[iOS] fix full width issues for TitleView (#3939)

* [iOS] fix full width issues for TitleView

* [iOS] simplified iOS 10

fixes #3881
fixes #3679

Xamarin.Forms.Controls/CoreGallery.cs

@@ -387,7 +387,7 @@ namespace Xamarin.Forms.Controls
 			if (navigationBehavior == NavigationBehavior.PushAsync && rootPage.GetType () == typeof (CoreNavigationPage))
 			{
 				_pages.Insert (0, new GalleryPageFactory(() => new NavigationBarGallery((NavigationPage)rootPage), "NavigationBar Gallery - Legacy"));
-				_pages.Insert(1, new GalleryPageFactory(() => new TitleView(), "TitleView"));
+				_pages.Insert(1, new GalleryPageFactory(() => new TitleView(true), "TitleView"));
 			}
 
 			var template = new DataTemplate(typeof(TextCell));

Xamarin.Forms.Controls/GalleryPages/TitleView.xaml

@@ -1,19 +1,29 @@
-<?xml version="1.0" encoding="utf-8" ?>
+<?xml version="1.0" encoding="utf-8" ?>
 <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              x:Class="Xamarin.Forms.Controls.GalleryPages.TitleView">
 
 	<NavigationPage.TitleView>
-		<StackLayout>
+		<StackLayout BackgroundColor="Pink">
 			<Label Text="This is my TitleView" />
 			<Label Text="I can be a subtitle" />
 		</StackLayout>
 	</NavigationPage.TitleView>
 
-	<StackLayout>
+	<ScrollView>
-		<Label Text="Welcome to Xamarin.Forms!"
+		<StackLayout BackgroundColor="Pink">
-                VerticalOptions="CenterAndExpand" 
+			<Button Clicked="masterDetailsPage_Clicked" Text="Master Details Page"></Button>
-                HorizontalOptions="CenterAndExpand" />
+			<Button Clicked="masterDetailsPageIcon_Clicked" Text="Toggle MDP Icon"></Button>
-	</StackLayout>
+			<Button Clicked="tabbedPage_Clicked" Text="Tabbed Page"></Button>
-
+			<Button Clicked="navigationPage_Clicked" Text="Navigation Page"></Button>
+			<Button Clicked="nextPage_Clicked" Text="Push a Page"></Button>
+			<Button Clicked="titleIcon_Clicked" Text="Toggle Title Icon"></Button>
+			<Button Clicked="toggleToolBarItem_Clicked" Text="Toggle Tool Bar Item" ></Button>
+			<Button Clicked="toggleSecondaryToolBarItem_Clicked" Text="Toggle Secondary Tool Bar Item" ></Button>
+			<Button Clicked="toggleLargeTitles_Clicked" Text="Toggle Large Titles" ></Button>
+			<Button Clicked="changeTitleView_Clicked" Text="Toggle Different Title Views"></Button>
+			<Button x:Name="btnToggleBackButtonTitle" Clicked="toggleBackButtonText_Clicked" Text="Toggle Back Button Title Text"></Button>
+			<Button Clicked="backToGallery_Clicked" Text="Back to Gallery"></Button>
+		</StackLayout>
+	</ScrollView>
 </ContentPage>

Xamarin.Forms.Controls/GalleryPages/TitleView.xaml.cs

@@ -5,6 +5,8 @@ using System.Text;
 using System.Threading.Tasks;
 
 using Xamarin.Forms;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.iOSSpecific;
 using Xamarin.Forms.Xaml;
 
