Move New Navigation Handler to Core and make it internal (#1800)

* Move navhost bits to core

* - windows

* - fix IEnumerable calls

* - fix up ios

* - revert to renderer

src/Compatibility/ControlGallery/src/Core/CoreGalleryPages/ListViewCoreGalleryPage.cs

@@ -175,7 +175,7 @@ public ListViewViewModel()
 					new Employee ("Andrew 3", TimeSpan.FromDays (1000), 60),
 				};
 
-				Enumerable.Range(0, 9000).Select(e => new Employee(e.ToString(), TimeSpan.FromDays(1), 60)).ForEach(e => Employees.Add(e));
+				Enumerable.Range(0, 9000).Select(e => new Employee(e.ToString(), TimeSpan.FromDays(1), 60)).ToList().ForEach(e => Employees.Add(e));
 			}
 		}
 

src/Compatibility/ControlGallery/src/Core/GalleryPages/GroupedListActionsGallery.cs

@@ -67,6 +67,17 @@ void OnPropertyChanged([CallerMemberName] string propertyName = null)
 				if (handler != null)
 					handler(this, new PropertyChangedEventArgs(propertyName));
 			}
+
+			public int IndexOf(Func<GroupAction, bool> selector)
+			{
+				for (int i = 0; i < this.Count; i++)
+				{
+					if (selector(this[i]))
+						return i;
+				}
+
+				return -1;
+			}
 		}
 
 		class GroupAction
@@ -139,11 +150,25 @@ public Group Parent
 			})
 		};
 
-		readonly ObservableList<Group> _groups;
+		readonly GroupObservableList _groups;
+
+		class GroupObservableList : ObservableList<Group>
+		{
+			public int IndexOf(Func<Group, bool> selector)
+			{
+				for (int i = 0; i < this.Count; i++)
+				{
+					if (selector(this[i]))
+						return i;
+				}
+
+				return -1;
+			}
+		}
 
-		ObservableList<Group> CreateItemSource()
+		GroupObservableList CreateItemSource()
 		{
-			return new ObservableList<Group> {
+			return new GroupObservableList {
 				new Group ("General") {
 					new GroupAction ("Change group name", ga => ga.Parent.Name += " (changed)"),
 					new GroupAction ("Change group short name", ga => ga.Parent.ShortName = ga.Parent.Name[1].ToString())

src/Compatibility/ControlGallery/src/Core/GalleryPages/MapGallery.xaml.cs

@@ -23,7 +23,7 @@ public MapGallery()
 			InitializeComponent();
 
 			Map = MakeMap();
-			Map.Pins.ForEach(pin =>
+			Map.Pins.ToList().ForEach(pin =>
 			{
 				pin.MarkerClicked += MarkerClicked;
 				pin.InfoWindowClicked += InfoWindowClicked;

src/Compatibility/ControlGallery/src/Core/GalleryPages/PlatformSpecificsGalleries/WindowsPlatformSpecificsGalleryHelpers.cs

@@ -57,7 +57,7 @@ public static Layout CreateChanger(Type enumType, string defaultOption, Action<P
 				picker.Items.Add(option);
 			}
 
-			picker.SelectedIndex = options.IndexOf(defaultOption);
+			picker.SelectedIndex = options.ToList().IndexOf(defaultOption);
 
 			picker.SelectedIndexChanged += (sender, args) =>
 			{

src/Compatibility/ControlGallery/src/Issues.Shared/Issue2680ScrollView.cs

@@ -43,7 +43,7 @@ protected override void Init()
 				AutomationId = FirstItemMark
 			});
 			Enumerable.Range(2, 50).Select(i => new Label { Text = $"Test label {i}" })
-				.ForEach(label => longStackLayout.Children.Add(label));
+				.ToList().ForEach(label => longStackLayout.Children.Add(label));
 
 			scrollView = new ScrollView
 			{

src/Compatibility/ControlGallery/src/Issues.Shared/Issue2976.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using Microsoft.Maui.Controls.CustomAttributes;
 using Microsoft.Maui.Controls.Internals;
+using System.Linq;
 
 #if UITEST
 using Xamarin.UITest;
@@ -111,7 +112,7 @@ public void NotifyItemSelected(object item)
 		{
 
 			if (ItemSelected != null)
-				ItemSelected(this, new SelectedItemChangedEventArgs(item, Items?.IndexOf(item) ?? -1));
+				ItemSelected(this, new SelectedItemChangedEventArgs(item, Items?.ToList().IndexOf($"{item}") ?? -1));
 		}
 
 		public NativeListView()
@@ -337,7 +338,7 @@ public void NotifyItemSelected(object item)
 		{
 
 			if (ItemSelected != null)
-				ItemSelected(this, new SelectedItemChangedEventArgs(item, Items?.IndexOf(item) ?? -1));
+				ItemSelected(this, new SelectedItemChangedEventArgs(item, Items?.ToList().IndexOf((DataSource)item) ?? -1));
 		}
 
 		public NativeListView2()

src/Compatibility/ControlGallery/src/Issues.Shared/Issue3089.cs

@@ -33,7 +33,7 @@ protected override void Init()
 		{
 			var oc = new ObservableCollection<string>(new[] { $"Click {reload}", "and this text should go away" });
 
-			Enumerable.Range(0, 100).ForEach(x => oc.Add(x.ToString()));
+			Enumerable.Range(0, 100).ToList().ForEach(x => oc.Add(x.ToString()));
 
