Fix Search Handler results to measure to the provided content (#13658) …

…fixes #13403

* Force Shell TitleView to height of container

* - fix collapse on scroll and scroll

* - fix android

* - uiitests

* - fix header positioning

* Fix search handler results to size to view

* Update ShellViewRenderer.cs

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

@@ -0,0 +1,79 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.ComponentModel;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.iOSSpecific;
+
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.None, 0, "Shell Search Handler Item Sizing",
+		PlatformAffected.All)]
+#if UITEST
+	[NUnit.Framework.Category(UITestCategories.Shell)]
+	[NUnit.Framework.Category(UITestCategories.UwpIgnore)]
+#endif
+	public class ShellSearchHandlerItemSizing : TestShell
+	{
+		protected override void Init()
+		{
+			ContentPage contentPage = new ContentPage();
+			AddFlyoutItem(contentPage, "Main Page");
+
+			Shell.SetSearchHandler(contentPage, new TestSearchHandler()
+			{
+				AutomationId = "SearchHandler"
+			});
+
+			contentPage.Content =
+				new StackLayout()
+				{
+					Children =
+					{
+						new Label()
+						{
+							Text = "Type into the search handler to display a list. Each item should be measured to the size of the content"
+						}
+					}
+				};
+		}
+
+
+		public class TestSearchHandler : SearchHandler
+		{
+			public TestSearchHandler()
+			{
+				ShowsResults = true;
+				ItemsSource = Enumerable.Range(0, 100)
+					.Select(_=> "searchresult")
+					.ToList();
+			}
+		}
+
+#if UITEST
+
+		[Test]
+		public void SearchHandlerSizesCorrectly()
+		{
+			RunningApp.WaitForElement("SearchHandler");
+			RunningApp.EnterText("SearchHandler", "Hello");
+			var contentSize = RunningApp.WaitForElement("searchresult")[0].Rect;
+			Assert.Less(contentSize.Height, 100);
+		}
+#endif
+	}
+}

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

@@ -16,6 +16,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Issue13126_2.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue13551.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)RadioButtonTemplateFromStyle.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)ShellSearchHandlerItemSizing.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)ShellWithCustomRendererDisabledAnimations.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)ShellFlyoutContent.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue4720.cs" />

Xamarin.Forms.Core/Shell/SearchHandler.cs

@@ -10,7 +10,6 @@ namespace Xamarin.Forms
 {
 	public class SearchHandler : BindableObject, ISearchHandlerController, IPlaceholderElement, IFontElement, ITextElement, ITextAlignmentElement
 	{
-
 		[EditorBrowsable(EditorBrowsableState.Never)]
 		public static readonly BindablePropertyKey IsFocusedPropertyKey = BindableProperty.CreateReadOnly(nameof(IsFocused),
 			typeof(bool), typeof(VisualElement), default(bool), propertyChanged: OnIsFocusedPropertyChanged);
@@ -261,6 +260,8 @@ void ISearchHandlerController.QueryConfirmed()
 			OnQueryConfirmed();
 		}
 
+		public static readonly BindableProperty AutomationIdProperty = BindableProperty.Create(nameof(AutomationId), typeof(string), typeof(SearchHandler), null);
+
 		public static readonly BindableProperty ClearIconHelpTextProperty =
 			BindableProperty.Create(nameof(ClearIconHelpText), typeof(string), typeof(SearchHandler), null, BindingMode.OneTime,
 				propertyChanged: (b, o, n) => ((SearchHandler)b).UpdateAutomationProperties());
@@ -345,6 +346,12 @@ void ISearchHandlerController.QueryConfirmed()
 
 		private ListProxy _listProxy;
 
+		public string AutomationId
+		{
+			get { return (string)GetValue(AutomationIdProperty); }
+			set { SetValue(AutomationIdProperty, value); }
+		}
+
 		public ImageSource ClearIcon
 		{
 			get { return (ImageSource)GetValue(ClearIconProperty); }

Xamarin.Forms.Platform.Android/FastRenderers/AutomationPropertiesProvider.cs

@@ -30,18 +30,28 @@ internal static void GetDrawerAccessibilityResources(global::Android.Content.Con
 			resourceIdClose = context.Resources.GetIdentifier($"{automationIdParent}{s_defaultDrawerIdCloseSuffix}", "string", context.ApplicationInfo.PackageName);
 		}
 
+
 		internal static void SetAutomationId(AView control, Element element, string value = null)
 		{
-			if (element == null || control == null)
+			if (!control.IsAlive() || element == null)
 			{
 				return;
 			}
 
-			value = element.AutomationId;
+			SetAutomationId(control, element.AutomationId, value);
+		}
+
+		internal static void SetAutomationId(AView control, string automationId, string value = null)
+		{
+			if (!control.IsAlive())
+			{
+				return;
+			}
 
-			if (!string.IsNullOrEmpty(value))
+			automationId = value ?? automationId;
+			if (!string.IsNullOrEmpty(automationId))
 			{
-				control.ContentDescription = value;
+				control.ContentDescription = automationId;
 			}
 		}
 

Xamarin.Forms.Platform.Android/Renderers/ContainerView.cs

@@ -29,6 +29,8 @@ protected ContainerView(IntPtr javaReference, JniHandleOwnership transfer) : bas
 
 		public bool MatchHeight { get; set; }
 
+		internal bool MeasureHeight { get; set; }
+
 		public bool MatchWidth { get; set; }
 
 		public View View
@@ -90,7 +92,15 @@ protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
 			var measureWidth = width > 0 ? Context.FromPixels(width) : double.PositiveInfinity;
 			var measureHeight = height > 0 ? Context.FromPixels(height) : double.PositiveInfinity;
 