 namespace Xamarin.Forms.Controls.GalleryPages
@@ -12,9 +14,216 @@ namespace Xamarin.Forms.Controls.GalleryPages
 	[XamlCompilation(XamlCompilationOptions.Compile)]
 	public partial class TitleView : ContentPage
 	{
-		public TitleView ()
+		public TitleView(bool initialLoad)
 		{
-			InitializeComponent ();
+			InitializeComponent();
+
+			if (initialLoad)
+			{
+				Device.BeginInvokeOnMainThread(() => masterDetailsPage_Clicked(this, EventArgs.Empty));
+			}
+		}
+
+		NavigationPage CreateNavigationPage()
+		{
+			return new NavigationPage(new TitleView(false) { Title = "Nav Title" });
+		}
+
+		public Page GetPage()
+		{
+			return new MasterDetailPage()
+			{
+				Detail = CreateNavigationPage(),
+				Master = new ContentPage() { Title = "Master" }
+			};
+		}
+
+		void masterDetailsPage_Clicked(object sender, EventArgs e)
+		{
+			App.Current.MainPage =
+				new MasterDetailPage()
+				{
+					Detail = CreateNavigationPage(),
+					Master = new ContentPage() { Title = "Master" },
+				};
+
+		}
+
+		void toggleBackButtonText_Clicked(object sender, EventArgs e)
+		{
+			var page = Navigation.NavigationStack.First();
+			var titleText = NavigationPage.GetBackButtonTitle(page);
+
+			if (titleText == null)
+				titleText = "Custom Text";
+			else if (titleText == "Custom Text")
+				titleText = "";
+			else
+				titleText = null;
+
+			NavigationPage.SetBackButtonTitle(page, titleText);
+			changeTitleView_Clicked(this, EventArgs.Empty);
+
+			string result = (titleText == null) ? "<null>" : titleText;
+			btnToggleBackButtonTitle.Text = $"Toggle Back Button Title Text: {result}";
+		}
+
+		void tabbedPage_Clicked(object sender, EventArgs e)
+		{
+
+			var page = new ContentPage() { Title = "other title page" };
+			NavigationPage.SetTitleView(page, createGrid());
+
+			App.Current.MainPage =
+				new TabbedPage()
+				{
+					Children =
+					{
+						CreateNavigationPage(),
+						new ContentPage(){ Title = "no title Page"},
+						new NavigationPage(page),
+					}
+				};
+		}
+
+		void navigationPage_Clicked(object sender, EventArgs e)
+		{
+			App.Current.MainPage = CreateNavigationPage();
+		}
+
+		void nextPage_Clicked(object sender, EventArgs e)
+		{
+			ContentPage page = null;
+			page = new ContentPage()
+			{
+				Title = "second page",
+				Content = new StackLayout()
+				{
+					Children =
+					{
+						new Button()
+						{
+							Text = "Toggle Back Button",
+							Command = new Command(()=>
+							{
+								NavigationPage.SetHasBackButton(page, !NavigationPage.GetHasBackButton(page));
+							})
+						},
+						new Button()
+						{
+							Text = "Toggle Title View",
+							Command = new Command(()=>
+							{
+								changeTitleView_Clicked(page, EventArgs.Empty);
+							})
+						}
+					}
+				}
+			};
+
+			NavigationPage.SetTitleView(page, createGrid());
+			Navigation.PushAsync(page);
+		}
+
+		View createSearchBarView()
+		{
+			return new SearchBar { BackgroundColor = Color.Cornsilk, HorizontalOptions = LayoutOptions.FillAndExpand, Margin = new Thickness(10, 0) };
+		}
+
+		View createGrid()
+		{
+			var grid = new Grid
+			{
+				BackgroundColor = Color.LightGray
+			};
+
+			grid.RowDefinitions.Add(new RowDefinition());
+			grid.RowDefinitions.Add(new RowDefinition());
+			grid.ColumnDefinitions.Add(new ColumnDefinition());
+			grid.ColumnDefinitions.Add(new ColumnDefinition() { Width = GridLength.Star });
+
+			var label = new Label { Text = "hello", HorizontalOptions = LayoutOptions.Start, BackgroundColor = Color.Yellow };
+			var label2 = new Label { Text = "hello 2", HorizontalOptions = LayoutOptions.Start, BackgroundColor = Color.Yellow };
+			grid.Children.Add(label);
+			grid.Children.Add(label2);
+			Grid.SetRow(label2, 1);
+
+			var label3 = new Label { Text = "right aligned", HorizontalTextAlignment = TextAlignment.End };
+			Grid.SetColumn(label3, 1);
+			grid.Children.Add(label3);
+			return grid;
+		}
+
+
+		void titleIcon_Clicked(object sender, EventArgs e)
+		{
+			var titleIcon = NavigationPage.GetTitleIcon(this);
+
+			if (titleIcon == null)
+				NavigationPage.SetTitleIcon(this, "coffee.png");
+			else
+				NavigationPage.SetTitleIcon(this, null);
+
+		}
+
+		void masterDetailsPageIcon_Clicked(object sender, EventArgs e)
+		{
+			if (App.Current.MainPage is MasterDetailPage mdp)
+			{
+				if (String.IsNullOrWhiteSpace(mdp.Master.Icon))
+					mdp.Master.Icon = "menuIcon";
+				else
+					mdp.Master.Icon = null;
+			}
+		}
+
+		void toggleLargeTitles_Clicked(object sender, EventArgs e)
+		{
+			var navPage = (NavigationPage)Navigation.NavigationStack.Last().Parent;
+			navPage.On<iOS>().SetPrefersLargeTitles(!navPage.On<iOS>().PrefersLargeTitles());
+		}
+
+		void backToGallery_Clicked(object sender, EventArgs e)
+		{
+			(App.Current as App).Reset();
+		}
+
+		void toggleToolBarItem_Clicked(object sender, EventArgs e)
+		{
+			var page = Navigation.NavigationStack.Last();
+			var items = page.ToolbarItems.Where(x => x.Order == ToolbarItemOrder.Primary).ToList();
+
+			if (items.Any())
+				foreach (var item in items)
+					page.ToolbarItems.Remove(item);
+			else
+				page.ToolbarItems.Add(new ToolbarItem() { Text = "Save", Order = ToolbarItemOrder.Primary });
+		}
+
+		void toggleSecondaryToolBarItem_Clicked(object sender, EventArgs e)
+		{
+			var page = Navigation.NavigationStack.Last();
+			var items = page.ToolbarItems.Where(x => x.Order == ToolbarItemOrder.Secondary).ToList();
+
+			if (items.Any())
+				foreach (var item in items)
+					page.ToolbarItems.Remove(item);
+			else
+				page.ToolbarItems.Add(new ToolbarItem() { Text = "Save", Order = ToolbarItemOrder.Secondary });
+		}
+
+
+		void changeTitleView_Clicked(object sender, EventArgs e)
+		{
+			var currentView = NavigationPage.GetTitleView(Navigation.NavigationStack.Last());
+
+			if (currentView is Grid)
+				NavigationPage.SetTitleView(Navigation.NavigationStack.Last(), createSearchBarView());
+			else if (currentView is SearchBar)
+				NavigationPage.SetTitleView(Navigation.NavigationStack.Last(), null);
+			else
+				NavigationPage.SetTitleView(Navigation.NavigationStack.Last(), createGrid());
+
 		}
 	}
 }

