Convert to using list of accessibility elements for iOS tab indexes (#…

…11077)

* Convert to using list of accessibility elements for iOS tab indexes

* - add issues

Co-authored-by: Samantha Houts <samhouts@users.noreply.github.com>

fixes #6667
fixes #11026

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue7606.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Text;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 7606, "[Bug] When a view appears it is not accessible via VoiceOver",
+		PlatformAffected.iOS)]
+#if UITEST
+	[NUnit.Framework.Category(Core.UITests.UITestCategories.Github10000)]
+	[NUnit.Framework.Category(UITestCategories.ManualReview)]
+	[NUnit.Framework.Category(UITestCategories.Accessibility)]
+#endif
+	public class Issue7606 : TestContentPage
+	{
+		protected override void Init()
+		{
+			Label visibilityLabel = new Label()
+			{
+				Text = "Swipe right and I should be read by voice over.",
+				IsVisible = false
+			};
+
+			Content = new StackLayout()
+			{
+				Children =
+				{
+					new Button()
+					{
+						Text = "Click Me",
+						Command = new Command(() => visibilityLabel.IsVisible = !visibilityLabel.IsVisible)
+					},
+					visibilityLabel
+				}
+			};
+		}
+
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue8613.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Text;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 8613, "[Bug] Accessibility, screenreader ignores or skips items in nested stacklayout",
+		PlatformAffected.iOS)]
+#if UITEST
+	[NUnit.Framework.Category(Core.UITests.UITestCategories.Github10000)]
+	[NUnit.Framework.Category(UITestCategories.ManualReview)]
+	[NUnit.Framework.Category(UITestCategories.Accessibility)]
+#endif
+	public class Issue8613 : TestContentPage
+	{
+		Label CreateLabel(bool? IsInAccessibleTree, string text)
+		{
+			Label label = new Label()
+			{
+				Text = text
+			};
+
+			if(IsInAccessibleTree.HasValue)
+				AutomationProperties.SetIsInAccessibleTree(label, IsInAccessibleTree);
+
+			return label;
+		}
+
+		Entry CreateEntry(bool IsInAccessibleTree, string placeholderText)
+		{
+			Entry entry = new Entry()
+			{
+				Placeholder = placeholderText
+			};
+
+			AutomationProperties.SetIsInAccessibleTree(entry, IsInAccessibleTree);
+			return entry;
+		}
+
+		protected override void Init()
+		{
+			// Based on Sample
+			// https://github.com/xamarin/xamarin-forms-samples/blob/master/UserInterface/Accessibility/Accessibility/AccessibilityPage.xaml
+			Content = new ScrollView()
+			{
+				Content =
+					new StackLayout()
+					{
+						Children =
+						{
+							CreateLabel(true, "Voice Over Swiping should progress sequentially through all visible elements"),
+							CreateLabel(true, "Second Label IsInAccessibleTree = true"),
+							new StackLayout()
+							{
+								Children =
+								{
+									new Label()
+									{
+										Text = "Enter Your Name: ",
+									},
+									CreateEntry(true, "If Voice Over swiping gets stuck here test has failed"),
+								},
+							},
+							CreateLabel(true, "Label After the Entry")
+						},
+					},
+			};
+		}
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue8691.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Text;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 8691, "[Bug] TabIndex is ignored for first element on page for VoiceOver",
+		PlatformAffected.iOS)]
+#if UITEST
+	[NUnit.Framework.Category(Core.UITests.UITestCategories.Github10000)]
+	[NUnit.Framework.Category(UITestCategories.ManualReview)]
+	[NUnit.Framework.Category(UITestCategories.Accessibility)]
+#endif
+	public class Issue8691 : TestContentPage
+	{
+		protected override void Init()
+		{
+
+			Content = new StackLayout()
+			{
+				Children =
+				{
+					new Label()
+					{
+						Text = "2nd TabIndex",
+						TabIndex = 20
+					},
+					new Label()
+					{
+						Text = "I should be the first element focused when voice over is on",
+						TabIndex = 10
+					},
+					new Label()
+					{
+						Text = "3rd TabIndex",
+						TabIndex = 30
+					},
+				}
+			};
+		}
+
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue9137.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Text;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 9137, "A11y: Image in a11y tree stops voiceover from hopping to the next element",
+		PlatformAffected.iOS)]
+#if UITEST
+	[NUnit.Framework.Category(Core.UITests.UITestCategories.Github10000)]
+	[NUnit.Framework.Category(UITestCategories.ManualReview)]
+	[NUnit.Framework.Category(UITestCategories.Accessibility)]
+#endif
+	public class Issue9137 : TestContentPage
+	{
+		Label CreateLabel(bool IsInAccessibleTree, string text)
+		{
+			Label label = new Label()
+			{
+				Text = text
+			};
+			AutomationProperties.SetIsInAccessibleTree(label, IsInAccessibleTree);
+			return label;
+		}
+
+		protected override void Init()
+		{
+			Content = new StackLayout()
+			{
+				Children =
+				{
+					new StackLayout()
+					{
+						Children =
+						{
+							CreateLabel(false, "IsInAccessibleTree is false")
+						},
+					},
+					new StackLayout()
+					{
+						Children =
+						{
+							new StackLayout()
+							{
+								Children =
+								{
+									new Label()
+									{
+										Text = "Turn Voice Over on and verify that you can swipe all the way forward and then backwards. If you get stuck toggling between the same two elements test has failed",
+										TabIndex = 10
+									},
+									new Image()
+									{
+										TabIndex = 20,
+										Source = "coffee.png"
+									},
+								},
+							},
+							new Label()
+							{
+								Text = "Tab Index 70",
+								TabIndex = 70
+							}
+						},
+					},
+				}
+			};
+		}
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -26,6 +26,10 @@
     </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Issue10744.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue10909.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue8613.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue9137.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue8691.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue7606.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11137.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11106.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue8291.cs" />