-			_shellViewRenderer.LayoutView(measureWidth, measureHeight);
+			double? maxHeight = null;
+
+			if(MeasureHeight)
+			{
+				maxHeight = measureHeight;
+				measureHeight = double.PositiveInfinity;
+			}
+
+			_shellViewRenderer.LayoutView(0, 0, measureWidth, measureHeight, null, maxHeight);
 
 			SetMeasuredDimension((MatchWidth && width != 0) ? width : (int)Context.ToPixels(View.Width),
 								 (MatchHeight && height != 0) ? height : (int)Context.ToPixels(View.Height));

Xamarin.Forms.Platform.Android/Renderers/SearchHandlerAppearanceTracker.cs

@@ -97,6 +97,10 @@ protected virtual void SearchHandlerPropertyChanged(object sender, System.Compon
 			{
 				UpdateVerticalTextAlignment();
 			}
+			else if (e.Is(SearchHandler.AutomationIdProperty))
+			{
+				UpdateAutomationId();
+			}
 		}
 
 		void UpdateSearchBarColors()
@@ -106,6 +110,15 @@ void UpdateSearchBarColors()
 			UpdateTextTransform();
 			UpdatePlaceholderColor();
 			UpdateCancelButtonColor();
+			UpdateAutomationId();
+		}
+
+		void UpdateAutomationId()
+		{
+			FastRenderers
+				.AutomationPropertiesProvider
+				.SetAutomationId(_editText, _searchHandler?.AutomationId);
+
 		}
 
 		void UpdateFont()

Xamarin.Forms.Platform.Android/Renderers/ShellFlyoutTemplatedContentRenderer.cs

@@ -276,7 +276,7 @@ void UpdateFooterLayout()
 		{
 			if (_footerView != null)
 			{
-				_footerView.LayoutView(_shellContext.AndroidContext.FromPixels(_rootView.LayoutParameters.Width), double.PositiveInfinity);
+				_footerView.LayoutView(0, 0, _shellContext.AndroidContext.FromPixels(_rootView.LayoutParameters.Width), double.PositiveInfinity);
 			}
 		}
 
@@ -294,7 +294,7 @@ void UpdateContentLayout()
 
 				var width = View.MeasuredWidth;
 
-				_contentView.LayoutView(
+				_contentView.LayoutView(0, 0,
 					ShellContext.AndroidContext.FromPixels(width),
 					ShellContext.AndroidContext.FromPixels(height));
 			}

Xamarin.Forms.Platform.Android/Renderers/ShellSearchViewAdapter.cs

@@ -105,6 +105,7 @@ public override AView GetView(int position, AView convertView, ViewGroup parent)
 
 				result = new ContainerView(parent.Context, view);
 				result.MatchWidth = true;
+				result.MeasureHeight = true;
 			}
 
 			return result;

Xamarin.Forms.Platform.Android/Renderers/ShellViewRenderer.cs

@@ -15,8 +15,16 @@ internal class ShellViewRenderer
 		public IVisualElementRenderer Renderer { get; private set; }
 		View _view;
 		WeakReference<Context> _context;
+
+		// These are used by layout calls made by android if the layouts
+		// are invalidated. This ensures that the layout is performed
+		// using the same input values
 		public double Width { get; private set; }
 		public double Height { get; private set; }
+		public double? MaxWidth { get; private set; }
+		public double? MaxHeight { get; private set; }
+		public double X { get; private set; }
+		public double Y { get; private set; }
 
 		public ShellViewRenderer(Context context, View view)
 		{
@@ -42,11 +50,6 @@ public void TearDown()
 			_context = null;
 		}
 
-		public void LayoutView(double width, double height, double? maxWidth = null, double? maxHeight = null)
-		{
-			LayoutView(0, 0, width, height, maxWidth, maxHeight);
-		}
-
 		public void LayoutView(double x, double y, double width, double height, double? maxWidth = null, double? maxHeight = null)
 		{
 			if (width == -1)
@@ -57,6 +60,11 @@ public void LayoutView(double x, double y, double width, double height, double?
 
 			Width = width;
 			Height = height;
+			MaxWidth = maxWidth;
+			MaxHeight = maxHeight;
+			X = x;
+			Y = y;
+
 			Context context;
 
 			if (Renderer == null || !(_context.TryGetTarget(out context)) || !Renderer.View.IsAlive())
@@ -134,7 +142,7 @@ public virtual void OnViewSet(View view)
 		}
 
 		void OnViewSizeChanged(object sender, EventArgs e) =>
-			LayoutView(Width, Height);
+			LayoutView(X, Y, Width, Height, MaxWidth, MaxHeight);
 
 		public AView NativeView
 		{

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

@@ -478,6 +478,16 @@ protected virtual void OnSearchHandlerPropertyChanged(object sender, PropertyCha
 				UpdateSearchVisibility(_searchController);
 			else if (e.PropertyName == SearchHandler.IsSearchEnabledProperty.PropertyName)
 				UpdateSearchIsEnabled(_searchController);
+			else if (e.Is(SearchHandler.AutomationIdProperty))
+			{
+				UpdateAutomationId();
+			}
+		}
+
+		void UpdateAutomationId()
+		{
+			if (_searchHandler?.AutomationId != null && _searchController?.SearchBar != null)
+				_searchController.SearchBar.AccessibilityIdentifier = _searchHandler.AutomationId;
 		}
 
 		protected virtual void RemoveSearchController(UINavigationItem navigationItem)
@@ -602,6 +612,7 @@ void AttachSearchController()
 			_searchHandlerAppearanceTracker = new SearchHandlerAppearanceTracker(searchBar, SearchHandler);
 
 			UpdateFlowDirection();
+			UpdateAutomationId();
 		}
 
 		void BookmarkButtonClicked(object sender, EventArgs e)