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

@@ -33,14 +33,14 @@ namespace Xamarin.Forms.Platform.iOS
 		UIImage _defaultNavBarShadowImage;
 		UIImage _defaultNavBarBackImage;
 
-		public NavigationRenderer()
+		public NavigationRenderer() : base(typeof(FormsNavigationBar), null)
 		{
 			MessagingCenter.Subscribe<IVisualElementRenderer>(this, UpdateToolbarButtons, sender =>
 			{
 				if (!ViewControllers.Any())
 					return;
 				var parentingViewController = (ParentingViewController)ViewControllers.Last();
-				UpdateLeftBarButtonItem(parentingViewController);
+				parentingViewController?.UpdateLeftBarButtonItem();
 			});
 		}
 
@@ -97,7 +97,7 @@ namespace Xamarin.Forms.Platform.iOS
 			View.SetNeedsLayout();
 
 			var parentingViewController = (ParentingViewController)ViewControllers.Last();
-			UpdateLeftBarButtonItem(parentingViewController);
+			parentingViewController?.UpdateLeftBarButtonItem();
 		}
 
 		public Task<bool> PopToRootAsync(Page page, bool animated = true)
@@ -180,7 +180,7 @@ namespace Xamarin.Forms.Platform.iOS
 
 			double trueBottom = toolbar.Hidden ? toolbarY : toolbar.Frame.Bottom;
 			var modelSize = _queuedSize.IsZero ? Element.Bounds.Size : _queuedSize;
-			PageController.ContainerArea = 
+			PageController.ContainerArea =
 				new Rectangle(0, toolbar.Hidden ? 0 : toolbar.Frame.Height, modelSize.Width, modelSize.Height - trueBottom);
 
 			if (!_queuedSize.IsZero)
@@ -356,7 +356,7 @@ namespace Xamarin.Forms.Platform.iOS
 			// otherwise the view controller is forced to 0,0
 			var pack = new ParentingViewController(this) { Child = page };
 
