[Indexer] File icons (#343)

- [x] **Closes:** #316

![image](https://github.com/user-attachments/assets/4daeff29-4f56-41c3-8648-8d866b971382)

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

@@ -1541,6 +1541,8 @@ SHFILEOPSTRUCT
 SHGDN
 SHGDNF
 SHGFI
+SHGFIICON
+SHGFILARGEICON
 shinfo
 shlwapi
 SHNAMEMAPPING

src/modules/cmdpal/Exts/Microsoft.CmdPal.Ext.Indexer/Pages/IndexerPage.cs

@@ -12,6 +12,7 @@ using Microsoft.CmdPal.Ext.Indexer.Indexer;
 using Microsoft.CmdPal.Ext.Indexer.Properties;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
+using Windows.Storage.Streams;
 
 namespace Microsoft.CmdPal.Ext.Indexer;
 
@@ -90,13 +91,21 @@ internal sealed partial class IndexerPage : DynamicListPage, IDisposable
 
                 while (!_searchQuery.SearchResults.IsEmpty && _searchQuery.SearchResults.TryDequeue(out result) && ++index <= limit)
                 {
+                    IconInfo icon = null;
+                    var stream = ThumbnailHelper.GetThumbnail(result.LaunchUri).Result;
+                    if (stream != null)
+                    {
+                        var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
+                        icon = new IconInfo(data, data);
+                    }
+
                     _indexerListItems.Add(new IndexerListItem(new IndexerItem
                     {
                         FileName = result.ItemDisplayName,
                         FullPath = result.LaunchUri,
                     })
                     {
-                        Icon = new IconInfo(result.IsFolder ? "\uE838" : "\uE8E5"),
+                        Icon = icon,
                     });
                 }
 

src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/IconCacheService.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation
+// 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.
 
@@ -28,7 +28,6 @@ public sealed class IconCacheService(DispatcherQueue dispatcherQueue)
             if (!string.IsNullOrEmpty(icon.Icon))
             {
                 var source = IconPathConverter.IconSourceMUX(icon.Icon, false);
-
                 return source;
             }
             else if (icon.Data != null)

src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/Microsoft.CommandPalette.Extensions.Toolkit.csproj

@@ -34,6 +34,7 @@
     </PackageReference>
     <PackageReference Include="Microsoft.WindowsAppSDK" />
     <PackageReference Include="Microsoft.Web.WebView2" />
+    <PackageReference Include="System.Drawing.Common" />
     <!-- This line forces the WebView2 version used by Windows App SDK to be the one we expect from Directory.Packages.props . -->
   </ItemGroup>
 

src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/NativeMethods.cs

@@ -0,0 +1,27 @@
+// 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.Runtime.InteropServices;
+
+namespace Microsoft.CommandPalette.Extensions.Toolkit;
+
+internal sealed class NativeMethods
+{
+    [DllImport("shell32.dll", CharSet = CharSet.Unicode)]
+    internal static extern IntPtr SHGetFileInfo(string pszPath, uint dwFileAttributes, ref SHFILEINFO psfi, uint cbFileInfo, uint uFlags);
+
+    [StructLayout(LayoutKind.Sequential)]
+    internal struct SHFILEINFO
+    {
+#pragma warning disable SA1307 // Accessible fields should begin with upper-case letter
+        public IntPtr hIcon;
+        public int iIcon;
+        public uint dwAttributes;
+        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
+        public string szDisplayName;
+        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]
+        public string szTypeName;
+#pragma warning restore SA1307 // Accessible fields should begin with upper-case letter
+    }
+}

src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/ThumbnailHelper.cs

@@ -0,0 +1,74 @@
+// 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.Drawing;
+using System.Globalization;
+using System.Runtime.InteropServices;
+using Windows.Storage;
+using Windows.Storage.FileProperties;
+using Windows.Storage.Streams;
+
+namespace Microsoft.CommandPalette.Extensions.Toolkit;
+
+public class ThumbnailHelper
+{
+    private static readonly string[] ImageExtensions =
+    [
+        ".png",
+        ".jpg",
+        ".jpeg",
+        ".gif",
+        ".bmp",
+        ".tiff",
+        ".ico",
+    ];
+
+    public static async Task<IRandomAccessStream> GetThumbnail(string path)
+    {
+        var extension = Path.GetExtension(path).ToLower(CultureInfo.InvariantCulture);
+        if (ImageExtensions.Contains(extension))
+        {
+            try
+            {
+                return await GetImageThumbnailAsync(path);
+            }
+            catch (Exception)
+            {
+            }
+        }
+
+        return await Task.FromResult(GetFileIconStream(path));
+    }
+
+    private const uint SHGFIICON = 0x000000100;
+    private const uint SHGFILARGEICON = 0x000000000;
+
+    private static IRandomAccessStream GetFileIconStream(string filePath)
+    {
+        var shinfo = default(NativeMethods.SHFILEINFO);
+        NativeMethods.SHGetFileInfo(filePath, 0, ref shinfo, (uint)Marshal.SizeOf(shinfo), SHGFIICON | SHGFILARGEICON);
+
+        using var icon = Icon.FromHandle(shinfo.hIcon);
+        var stream = new InMemoryRandomAccessStream();
+        using (var memoryStream = new MemoryStream())
+        {
+            icon.ToBitmap().Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
+            memoryStream.Position = 0;
+
+            using var outputStream = stream.GetOutputStreamAt(0);
+            using var dataWriter = new DataWriter(outputStream);
+            dataWriter.WriteBytes(memoryStream.ToArray());
+            dataWriter.StoreAsync().GetAwaiter().GetResult();
+        }
+
+        return stream;
+    }
+
+    private static async Task<IRandomAccessStream> GetImageThumbnailAsync(string filePath)
+    {
+        var file = await StorageFile.GetFileFromPathAsync(filePath);
+        var thumbnail = await file.GetThumbnailAsync(ThumbnailMode.PicturesView);
+        return thumbnail;
+    }
+}