WinUI Modal Navigation

src/Controls/samples/Controls.Sample/Pages/Core/ModalPage.xaml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<views:BasePage 
+ xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+ xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+ x:Class="Maui.Controls.Sample.Pages.ModalPage"
+ xmlns:views="clr-namespace:Maui.Controls.Sample.Pages.Base">
+ <views:BasePage.Content>
+ <StackLayout
+ Margin="12">
+ <Button Clicked="PushModalClicked" Text="Push Modal Page" />
+ <Button x:Name="PushModal" Clicked="PopModalClicked" Text="Pop Modal Page" />
+ </StackLayout>
+ </views:BasePage.Content>
+</views:BasePage>

src/Controls/samples/Controls.Sample/Pages/Core/ModalPage.xaml.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Graphics;
+
+namespace Maui.Controls.Sample.Pages
+{
+ public partial class ModalPage
+ {
+ public ModalPage()
+ {
+ InitializeComponent();
+ BackgroundColor = Colors.Purple;
+ }
+
+ protected override void OnAppearing()
+ {
+ base.OnAppearing();
+ PushModal.IsVisible = Navigation.ModalStack.Count > 0;
+ }
+
+ async void PushModalClicked(object sender, EventArgs e)
+ {
+ await Navigation.PushModalAsync(new ModalPage()
+ {
+ BackgroundColor = 
+ (BackgroundColor == Colors.Purple) ? Colors.Pink : Colors.Purple
+ });
+ }
+
+ async void PopModalClicked(object sender, EventArgs e)
+ {
+ await Navigation.PopModalAsync();
+ }
+ }
+}

src/Controls/samples/Controls.Sample/ViewModels/CoreViewModel.cs

@@ -26,6 +26,9 @@ protected override IEnumerable<SectionModel> CreateItems() => new[]
 
  new SectionModel(typeof(TransformationsPage), "Transformations",
  "Apply scale transformations, rotation, etc. to a View."),
+
+ new SectionModel(typeof(ModalPage), "Modal",
+ "Allows you to push and pop Modal Pages."),
  };
  }
 }

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

@@ -26,7 +26,7 @@ public partial class Window : NavigableElement, IWindow
  public Window()
  {
  AlertManager = new AlertManager(this);
- ModalNavigationService = new ModalNavigationService(this);
+ ModalNavigationManager = new ModalNavigationManager(this);
  Navigation = new NavigationImpl(this);
 
  InternalChildren.CollectionChanged += OnCollectionChanged;
@@ -75,7 +75,7 @@ protected override void OnPropertyChanged([CallerMemberName] string? propertyNam
 
  internal AlertManager AlertManager { get; }
 
- internal ModalNavigationService ModalNavigationService { get; }
+ internal ModalNavigationManager ModalNavigationManager { get; }
 
  internal IMauiContext MauiContext =>
  Handler?.MauiContext ?? throw new InvalidOperationException("MauiContext is null.");
@@ -138,7 +138,7 @@ static void OnPageChanged(BindableObject bindable, object oldValue, object newVa
  newPage.NavigationProxy.Inner = window.NavigationProxy;
  }
 
- window.ModalNavigationService.SettingNewPage();
+ window.ModalNavigationManager.SettingNewPage();
 
  if (newPage != null)
  {
@@ -148,7 +148,7 @@ static void OnPageChanged(BindableObject bindable, object oldValue, object newVa
 
  void OnPageAttachedHandler(object? sender, EventArgs e)
  {
- window.ModalNavigationService.PageAttachedHandler();
+ window.ModalNavigationManager.PageAttachedHandler();
  window.AlertManager.Subscribe();
  }
 
@@ -208,19 +208,19 @@ public NavigationImpl(Window owner)
 
  protected override IReadOnlyList<Page> GetModalStack()
  {
- return _owner.ModalNavigationService.ModalStack;
+ return _owner.ModalNavigationManager.ModalStack;
  }
 
  protected override async Task<Page?> OnPopModal(bool animated)
  {
- Page modal = _owner.ModalNavigationService.ModalStack[_owner.ModalNavigationService.ModalStack.Count - 1];
+ Page modal = _owner.ModalNavigationManager.ModalStack[_owner.ModalNavigationManager.ModalStack.Count - 1];
  if (_owner.OnModalPopping(modal))
  {
  _owner.OnPopCanceled();
  return null;
  }
 