-			UpdateTitleArea(pack, page);
+			pack.UpdateTitleArea(page);
 
 			var pageRenderer = Platform.GetRenderer(page);
 			pack.View.AddSubview(pageRenderer.ViewController.View);
@@ -450,7 +450,7 @@ namespace Xamarin.Forms.Platform.iOS
 			else if (e.PropertyName == NavigationPage.BackButtonTitleProperty.PropertyName)
 			{
 				var pack = (ParentingViewController)TopViewController;
-				UpdateTitleArea(pack, pack.Child);
+				pack?.UpdateTitleArea(pack.Child);
 			}
 			else if (e.PropertyName == HideNavigationBarSeparatorProperty.PropertyName)
 			{
@@ -462,7 +462,7 @@ namespace Xamarin.Forms.Platform.iOS
 		{
 			//if the last time we did ViewDidLayoutSubviews we had other value for _hasNavigationBar
 			//we will need to relayout. This is because Current is updated async of the layout happening
-			if(_hasNavigationBar != NavigationPage.GetHasNavigationBar(newCurrentPage))
+			if (_hasNavigationBar != NavigationPage.GetHasNavigationBar(newCurrentPage))
 				ViewDidLayoutSubviews();
 		}
 
@@ -480,7 +480,7 @@ namespace Xamarin.Forms.Platform.iOS
 				NavigationBar.ShadowImage = _defaultNavBarShadowImage;
 
 			if (!Forms.IsiOS11OrNewer)
-			{ 
+			{
 				// For iOS 10 and lower, you need to set the background image. 
 				// If you set this for iOS11, you'll remove the background color.
 				if (_defaultNavBarBackImage == null)
@@ -507,118 +507,6 @@ namespace Xamarin.Forms.Platform.iOS
 				NavigationBar.PrefersLargeTitles = NavPage.OnThisPlatform().PrefersLargeTitles();
 		}
 
