Navigation Events

src/Compatibility/Core/src/Windows/NavigationPageRenderer.cs

@@ -460,7 +460,8 @@ void OnUnloaded(object sender, RoutedEventArgs args)
 
 		void PushExistingNavigationStack()
 		{
-			foreach (var page in Element.Pages)
+			INavigationPageController navigationPageController = Element;
+			foreach (var page in navigationPageController.Pages)
 			{
 				SetPage(page, false, false);
 			}

src/Compatibility/Core/src/iOS/Renderers/NavigationRenderer.cs

@@ -52,6 +52,7 @@ public NavigationRenderer() : base(typeof(FormsNavigationBar), null)
 		IPageController PageController => Element as IPageController;
 
 		NavigationPage NavPage => Element as NavigationPage;
+		INavigationPageController NavPageController => NavPage;
 
 		public VisualElement Element { get; private set; }
 
@@ -237,7 +238,7 @@ public override void ViewDidLoad()
 				SetNeedsUpdateOfHomeIndicatorAutoHidden();
 
 			// If there is already stuff on the stack we need to push it
-			navPage.Pages.ForEach(async p => await PushPageAsync(p, false));
+			NavPageController.Pages.ForEach(async p => await PushPageAsync(p, false));
 
 			_tracker = new VisualElementTracker(this);
 
@@ -1218,7 +1219,7 @@ internal void UpdateLeftBarButtonItem(Page pageBeingRemoved = null)
 					return;
 
 				var currentChild = this.Child;
-				var firstPage = n.NavPage.Pages.FirstOrDefault();
+				var firstPage = n.NavPageController.Pages.FirstOrDefault();
 
 
 				if (n._parentFlyoutPage == null)

src/Controls/src/Core/FlyoutPage.cs

@@ -40,12 +40,19 @@ public Page Detail
 				if (value.RealParent != null)
 					throw new InvalidOperationException("Detail must not already have a parent.");
 
+				var previousDetail = _detail;
+				// TODO MAUI refine this to fire earlier
+				_detail?.SendNavigatingFrom(new NavigatingFromEventArgs());
+
 				OnPropertyChanging();
 				if (_detail != null)
 					InternalChildren.Remove(_detail);
 				_detail = value;
 				InternalChildren.Add(_detail);
 				OnPropertyChanged();
+
+				previousDetail?.SendNavigatedFrom(new NavigatedFromEventArgs(_detail));
+				_detail?.SendNavigatedTo(new NavigatedToEventArgs(previousDetail));
 			}
 		}
 
@@ -78,12 +85,20 @@ public Page Flyout
 				if (value.RealParent != null)
 					throw new InvalidOperationException("Flyout must not already have a parent.");
 
+				// TODO MAUI refine this to fire earlier
+				var previousFlyout = _flyout;
+				// TODO MAUI refine this to fire earlier
+				_flyout?.SendNavigatingFrom(new NavigatingFromEventArgs());
+
 				OnPropertyChanging();
 				if (_flyout != null)
 					InternalChildren.Remove(_flyout);
 				_flyout = value;
 				InternalChildren.Add(_flyout);
 				OnPropertyChanged();
+
+				previousFlyout?.SendNavigatedFrom(new NavigatedFromEventArgs(_flyout));
+				_flyout?.SendNavigatedTo(new NavigatedToEventArgs(previousFlyout));
 			}
 		}
 

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

@@ -1,4 +1,5 @@
-using Microsoft.Maui.Controls.Internals;
+using System;
+using Microsoft.Maui.Controls.Internals;
 using Microsoft.Maui.Graphics;
 
 namespace Microsoft.Maui.Controls
@@ -9,5 +10,56 @@ public partial class Page : IPage
 
 		// TODO ezhart super sus
 		public Thickness Margin => Thickness.Zero;
+
+		internal void SendNavigatedTo(NavigatedToEventArgs args)
+		{
+			NavigatedTo?.Invoke(this, args);
+			OnNavigatedTo(args);
+		}
+
+		internal void SendNavigatingFrom(NavigatingFromEventArgs args)
+		{
+			NavigatingFrom?.Invoke(this, args);
+			OnNavigatingFrom(args);
+		}
+
+		internal void SendNavigatedFrom(NavigatedFromEventArgs args)
+		{
+			NavigatedFrom?.Invoke(this, args);
+			OnNavigatedFrom(args);
+		}
+
+		public event EventHandler<NavigatedToEventArgs> NavigatedTo;
+		public event EventHandler<NavigatingFromEventArgs> NavigatingFrom;
+		public event EventHandler<NavigatedFromEventArgs> NavigatedFrom;
+
+		protected virtual void OnNavigatedTo(NavigatedToEventArgs args) { }
+		protected virtual void OnNavigatingFrom(NavigatingFromEventArgs args) { }
+		protected virtual void OnNavigatedFrom(NavigatedFromEventArgs args) { }
+	}
+
+	public sealed class NavigatingFromEventArgs : EventArgs
+	{
+
+	}
+
+	public sealed class NavigatedToEventArgs : EventArgs
+	{
+		internal NavigatedToEventArgs(Page previousPage)
+		{
+			PreviousPage = previousPage;
+		}
+
+		internal Page PreviousPage { get; }
+	}
+
+	public sealed class NavigatedFromEventArgs : EventArgs
+	{
+		internal NavigatedFromEventArgs(Page destinationPage)
+		{
+			DestinationPage = destinationPage;
+		}
+
+		internal Page DestinationPage { get; }
 	}
 }

