Initial work on the new fast splash screen (#186)

* new fast and simple splash screen

docs/concepts/Splashscreen.md

@@ -1,7 +1,73 @@
 ## Splash Screen
 
+WinUIEx provides two kinds of splash screens:
+ - `SimpleSplashScreen`: A simple splash screen that shows just an image and can be launched before any UI loads.
+ - `SplashScreen`: A more advanced splash screen that can show any XAML including a progress bar and status text.
+
+
+### SimpleSplashScreen
+
+`SimpleSplashScreen` will show an image while the app is loading. To use it, create a new `SimpleSplashScreen` in App.xaml.cs:
+
+```cs
+private SimpleSplashScreen vss { get; set; }
+
+public App()
+{
+  fss = SimpleSplashScreen.ShowDefaultSplashScreen(); // Shows the splash screen you already defined in your app manifest. For unpackaged apps use .ShowSplashScreenImage(imagepath):
+  // fss = SimpleSplashScreen.ShowSplashScreenImage(full_path_to_image_); // Shows a custom splash screen image. Must be a full-path (no relative paths)
+  this.InitializeComponent();
+}
+```
+
+Once your window is activated, you can remove the splash screen by either calling `.Dispose()` or `Hide()`.
+
+```cs
+protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
+{
+  m_window = new MainWindow();
+  m_window.Activate();
+  Window_Activated += Window_Activated;
+
+}
+
+private void Window_Activated(object sender, WindowActivatedEventArgs args)
+{
+  ((Window)sender).Activated -= Window_Activated;
+  fss?.Hide();
+  fss = null;
+}
+```
+
+For even faster splash screen, disable the XAML generated main method by defining the `DISABLE_XAML_GENERATED_MAIN` preprocessor directive
+and instead defining your own start method. You'll then be able to display the splash screen as the very first thing before the application is created. For example:
+
+```cs
+#if DISABLE_XAML_GENERATED_MAIN
+  public static class Program
+  {
+    [System.STAThreadAttribute]
+    static void Main(string[] args)
+    {
+      // If you're using the WebAuthenticator, make sure you call this method first before the splashscreen shows
+      if (WebAuthenticator.CheckOAuthRedirectionActivation(true))
+        return;
+      var fss = SimpleSplashScreen.ShowDefaultSplashScreen();
+      WinRT.ComWrappersSupport.InitializeComWrappers();
+      Microsoft.UI.Xaml.Application.Start((p) => {
+        var context = new Microsoft.UI.Dispatching.DispatcherQueueSynchronizationContext(Microsoft.UI.Dispatching.DispatcherQueue.GetForCurrentThread());
+        System.Threading.SynchronizationContext.SetSynchronizationContext(context);
+        new App(fss); // Pass the splash screen to your app so it can close it on activation
+      });
+    }
+  }
+#endif
+```
+
+### SplashScreen
+
 To create a new splash screen, first create a new WinUI Window.
-Next change the baseclass from "Window" to SplashScreen:
+Next change the baseclass from `Window` to `SplashScreen`:
 
 Before:
 ```xml
@@ -21,52 +87,52 @@ Before:
 ```cs
 public sealed partial class SplashScreen : Window
 {
-        public SplashScreen()
-        {
-            this.InitializeComponent();
-        }
+  public SplashScreen()
+  {
+    this.InitializeComponent();
+  }
 }
 ```
 After:
 ```cs
 public sealed partial class SplashScreen : WinUIEx.SplashScreen
 {
-        public SplashScreen(Type window) : base(window)
-        {
-            this.InitializeComponent();
-        }
+  public SplashScreen(Type window) : base(window)
+  {
+    this.InitializeComponent();
+  }
 }
 ```
 
 Next in App.xaml.cs, change OnLaunched from:
 ```cs
-        protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
-        {
-            m_window = new MainWindow();
-            m_window.Activate();
-        }
+protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
+{
+  m_window = new MainWindow();
+  m_window.Activate();
+}
 ```
 To:
 ```cs
-        protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
-        {
-             var splash = new SplashScreen(typeof(MainWindow));
-             splash.Completed += (s, e) => m_window = e;
-        }
+protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
+{
+  var splash = new SplashScreen(typeof(MainWindow));
+  splash.Completed += (s, e) => m_window = e;
+}
 ```
 
 Lastly, override OnLoading, to create some long-running setup work - once this method completes, the splash screen will close and the window in the type parameter will launch.
 
 Example:
-```
-       protected override async Task OnLoading()
-       {
-            //TODO: Do some actual work
-            for (int i = 0; i < 100; i+=5)
-            {
-                statusText.Text = $"Loading {i}%...";
-                progressBar.Value = i;
-                await Task.Delay(50);
-            }
-       }
+```cs
+protected override async Task OnLoading()
+{
+  //TODO: Do some actual work
+  for (int i = 0; i < 100; i+=5)
+  {
+    statusText.Text = $"Loading {i}%...";
+    progressBar.Value = i;
+    await Task.Delay(50);
+  }
+}
 ```

src/Directory.Build.targets

@@ -17,7 +17,7 @@
     <Authors>Morten Nielsen - https://xaml.dev</Authors>
     <Company>Morten Nielsen - https://xaml.dev</Company>
     <PackageIcon>logo.png</PackageIcon>
-    <Version>2.4.2</Version>
+    <Version>2.5.0</Version>
     <!--<PackageValidationBaselineVersion>2.3.4</PackageValidationBaselineVersion>-->
   </PropertyGroup>
 

src/WinUIEx/NativeMethods.txt

@@ -54,4 +54,15 @@ DwmExtendFrameIntoClientArea
 CreateRectRgn
 CreateSolidBrush
 FillRect
-GetDC
+GetDC
+ReleaseDC
+GdiplusStartup
+GdiplusShutdown
+GetObject
+GdipCreateBitmapFromFile
+GdipCreateHBITMAPFromBitmap
+WNDCLASSEXW
+RegisterClassEx
+CreateCompatibleDC
+SelectObject
+MonitorFromPoint