-		void UpdateTitleArea(ParentingViewController pack, Page page)
-		{
-			if (pack == null || page == null)
-				return;
-
-			if (!string.IsNullOrWhiteSpace(page.Title))
-				pack.NavigationItem.Title = page.Title;
-
-			// First page and we have a master detail to contend with
-			UpdateLeftBarButtonItem(pack);
-
-			var titleText = NavigationPage.GetBackButtonTitle(page);
-			if (titleText != null)
-			{
-				// adding a custom event handler to UIBarButtonItem for navigating back seems to be ignored.
-				pack.NavigationItem.BackBarButtonItem = new UIBarButtonItem { Title = titleText, Style = UIBarButtonItemStyle.Plain };
-			}
-
-			FileImageSource titleIcon = NavigationPage.GetTitleIcon(page);
-			VisualElement titleView = NavigationPage.GetTitleView(page);
-
-			ClearTitleViewContainer(pack);
-
-			bool needContainer = titleView != null || titleIcon != null;
-
-			if (needContainer)
-			{
-				Container titleViewContainer = new Container();
-
-				pack.NavigationItem.TitleView = titleViewContainer;
-
-				UpdateTitleImage(titleViewContainer, titleIcon);
-				UpdateTitleView(titleViewContainer, titleView);
-
-				// Need to call this for iOS10 to properly frame the renderer
-				TopViewController?.NavigationItem?.TitleView?.SizeToFit();
-				TopViewController?.NavigationItem?.TitleView?.LayoutSubviews();
-			}
-		}
-
-		async void UpdateTitleImage(Container titleViewContainer, FileImageSource titleIcon)
-		{
-			if (titleViewContainer == null)
-				return;
-
-			if (string.IsNullOrWhiteSpace(titleIcon))
-			{
-				titleViewContainer.Icon = null;
-			}
-			else
-			{
-				var source = Internals.Registrar.Registered.GetHandlerForObject<IImageSourceHandler>(titleIcon);
-				var image = await source.LoadImageAsync(titleIcon);
-
-				try
-				{
-					titleViewContainer.Icon = new UIImageView(image) { };
-				}
-				catch
-				{
-					//UIImage ctor throws on file not found if MonoTouch.ObjCRuntime.Class.ThrowOnInitFailure is true;
-				}
-			}
-		}
-
-		void ClearTitleViewContainer(UIViewController pack)
-		{
-			if (pack == null)
-				return;
-
-			if (pack.NavigationItem.TitleView != null && pack.NavigationItem.TitleView is Container titleViewContainer)
-			{
-				titleViewContainer.Dispose();
-				titleViewContainer = null;
-				pack.NavigationItem.TitleView = null;
-			}
-		}
-
-		void UpdateTitleView(Container titleViewContainer, VisualElement titleView)
-		{
-			if (titleViewContainer == null)
-				return;
-
-			var titleViewRenderer = titleViewContainer.Child;
-
-			if (titleView != null)
-			{
-				if (titleViewRenderer != null)
-				{
-					var rendererType = titleViewRenderer is System.Reflection.IReflectableType reflectableType 
-						? reflectableType.GetTypeInfo().AsType() 
-						: titleViewRenderer.GetType();
-
-					if (titleView != null && rendererType == Internals.Registrar.Registered.GetHandlerTypeForObject(titleView))
-					{
-						if (titleViewContainer != null)
-							titleViewContainer.Child = null;
-						titleViewRenderer.SetElement(titleView);
-						return;
-					}
-					titleViewContainer?.DisposeChild();
-				}
-
-				titleViewRenderer = Platform.CreateRenderer(titleView);
-				titleViewContainer.Child = titleViewRenderer;
-			}
-			else if (titleViewRenderer != null)
-			{
-				titleViewContainer?.DisposeChild();
-			}
-		}
-
 		void UpdateTranslucent()
 		{
 			NavigationBar.Translucent = NavPage.OnThisPlatform().IsNavigationBarTranslucent();
@@ -695,7 +583,7 @@ namespace Xamarin.Forms.Platform.iOS
 				ViewControllers = _removeControllers;
 			}
 			var parentingViewController = ViewControllers.Last() as ParentingViewController;
-			UpdateLeftBarButtonItem(parentingViewController, page);
+			parentingViewController?.UpdateLeftBarButtonItem(page);
 		}
 
 		void RemoveViewControllers(bool animated)
@@ -794,17 +682,6 @@ namespace Xamarin.Forms.Platform.iOS
 			}
 		}
 
-		void UpdateLeftBarButtonItem(ParentingViewController containerController, Page pageBeingRemoved = null)
-		{
-			if (containerController == null)
-				return;
-			var currentChild = containerController.Child;
-			var firstPage = NavPage.Pages.FirstOrDefault();
-			if ((firstPage != pageBeingRemoved && currentChild != firstPage && NavigationPage.GetHasBackButton(currentChild)) || _parentMasterDetailPage == null)
-				return;
-
-			SetMasterLeftBarButton(containerController, _parentMasterDetailPage);
-		}
 
