Fix navigation

Net.Maui.Extensions/ControlFlow/IMainPagePresenter.cs

@@ -0,0 +1,6 @@
+namespace Net.Maui.Extensions.ControlFlow;
+
+public interface IMainPagePresenter<TMainPage>
+    where TMainPage : ContentPage
+{
+}

Net.Maui.Extensions/ControlFlow/INavigationService.cs

@@ -2,15 +2,10 @@
 
 public interface INavigationService
 {
-    Task GoTo<T>(bool animated = false)
+    void GoTo<T>(bool animated = false)
         where T : ContentPage;
 
-    Task GoToModal<T>(bool animated = false)
-        where T : ContentPage;
+    void GoBack(bool animated = false);
 
-    Task GoBack(bool animated = false);
-
-    Task GoBackModal(bool animated = false);
-
-    Task GoBackToRoot(bool animated = false);
+    void GoBackToRoot(bool animated = false);
 }

Net.Maui.Extensions/ControlFlow/NavigationService.cs

@@ -1,54 +1,106 @@
 using Microsoft.Extensions.Logging;
 using System.Core.Extensions;
+using System.Extensions;
 using System.Extensions.Core;
 
 namespace Net.Maui.Extensions.ControlFlow;
 
 internal sealed class NavigationService : INavigationService
 {
-    private readonly ScopedApplicationShell scopedApplicationShell;
+    private readonly Stack<ScopedPageContext> modalStack = new();
+    private readonly Stack<ScopedPageContext> navigationStack = new();
+    private readonly IServiceProvider serviceProvider;
     private readonly ILogger<NavigationService> logger;
 
+    private ExtendedApplication? extendedApplication;
+
     public NavigationService(
-        ScopedApplicationShell scopedApplicationShell,
+        IServiceProvider serviceProvider,
         ILogger<NavigationService> logger)
     {
-        this.scopedApplicationShell = scopedApplicationShell.ThrowIfNull();
+        this.serviceProvider = serviceProvider.ThrowIfNull();
         this.logger = logger.ThrowIfNull();
     }
 
-    public async Task GoBack(bool animated = false)
+    public void GoBack(bool animated = false)
     {
         var scopedLogger = this.logger.CreateScopedLogger();
-        scopedLogger.LogInformation("Going back");
-        await this.scopedApplicationShell.Navigation.PopAsync(animated);
+        if (this.navigationStack.Count <= 1)
+        {
+            scopedLogger.LogError("Cannot go back. Navigation stack is at root");
+            return;
+        }
+
+        scopedLogger.LogDebug("Going back");
+        if (this.navigationStack.TryPop(out var context))
+        {
+            context.Scope?.Dispose();
+        }
+
+        this.ShowCurrentPage();
     }
 
-    public async Task GoBackModal(bool animated = false)
+    public void GoBackToRoot(bool animated = false)
     {
         var scopedLogger = this.logger.CreateScopedLogger();
-        scopedLogger.LogInformation("Going back");
-        await this.scopedApplicationShell.Navigation.PopModalAsync(animated);
+        scopedLogger.LogDebug("Going back to root");
+        while (this.navigationStack.Count > 1 && this.navigationStack.TryPop(out var context))
+        {
+            context.Scope?.Dispose();
+        }
+
+        this.ShowCurrentPage();
     }
 
-    public async Task GoBackToRoot(bool animated = false)
+    public void GoTo<T>(bool animated = false) where T : ContentPage
     {
         var scopedLogger = this.logger.CreateScopedLogger();
-        scopedLogger.LogInformation("Going back to root");
-        await this.scopedApplicationShell.Navigation.PopToRootAsync(animated);
+        scopedLogger.LogDebug($"Going to {typeof(T).Name}");
+
+        var context = this.GetScopedPageAndProvider<T>();
+        this.navigationStack.Push(context);
+        this.ShowCurrentPage();
     }
 
