Map LayoutViewRegionAdapter to Maui Layout

src/Maui/Prism.Maui/Ioc/RegionNavigationRegistrationExtensions.cs

@@ -1,5 +1,4 @@
 using System.Diagnostics.CodeAnalysis;
-using Microsoft.Maui.Controls.Compatibility;
 using Prism.Mvvm;
 using Prism.Navigation.Regions;
 using Prism.Navigation.Regions.Adapters;
@@ -115,7 +114,8 @@ internal static IContainerRegistry RegisterRegionServices(this IContainerRegistr
             // TODO: CollectionView is buggy with only last View showing despite multiple Active Views
             // BUG: iOS Crash with CollectionView https://github.com/xamarin/Xamarin.Forms/issues/9970
             //regionAdapterMappings.RegisterDefaultMapping<CollectionView, CollectionViewRegionAdapter>();
-            regionAdapterMappings.RegisterDefaultMapping<Layout<View>, LayoutViewRegionAdapter>();
+            regionAdapterMappings.RegisterDefaultMapping<Microsoft.Maui.Controls.Compatibility.Layout<View>, LayoutViewRegionAdapter>();
+            regionAdapterMappings.RegisterDefaultMapping<Layout, LayoutRegionAdapter>();
             regionAdapterMappings.RegisterDefaultMapping<ScrollView, ScrollViewRegionAdapter>();
             regionAdapterMappings.RegisterDefaultMapping<ContentView, ContentViewRegionAdapter>();
             return regionAdapterMappings;

src/Maui/Prism.Maui/Navigation/Regions/Adapters/LayoutRegionAdapter.cs

@@ -0,0 +1,50 @@
+using Prism.Properties;
+
+namespace Prism.Navigation.Regions.Adapters;
+
+/// <summary>
+/// Adapter that creates a new <see cref="Region"/> and monitors its
+/// active view to set it on the adapted <see cref="Layout"/>.
+/// </summary>
+public class LayoutRegionAdapter : RegionAdapterBase<Layout>
+{
+    /// <summary>
+    /// Initializes a new instance of <see cref="LayoutRegionAdapter"/>.
+    /// </summary>
+    /// <param name="regionBehaviorFactory">The factory used to create the region behaviors to attach to the created regions.</param>
+    public LayoutRegionAdapter(IRegionBehaviorFactory regionBehaviorFactory)
+        : base(regionBehaviorFactory)
+    {
+    }
+
+    /// <summary>
+    /// Adapts a <see cref="Layout"/> to an <see cref="IRegion"/>.
+    /// </summary>
+    /// <param name="region">The new region being used.</param>
+    /// <param name="regionTarget">The object to adapt.</param>
+    protected override void Adapt(IRegion region, Layout regionTarget)
+    {
+        if (region == null)
+            throw new ArgumentNullException(nameof(region));
+
+        if (regionTarget == null)
+            throw new ArgumentNullException(nameof(regionTarget));
+
+        bool itemsSourceIsSet = regionTarget.Children?.Any() ?? false || regionTarget.IsSet(BindableLayout.ItemsSourceProperty);
+
+        if (itemsSourceIsSet)
+        {
+            throw new InvalidOperationException(Resources.LayoutViewHasChildrenException);
+        }
+
+        BindableLayout.SetItemsSource(regionTarget, region.Views);
+        BindableLayout.SetItemTemplate(regionTarget, new RegionItemsSourceTemplate());
+    }
+
+    /// <summary>
+    /// Creates a new instance of <see cref="IRegion"/>.
+    /// </summary>
+    /// <returns>A new instance of <see cref="Region"/>.</returns>
+    protected override IRegion CreateRegion(IContainerProvider container) =>
+        container.Resolve<Region>();
+}

src/Maui/Prism.Maui/Navigation/Regions/Adapters/LayoutViewRegionAdapter.cs

@@ -1,5 +1,4 @@
-using Microsoft.Maui.Controls.Compatibility;
-using Prism.Ioc;
+using Microsoft.Maui.Controls.Compatibility;
 using Prism.Properties;
 
 namespace Prism.Navigation.Regions.Adapters;

tests/Maui/Prism.DryIoc.Maui.Tests/Fixtures/Regions/RegionFixture.cs

@@ -1,4 +1,4 @@
-using Prism.DryIoc.Maui.Tests.Mocks.ViewModels;
+using Prism.DryIoc.Maui.Tests.Mocks.ViewModels;
 using Prism.DryIoc.Maui.Tests.Mocks.Views;
 using Prism.Navigation.Xaml;
 
