Application cross lifecycle events

src/Controls/samples/Controls.Sample.SingleProject/MyApp.cs

@@ -1,10 +1,11 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Maui;
 using Microsoft.Maui.Hosting;
+using Application = Microsoft.Maui.Application;
 
 namespace Maui.Controls.Sample.SingleProject
 {
-	public class MyApp : MauiApp
+	public class MyApp : Application
 	{
 		public override IAppHostBuilder CreateBuilder() => 
 			base.CreateBuilder().ConfigureServices((ctx, services) =>

src/Controls/samples/Controls.Sample/MainWindow.cs

@@ -1,14 +1,13 @@
 using Maui.Controls.Sample.Controls;
-using Maui.Controls.Sample.Pages;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Maui;
-using Microsoft.Maui.Controls;
+using MauiApplication = Microsoft.Maui.Application;
 
 namespace Maui.Controls.Sample
 {
 	public class MainWindow : Window
 	{
-		public MainWindow() : this(App.Current.Services.GetRequiredService<IPage>())
+		public MainWindow() : this(MauiApplication.Current.Services.GetRequiredService<IPage>())
 		{
 		}
 

src/Controls/samples/Controls.Sample/MyApp.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using Maui.Controls.Sample.Pages;
 using Maui.Controls.Sample.Services;
 using Maui.Controls.Sample.ViewModel;
@@ -10,10 +11,11 @@
 using Microsoft.Maui.Controls;
 using Microsoft.Maui.Controls.Compatibility;
 using Microsoft.Maui.Hosting;
+using Application = Microsoft.Maui.Application;
 
 namespace Maui.Controls.Sample
 {
-	public class MyApp : MauiApp
+	public class MyApp : Application
 	{
 		public readonly static bool UseXamlPage = false;
 
@@ -45,15 +47,35 @@ public override IAppHostBuilder CreateBuilder() =>
 					fonts.AddFont("dokdo_regular.ttf", "Dokdo");
 				});
 
-		//IAppState state
+		// IAppState state
 		public override IWindow CreateWindow(IActivationState state)
 		{
 			Forms.Init(state);
 			return Services.GetRequiredService<IWindow>();
 		}
+
+		public override void OnCreated()
+		{
+			Debug.WriteLine("Application Created.");
+		}
+
+		public override void OnPaused()
+		{
+			Debug.WriteLine("Application Paused.");
+		}
+
+		public override void OnResumed()
+		{
+			Debug.WriteLine("Application Resumed.");
+		}
+
+		public override void OnStopped()
+		{
+			Debug.WriteLine("Application Stopped.");
+		}
 	}
 
-	//to use DI ServiceCollection and not the MAUI one
+	// To use DI ServiceCollection and not the MAUI one
 	public class DIExtensionsServiceProviderFactory : IServiceProviderFactory<ServiceCollection>
 	{
 		public ServiceCollection CreateBuilder(IServiceCollection services)

src/Controls/samples/Controls.Sample/Pages/MainPage.cs

@@ -2,14 +2,15 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Maui;
 using Microsoft.Maui.Controls;
+using MauiApplication = Microsoft.Maui.Application;
 
 namespace Maui.Controls.Sample.Pages
 {
 	public class MainPage : ContentPage, IPage
 	{
-		MainPageViewModel _viewModel;
+		readonly MainPageViewModel _viewModel;
 
-		public MainPage() : this(App.Current.Services.GetService<MainPageViewModel>())
+		public MainPage() : this(MauiApplication.Current.Services.GetService<MainPageViewModel>())
 		{
 
 		}

src/Controls/samples/Controls.Sample/ViewModel/MainPageViewModel.cs

@@ -5,21 +5,22 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Maui;
+using MauiApplication = Microsoft.Maui.Application;
 
 namespace Maui.Controls.Sample.ViewModel
 {
 	public class MainPageViewModel : ViewModelBase
 	{
-		private readonly IConfiguration Configuration;
+		readonly IConfiguration Configuration;
 		ITextService textService;
 
-		public MainPageViewModel() : this(new ITextService[] { App.Current.Services.GetService<ITextService>() })
+		public MainPageViewModel() : this(new ITextService[] { MauiApplication.Current.Services.GetService<ITextService>() })
 		{
 		}
 
 		public MainPageViewModel(IEnumerable<ITextService> textServices)
 		{
-			Configuration = App.Current.Services.GetService<IConfiguration>();
+			Configuration = MauiApplication.Current.Services.GetService<IConfiguration>();
 
 			//var logger = App.Current.Services.GetService<ILogger<MainPageViewModel>>();
 

src/Core/src/App.cs → src/Core/src/Application.cs

@@ -1,41 +1,38 @@
 using System;
-using System.Collections.Generic;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Maui.Hosting;
 
 namespace Microsoft.Maui
 {
-	public abstract class App : IApp
+	public abstract class Application : IApplication
 	{
 		IServiceProvider? _serviceProvider;
 		IMauiContext? _context;
 
