[WIP] Fluent API + Micosoft.Extensions.Hosting for initialization of Xamarin.Forms

Xamarin.Forms.ControlGallery.Android/FormsAppCompatActivity.cs

@@ -40,17 +40,19 @@ protected override void OnCreate(Bundle bundle)
 
 			base.OnCreate(bundle);
 
+			Forms.Create(this, bundle)
+
 #if TEST_EXPERIMENTAL_RENDERERS
-			// Fake_Flag is here so we can test for flag initialization issues
-			Forms.SetFlags("Fake_Flag"/*, "CollectionView_Experimental", "Shell_Experimental"*/); 
+				// Fake_Flag is here so we can test for flag initialization issues
+				.WithFlags("Fake_Flag"/*, "CollectionView_Experimental", "Shell_Experimental"*/)
 #else
-			Forms.SetFlags("UseLegacyRenderers"/*, "CollectionView_Experimental", "Shell_Experimental" */);
+				.WithFlags("UseLegacyRenderers"/*, "CollectionView_Experimental", "Shell_Experimental" */)
 #endif
-			Forms.Init(this, bundle);
+				.WithMaps(this, bundle)
+				.WithMaterial()
+				.WithAppLinks(this)
+				.Init();
 
-			FormsMaps.Init(this, bundle);
-			FormsMaterial.Init(this, bundle);
-			AndroidAppLinks.Init(this);
 			Forms.ViewInitialized += (sender, e) => {
 				//				if (!string.IsNullOrWhiteSpace(e.View.StyleId)) {
 				//					e.NativeView.ContentDescription = e.View.StyleId;

Xamarin.Forms.ControlGallery.GTK/Program.cs

@@ -11,56 +11,57 @@
 [assembly: ExportRenderer(typeof(DisposeLabel), typeof(DisposeLabelRenderer))]
 namespace Xamarin.Forms.ControlGallery.GTK
 {
-    class Program
-    {
-        [STAThread]
-        static void Main(string[] args)
-        {
-            ExceptionManager.UnhandledException += OnUnhandledException;
+	class Program
+	{
+		[STAThread]
+		static void Main(string[] args)
+		{
+			ExceptionManager.UnhandledException += OnUnhandledException;
 
-            GtkOpenGL.Init();
-            GtkThemes.Init();
-            Gtk.Application.Init();
-            FormsMaps.Init(string.Empty);
-            Forms.Init();
-            var app = new App();
-            var window = new FormsWindow();
-            window.LoadApplication(app);
-            window.SetApplicationTitle("Xamarin.Forms GTK# Backend");
-            window.SetApplicationIcon("xamarinlogo.png");
-            window.Show();
-            Gtk.Application.Run();
-        }
+			GtkOpenGL.Init();
+			GtkThemes.Init();
+			Gtk.Application.Init();
+			Forms.Create()
+				.WithMaps(string.Empty)
+				.Init();
+			var app = new App();
+			var window = new FormsWindow();
+			window.LoadApplication(app);
+			window.SetApplicationTitle("Xamarin.Forms GTK# Backend");
+			window.SetApplicationIcon("xamarinlogo.png");
+			window.Show();
+			Gtk.Application.Run();
+		}
 
-        private static void OnUnhandledException(UnhandledExceptionArgs args)
-        {
-            System.Diagnostics.Debug.WriteLine($"Unhandled GTK# exception: {args.ExceptionObject}");
-        }
-    }
+		private static void OnUnhandledException(UnhandledExceptionArgs args)
+		{
+			System.Diagnostics.Debug.WriteLine($"Unhandled GTK# exception: {args.ExceptionObject}");
+		}
+	}
 
-    public class DisposePageRenderer : PageRenderer
-    {
-        protected override void Dispose(bool disposing)
-        {
-            if (disposing)
-            {
-                ((DisposePage)Element).SendRendererDisposed();
-            }
+	public class DisposePageRenderer : PageRenderer
+	{
+		protected override void Dispose(bool disposing)
+		{
+			if (disposing)
+			{
+				((DisposePage)Element).SendRendererDisposed();
+			}
 
-            base.Dispose(disposing);
-        }
-    }
+			base.Dispose(disposing);
+		}
+	}
 
-    public class DisposeLabelRenderer : LabelRenderer
-    {
-        protected override void Dispose(bool disposing)
-        {
-            if (disposing)
-            {
-                ((DisposeLabel)Element).SendRendererDisposed();
-            }
+	public class DisposeLabelRenderer : LabelRenderer
+	{
+		protected override void Dispose(bool disposing)
+		{
+			if (disposing)
+			{
+				((DisposeLabel)Element).SendRendererDisposed();
+			}
 
-            base.Dispose(disposing);
-        }
-    }
+			base.Dispose(disposing);
+		}
+	}
 }