- Page result = await _owner.ModalNavigationService.PopModalAsync(animated);
+ Page result = await _owner.ModalNavigationManager.PopModalAsync(animated);
  result.Parent = null;
  _owner.OnModalPopped(result);
  return result;
@@ -235,11 +235,11 @@ protected override async Task OnPushModal(Page modal, bool animated)
  if (modal.NavigationProxy.ModalStack.Count == 0)
  {
  modal.NavigationProxy.Inner = this;
- await _owner.ModalNavigationService.PushModalAsync(modal, animated);
+ await _owner.ModalNavigationManager.PushModalAsync(modal, animated);
  }
  else
  {
- await _owner.ModalNavigationService.PushModalAsync(modal, animated);
+ await _owner.ModalNavigationManager.PushModalAsync(modal, animated);
  modal.NavigationProxy.Inner = this;
  }
 

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

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Microsoft.Maui.Controls
+{
+ public partial class Window
+ {
+ internal UI.Xaml.Window NativeWindow =>
+ (Handler?.NativeView as UI.Xaml.Window) ?? throw new InvalidOperationException("Window Handler should have a Window set.");
+ }
+}

src/Controls/src/Core/Platform/ModalNavigationService/ModalNavigationService.Android.cs → src/Controls/src/Core/Platform/ModalNavigationManager/ModalNavigationManager.Android.cs

@@ -12,7 +12,7 @@
 
 namespace Microsoft.Maui.Controls.Platform
 {
- internal partial class ModalNavigationService
+ internal partial class ModalNavigationManager
  {
  partial void OnPageAttachedHandler()
  {
@@ -166,9 +166,9 @@ internal bool HandleBackPressed()
  class BackButtonCallBack : OnBackPressedCallback
  {
  WeakReference<Context> _weakReference;
- ModalNavigationService? _service;
+ ModalNavigationManager? _service;
 
- public BackButtonCallBack(ModalNavigationService service, Context context) : base(true)
+ public BackButtonCallBack(ModalNavigationManager service, Context context) : base(true)
  {
  _service = service;
  _weakReference = new WeakReference<Context>(context);

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

@@ -7,7 +7,7 @@
 
 namespace Microsoft.Maui.Controls.Platform
 {
- internal partial class ModalNavigationService
+ internal partial class ModalNavigationManager
  {
  public Task<Page> PopModalAsync(bool animated)
  {

