[CmdPal] WindowWalker Show the actual window icon instead of the process icon (#42316)

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## Summary of the Pull Request

This is a PR for issue **#42260**.
It targets **CmdPal’s WindowWalker** and changes the icon retrieval to
use **SendMessage** to obtain the window’s actual icon, instead of using
the **process icon**.

To support this, I added a new configuration option.

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## PR Checklist

- [ ] Closes: #42260
- [ ] **Communication:** @jiripolasek 
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
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pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
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- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
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## Detailed Description of the Pull Request / Additional comments


Actully, The `ThumbnailHelper` already contains code that converts an
`IntPtr` `hIcon` into an `IRandomAccessStream`, as shown below:

```
 private static MemoryStream GetMemoryStreamFromIcon(IntPtr hIcon)
 {
     var memoryStream = new MemoryStream();

     // Ensure disposing the icon before freeing the handle
     using (var icon = Icon.FromHandle(hIcon))
     {
         icon.ToBitmap().Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
     }

     // Clean up the unmanaged handle without risking a use-after-free.
     NativeMethods.DestroyIcon(hIcon);

     memoryStream.Position = 0;
     return memoryStream;
 }

 private static async Task<IRandomAccessStream?> FromHIconToStream(IntPtr hIcon)
 {
     var stream = new InMemoryRandomAccessStream();

     using var memoryStream = GetMemoryStreamFromIcon(hIcon); // this will DestroyIcon hIcon
     using var outputStream = stream.GetOutputStreamAt(0);
     using var dataWriter = new DataWriter(outputStream);

     dataWriter.WriteBytes(memoryStream.ToArray());
     await dataWriter.StoreAsync();
     await dataWriter.FlushAsync();

     return stream;
 }
```

Without modifying (or using) this code, I implemented the almost same
logic directly in `SwitchToWindowCommand` (calling the async code with
`Wait` to block synchronously). The reasons are:

1. I wanted to limit changes to the **WindowWalker** project area. I
don’t expect other extensions to need this behavior.
2. Because this is resource-related work, exposing a public helper that
pulls memory from an `hIcon` pointer seems risky—especially in a class
like `ThumbnailHelper`.

Therefore, I implemented behavior that is nearly identical to the
snippet above.

I did use `using`/`Dispose` where appropriate, but the
`InMemoryRandomAccessStream` created for `IconInfo.FromStream` appears
to use internal referencing; disposing it would be incorrect. For that
reason I didn’t wrap it in a `using`. I’m not entirely sure whether GC
will handle this cleanly.

However, based on the implementation of `FromStream` itself and its
usage elsewhere (e.g., in `ThumbnailHelper`), this seems to be the
correct usage pattern, though I’m not entirely sure.

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wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed

---------

Co-authored-by: Jiří Polášek <me@jiripolasek.com>

.github/actions/spell-check/expect.txt

@@ -639,6 +639,7 @@ Hiber
 Hiberboot
 HIBYTE
 hicon
+HICONSM
 HIDEREADONLY
 HIDEWINDOW
 Hif

src/modules/cmdpal/Tests/Microsoft.CmdPal.Ext.WindowWalker.UnitTests/Settings.cs

@@ -17,6 +17,7 @@ public class Settings : ISettingsInterface
     private readonly bool hideKillProcessOnElevatedProcesses;
     private readonly bool hideExplorerSettingInfo;
     private readonly bool inMruOrder;
+    private readonly bool useWindowIcon;
 
     public Settings(
         bool resultsFromVisibleDesktopOnly = false,
@@ -27,7 +28,8 @@ public class Settings : ISettingsInterface
         bool openAfterKillAndClose = false,
         bool hideKillProcessOnElevatedProcesses = false,
         bool hideExplorerSettingInfo = true,
-        bool inMruOrder = true)
+        bool inMruOrder = true,
+        bool useWindowIcon = true)
     {
         this.resultsFromVisibleDesktopOnly = resultsFromVisibleDesktopOnly;
         this.subtitleShowPid = subtitleShowPid;
@@ -38,6 +40,7 @@ public class Settings : ISettingsInterface
         this.hideKillProcessOnElevatedProcesses = hideKillProcessOnElevatedProcesses;
         this.hideExplorerSettingInfo = hideExplorerSettingInfo;
         this.inMruOrder = inMruOrder;
+        this.useWindowIcon = useWindowIcon;
     }
 
     public bool ResultsFromVisibleDesktopOnly => resultsFromVisibleDesktopOnly;
@@ -57,4 +60,6 @@ public class Settings : ISettingsInterface
     public bool HideExplorerSettingInfo => hideExplorerSettingInfo;
 
     public bool InMruOrder => inMruOrder;
+
+    public bool UseWindowIcon => useWindowIcon;
 }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Commands/SwitchToWindowCommand.cs

@@ -2,11 +2,16 @@
 // 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;
 using System.Diagnostics;
+using System.Drawing;
+using System.IO;
 using Microsoft.CmdPal.Ext.WindowWalker.Components;
+using Microsoft.CmdPal.Ext.WindowWalker.Helpers;
 using Microsoft.CmdPal.Ext.WindowWalker.Properties;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.Storage.Streams;
 
 namespace Microsoft.CmdPal.Ext.WindowWalker.Commands;
 