-		protected App()
+		protected Application()
 		{
 			if (Current != null)
-				throw new InvalidOperationException($"Only one {nameof(App)} instance is allowed");
+				throw new InvalidOperationException($"Only one {nameof(Application)} instance is allowed");
+
 			Current = this;
 		}
 
-		public static App? Current { get; internal set; }
+		public static Application? Current { get; internal set; }
 
 		public IServiceProvider? Services => _serviceProvider;
 
 		public IMauiContext? Context => _context;
 
-		//move to abstract
+		// Move to abstract
 		public virtual IAppHostBuilder CreateBuilder() => CreateDefaultBuilder();
 
-		internal void SetServiceProvider(IServiceProvider provider)
-		{
-			_serviceProvider = provider;
-			SetHandlerContext(provider.GetService<IMauiContext>());
-		}
+		public event EventHandler? Created;
 
-		internal void SetHandlerContext(IMauiContext? context)
-		{
-			_context = context;
-		}
+		public event EventHandler? Resumed;
+
+		public event EventHandler? Paused;
+
+		public event EventHandler? Stopped;
 
 		public static IAppHostBuilder CreateDefaultBuilder()
 		{
@@ -46,5 +43,38 @@ public static IAppHostBuilder CreateDefaultBuilder()
 
 			return builder;
 		}
+
+		public abstract IWindow CreateWindow(IActivationState state);
+
+		public virtual void OnCreated()
+		{
+			Created?.Invoke(this, EventArgs.Empty);
+		}
+
+		public virtual void OnResumed()
+		{
+			Resumed?.Invoke(this, EventArgs.Empty);
+		}
+
+		public virtual void OnPaused()
+		{
+			Paused?.Invoke(this, EventArgs.Empty);
+		}
+
+		public virtual void OnStopped()
+		{
+			Stopped?.Invoke(this, EventArgs.Empty);
+		}
+
+		internal void SetServiceProvider(IServiceProvider provider)
+		{
+			_serviceProvider = provider;
+			SetHandlerContext(provider.GetService<IMauiContext>());
+		}
+
+		internal void SetHandlerContext(IMauiContext? context)
+		{
+			_context = context;
+		}
 	}
 }

src/Core/src/Core/IApplication.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Microsoft.Maui
+{
+	/// <summary>
+	/// Encapsulates the Application and its available services.
+	/// </summary>
+	public interface IApplication : IApplicationLifetime
+	{
+		/// <summary>
+		/// Gets a collection of application-scoped services.
+		/// </summary>
+		IServiceProvider? Services { get; }
+	}
+}

src/Core/src/Core/IApplicationLifetime.cs

@@ -0,0 +1,50 @@
+using System;
+
+namespace Microsoft.Maui
+{
+	/// <summary>
+	/// Provides the methods and events to respond to Application lifecycle changes.
+	/// </summary>
+	public interface IApplicationLifetime
+	{
+		/// <summary>
+		/// Called when the application is first created.
+		/// </summary>
+		void OnCreated();
+
+		/// <summary>
+		/// Called when the application content will start interacting with the user.
+		/// </summary>
+		void OnResumed();
+
+		/// <summary>
+		/// Called when the application is not visible to the user.
+		/// </summary>
+		void OnPaused();
+
+		/// <summary>
+		/// Called before the application is closed.
+		/// </summary>
+		void OnStopped();
+
+		/// <summary>
+		/// This event is raised when the application is closed.
+		/// </summary>
+		event EventHandler? Created;
+
+		/// <summary>
+		/// This event is raised when the application is resumed.
+		/// </summary>
+		event EventHandler? Resumed;
+
+		/// <summary>
+		/// This event is raised when the application is pasued.
+		/// </summary>
+		event EventHandler? Paused;
+
+		/// <summary>
+		/// This event is raised when the application is closed.
+		/// </summary>
+		event EventHandler? Stopped;
+	}
+}

src/Core/src/Core/IWindow.cs

@@ -3,7 +3,7 @@ namespace Microsoft.Maui
 	/// <summary>
 	/// Provides the ability to create, configure, show, and manage Windows.
 	/// </summary>
-	public interface IWindow
+	public interface IWindow 
 	{
 		/// <summary>
 		/// Gets or sets the .NET MAUI Context.