Xamarin.Forms.Core.UITests.Shared/UITestCategories.cs

@@ -64,6 +64,7 @@ internal static class UITestCategories
 		public const string Github5000 = "Github5000";
 		public const string Github10000 = "Github10000";
 		public const string RadioButton = "RadioButton";
+		public const string Accessibility = "Accessibility";
 		public const string Shape = "Shape";
 	}
 }

Xamarin.Forms.Platform.iOS/Renderers/PageContainer.cs

@@ -1,4 +1,5 @@
 using Foundation;
+using ObjCRuntime;
 using System;
 using System.Collections.Generic;
 using UIKit;
@@ -8,8 +9,9 @@ namespace Xamarin.Forms.Platform.iOS
 	internal class PageContainer : UIView, IUIAccessibilityContainer
 	{
 		readonly IAccessibilityElementsController _parent;
-		List<NSObject> _accessibilityElements = null;
+		NSArray _accessibilityElements = null;
 		bool _disposed;
+		bool _loaded;
 
 		public PageContainer(IAccessibilityElementsController parent)
 		{
@@ -22,22 +24,40 @@ public PageContainer()
 			IsAccessibilityElement = false;
 		}
 
-		List<NSObject> AccessibilityElements
+		public override bool IsAccessibilityElement
 		{
+			get => false;
+			set => base.IsAccessibilityElement = value;
+		}
+
+		[Internals.Preserve(Conditional = true)]
+		public virtual NSArray AccessibilityElements
+		{
+			[Export("accessibilityElements", ArgumentSemantic.Copy)]
 			get
 			{
+				if (_loaded)
+					return _accessibilityElements;
+
 				// lazy-loading this list so that the expensive call to GetAccessibilityElements only happens when VoiceOver is on.
 				if (_accessibilityElements == null || _accessibilityElements.Count == 0)
 				{
-					_accessibilityElements = _parent.GetAccessibilityElements();
+					var elements =_parent.GetAccessibilityElements();
+					if(elements != null)
+					{
+						_accessibilityElements = NSArray.FromNSObjects(elements.ToArray());
+					}
 				}
+
+				_loaded = true;
 				return _accessibilityElements;
 			}
 		}
 
 		public void ClearAccessibilityElements()
 		{
 			_accessibilityElements = null;
+			_loaded = false;
 		}
 
 		protected override void Dispose(bool disposing)
@@ -49,38 +69,5 @@ protected override void Dispose(bool disposing)
 			}
 			base.Dispose(disposing);
 		}
-
-		[Export("accessibilityElementCount")]
-		[Internals.Preserve(Conditional = true)]
-		nint AccessibilityElementCount()
-		{
-			if (AccessibilityElements == null || AccessibilityElements.Count == 0)
-				return 0;
-
-			// Note: this will only be called when VoiceOver is enabled
-			return AccessibilityElements.Count;
-		}
-
-		[Export("accessibilityElementAtIndex:")]
-		[Internals.Preserve(Conditional = true)]
-		NSObject GetAccessibilityElementAt(nint index)
-		{
-			if (AccessibilityElements == null || AccessibilityElements.Count == 0)
-				return NSNull.Null;
-
-			// Note: this will only be called when VoiceOver is enabled
-			return AccessibilityElements[(int)index];
-		}
-
-		[Export("indexOfAccessibilityElement:")]
-		[Internals.Preserve(Conditional = true)]
-		int GetIndexOfAccessibilityElement(NSObject element)
-		{
-			if (AccessibilityElements == null || AccessibilityElements.Count == 0)
-				return int.MaxValue;
-
-			// Note: this will only be called when VoiceOver is enabled
-			return AccessibilityElements.IndexOf(element);
-		}
 	}
 }