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

@@ -0,0 +1,154 @@
+#nullable enable
+
+using System;
+using System.Threading.Tasks;
+using Microsoft.Maui.Graphics;
+using Microsoft.UI.Xaml.Controls;
+
+namespace Microsoft.Maui.Controls.Platform
+{
+ internal partial class ModalNavigationManager
+ {
+ Page? _modalBackgroundPage;
+
+ Panel Container
+ {
+ get
+ {
+ if (_window.NativeWindow.Content is Panel p)
+ return p;
+
+ throw new InvalidOperationException("Root container Panel not found");
+ }
+ }
+
+ Rectangle ContainerBounds
+ {
+ get { return new Rectangle(0, 0, Container.ActualWidth, Container.ActualHeight); }
+ }
+
+ public Task<Page> PopModalAsync(bool animated)
+ {
+ var tcs = new TaskCompletionSource<Page>();
+ var currentPage = _navModel.CurrentPage;
+ Page result = _navModel.PopModal();
+ SetCurrent(_navModel.CurrentPage, currentPage, true, () => tcs.SetResult(result));
+ return tcs.Task;
+ }
+
+ public Task PushModalAsync(Page modal, bool animated)
+ {
+ if (modal == null)
+ throw new ArgumentNullException(nameof(modal));
+
+ var tcs = new TaskCompletionSource<bool>();
+ var currentPage = _navModel.CurrentPage;
+ _navModel.PushModal(modal);
+ SetCurrent(modal, currentPage, false, () => tcs.SetResult(true));
+ return tcs.Task;
+ }
+
+ void AddPage(Page page)
+ {
+ if (Container == null || page == null)
+ return;
+
+ if (_modalBackgroundPage != null)
+ _modalBackgroundPage.GetCurrentPage()?.SendDisappearing();
+
+ page.ToNative(MauiContext);
+
+ var pageHandler = (INativeViewHandler)page.Handler;
+
+
+ if (pageHandler.ContainerView != null && !Container.Children.Contains(pageHandler.ContainerView))
+ Container.Children.Add(pageHandler.ContainerView);
+ else if (!Container.Children.Contains(pageHandler.NativeView))
+ Container.Children.Add(pageHandler.NativeView);
+
+ (page as IFrameworkElement).Measure(Container.ActualWidth, Container.ActualHeight);
+ (page as IFrameworkElement).Arrange(ContainerBounds);
+
+ page.Layout(ContainerBounds);
+ }
+
+ void RemovePage(Page page)
+ {
+ if (Container == null || page == null)
+ return;
+
+ if (_modalBackgroundPage != null)
+ _modalBackgroundPage.GetCurrentPage()?.SendAppearing();
+
+ var pageHandler = (INativeViewHandler)page.Handler;
+
+ if (Container.Children.Contains(pageHandler.NativeView))
+ Container.Children.Remove(pageHandler.NativeView);
+
+ if (Container.Children.Contains(pageHandler.ContainerView))
+ Container.Children.Remove(pageHandler.ContainerView);
+ }
+
+ partial void OnPageAttachedHandler()
+ {
+ if (_modalBackgroundPage != null)
+ {
+ RemovePage(_modalBackgroundPage);
+ _modalBackgroundPage.Cleanup();
+ _modalBackgroundPage.Parent = null;
+ }
+ }
+
+ void SetCurrent(Page newPage, Page previousPage, bool popping, Action? completedCallback = null)
+ {
+ bool modal = true;
+ try
+ {
+ if (modal && !popping && !newPage.BackgroundColor.IsDefault())
+ _modalBackgroundPage = previousPage;
+ else
+ {
+ RemovePage(previousPage);
+
+ if (!modal && _modalBackgroundPage != null)
+ {
+ RemovePage(_modalBackgroundPage);
+ _modalBackgroundPage.Cleanup();
+ _modalBackgroundPage.Parent = null;
+ }
+
+ _modalBackgroundPage = null;
+ }
+
+ if (popping)
+ {
+ //// Un-parent the page; otherwise the Resources Changed Listeners won't be unhooked and the 
+ //// page will leak 
+
+ previousPage.Cleanup();
+ previousPage.Parent = null;
+ }
+
+ newPage.Layout(ContainerBounds);
+
+ AddPage(newPage);
+
+ completedCallback?.Invoke();
+
+ // TODO MAUI WINUI STill needs a Toolbar
+ //UpdateToolbarTracker();
+ //await UpdateToolbarItems();
+ }
+ catch (Exception error)
+ {
+ //This exception prevents the Main Page from being changed in a child 
+ //window or a different thread, except on the Main thread. 
+ //HEX 0x8001010E 
+ if (error.HResult == -2147417842)
+ throw new InvalidOperationException("Changing the current page is only allowed if it's being called from the same UI thread." +
+ "Please ensure that the new page is in the same UI thread as the current page.");
+ throw;
+ }
+ }
+ }
+}

src/Controls/src/Core/Platform/ModalNavigationService/ModalNavigationService.cs → src/Controls/src/Core/Platform/ModalNavigationManager/ModalNavigationManager.cs

@@ -8,7 +8,7 @@
 
 namespace Microsoft.Maui.Controls.Platform
 {
- internal partial class ModalNavigationService
+ internal partial class ModalNavigationManager
  {
  Window _window;
  public IReadOnlyList<Page> ModalStack => _navModel.Modals;
@@ -17,7 +17,7 @@ internal partial class ModalNavigationService
  NavigationModel? _previousNavModel = null;
  Page? _previousPage;
 
- public ModalNavigationService(Window window)
+ public ModalNavigationManager(Window window)
  {
  _window = window;
  }
@@ -60,6 +60,7 @@ internal void SettingNewPage()
  }
 
  partial void OnPageAttachedHandler();
+
  public void PageAttachedHandler() => OnPageAttachedHandler();
  }
 }

src/Controls/src/Core/Platform/ModalNavigationService/ModalNavigationService.iOS.cs → src/Controls/src/Core/Platform/ModalNavigationManager/ModalNavigationManager.iOS.cs

@@ -10,7 +10,7 @@
 
 namespace Microsoft.Maui.Controls.Platform
 {
- internal partial class ModalNavigationService
+ internal partial class ModalNavigationManager
  {
  UIViewController? _renderer
  {