-    public async Task GoTo<T>(bool animated = false) where T : ContentPage
+    public void SetNavigationRoot(ExtendedApplication extendedApplication, Type rootPageType)
     {
         var scopedLogger = this.logger.CreateScopedLogger();
-        scopedLogger.LogInformation($"Going to {typeof(T).Name}");
-        await this.scopedApplicationShell.PushScoped<T>();
+        scopedLogger.LogDebug($"Setting navigation root {rootPageType.Name}");
+
+        this.extendedApplication = extendedApplication.ThrowIfNull();
+        var context = this.GetScopedPageAndProvider(rootPageType);
+        this.navigationStack.Push(context);
+        this.ShowCurrentPage();
     }
 
-    public async Task GoToModal<T>(bool animated = false) where T : ContentPage
+    private void ShowCurrentPage()
     {
-        var scopedLogger = this.logger.CreateScopedLogger();
-        scopedLogger.LogInformation($"Going to {typeof(T).Name}");
-        await this.scopedApplicationShell.PushModalScoped<T>();
+        if (this.extendedApplication is null)
+        {
+            return;
+        }
+
+        if (this.navigationStack.TryPeek(out var currentContext))
+        {
+            this.extendedApplication.MainPage = currentContext.Page;
+        }
+    }
+
+    private ScopedPageContext GetScopedPageAndProvider<T>()
+        where T : ContentPage
+    {
+        var scope = this.serviceProvider.CreateScope();
+        return new ScopedPageContext { Page = scope.ServiceProvider.GetRequiredService<T>(), Scope = scope };
+    }
+
+    private ScopedPageContext GetScopedPageAndProvider(Type type)
+    {
+        if (!type.IsAssignableTo(typeof(ContentPage)))
+        {
+            throw new InvalidOperationException($"{type.Name} must be of type {nameof(ContentPage)}");
+        }
+
+        var scope = this.serviceProvider.CreateScope();
+        return new ScopedPageContext { Page = scope.ServiceProvider.GetRequiredService(type).Cast<ContentPage>(), Scope = scope };
     }
 }

Net.Maui.Extensions/ControlFlow/ScopedApplicationShell.cs

@@ -1,35 +0,0 @@
-using System.Core.Extensions;
-
-namespace Net.Maui.Extensions.ControlFlow;
-
-public class ScopedApplicationShell : Shell
-{
-    private readonly IServiceProvider serviceProvider;
-
-    internal ScopedApplicationShell(
-        IServiceProvider serviceProvider)
-    {
-        this.serviceProvider = serviceProvider.ThrowIfNull();
-    }
-
-    public async Task PushScoped<T>()
-        where T : ContentPage
-    {
-        var page = this.GetScopedPage<T>();
-        await this.Navigation.PushAsync(page);
-    }
-
-    public async Task PushModalScoped<T>()
-        where T : ContentPage
-    {
-        var page = this.GetScopedPage<T>();
-        await this.Navigation.PushModalAsync(page);
-    }
-
-    private T GetScopedPage<T>()
-        where T : ContentPage
-    {
-        using var scope = this.serviceProvider.CreateScope();
-        return scope.ServiceProvider.GetRequiredService<T>();
-    }
-}

Net.Maui.Extensions/ControlFlow/ScopedPageContext.cs

@@ -0,0 +1,7 @@
+namespace Net.Maui.Extensions.ControlFlow;
+
+internal sealed class ScopedPageContext
+{
+    public ContentPage? Page { get; init; }
+    public IServiceScope? Scope { get; init; }
+}

Net.Maui.Extensions/ExtendedApplication.cs

@@ -1,20 +1,35 @@
 using Net.Maui.Extensions.ControlFlow;
 using System.Core.Extensions;
+using System.Extensions;
 
 namespace Net.Maui.Extensions;
 
 public abstract class ExtendedApplication : Application
 {
-    public ScopedApplicationShell ScopedShell { get; }
+    private readonly INavigationService navigationService;
 
