Prevent window from stealing focus

Hyperbar.Windows.Controls/DesktopFlyout/DesktopFlyoutHost.cs

@@ -4,7 +4,7 @@ using Hyperbar.Windows.UI;
 using Windows.Foundation;
 using WinUIEx;
 using WindowStyle = Hyperbar.Windows.Interop.WindowStyle;
-using System.Diagnostics;
+using ExtendedWindowStyle = Hyperbar.Windows.Interop.ExtendedWindowStyle;
 
 namespace Hyperbar.Windows.Controls;
 
@@ -16,19 +16,25 @@ internal class DesktopFlyoutHost : Window
 
     public DesktopFlyoutHost(DesktopFlyoutPresenter presenter)
     {
+        SystemBackdrop = new TransparentTintBackdrop();
+
+        this.SetOpacity(0);
+        this.Snap(WindowPlacement.Top, 0, 0);
+
+        this.SetStyle(WindowStyle.SysMenu | WindowStyle.Visible);
+        this.SetStyle(ExtendedWindowStyle.NoActivate);
+
+        this.SetTopMost(true);
+        this.SetIsAvailableInSwitchers(false);
+
         Border root = new();
         root.Loaded += OnLoaded;
         Content = root;
 
         this.presenter = presenter;
-
-        this.SetOpacity(0);
-        this.SetStyle(WindowStyle.SysMenu | WindowStyle.Visible);
-        this.SetTopMost(true);
-        this.SetIsShownInSwitchers2(false);
     }
 
-    internal async void UpdatePlacement(DesktopFlyoutPlacement placement)
+    internal void UpdatePlacement(DesktopFlyoutPlacement placement)
     {
         this.placement = placement;
 
@@ -43,9 +49,6 @@ internal class DesktopFlyoutHost : Window
         double height = presenter.DesiredSize.Height;
         double width = presenter.DesiredSize.Width;
 
-        Debug.WriteLine(height);
-        Debug.WriteLine(width);
-
         switch (placement)
         {
             case DesktopFlyoutPlacement.Left:
@@ -74,8 +77,6 @@ internal class DesktopFlyoutHost : Window
         presenter.TemplateSettings.SetValue(DesktopFlyoutPresenterTemplateSettings.NegativeHeightProperty, -height);
         presenter.TemplateSettings.SetValue(DesktopFlyoutPresenterTemplateSettings.NegativeWidthProperty, -width);
 
-        await Task.Delay(TimeSpan.FromSeconds(4));
-
         presenter.UpdatePlacementState(placement);
     }
 
@@ -85,7 +86,6 @@ internal class DesktopFlyoutHost : Window
     private void OnLoaded(object sender,
         RoutedEventArgs args)
     {
-        SystemBackdrop = new TransparentTintBackdrop();
         this.SetOpacity(255);
 
         if (Content is Border border)

Hyperbar.Windows.Interop/ExtendedWindowStyle.cs

@@ -0,0 +1,33 @@
+namespace Hyperbar.Windows.Interop;
+
+[Flags]
+public enum ExtendedWindowStyle
+{
+    AcceptFiles = 0x10,
+    AppWindow = 0x40000,
+    ClientEdge = 0x200,
+    Composited = 0x2000000,
+    ContextHelp = 0x400,
+    ControlParent = 0x10000,
+    DlgModalFrame = 1,
+    Layered = 0x80000,
+    LayoutRtl = 0x400000,
+    Left = 0,
+    LeftScrollBar = 0x4000,
+    LtrReading = 0,
+    MdiChild = 0x40,
+    NoActivate = 0x8000000,
+    NoInheritLayout = 0x100000,
+    NoParentNotify = 4,
+    NoRedirectionBitmap = 0x200000,
+    OverlappedWindow = 0x300,
+    PaletteWindow = 0x188,
+    Right = 0x1000,
+    RightScrollBar = 0,
+    RtlReading = 0x2000,
+    StaticEdge = 0x20000,
+    ToolWindow = 0x80,
+    TopMost = 8,
+    Transparent = 0x20,
+    WindowEdge = 0x100
+}

Hyperbar.Windows.Interop/HwndExtensions.cs

@@ -15,8 +15,23 @@ public static class HwndExtensions
         WS_EX_LAYERED = 0x80000
     }
 
+    public static void SetExtendedWindowStyle(this IntPtr hwnd, ExtendedWindowStyle newStyle)
+    {
+        int windowLong = PInvoke.GetWindowLong(new(hwnd), WINDOW_LONG_PTR_INDEX.GWL_EXSTYLE);
+        if (PInvoke.SetWindowLong(new(hwnd), WINDOW_LONG_PTR_INDEX.GWL_EXSTYLE, (int)newStyle) != windowLong)
+        {
+            Marshal.ThrowExceptionForHR(Marshal.GetLastWin32Error());
+        }
+
+        PInvoke.SetWindowPos(new(hwnd), new HWND(0), 0, 0, 0, 0, SET_WINDOW_POS_FLAGS.SWP_DRAWFRAME |
+            SET_WINDOW_POS_FLAGS.SWP_NOMOVE |
+            SET_WINDOW_POS_FLAGS.SWP_NOOWNERZORDER |
+            SET_WINDOW_POS_FLAGS.SWP_NOSIZE |
+            SET_WINDOW_POS_FLAGS.SWP_NOZORDER);
+    }
+
     public static void SetWindowOpacity(this IntPtr hWnd,
-        byte value)
+            byte value)
     {
         HWND hWND = new(hWnd);
         WindowStyles windowLong = (WindowStyles)PInvoke.GetWindowLong(hWND, WINDOW_LONG_PTR_INDEX.GWL_EXSTYLE);
@@ -30,7 +45,6 @@ public static class HwndExtensions
             Marshal.ThrowExceptionForHR(Marshal.GetLastWin32Error());
         }
     }
-
     public static void SetWindowStyle(this IntPtr hwnd,
         WindowStyle newStyle)
     {

Hyperbar.Windows.Interop/WindowStyle.cs

@@ -30,4 +30,4 @@ public enum WindowStyle
     TiledWindow = 0xCF0000,
     Visible = 0x10000000,
     VScroll = 0x200000
-}
+}

Hyperbar.Windows.UI/Extensions/WindowExtensions.cs

@@ -10,7 +10,7 @@ public static class WindowExtensions
     public static IntPtr GetHandle(this Window window) =>
         window is not null ? WindowNative.GetWindowHandle(window) : default;
 
-    public static void SetIsShownInSwitchers2(this Window window,
+    public static void SetIsAvailableInSwitchers(this Window window,
         bool value) => window.AppWindow.IsShownInSwitchers = value;
 
     public static void SetOpacity(this Window window,
@@ -19,6 +19,9 @@ public static class WindowExtensions
     public static void SetStyle(this Window window,
         WindowStyle style) => window.GetHandle().SetWindowStyle(style);
 
+    public static void SetStyle(this Window window,
+        ExtendedWindowStyle style) => window.GetHandle().SetExtendedWindowStyle(style);
+
     public static void SetTopMost(this Window window,
         bool value)
     {