 		void UpdateTint()
 		{
@@ -1103,10 +980,117 @@ namespace Xamarin.Forms.Platform.iOS
 					UpdateLargeTitles();
 				else if (e.PropertyName == NavigationPage.TitleIconProperty.PropertyName ||
 					 e.PropertyName == NavigationPage.TitleViewProperty.PropertyName)
+					UpdateTitleArea(Child);
+			}
+
+
+			internal void UpdateLeftBarButtonItem(Page pageBeingRemoved = null)
+			{
+				NavigationRenderer n;
+				if (!_navigation.TryGetTarget(out n))
+					return;
+
+				var currentChild = this.Child;
+				var firstPage = n.NavPage.Pages.FirstOrDefault();
+
+
+				if (n._parentMasterDetailPage == null)
+					return;
+
+				if (firstPage != pageBeingRemoved && currentChild != firstPage && NavigationPage.GetHasBackButton(currentChild))
+				{
+					NavigationItem.LeftBarButtonItem = null;
+					return;
+				}
+
+				SetMasterLeftBarButton(this, n._parentMasterDetailPage);
+			}
+
+
+			public bool NeedsTitleViewContainer(Page page) => NavigationPage.GetTitleIcon(page) != null || NavigationPage.GetTitleView(page) != null;
+
+			internal void UpdateBackButtonTitle(Page page) => UpdateBackButtonTitle(page.Title, NavigationPage.GetBackButtonTitle(page));
+
+			internal void UpdateBackButtonTitle(string title, string backButtonTitle)
+			{
+				if (!string.IsNullOrWhiteSpace(title))
+					NavigationItem.Title = title;
+
+				if (backButtonTitle != null)
+					// adding a custom event handler to UIBarButtonItem for navigating back seems to be ignored.
+					NavigationItem.BackBarButtonItem = new UIBarButtonItem { Title = backButtonTitle, Style = UIBarButtonItemStyle.Plain };
+				else
+					NavigationItem.BackBarButtonItem = null;
+			}
+
+			internal void UpdateTitleArea(Page page)
+			{
+				if (page == null)
+					return;
+
+				FileImageSource titleIcon = NavigationPage.GetTitleIcon(page);
+				View titleView = NavigationPage.GetTitleView(page);
+				bool needContainer = titleView != null || titleIcon != null;
+
+				string backButtonText = NavigationPage.GetBackButtonTitle(page);
+				bool isBackButtonTextSet = page.IsSet(NavigationPage.BackButtonTitleProperty);
+
+				// on iOS 10 if the user hasn't set the back button text
+				// we set it to an empty string so it's consistent with iOS 11
+				if (!Forms.IsiOS11OrNewer && !isBackButtonTextSet)
+					backButtonText = "";
+
+				// First page and we have a master detail to contend with
+				UpdateLeftBarButtonItem();
+				UpdateBackButtonTitle(page.Title, backButtonText);
+
+				//var hadTitleView = NavigationItem.TitleView != null;
+				ClearTitleViewContainer();
+				if (needContainer)
 				{
 					NavigationRenderer n;
-					if (_navigation.TryGetTarget(out n))
+					if (!_navigation.TryGetTarget(out n))
-						n.UpdateTitleArea(this, Child);
+						return;
+
+					Container titleViewContainer = new Container(titleView, n.NavigationBar);
+
+					UpdateTitleImage(titleViewContainer, titleIcon);
+					NavigationItem.TitleView = titleViewContainer;
+				}
+			}
+
+			async void UpdateTitleImage(Container titleViewContainer, FileImageSource titleIcon)
+			{
+				if (titleViewContainer == null)
+					return;
+
+				if (string.IsNullOrWhiteSpace(titleIcon))
+				{
+					titleViewContainer.Icon = null;
+				}
+				else
+				{
+					var source = Internals.Registrar.Registered.GetHandlerForObject<IImageSourceHandler>(titleIcon);
+					var image = await source.LoadImageAsync(titleIcon);
+
+					try
+					{
+						titleViewContainer.Icon = new UIImageView(image) { };
+					}
+					catch
+					{
+						//UIImage ctor throws on file not found if MonoTouch.ObjCRuntime.Class.ThrowOnInitFailure is true;
+					}
+				}
+			}
+
+			void ClearTitleViewContainer()
+			{
+				if (NavigationItem.TitleView != null && NavigationItem.TitleView is Container titleViewContainer)
+				{
+					titleViewContainer.Dispose();
+					titleViewContainer = null;
+					NavigationItem.TitleView = null;
 				}
 			}
 
@@ -1123,10 +1107,17 @@ namespace Xamarin.Forms.Platform.iOS
 
 			void UpdateHasBackButton()
 			{
-				if (Child == null)
+				if (Child == null || NavigationItem.HidesBackButton == !NavigationPage.GetHasBackButton(Child))
 					return;
 