@@ -53,6 +53,33 @@ public void FrameRegion_CreatedBy_RegisterViewWithRegion()
         Assert.IsType<MockRegionViewAViewModel>(page.FrameRegion.Content.BindingContext);
     }
 
+    [Fact]
+    public void Issue3159_LayoutRegion_CreatedBy_RegisterViewWithRegion()
+    {
+        var mauiApp = CreateBuilder(prism =>
+                prism.RegisterTypes(container =>
+                {
+                    container.RegisterForNavigation<MockContentRegionPage, MockContentRegionPageViewModel>();
+                    container.RegisterForRegionNavigation<MockRegionViewA, MockRegionViewAViewModel>();
+                })
+                .OnInitialized(container =>
+                {
+                    var regionManager = container.Resolve<IRegionManager>();
+                    regionManager.RegisterViewWithRegion("LayoutRegion", "MockRegionViewA");
+                })
+                .CreateWindow("MockContentRegionPage"))
+            .Build();
+        var window = GetWindow(mauiApp);
+
+        Assert.IsType<MockContentRegionPage>(window.Page);
+        var page = window.Page as MockContentRegionPage;
+
+        Assert.NotNull(page.LayoutRegion.Children);
+        Assert.NotEmpty(page.LayoutRegion.Children);
+        Assert.IsType<ContentView>(page.LayoutRegion.Children.First());
+        Assert.IsType<MockRegionViewAViewModel>(((ContentView)page.LayoutRegion.First()).Content.BindingContext);
+    }
+
     [Fact]
     public void RegionsShareContainer_WithPage()
     {
@@ -76,7 +103,7 @@ public void RegionsShareContainer_WithPage()
 
         var regionManager = mauiApp.Services.GetRequiredService<IRegionManager>();
         var regions = regionManager.Regions.Cast<ITargetAwareRegion>();
-        Assert.Equal(2, regions.Count());
+        Assert.Equal(3, regions.Count());
         foreach (var region in regions)
         {
             Assert.Same(page.GetContainerProvider(), region.Container);
@@ -110,7 +137,7 @@ public void RegionViewModel_HasPageAccessor_WithCorrectPage()
     }
 
     [Fact]
-    public void RegionManager_HasTwoRegions()
+    public void RegionManager_HasRegionsAmount()
     {
         var mauiApp = CreateBuilder(prism =>
                 prism.RegisterTypes(container =>
@@ -122,7 +149,7 @@ public void RegionManager_HasTwoRegions()
         var window = GetWindow(mauiApp);
 
         var regionManager = mauiApp.Services.GetRequiredService<IRegionManager>();
-        Assert.Equal(2, regionManager.Regions.Count());
+        Assert.Equal(3, regionManager.Regions.Count());
     }
 
     [Fact]

tests/Maui/Prism.DryIoc.Maui.Tests/Mocks/Views/MockContentRegionPage.cs

@@ -1,4 +1,4 @@
-namespace Prism.DryIoc.Maui.Tests.Mocks.Views;
+namespace Prism.DryIoc.Maui.Tests.Mocks.Views;
 
 public class MockContentRegionPage : ContentPage
 {
@@ -10,14 +10,20 @@ public MockContentRegionPage()
         FrameRegion = new Frame();
         FrameRegion.SetValue(Prism.Navigation.Regions.Xaml.RegionManager.RegionNameProperty, nameof(FrameRegion));
 
+        LayoutRegion = new StackLayout();
+        LayoutRegion.SetValue(Prism.Navigation.Regions.Xaml.RegionManager.RegionNameProperty, nameof(LayoutRegion));
+
         Content = new StackLayout
         {
             ContentRegion,
-            FrameRegion
+            FrameRegion,
+            LayoutRegion
         };
     }
 
     public ContentView ContentRegion { get; }
 
     public Frame FrameRegion { get; }
+
+    public Layout LayoutRegion { get; }
 }