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

@@ -263,9 +263,24 @@ protected override IReadOnlyList<Page> GetModalStack()
 					return null;
 				}
 
+				modal.SendNavigatingFrom(new NavigatingFromEventArgs());
+				Page? nextPage;
+				if (modal.NavigationProxy.ModalStack.Count == 1)
+				{
+					nextPage = _owner.Page;
+				}
+				else
+				{
+					nextPage = _owner.ModalNavigationManager.ModalStack[_owner.ModalNavigationManager.ModalStack.Count - 2];
+				}
+
 				Page result = await _owner.ModalNavigationManager.PopModalAsync(animated);
 				result.Parent = null;
 				_owner.OnModalPopped(result);
+
+				modal.SendNavigatedFrom(new NavigatedFromEventArgs(nextPage));
+				nextPage?.SendNavigatedTo(new NavigatedToEventArgs(modal));
+
 				return result;
 			}
 
@@ -277,13 +292,20 @@ protected override async Task OnPushModal(Page modal, bool animated)
 
 				if (modal.NavigationProxy.ModalStack.Count == 0)
 				{
+					_owner.Page?.SendNavigatingFrom(new NavigatingFromEventArgs());
 					modal.NavigationProxy.Inner = this;
 					await _owner.ModalNavigationManager.PushModalAsync(modal, animated);
+					_owner.Page?.SendNavigatedFrom(new NavigatedFromEventArgs(modal));
+					modal.SendNavigatedTo(new NavigatedToEventArgs(_owner.Page));
 				}
 				else
 				{
+					var previousModalPage = modal.NavigationProxy.ModalStack[modal.NavigationProxy.ModalStack.Count - 1];
+					previousModalPage.SendNavigatingFrom(new NavigatingFromEventArgs());
 					await _owner.ModalNavigationManager.PushModalAsync(modal, animated);
 					modal.NavigationProxy.Inner = this;
+					previousModalPage.SendNavigatedFrom(new NavigatedFromEventArgs(modal));
+					modal.SendNavigatedTo(new NavigatedToEventArgs(previousModalPage));
 				}
 
 				_owner.OnModalPushed(modal);

src/Controls/src/Core/MultiPage.cs

@@ -76,10 +76,18 @@ public T CurrentPage
 				if (_current == value)
 					return;
 
+				var previousPage = _current;
 				OnPropertyChanging();
+
+				// TODO MAUI refine this to fire earlier
+				_current?.SendNavigatingFrom(new NavigatingFromEventArgs());
+
 				_current = value;
 				OnPropertyChanged();
 				OnCurrentPageChanged();
+
+				previousPage?.SendNavigatedFrom(new NavigatedFromEventArgs(_current));
+				_current?.SendNavigatedTo(new NavigatedToEventArgs(previousPage));
 			}
 		}
 

src/Controls/src/Core/NavigationPage.cs

@@ -87,8 +87,7 @@ public Page Peek(int depth)
 			return (Page)InternalChildren[InternalChildren.Count - depth - 1];
 		}
 
-		[EditorBrowsable(EditorBrowsableState.Never)]
-		public IEnumerable<Page> Pages => InternalChildren.Cast<Page>();
+		IEnumerable<Page> INavigationPageController.Pages => InternalChildren.Cast<Page>();
 
 		int INavigationPageController.StackDepth
 		{
@@ -238,7 +237,7 @@ public async Task PushAsync(Page page, bool animated)
 				tcs.SetResult(true);
 				return;
 			}
-
+			
 			CurrentNavigationTask = PushAsyncInner(page, animated);
 			await CurrentNavigationTask;
 		}
@@ -298,6 +297,10 @@ protected override bool OnBackButtonPressed()
 			remove => _insertPageBeforeRequested -= value;
 		}
 
+		internal void InitialNativeNavigationStackLoaded()
+		{
+			SendNavigated(null);
+		}
 
 		internal async Task<Page> PopAsyncInner(
 			bool animated,
@@ -310,7 +313,11 @@ protected override bool OnBackButtonPressed()
 			}
 
 			var page = (Page)InternalChildren.Last();
-			return await RemoveAsyncInner(page, animated, fast, requestedFromHandler);
+			var previousPage = CurrentPage;
+			SendNavigating();
+			var removedPage = await RemoveAsyncInner(page, animated, fast, requestedFromHandler);
+			SendNavigated(previousPage);
+			return removedPage;
 		}
 
 		internal async Task<Page> RemoveAsyncInner(
@@ -355,6 +362,18 @@ protected override bool OnBackButtonPressed()
 			return page;
 		}
 