@@ -16,9 +21,41 @@ internal sealed partial class SwitchToWindowCommand : InvokableCommand
 
     public SwitchToWindowCommand(Window? window)
     {
+        Icon = Icons.GenericAppIcon; // Fallback to default icon
         Name = Resources.switch_to_command_title;
         _window = window;
         if (_window is not null)
+        {
+            // Use window icon
+            if (SettingsManager.Instance.UseWindowIcon)
+            {
+                if (_window.TryGetWindowIcon(out var icon) && icon is not null)
+                {
+                    try
+                    {
+                        using var bitmap = icon.ToBitmap();
+                        using var memoryStream = new MemoryStream();
+                        bitmap.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
+                        var raStream = new InMemoryRandomAccessStream();
+                        using var outputStream = raStream.GetOutputStreamAt(0);
+                        using var dataWriter = new DataWriter(outputStream);
+                        dataWriter.WriteBytes(memoryStream.ToArray());
+                        dataWriter.StoreAsync().AsTask().Wait();
+                        dataWriter.FlushAsync().AsTask().Wait();
+                        Icon = IconInfo.FromStream(raStream);
+                    }
+                    catch
+                    {
+                    }
+                    finally
+                    {
+                        icon.Dispose();
+                    }
+                }
+            }
+
+            // Use process icon
+            else
             {
                 var p = Process.GetProcessById((int)_window.Process.ProcessID);
                 if (p is not null)
@@ -34,6 +71,7 @@ internal sealed partial class SwitchToWindowCommand : InvokableCommand
                 }
             }
         }
+    }
 
     public override ICommandResult Invoke()
     {

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Components/Window.cs

@@ -188,6 +188,62 @@ internal sealed class Window
         thread.Start();
     }
 
+    /// <summary>
+    /// Tries to get the window icon.
+    /// </summary>
+    /// <param name="icon">The window icon if found; otherwise, null.</param>
+    /// <returns>True if an icon was found; otherwise, false.</returns>
+    internal bool TryGetWindowIcon(out System.Drawing.Icon? icon)
+    {
+        icon = null;
+
+        if (hwnd == IntPtr.Zero)
+        {
+            return false;
+        }
+
+        // Try WM_GETICON with SendMessageTimeout
+        if (NativeMethods.SendMessageTimeout(hwnd, Win32Constants.WM_GETICON, (UIntPtr)Win32Constants.ICON_BIG, IntPtr.Zero, Win32Constants.SMTO_ABORTIFHUNG, 100, out var result) != 0 && result != 0)
+        {
+            icon = System.Drawing.Icon.FromHandle((IntPtr)result);
+            NativeMethods.DestroyIcon((IntPtr)result);
+            return true;
+        }
+
+        if (NativeMethods.SendMessageTimeout(hwnd, Win32Constants.WM_GETICON, (UIntPtr)Win32Constants.ICON_SMALL, IntPtr.Zero, Win32Constants.SMTO_ABORTIFHUNG, 100, out result) != 0 && result != 0)
+        {
+            icon = System.Drawing.Icon.FromHandle((IntPtr)result);
+            NativeMethods.DestroyIcon((IntPtr)result);
+            return true;
+        }
+
+        if (NativeMethods.SendMessageTimeout(hwnd, Win32Constants.WM_GETICON, (UIntPtr)Win32Constants.ICON_SMALL2, IntPtr.Zero, Win32Constants.SMTO_ABORTIFHUNG, 100, out result) != 0 && result != 0)
+        {
+            icon = System.Drawing.Icon.FromHandle((IntPtr)result);
+            NativeMethods.DestroyIcon((IntPtr)result);
+            return true;
+        }
+
+        // Fallback to GetClassLongPtr
+        var iconHandle = NativeMethods.GetClassLongPtr(hwnd, Win32Constants.GCLP_HICON);
+        if (iconHandle != IntPtr.Zero)
+        {
+            icon = System.Drawing.Icon.FromHandle(iconHandle);
+            NativeMethods.DestroyIcon((IntPtr)iconHandle);
+            return true;
+        }
+
+        iconHandle = NativeMethods.GetClassLongPtr(hwnd, Win32Constants.GCLP_HICONSM);
+        if (iconHandle != IntPtr.Zero)
+        {
+            icon = System.Drawing.Icon.FromHandle(iconHandle);
+            NativeMethods.DestroyIcon((IntPtr)iconHandle);
+            return true;
+        }
+
+        return false;
+    }
+
     /// <summary>
     /// Converts the window name to string along with the process name
     /// </summary>

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Helpers/ISettingsInterface.cs

@@ -23,4 +23,6 @@ public interface ISettingsInterface
     public bool HideExplorerSettingInfo { get; }
 
     public bool InMruOrder { get; }
+
+    public bool UseWindowIcon { get; }
 }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Helpers/NativeMethods.cs

