeer" />.
+        /// </param>
+        public BladeItemAutomationPeer(BladeItem owner)
+            : base(owner)
+        {
+        }
+
+        private BladeItem OwnerBladeItem
+        {
+            get { return this.Owner as BladeItem; }
+        }
+
+        /// <summary>
+        /// Gets the control type for the element that is associated with the UI Automation peer.
+        /// </summary>
+        /// <returns>The control type.</returns>
+        protected override AutomationControlType GetAutomationControlTypeCore()
+        {
+            return AutomationControlType.ListItem;
+        }
+
+        /// <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 BladeItem
+        /// - BladeItem class name
+        /// </returns>
+        protected override string GetNameCore()
+        {
+            string name = AutomationProperties.GetName(this.OwnerBladeItem);
+            if (!string.IsNullOrEmpty(name))
+            {
+                return name;
+            }
+
+            name = this.OwnerBladeItem.Name;
+            if (!string.IsNullOrEmpty(name))
+            {
+                return name;
+            }
+
+            name = this.OwnerBladeItem.Header?.ToString();
+            if (!string.IsNullOrEmpty(name))
+            {
+                return name;
+            }
+
+            TextBlock textBlock = this.OwnerBladeItem.FindDescendant<TextBlock>();
+            if (textBlock != null)
+            {
+                return textBlock.Text;
+            }
+
+            name = base.GetNameCore();
+            if (!string.IsNullOrEmpty(name))
+            {
+                return name;
+            }
+
+            return string.Empty;
+        }
+
+        /// <summary>
+        /// Called by GetAutomationId that gets the **AutomationId** of the element that is associated with the automation peer.
+        /// </summary>
+        /// <returns>
+        /// The string that contains the automation ID.
+        /// </returns>
+        protected override string GetAutomationIdCore()
+        {
+            string automationId = base.GetAutomationIdCore();
+            if (!string.IsNullOrEmpty(automationId))
+            {
+                return automationId;
+            }
+
+            if (this.OwnerBladeItem != null)
+            {
+                return this.GetNameCore();
+            }
+
+            return string.Empty;
+        }
+
+        /// <summary>
+        /// Returns the size of the set where the element that is associated with the automation peer is located.
+        /// </summary>
+        /// <returns>
+        /// The size of the set.
+        /// </returns>
+        protected override int GetSizeOfSetCore()
+        {
+            int sizeOfSet = base.GetSizeOfSetCore();
+
+            if (sizeOfSet != -1)
+            {
+                return sizeOfSet;
+            }
+
+            BladeItem owner = this.OwnerBladeItem;
+            BladeView parent = owner.ParentBladeView;
+            sizeOfSet = parent.Items.Count;
+
+            return sizeOfSet;
+        }
+
+        /// <summary>
+        /// Returns the ordinal position in the set for the element that is associated with the automation peer.
+        /// </summary>
+        /// <returns>
+        /// The ordinal position in the set.
+        /// </returns>
+        protected override int GetPositionInSetCore()
+        {
+            int positionInSet = base.GetPositionInSetCore();
+
+            if (positionInSet != -1)
+            {
+                return positionInSet;
+            }
+
+            BladeItem owner = this.OwnerBladeItem;
+            BladeView parent = owner.ParentBladeView;
+            positionInSet = parent.IndexFromContainer(owner);
+
+            return positionInSet;
+        }
+    }
+}

Microsoft.Toolkit.Uwp.UI.Controls/BladeView/BladeView.cs

@@ -6,11 +6,13 @@
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
+using Microsoft.Toolkit.Uwp.UI.Automation.Peers;
 using Microsoft.Toolkit.Uwp.UI.Extensions;
 using Windows.Foundation;
 using Windows.Foundation.Collections;
 using Windows.UI.Core;
 using Windows.UI.Xaml;
+using Windows.UI.Xaml.Automation.Peers;
 using Windows.UI.Xaml.Controls;
 
 namespace Microsoft.Toolkit.Uwp.UI.Controls
@@ -65,6 +67,7 @@ protected override void PrepareContainerForItemOverride(DependencyObject element
             if (blade != null)
             {
                 blade.VisibilityChanged += BladeOnVisibilityChanged;
+                blade.ParentBladeView = this;
             }
 
             base.PrepareContainerForItemOverride(element, item);
@@ -83,6 +86,15 @@ protected override void ClearContainerForItemOverride(DependencyObject element,
             base.ClearContainerForItemOverride(element, item);
         }
 
+        /// <summary>
+        /// Creates AutomationPeer (<see cref="UIElement.OnCreateAutomationPeer"/>)
+        /// </summary>
+        /// <returns>An automation peer for this <see cref="BladeView"/>.</returns>
+        protected override AutomationPeer OnCreateAutomationPeer()
+        {
+            return new BladeViewAutomationPeer(this);
+        }
+
         private void CycleBlades()
         {
             ActiveBlades = new ObservableCollection<BladeItem>();

Microsoft.Toolkit.Uwp.UI.Controls/BladeView/BladeViewAutomationPeer.cs

@@ -0,0 +1,115 @@
+// 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="BladeView"/> control.
+    /// </summary>
+    public class BladeViewAutomationPeer : ItemsControlAutomationPeer
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BladeViewAutomationPeer"/> class.
+        /// </summary>
+        /// <param name="owner">
+        /// The <see cref="BladeView" /> that is associated with this <see cref="T:Windows.UI.Xaml.Automation.Peers.BladeViewAutomationPeer" />.
+        /// </param>
+        public BladeViewAutomationPeer(BladeView owner)
+            : base(owner)
+        {
+        }
+
+        private BladeView OwningBladeView
+        {
+            get
+            {
+                return Owner as BladeView;
+            }
+        }
+
+        /// <summary>
+        /// Gets the control type for the element that is associated with the UI Automation peer.
+        /// </summary>
+        /// <returns>The control type.</returns>
+        protected override AutomationControlType GetAutomationControlTypeCore()
+        {
+            return AutomationControlType.List;
+        }
+
+        /// <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 BladeView
+        /// - BladeView class name
+        /// </returns>
+        protected override string GetNameCore()
+        {
+            string name = AutomationProperties.GetName(this.OwningBladeView);
+            if (!string.IsNullOrEmpty(name))
+            {
+                return name;
+            }
+
+            name = this.OwningBladeView.Name;
+            if (!string.IsNullOrEmpty(name))
+            {
+                return name;
+            }
+
+            name = base.GetNameCore();
+            if (!string.IsNullOrEmpty(name))
+            {
+                return name;
+            }
+
+            return string.Empty;
+        }
+
+        /// <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()
+        {
+            BladeView owner = OwningBladeView;
+
+            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 BladeItem element)
+                {
+                    peers.Add(FromElement(element) ?? CreatePeerForElement(element));
+                }
+            }
+
+            return peers;
+        }
+    }
+}