 			PushAsync(new MainPageCode
 			{

src/Compatibility/ControlGallery/src/Issues.Shared/Issue4597.cs

@@ -149,7 +149,7 @@ protected override void Init()
 						Command = new Command(() =>
 						{
 							var activeImage = layout.Children.Last();
-							int nextIndex = imageControls.IndexOf(activeImage) + 1;
+							int nextIndex = imageControls.ToList().IndexOf(activeImage) + 1;
 
 							if(nextIndex >= imageControls.Length)
 								nextIndex = 0;

src/Compatibility/ControlGallery/src/Issues.Shared/RefreshViewTests.cs

@@ -35,6 +35,7 @@ protected override void Init()
 			Enumerable
 				.Range(0, 10)
 				.Select(_ => new Label() { HeightRequest = 200, Text = "Pull me down to refresh me" })
+				.ToList()
 				.ForEach(x => scrollViewContent.Children.Add(x));
 
 

src/Controls/src/Core/EnumerableExtensions.cs

@@ -59,60 +59,5 @@ static class EnumerableExtensions
 				}
 			}
 		}
-
-		public static void ForEach<T>(this IEnumerable<T> enumeration, Action<T> action)
-		{
-			foreach (T item in enumeration)
-			{
-				action(item);
-			}
-		}
-
-		public static IDictionary<TKey, List<TSource>> GroupToDictionary<TSource, TKey>(this IEnumerable<TSource> enumeration, Func<TSource, TKey> func)
-		{
-			var result = new Dictionary<TKey, List<TSource>>();
-			foreach (TSource item in enumeration)
-			{
-				var group = func(item);
-				if (!result.ContainsKey(group))
-					result.Add(group, new List<TSource> { item });
-				else
-					result[group].Add(item);
-			}
-			return result;
-		}
-
-		public static int IndexOf<T>(this IEnumerable<T> enumerable, T item)
-		{
-			if (enumerable == null)
-				throw new ArgumentNullException("enumerable");
-
-			var i = 0;
-			foreach (T element in enumerable)
-			{
-				if (Equals(element, item))
-					return i;
-
-				i++;
-			}
-
-			return -1;
-		}
-
-		public static int IndexOf<T>(this IEnumerable<T> enumerable, Func<T, bool> predicate)
-		{
-			var i = 0;
-			foreach (T element in enumerable)
-			{
-				if (predicate(element))
-					return i;
-
-				i++;
-			}
-
-			return -1;
-		}
-
-		public static T Last<T>(this IList<T> self) => self[self.Count - 1];
 	}
 }

src/Controls/src/Core/HandlerImpl/NavigationPage.Impl.cs

@@ -1,16 +1,33 @@
 using System;
 using System.Collections.Generic;
 using System.Text;
+using System.Threading.Tasks;
 using Microsoft.Maui.Controls.Internals;
 using Microsoft.Maui.Graphics;
 using Microsoft.Maui.Layouts;
 
 namespace Microsoft.Maui.Controls
 {
-	public partial class NavigationPage : IView
+	public partial class NavigationPage : INavigationView
 	{
 		Thickness IView.Margin => Thickness.Zero;
 
+		partial void Init()
+		{
+			PushRequested += (_, args) =>
+			{
+				var request = new MauiNavigationRequestedEventArgs(args.Page, args.BeforePage, args.Animated);
+				Handler?.Invoke(nameof(INavigationView.PushAsync), request);
+
+			};
+
+			PopRequested += (_, args) =>
+			{
+				var request = new MauiNavigationRequestedEventArgs(args.Page, args.BeforePage, args.Animated);
+				Handler?.Invoke(nameof(INavigationView.PopAsync), request);
+			};
+		}
+
 		protected override Size MeasureOverride(double widthConstraint, double heightConstraint)
 		{
 			if (Content is IFrameworkElement frameworkElement)
@@ -35,8 +52,60 @@ protected override Size ArrangeOverride(Rectangle bounds)
 			return Frame.Size;
 		}
 
+		void INavigationView.InsertPageBefore(IView page, IView before)
+		{
+			throw new NotImplementedException();
+		}
+
+		Task<IView> INavigationView.PopAsync() =>
+			(this as INavigationView).PopAsync(true);
+
+		async Task<IView> INavigationView.PopAsync(bool animated)
+		{
+			var thing = await this.PopAsync(animated);
+			return thing;
+		}
+
+		Task<IView> INavigationView.PopModalAsync()
+		{
+			throw new NotImplementedException();
+		}
+
+		Task<IView> INavigationView.PopModalAsync(bool animated)
+		{
+			throw new NotImplementedException();
+		}
+
+		Task INavigationView.PushAsync(IView page) =>
+			(this as INavigationView).PushAsync(page, true);
+
+		Task INavigationView.PushAsync(IView page, bool animated)
+		{
+			return this.PushAsync((Page)page, animated);
+		}
+
+		Task INavigationView.PushModalAsync(IView page)
+		{
+			throw new NotImplementedException();
+		}
+
+		Task INavigationView.PushModalAsync(IView page, bool animated)
+		{
+			throw new NotImplementedException();
+		}
+
+		void INavigationView.RemovePage(IView page)
+		{
+			throw new NotImplementedException();
+		}
+
 		IFrameworkElement Content =>
 			this.CurrentPage;
+
+		IReadOnlyList<IView> INavigationView.ModalStack => throw new NotImplementedException();
+
+		IReadOnlyList<IView> INavigationView.NavigationStack =>
+			this.Navigation.NavigationStack;
 	}
 
 }