@@ -84,6 +84,12 @@ public static partial class NativeMethods
     [DllImport("user32.dll")]
     public static extern int SendMessageTimeout(IntPtr hWnd, uint msg, UIntPtr wParam, IntPtr lParam, int fuFlags, int uTimeout, out int lpdwResult);
 
+    [DllImport("user32.dll", EntryPoint = "GetClassLongPtr")]
+    public static extern IntPtr GetClassLongPtr(IntPtr hWnd, int nIndex);
+
+    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
+    internal static extern bool DestroyIcon(IntPtr hIcon);
+
     [DllImport("kernel32.dll")]
     [return: MarshalAs(UnmanagedType.Bool)]
     public static extern bool CloseHandle(IntPtr hObject);
@@ -143,6 +149,41 @@ public static class Win32Constants
     /// </summary>
     public const int SC_CLOSE = 0xF060;
 
+    /// <summary>
+    /// Sent to a window to retrieve a handle to the large or small icon associated with a window.
+    /// </summary>
+    public const uint WM_GETICON = 0x007F;
+
+    /// <summary>
+    /// Retrieve the large icon for the window.
+    /// </summary>
+    public const int ICON_BIG = 1;
+
+    /// <summary>
+    /// Retrieve the small icon for the window.
+    /// </summary>
+    public const int ICON_SMALL = 0;
+
+    /// <summary>
+    /// Retrieve the small icon provided by the application.
+    /// </summary>
+    public const int ICON_SMALL2 = 2;
+
+    /// <summary>
+    /// The function returns if the receiving thread does not respond within the timeout period.
+    /// </summary>
+    public const int SMTO_ABORTIFHUNG = 0x0002;
+
+    /// <summary>
+    /// Retrieves a handle to the icon associated with the class.
+    /// </summary>
+    public const int GCLP_HICON = -14;
+
+    /// <summary>
+    /// Retrieves a handle to the small icon associated with the class.
+    /// </summary>
+    public const int GCLP_HICONSM = -34;
+
     /// <summary>
     /// RPC call succeeded
     /// </summary>

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Helpers/SettingsManager.cs

@@ -70,6 +70,12 @@ public class SettingsManager : JsonSettingsManager, ISettingsInterface
         Resources.windowwalker_SettingInMruOrder_Description,
         true);
 
+    private readonly ToggleSetting _useWindowIcon = new(
+        Namespaced(nameof(UseWindowIcon)),
+        Resources.windowwalker_SettingUseWindowIcon,
+        Resources.windowwalker_SettingUseWindowIcon_Description,
+        true);
+
     public bool ResultsFromVisibleDesktopOnly => _resultsFromVisibleDesktopOnly.Value;
 
     public bool SubtitleShowPid => _subtitleShowPid.Value;
@@ -88,6 +94,8 @@ public class SettingsManager : JsonSettingsManager, ISettingsInterface
 
     public bool InMruOrder => _inMruOrder.Value;
 
+    public bool UseWindowIcon => _useWindowIcon.Value;
+
     internal static string SettingsJsonPath()
     {
         var directory = Utilities.BaseSettingsPath("Microsoft.CmdPal");
@@ -110,6 +118,7 @@ public class SettingsManager : JsonSettingsManager, ISettingsInterface
         Settings.Add(_hideKillProcessOnElevatedProcesses);
         Settings.Add(_hideExplorerSettingInfo);
         Settings.Add(_inMruOrder);
+        Settings.Add(_useWindowIcon);
 
         // Load settings from file upon initialization
         LoadSettings();

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Icons.cs

@@ -15,4 +15,6 @@ internal sealed class Icons
     internal static IconInfo CloseWindow { get; } = new IconInfo("\uE894"); // Clear
 
     internal static IconInfo Info { get; } = new IconInfo("\uE946"); // Info
+
+    internal static IconInfo GenericAppIcon { get; } = new("\uE737"); // Favicon
 }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Properties/Resources.Designer.cs

@@ -401,5 +401,23 @@ namespace Microsoft.CmdPal.Ext.WindowWalker.Properties {
                 return ResourceManager.GetString("windowwalker_SettingTagPid", resourceCulture);
             }
         }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Use window icons.
+        /// </summary>
+        public static string windowwalker_SettingUseWindowIcon {
+            get {
+                return ResourceManager.GetString("windowwalker_SettingUseWindowIcon", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Show the actual window icon instead of the process icon.
+        /// </summary>
+        public static string windowwalker_SettingUseWindowIcon_Description {
+            get {
+                return ResourceManager.GetString("windowwalker_SettingUseWindowIcon_Description", resourceCulture);
+            }
+        }
     }
 }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Properties/Resources.resx

@@ -235,4 +235,10 @@
   <data name="windowwalker_NoResultsMessage" xml:space="preserve">
     <value>No open windows found</value>
   </data>
+  <data name="windowwalker_SettingUseWindowIcon" xml:space="preserve">
+    <value>Use window icons</value>
+  </data>
+  <data name="windowwalker_SettingUseWindowIcon_Description" xml:space="preserve">
+    <value>Show the actual window icon instead of the process icon</value>
+  </data>
 </root>