Xamarin.Forms.ControlGallery.MacOS/AppDelegate.cs

@@ -39,8 +39,9 @@ public override NSWindow MainWindow
 
 		public override void DidFinishLaunching(NSNotification notification)
 		{
-			Forms.Init();
-			FormsMaps.Init();
+			Forms.Create()
+				.WithMaps()
+				.Init();
 
 			var app = new App();
 			SetupMenu(app);

Xamarin.Forms.ControlGallery.Tizen/ControlGallery.Tizen.cs

@@ -21,10 +21,13 @@ protected override void OnCreate()
 		static void Main(string[] args)
 		{
 			var app = new MainApplication();
-			FormsMaps.Init("HERE", "write-your-API-key-here");
-			Forms.SetFlags("CollectionView_Experimental", "Shell_Experimental");
-			Forms.Init(app);
-			FormsMaterial.Init();
+
+			Forms.Create(app)
+				.WithFlags("CollectionView_Experimental", "Shell_Experimental")
+				.WithMaps("HERE", "write-your-API-key-here")
+				.WithMaterial()
+				.Init();
+
 			app.Run(args);
 		}
 	}

Xamarin.Forms.ControlGallery.WPF/MainWindow.xaml.cs

@@ -2,17 +2,18 @@
 
 namespace Xamarin.Forms.ControlGallery.WPF
 {
-    /// <summary>
-    /// Logique d'interaction pour MainWindow.xaml
-    /// </summary>
-    public partial class MainWindow : FormsApplicationPage
+	/// <summary>
+	/// Logique d'interaction pour MainWindow.xaml
+	/// </summary>
+	public partial class MainWindow : FormsApplicationPage
 	{
 		public MainWindow()
 		{
 			InitializeComponent();
-			Xamarin.Forms.Forms.Init();
-			FormsMaps.Init("");
+			Xamarin.Forms.Forms.Create()
+				.WithMaps("")
+				.Init();
 			LoadApplication(new Controls.App());
-        }
+		}
 	}
 }

Xamarin.Forms.ControlGallery.WindowsUniversal/App.xaml.cs

@@ -22,28 +22,28 @@
 
 namespace Xamarin.Forms.ControlGallery.WindowsUniversal
 {
-    /// <summary>
-    /// Provides application-specific behavior to supplement the default Application class.
-    /// </summary>
-    sealed partial class App
-    {
+	/// <summary>
+	/// Provides application-specific behavior to supplement the default Application class.
+	/// </summary>
+	sealed partial class App
+	{
 		/// <summary>
 		/// Initializes the singleton application object.  This is the first line of authored code
 		/// executed, and as such is the logical equivalent of main() or WinMain().
 		/// </summary>
 		public App()
-        {
-            InitializeComponent();
-            Suspending += OnSuspending;
-        }
+		{
+			InitializeComponent();
+			Suspending += OnSuspending;
+		}
 
-        /// <summary>
-        /// Invoked when the application is launched normally by the end user.  Other entry points
-        /// will be used such as when the application is launched to open a specific file.
-        /// </summary>
-        /// <param name="e">Details about the launch request and process.</param>
-        protected override void OnLaunched(LaunchActivatedEventArgs e)
-        {
+		/// <summary>
+		/// Invoked when the application is launched normally by the end user.  Other entry points
+		/// will be used such as when the application is launched to open a specific file.
+		/// </summary>
+		/// <param name="e">Details about the launch request and process.</param>
+		protected override void OnLaunched(LaunchActivatedEventArgs e)
+		{
 			/* uncomment if you want to run tests without preloading
 			 * issues list or change other behavior based on if tests
 			 * are running in UI Harness
@@ -52,39 +52,40 @@ protected override void OnLaunched(LaunchActivatedEventArgs e)
 				Controls.App.PreloadTestCasesIssuesList = false;*/
 #if DEBUG
 			if (System.Diagnostics.Debugger.IsAttached)
-            {
-             //   DebugSettings.EnableFrameRateCounter = true;
-            }
+			{
+			 //   DebugSettings.EnableFrameRateCounter = true;
+			}
 #endif
 
-            var rootFrame = Window.Current.Content as Windows.UI.Xaml.Controls.Frame;
+			var rootFrame = Window.Current.Content as Windows.UI.Xaml.Controls.Frame;
 
-            // Do not repeat app initialization when the Window already has content,
-            // just ensure that the window is active
-            if (rootFrame == null)
-            {
-                // Create a Frame to act as the navigation context and navigate to the first page
-                rootFrame = new Windows.UI.Xaml.Controls.Frame();
-                // Set the default language
-                rootFrame.Language = Windows.Globalization.ApplicationLanguages.Languages[0];
+			// Do not repeat app initialization when the Window already has content,
+			// just ensure that the window is active
+			if (rootFrame == null)
+			{
+				// Create a Frame to act as the navigation context and navigate to the first page
+				rootFrame = new Windows.UI.Xaml.Controls.Frame();
+				// Set the default language
+				rootFrame.Language = Windows.Globalization.ApplicationLanguages.Languages[0];
 