src/Core/src/Handlers/Button/ButtonHandler.Android.cs

@@ -55,7 +55,7 @@ public static void MapTextColor(ButtonHandler handler, IButton button)
 
 		public static void MapFont(ButtonHandler handler, IButton button)
 		{
-			var services = App.Current?.Services
+			var services = Application.Current?.Services
 				?? throw new InvalidOperationException($"Unable to find service provider, the App.Current.Services was null.");
 			var fontManager = services.GetRequiredService<IFontManager>();
 

src/Core/src/Handlers/Button/ButtonHandler.iOS.cs

@@ -61,7 +61,7 @@ public static void MapPadding(ButtonHandler handler, IButton button)
 
 		public static void MapFont(ButtonHandler handler, IButton button)
 		{
-			var services = App.Current?.Services ??
+			var services = Application.Current?.Services ??
 				throw new InvalidOperationException($"Unable to find service provider, the App.Current.Services was null.");
 			var fontManager = services.GetRequiredService<IFontManager>();
 

src/Core/src/Handlers/Entry/EntryHandler.Android.cs

@@ -62,7 +62,7 @@ public static void MapPlaceholder(EntryHandler handler, IEntry entry)
 
 		public static void MapFont(EntryHandler handler, IEntry entry)
 		{
-			var services = App.Current?.Services
+			var services = Application.Current?.Services
 				?? throw new InvalidOperationException($"Unable to find service provider, the App.Current.Services was null.");
 			var fontManager = services.GetRequiredService<IFontManager>();
 

src/Core/src/Handlers/Entry/EntryHandler.iOS.cs

@@ -93,7 +93,7 @@ void OnTextChanged()
 
 		public static void MapFont(EntryHandler handler, IEntry entry)
 		{
-			var services = App.Current?.Services
+			var services = Application.Current?.Services
 				?? throw new InvalidOperationException($"Unable to find service provider, the App.Current.Services was null.");
 			var fontManager = services.GetRequiredService<IFontManager>();
 

src/Core/src/Handlers/Label/LabelHandler.Android.cs

@@ -64,8 +64,8 @@ public static void MapTextDecorations(LabelHandler handler, ILabel label)
 
 		public static void MapFont(LabelHandler handler, ILabel label)
 		{
-			var services = App.Current?.Services
-				?? throw new InvalidOperationException($"Unable to find service provider, the App.Current.Services was null.");
+			var services = Application.Current?.Services
+				?? throw new InvalidOperationException($"Unable to find service provider, the Application.Current.Services was null.");
 			var fontManager = services.GetRequiredService<IFontManager>();
 
 			handler.TypedNativeView?.UpdateFont(label, fontManager);

src/Core/src/Handlers/Label/LabelHandler.iOS.cs

@@ -50,8 +50,8 @@ public static void MapTextDecorations(LabelHandler handler, ILabel label)
 
 		public static void MapFont(LabelHandler handler, ILabel label)
 		{
-			var services = App.Current?.Services ??
-				throw new InvalidOperationException($"Unable to find service provider, the App.Current.Services was null.");
+			var services = Application.Current?.Services ??
+				throw new InvalidOperationException($"Unable to find service provider, the Application.Current.Services was null.");
 			var fontManager = services.GetRequiredService<IFontManager>();
 
 			handler.TypedNativeView?.UpdateFont(label, fontManager);

src/Core/src/Handlers/Layout/LayoutHandler.Android.cs

@@ -1,6 +1,4 @@
 using System;
-using System.Collections.Generic;
-using System.Text;
 using Android.Views;
 
 namespace Microsoft.Maui.Handlers
@@ -29,24 +27,24 @@ public override void SetVirtualView(IView view)
 
 			_ = TypedNativeView ?? throw new InvalidOperationException($"{nameof(TypedNativeView)} should have been set by base class.");
 			_ = VirtualView ?? throw new InvalidOperationException($"{nameof(VirtualView)} should have been set by base class.");
-			_ = MauiApp.Current?.Context ?? throw new InvalidOperationException($"The MauiApp.Current.Context can't be null.");
+			_ = Application.Current?.Context ?? throw new InvalidOperationException($"The MauiApp.Current.Context can't be null.");
 
 			TypedNativeView.CrossPlatformMeasure = VirtualView.Measure;
 			TypedNativeView.CrossPlatformArrange = VirtualView.Arrange;
 
 			foreach (var child in VirtualView.Children)
 			{
-				TypedNativeView.AddView(child.ToNative(MauiApp.Current.Context));
+				TypedNativeView.AddView(child.ToNative(Application.Current.Context));
 			}
 		}
 
 		public void Add(IView child)
 		{
 			_ = TypedNativeView ?? throw new InvalidOperationException($"{nameof(TypedNativeView)} should have been set by base class.");
 			_ = VirtualView ?? throw new InvalidOperationException($"{nameof(VirtualView)} should have been set by base class.");
-			_ = MauiApp.Current?.Context ?? throw new InvalidOperationException($"The MauiApp.Current.Context can't be null.");
+			_ = Application.Current?.Context ?? throw new InvalidOperationException($"The MauiApp.Current.Context can't be null.");
 
-			TypedNativeView.AddView(child.ToNative(MauiApp.Current.Context!), 0);
+			TypedNativeView.AddView(child.ToNative(Application.Current.Context!), 0);
 		}
 
 		public void Remove(IView child)