[Settings, OOBE] set location to center screen (#10022)

and ensure the window is inside the screen work area

src/settings-ui/PowerToys.Settings/App.xaml.cs

@@ -33,20 +33,8 @@ namespace PowerToys.Settings
         {
             settingsWindow = new MainWindow();
 
-            // To avoid visual flickering, show the window with a size of 0,0
+            Utils.ShowHide(settingsWindow);
-            // and don't show it in the taskbar
+            Utils.CenterToScreen(settingsWindow);
-            var originalHight = settingsWindow.Height;
-            var originalWidth = settingsWindow.Width;
-            settingsWindow.Height = 0;
-            settingsWindow.Width = 0;
-            settingsWindow.ShowInTaskbar = false;
-
-            settingsWindow.Show();
-            settingsWindow.Hide();
-
-            settingsWindow.Height = originalHight;
-            settingsWindow.Width = originalWidth;
-            settingsWindow.ShowInTaskbar = true;
         }
 
         private void Application_Startup(object sender, StartupEventArgs e)

src/settings-ui/PowerToys.Settings/MainWindow.xaml

@@ -7,7 +7,15 @@
         xmlns:Controls="clr-namespace:Microsoft.Toolkit.Wpf.UI.Controls;assembly=Microsoft.Toolkit.Wpf.UI.Controls"
         xmlns:xaml="clr-namespace:Microsoft.Toolkit.Wpf.UI.XamlHost;assembly=Microsoft.Toolkit.Wpf.UI.XamlHost"
         mc:Ignorable="d"
-        Title="PowerToys Settings" MinWidth="480" Height="800" Width="1100" Closing="MainWindow_Closing" Loaded="MainWindow_Loaded" Activated="MainWindow_Activated">
+        Title="PowerToys Settings"
+        Height="860"
+        MinHeight="400"
+        Width="1180"
+        MinWidth="480"
+        WindowStartupLocation="CenterScreen"
+        Closing="MainWindow_Closing"
+        Loaded="MainWindow_Loaded"
+        Activated="MainWindow_Activated">
     <Grid>
         <xaml:WindowsXamlHost InitialTypeName="Microsoft.PowerToys.Settings.UI.Views.ShellPage" ChildChanged="WindowsXamlHost_ChildChanged" />
     </Grid>

src/settings-ui/PowerToys.Settings/MainWindow.xaml.cs

@@ -26,6 +26,9 @@ namespace PowerToys.Settings
             bootTime.Start();
 
             this.InitializeComponent();
+
+            Utils.FitToScreen(this);
+
             bootTime.Stop();
 
             PowerToysTelemetry.Log.WriteEvent(new SettingsBootEvent() { BootTimeMs = bootTime.ElapsedMilliseconds });

src/settings-ui/PowerToys.Settings/OobeWindow.xaml.cs

@@ -30,6 +30,7 @@ namespace PowerToys.Settings
         public OobeWindow()
         {
             InitializeComponent();
+            Utils.FitToScreen(this);
         }
 
         private void Window_Closed(object sender, EventArgs e)

src/settings-ui/PowerToys.Settings/Utils.cs

@@ -0,0 +1,70 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Windows;
+
+namespace PowerToys.Settings
+{
+    internal class Utils
+    {
+        public static void FitToScreen(Window window)
+        {
+            if (SystemParameters.WorkArea.Width < window.Width)
+            {
+                window.Width = SystemParameters.WorkArea.Width;
+            }
+
+            if (SystemParameters.WorkArea.Height < window.Height)
+            {
+                window.Height = SystemParameters.WorkArea.Height;
+            }
+        }
+
+        public static void CenterToScreen(Window window)
+        {
+            if (SystemParameters.WorkArea.Height <= window.Height)
+            {
+                window.Top = 0;
+            }
+            else
+            {
+                window.Top = (SystemParameters.WorkArea.Height - window.Height) / 2;
+            }
+
+            if (SystemParameters.WorkArea.Width <= window.Width)
+            {
+                window.Left = 0;
+            }
+            else
+            {
+                window.Left = (SystemParameters.WorkArea.Width - window.Width) / 2;
+            }
+        }
+
+        public static void ShowHide(Window window)
+        {
+            // To limit the visual flickering, show the window with a size of 0,0
+            // and don't show it in the taskbar
+            var originalHeight = window.Height;
+            var originalWidth = window.Width;
+            var originalMinHeight = window.MinHeight;
+            var originalMinWidth = window.MinWidth;
+
+            window.MinHeight = 0;
+            window.MinWidth = 0;
+            window.Height = 0;
+            window.Width = 0;
+            window.ShowInTaskbar = false;
+
+            window.Show();
+            window.Hide();
+
+            window.Height = originalHeight;
+            window.Width = originalWidth;
+            window.MinHeight = originalMinHeight;
+            window.MinWidth = originalMinWidth;
+            window.ShowInTaskbar = true;
+        }
+    }
+}