+		void SendNavigated(Page previousPage)
+		{
+			previousPage?.SendNavigatedFrom(new NavigatedFromEventArgs(CurrentPage));
+			CurrentPage.SendNavigatedTo(new NavigatedToEventArgs(previousPage));
+		}
+
+		void SendNavigating()
+		{
+			CurrentPage?.SendNavigatingFrom(new NavigatingFromEventArgs());
+		}
+
+
 		Task<Page> INavigationPageController.PopAsyncInner(bool animated, bool fast)
 		{
 			return PopAsyncInner(animated, fast, false);
@@ -409,6 +428,8 @@ async Task PopToRootAsyncInner(bool animated)
 			if (NavigationPageController.StackDepth == 1)
 				return;
 
+			var previousPage = CurrentPage;
+			SendNavigating();
 			FireDisappearing(CurrentPage);
 			FireAppearing((Page)InternalChildren[0]);
 
@@ -430,6 +451,7 @@ async Task PopToRootAsyncInner(bool animated)
 			}
 
 			PoppedToRoot?.Invoke(this, new PoppedToRootEventArgs(RootPage, childrenToRemove.OfType<Page>().ToList()));
+			SendNavigated(previousPage);
 		}
 
 		void FireDisappearing(Page page)
@@ -449,6 +471,8 @@ async Task PushAsyncInner(Page page, bool animated)
 			if (InternalChildren.Contains(page))
 				return;
 
+			var previousPage = CurrentPage;
+			SendNavigating();
 			FireDisappearing(CurrentPage);
 			FireAppearing(page);
 
@@ -465,6 +489,7 @@ async Task PushAsyncInner(Page page, bool animated)
 					await args.Task;
 			}
 
+			SendNavigated(previousPage);
 			Pushed?.Invoke(this, args);
 		}
 

src/Controls/src/Core/Platform/ModalNavigationManager/ModalNavigationManager.Standard.cs

@@ -4,19 +4,24 @@
 using System.Collections.Generic;
 using System.Text;
 using System.Threading.Tasks;
+using Microsoft.Maui.Controls.Internals;
 
 namespace Microsoft.Maui.Controls.Platform
 {
 	internal partial class ModalNavigationManager
 	{
 		public Task<Page> PopModalAsync(bool animated)
 		{
-			throw new NotImplementedException();
+			if (ModalStack.Count == 0)
+				throw new InvalidOperationException();
+
+			return Task.FromResult(_navModel.PopModal());
 		}
 
 		public Task PushModalAsync(Page modal, bool animated)
 		{
-			throw new NotImplementedException();
+			_navModel.PushModal(modal);
+			return Task.CompletedTask;
 		}
 	}
 }

src/Controls/src/Core/Routing.cs

@@ -47,7 +47,7 @@ internal static void RegisterImplicitPageRoutes(Shell shell)
 						var page = section.Navigation.ModalStack[i];
 						RegisterImplicitPageRoute(page);
 
-						if (page is NavigationPage np)
+						if (page is INavigationPageController np)
 						{
 							foreach (var npPages in np.Pages)
 							{

src/Controls/src/Core/Shell/Shell.cs

@@ -582,6 +582,7 @@ public void RemoveLogicalChild(Element element)
 		View _flyoutFooterView;
 		ShellNavigationManager _navigationManager;
 		ShellFlyoutItemsManager _flyoutManager;
+		Page _previousPage;
 
 		ObservableCollection<Element> _logicalChildren = new ObservableCollection<Element>();
 
@@ -591,17 +592,8 @@ public void RemoveLogicalChild(Element element)
 		public Shell()
 		{
 			_navigationManager = new ShellNavigationManager(this);
-			_navigationManager.Navigated += (_, args) =>
-			{
-				OnNavigated(args);
-				Navigated?.Invoke(this, args);
-			};
-
-			_navigationManager.Navigating += (_, args) =>
-			{
-				Navigating?.Invoke(this, args);
-				OnNavigating(args);
-			};
+			_navigationManager.Navigated += (_, args) => SendNavigated(args);
+			_navigationManager.Navigating += (_, args) => SendNavigating(args);
 
 			_flyoutManager = new ShellFlyoutItemsManager(this);
 			Navigation = new NavigationImpl(this);
@@ -892,6 +884,28 @@ async void NavigationPop()
 
 		bool ValidDefaultShellItem(Element child) => !(child is MenuShellItem);
 
+		void SendNavigated(ShellNavigatedEventArgs args)
+		{
+			Navigated?.Invoke(this, args);
+			OnNavigated(args);
+
+			_previousPage?.SendNavigatedFrom(new NavigatedFromEventArgs(CurrentPage));
+			CurrentPage?.SendNavigatedTo(new NavigatedToEventArgs(_previousPage));
+			_previousPage = null;
+		}
+
+		void SendNavigating(ShellNavigatingEventArgs args)
+		{
+			Navigating?.Invoke(this, args);
+			OnNavigating(args);
+
+			if (!args.Cancelled)
+			{
+				_previousPage = CurrentPage;
+				CurrentPage?.SendNavigatingFrom(new NavigatingFromEventArgs());
+			}
+		}
+
 		protected virtual void OnNavigated(ShellNavigatedEventArgs args)
 		{
 		}