-                rootFrame.NavigationFailed += OnNavigationFailed;
+				rootFrame.NavigationFailed += OnNavigationFailed;
 
-				Forms.SetFlags("Shell_UWP_Experimental");
-				Forms.Init (e);
-				//FormsMaps.Init (Controls.App.Config["UWPMapsAuthKey"]);
+				Forms.Create(e)
+					.WithFlags("Shell_UWP_Experimental")
+					//.WithMaps(Controls.App.Config["UWPMapsAuthKey"])
+					.Init();
 
 				// Place the frame in the current Window
 				Window.Current.Content = rootFrame;
-            }
+			}
 
-            if (rootFrame.Content == null)
-            {
-                // When the navigation stack isn't restored navigate to the first page,
-                // configuring the new page by passing required information as a navigation
-                // parameter
-                rootFrame.Navigate(typeof(MainPage), e.Arguments);
-            }
+			if (rootFrame.Content == null)
+			{
+				// When the navigation stack isn't restored navigate to the first page,
+				// configuring the new page by passing required information as a navigation
+				// parameter
+				rootFrame.Navigate(typeof(MainPage), e.Arguments);
+			}
 
 			//// Uncomment to test overriding the status bar color
 			//if (ApiInformation.IsTypePresent("Windows.UI.ViewManagement.StatusBar"))
@@ -100,30 +101,30 @@ protected override void OnLaunched(LaunchActivatedEventArgs e)
 
 			// Ensure the current window is active
 			Window.Current.Activate();
-        }
+		}
 
-        /// <summary>
-        /// Invoked when Navigation to a certain page fails
-        /// </summary>
-        /// <param name="sender">The Frame which failed navigation</param>
-        /// <param name="e">Details about the navigation failure</param>
-        void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
-        {
-            throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
-        }
+		/// <summary>
+		/// Invoked when Navigation to a certain page fails
+		/// </summary>
+		/// <param name="sender">The Frame which failed navigation</param>
+		/// <param name="e">Details about the navigation failure</param>
+		void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
+		{
+			throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
+		}
 
-        /// <summary>
-        /// Invoked when application execution is being suspended.  Application state is saved
-        /// without knowing whether the application will be terminated or resumed with the contents
-        /// of memory still intact.
-        /// </summary>
-        /// <param name="sender">The source of the suspend request.</param>
-        /// <param name="e">Details about the suspend request.</param>
-        void OnSuspending(object sender, SuspendingEventArgs e)
-        {
-            var deferral = e.SuspendingOperation.GetDeferral();
-            //TODO: Save application state and stop any background activity
-            deferral.Complete();
-        }
-    }
+		/// <summary>
+		/// Invoked when application execution is being suspended.  Application state is saved
+		/// without knowing whether the application will be terminated or resumed with the contents
+		/// of memory still intact.
+		/// </summary>
+		/// <param name="sender">The source of the suspend request.</param>
+		/// <param name="e">Details about the suspend request.</param>
+		void OnSuspending(object sender, SuspendingEventArgs e)
+		{
+			var deferral = e.SuspendingOperation.GetDeferral();
+			//TODO: Save application state and stop any background activity
+			deferral.Complete();
+		}
+	}
 }

Xamarin.Forms.ControlGallery.iOS/AppDelegate.cs

@@ -150,10 +150,12 @@ public override bool FinishedLaunching(UIApplication uiApplication, NSDictionary
 			App.IOSVersion = int.Parse(versionPart[0]);
 
 			Xamarin.Calabash.Start();
-			// Forms.SetFlags("CollectionView_Experimental", "Shell_Experimental");
-			Forms.Init();
-			FormsMaps.Init();
-			FormsMaterial.Init();
+
+			Forms.Create()
+				 //.WithFlags("CollectionView_Experimental", "Shell_Experimental")
+				.WithMaps()
+				.WithMaterial()
+				.Init();
 
 			Forms.ViewInitialized += (object sender, ViewInitializedEventArgs e) =>
 			{

Xamarin.Forms.Core.UnitTests/FormsInitTests.cs

@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+using NUnit.Framework;
+
+namespace Xamarin.Forms.Core.UnitTests
+{
+	[TestFixture]
+	public class FormsInitTests : BaseTestFixture
+	{
+		[Test]
+		public void InitTest()
+		{
+			var list = new List<string>();
+
+			var formsInit = new FormsInit(() => list.Add("init"));
+			formsInit.PostInit(() => list.Add("post1"));
+			formsInit.PreInit(() => list.Add("pre1"));
+			formsInit.PreInit(() => list.Add("pre2"));
+			formsInit.PostInit(() => list.Add("post2"));
+			formsInit.Init();
+
+			Assert.IsTrue(list[0] == "pre1");
+			Assert.IsTrue(list[1] == "pre2");
+			Assert.IsTrue(list[2] == "init");
+			Assert.IsTrue(list[3] == "post1");
+			Assert.IsTrue(list[4] == "post2");
+		}
+	}
+}