-    public ExtendedApplication(ScopedApplicationShell shell)
+    public ExtendedApplication(
+        INavigationService navigationService)
     {
-        if (shell is not ScopedApplicationShell)
+        this.navigationService = navigationService.ThrowIfNull();
+        this.SetMainPage();
+    }
+
+    private void SetMainPage()
+    {
+        var currentType = this.GetType();
+
+        // Find the interface that implements IMainPagePresenter<>
+        var interfaceType = currentType
+            .GetInterfaces()
+            .FirstOrDefault(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IMainPagePresenter<>));
+
+        if (interfaceType is null)
         {
-            throw new InvalidOperationException($"Shell is not of type {typeof(ScopedApplicationShell).Name}");
+            throw new InvalidOperationException($"{currentType.Name} must implement IMainPagePresenter<TMainPage>");
         }
 
-        this.MainPage = shell.ThrowIfNull();
-        this.ScopedShell = shell.ThrowIfNull();
+        var mainPageType = interfaceType.GetGenericArguments()[0];
+        this.navigationService.Cast<NavigationService>().SetNavigationRoot(this, mainPageType);
     }
 }

Net.Maui.Extensions/MauiAppBuilderExtensions.cs

@@ -1,8 +1,10 @@
 using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging;
 using Net.Maui.Extensions.Attributes;
 using Net.Maui.Extensions.Context;
 using Net.Maui.Extensions.ControlFlow;
 using System.Core.Extensions;
+using System.Extensions;
 using System.Reflection;
 
 namespace Net.Maui.Extensions;
@@ -46,19 +48,18 @@ public static class MauiAppBuilderExtensions
         return appBuilder;
     }
 
-    public static MauiAppBuilder WithExtendedApp<T>(this MauiAppBuilder appBuilder)
-        where T : ExtendedApplication
+    public static MauiAppBuilder WithExtendedApp<TApp, TMainPage>(this MauiAppBuilder appBuilder)
+        where TApp : ExtendedApplication, IMainPagePresenter<TMainPage>
+        where TMainPage : ContentPage
     {
-        appBuilder.ThrowIfNull().UseMauiApp<T>();
+        appBuilder.ThrowIfNull().UseMauiApp<TApp>();
         return appBuilder;
     }
 
     public static MauiAppBuilder WithNavigation(this MauiAppBuilder appBuilder)
     {
         appBuilder.ThrowIfNull();
-        appBuilder.Services.AddScoped<ScopedApplicationShell, ScopedApplicationShell>(sp => new ScopedApplicationShell(sp));
-        appBuilder.Services.AddScoped<Shell, ScopedApplicationShell>(sp => sp.GetRequiredService<ScopedApplicationShell>());
-        appBuilder.Services.AddScoped<INavigationService, NavigationService>();
+        appBuilder.Services.AddSingleton<INavigationService, NavigationService>(sp => new NavigationService(sp, sp.GetRequiredService<ILogger<NavigationService>>()));
 
         return appBuilder;
     }

Net.Maui.Extensions/Net.Maui.Extensions.csproj

@@ -20,7 +20,7 @@
 		<ImplicitUsings>enable</ImplicitUsings>
 		<Nullable>enable</Nullable>
     <IsPackable>true</IsPackable>
-    <Version>0.2.3</Version>
+    <Version>0.2.4</Version>
     <Authors>Alexandru Macocian</Authors>
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
@@ -52,7 +52,7 @@
 		<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="8.0.0" />
 		<PackageReference Include="System.Net.Http" Version="4.3.4" />
 		<PackageReference Include="System.Text.RegularExpressions" Version="4.3.1" />
-		<PackageReference Include="SystemExtensions.NetCore" Version="1.6.5" />
+		<PackageReference Include="SystemExtensions.NetCore" Version="1.6.6" />
 	</ItemGroup>
 
 </Project>