 				NavigationItem.HidesBackButton = !NavigationPage.GetHasBackButton(Child);
+
+				NavigationRenderer n;
+				if (!_navigation.TryGetTarget(out n))
+					return;
+
+				if (!Forms.IsiOS11OrNewer || n._parentMasterDetailPage != null)
+					UpdateTitleArea(Child);
 			}
 
 			void UpdateNavigationBarVisibility(bool animated)
@@ -1257,25 +1248,136 @@ namespace Xamarin.Forms.Platform.iOS
 			VisualElementRenderer<VisualElement>.RegisterEffect(effect, View);
 		}
 
+		internal class FormsNavigationBar : UINavigationBar
+		{
+			public FormsNavigationBar() : base()
+			{
+			}
+
+			public FormsNavigationBar(Foundation.NSCoder coder) : base(coder)
+			{
+			}
+
+			protected FormsNavigationBar(Foundation.NSObjectFlag t) : base(t)
+			{
+			}
+
+			protected internal FormsNavigationBar(IntPtr handle) : base(handle)
+			{
+			}
+
+			public FormsNavigationBar(RectangleF frame) : base(frame)
+			{
+			}
+
+			public RectangleF BackButtonFrameSize { get; private set; }
+			public UILabel NavBarLabel { get; private set; }
+
+			public override void LayoutSubviews()
+			{
+				if (!Forms.IsiOS11OrNewer)
+				{
+					for (int i = 0; i < this.Subviews.Length; i++)
+					{
+						if (Subviews[i] is UIView view)
+						{
+							if (view.Class.Name == "_UINavigationBarBackIndicatorView")
+							{
+								if (view.Alpha == 0)
+									BackButtonFrameSize = CGRect.Empty;
+								else
+									BackButtonFrameSize = view.Frame;
+
+								break;
+							}
+							else if(view.Class.Name == "UINavigationItemButtonView")
+							{
+								if (view.Subviews.Length == 0)
+									NavBarLabel = null;
+								else if (view.Subviews[0] is UILabel titleLabel)
+									NavBarLabel = titleLabel;
+							}
+						}
+					}
+				}
+
+				base.LayoutSubviews();
+			}
+		}
+
 		class Container : UIView
 		{
+			View _view;
+			FormsNavigationBar _bar;
 			IVisualElementRenderer _child;
 			UIImageView _icon;
 
-			nfloat IconHeight => _icon?.Frame.Height ?? 0;
+			public Container(View view, UINavigationBar bar) : base(bar.Bounds)
+			{
+				if (Forms.IsiOS11OrNewer)
+				{
+					TranslatesAutoresizingMaskIntoConstraints = false;
+				}
+				else
+				{
+					TranslatesAutoresizingMaskIntoConstraints = true;
+					AutoresizingMask = UIViewAutoresizing.FlexibleHeight | UIViewAutoresizing.FlexibleWidth;
+				}
 
+				_bar = bar as FormsNavigationBar;
+				if (view != null)
+				{
+					_view = view;
+					_child = Platform.CreateRenderer(view);
+					Platform.SetRenderer(view, _child);
+					AddSubview(_child.NativeView);
+				}
+
+				ClipsToBounds = true;
+			}
+
+			public override CGSize IntrinsicContentSize => UILayoutFittingExpandedSize;
+
+			nfloat IconHeight => _icon?.Frame.Height ?? 0;
 			nfloat IconWidth => _icon?.Frame.Width ?? 0;
 
-			protected override void Dispose(bool disposing)
+			// Navigation bar will not stretch past these values. Prevent content clipping.
+			// iOS11 does this for us automatically, but apparently iOS10 doesn't.
+			nfloat ToolbarHeight
 			{
-				if (disposing)
+				get
 				{
-					DisposeChild();
+					if (Superview?.Bounds.Height > 0)
+						return Superview.Bounds.Height;
 
-					_icon?.Dispose();
+					return (Device.Idiom == TargetIdiom.Phone && Device.Info.CurrentOrientation.IsLandscape()) ? 32 : 44;
-					_icon = null;
+				}
+			}
+
+			public override CGRect Frame
+			{
+				get => base.Frame;
+				set
+				{
+					if (Superview != null)
+					{
+						if (!Forms.IsiOS11OrNewer)
+						{
+							value.Y = Superview.Bounds.Y;
+
+							if (_bar != null && String.IsNullOrWhiteSpace(_bar.NavBarLabel?.Text) && _bar.BackButtonFrameSize != RectangleF.Empty)
+							{
+								var xSpace = _bar.BackButtonFrameSize.Width + (_bar.BackButtonFrameSize.X * 2);
+								value.Width = (value.X - xSpace) + value.Width;
+								value.X = xSpace;
+							}
+						};
+
+						value.Height = ToolbarHeight;
+					}
+
+					base.Frame = value;
 				}
-				base.Dispose(disposing);
 			}
 
 			public UIImageView Icon
@@ -1292,65 +1394,53 @@ namespace Xamarin.Forms.Platform.iOS
 				}
 			}
 
-			public IVisualElementRenderer Child
-			{
-				get { return _child; }
-				set
-				{
-					if (_child != null)
-						DisposeChild();
-
-					_child = value;
-
-					if (value != null)
-						AddSubview(value.NativeView);
-				}
-			}
-
 			public override SizeF SizeThatFits(SizeF size)
 			{
-				IVisualElementRenderer renderer = _child;
+				return new SizeF(size.Width, ToolbarHeight);
-
-				if (renderer == null || renderer.Element == null || renderer.Element.Parent == null)
-					return new SizeF(IconWidth, IconHeight);
-
-				var result = renderer.Element.Measure(double.PositiveInfinity, double.PositiveInfinity, MeasureFlags.IncludeMargins);
-
-				return new SizeF(result.Request.Width + IconWidth, Math.Max(IconHeight, result.Request.Height));
 			}
 
 			public override void LayoutSubviews()
 			{
 				base.LayoutSubviews();
+				if (Frame == CGRect.Empty || Frame.Width >= 10000 || Frame.Height >= 10000)
+					return;
 
-				// Navigation bar will not stretch past these values. Prevent content clipping.
+				nfloat toolbarHeight = ToolbarHeight;
-				// iOS11 does this for us automatically, but apparently iOS10 doesn't.
-				int toolbarHeight = 44;
-				if (Device.Idiom == TargetIdiom.Phone && Device.Info.CurrentOrientation.IsLandscape())
-					toolbarHeight = 32;
 
 				double height = Math.Min(toolbarHeight, Bounds.Height);
 
-				Frame = new RectangleF(Frame.X, Frame.Y, Bounds.Width, height);
-
 				if (_icon != null)
 					_icon.Frame = new RectangleF(0, 0, IconWidth, Math.Min(toolbarHeight, IconHeight));
 
 				if (_child?.Element != null)
-					Layout.LayoutChildIntoBoundingRegion(_child.Element, new Rectangle(IconWidth, 0, Bounds.Width - IconWidth, height));
+				{
+					var layoutBounds = new Rectangle(IconWidth, 0, Bounds.Width - IconWidth, height);
+					if (_child.Element.Bounds != layoutBounds)
+						Layout.LayoutChildIntoBoundingRegion(_child.Element, layoutBounds);
+				}
 			}
 
-			public void DisposeChild()
+			protected override void Dispose(bool disposing)
 			{
-				if (_child == null)
+				if (disposing)
-					return;
+				{
 
-				if (_child.Element.Platform is Platform platform)
+					if (_child != null)
-					platform.DisposeModelAndChildrenRenderers(_child.Element);
+					{
+						if (_child.Element.Platform is Platform platform)
+							platform.DisposeModelAndChildrenRenderers(_child.Element);
 
-				_child.NativeView.RemoveFromSuperview();
+						_child.NativeView.RemoveFromSuperview();
-				_child.Dispose();
+						_child.Dispose();
-				_child = null;
+						_child = null;
+					}
+
+					_view = null;
+
+					_icon?.Dispose();
+					_icon = null;
+				}
+				base.Dispose(disposing);
 			}
 		}
 	}