Feature: Added thumbnail generation for items in the Windows Fonts folder

src/Files.App/Utils/Storage/Helpers/FileThumbnailHelper.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Files Community
 // Licensed under the MIT License.
 
+using Files.Shared.Helpers;
+using System.IO;
 using Windows.Storage.FileProperties;
 
 namespace Files.App.Utils.Storage
@@ -16,6 +18,26 @@ public static class FileThumbnailHelper
 			// Ensure size is at least 1 to prevent layout errors
 			size = Math.Max(1, size);
 
+			if (!isFolder && !iconOptions.HasFlag(IconOptions.ReturnIconOnly))
+			{
+				var extension = Path.GetExtension(path);
+
+				//Restrict to only %windir%\fonts
+				if (FileExtensionHelpers.IsFontFile(extension) && PathHelpers.IsInSystemFontsFolder(path))
+				{
+					var winrtThumbnail = await FontFileHelper.GetWinRTThumbnailAsync(path, (uint)size);
+					if (winrtThumbnail is not null)
+						return winrtThumbnail;
+
+					if (!extension.Equals(".fon", StringComparison.OrdinalIgnoreCase))
+					{
+						var fontThumbnail = await STATask.Run(() => FontFileHelper.GenerateFontThumbnail(path, (int)size), App.Logger);
+						if (fontThumbnail is not null)
+							return fontThumbnail;
+					}
+				}
+			}
+
 			var resolvedPath = path is not null && path.StartsWith(@"\\?\", StringComparison.Ordinal)
 				? MtpHelpers.ResolveMtpShellPath(path) ?? path
 				: path;

src/Files.App/Utils/Storage/Helpers/FontFileHelper.cs

@@ -0,0 +1,281 @@
+// Copyright (c) Files Community
+// Licensed under the MIT License.
+
+using Microsoft.Extensions.Logging;
+using Microsoft.Graphics.Canvas.Text;
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using System.Drawing.Imaging;
+using System.Drawing.Text;
+using System.IO;
+using System.Text;
+using Windows.Storage;
+using Windows.Storage.FileProperties;
+
+namespace Files.App.Utils.Storage
+{
+	public static class FontFileHelper
+	{
+		private const float FontSizeRatio = 0.35f;
+		private const string PreviewText = "Abg";
+
+		public static async Task<byte[]?> GetWinRTThumbnailAsync(string fontPath, uint size)
+		{
+			StorageFile? file = null;
+			StorageItemThumbnail? thumbnail = null;
+			try
+			{
+				file = await StorageFile.GetFileFromPathAsync(fontPath);
+				thumbnail = await file.GetThumbnailAsync(ThumbnailMode.SingleItem, size);
+
+				if (thumbnail is null || thumbnail.Size == 0)
+				{
+					return null;
+				}
+
+				using (var stream = thumbnail.AsStream())
+				{
+					using var memoryStream = new MemoryStream((int)thumbnail.Size);
+					await stream.CopyToAsync(memoryStream);
+
+					return memoryStream.ToArray();
+				}
+			}
+			catch (Exception ex) 
+			{			
+				App.Logger.LogError(ex, $"Exception while getting WinRT thumbnail for {fontPath}.");
+				return null;
+			}
+			finally
+			{
+				thumbnail?.Dispose();
+			}
+		}
+
+		public static byte[]? GenerateFontThumbnail(string fontPath, int size)
+		{
+			try
+			{
+				if (!File.Exists(fontPath))
+					return null;
+
+				using var fontCollection = new PrivateFontCollection();
+				fontCollection.AddFontFile(fontPath);
+
+				if (fontCollection.Families.Length == 0)
+					return null;
+
+				var fontFamily = fontCollection.Families[0];
+				var style = GetAvailableFontStyle(fontFamily);
+
+				using var bitmap = new Bitmap(size, size);
+				using var graphics = Graphics.FromImage(bitmap);
+
+				graphics.Clear(Color.White);
+				graphics.SmoothingMode = SmoothingMode.AntiAlias;
+				graphics.TextRenderingHint = TextRenderingHint.AntiAlias;
+
+				var fontSize = size * FontSizeRatio;
+				using var font = new Font(fontFamily, fontSize, style, GraphicsUnit.Pixel);
+
+				var textSize = graphics.MeasureString(PreviewText, font);
+
+				var x = (size - textSize.Width) / 2;
+				var y = (size - textSize.Height) / 2;
+
+				using var brush = new SolidBrush(Color.Black);
+				graphics.DrawString(PreviewText, font, brush, x, y);
+
+				using var ms = new MemoryStream();
+				bitmap.Save(ms, ImageFormat.Png);
+				return ms.ToArray();
+			}
+			catch (Exception ex)
+			{
+				App.Logger.LogError(ex, $"Exception while generating font thumbnail for {fontPath}.");
+				return null;
+			}
+		}
+
+		public static string? GetFontName(string fontPath)
+		{
+			try
+			{
+				if (!File.Exists(fontPath))
+					return null;
+
+				var fullName = ExtractFontNameFromTable(fontPath);
+				if (!string.IsNullOrEmpty(fullName))
+					return fullName;
+
+				using var fontCollection = new PrivateFontCollection();
+				fontCollection.AddFontFile(fontPath);
+
+				if (fontCollection.Families.Length == 0)
+					return null;
+
+				return fontCollection.Families[0].Name;
+			}
+			catch
+			{
+				App.Logger.LogError($"Failed to get font name for file: {fontPath}");
+				return null;
+			}
+		}
+
+		private static string? ExtractFontNameFromTable(string fontPath)
+		{
+			try
+			{
+				using var fileStream = File.OpenRead(fontPath);
+				using var reader = new BinaryReader(fileStream);
+
+				// Read TTF header to find table directory
+				var sfntVersion = ReadUInt32BigEndian(reader);
+
+				// Check if it's a TrueType Collection (.ttc)
+				if (sfntVersion == 0x74746366) // 'ttcf'
+				{
+					// For TTC files, read the first font in the collection
+					reader.ReadUInt32(); // version
+					var numFonts = ReadUInt32BigEndian(reader);
+					if (numFonts == 0)
+						return null;
+
+					// Read offset to first font
+					var firstFontOffset = ReadUInt32BigEndian(reader);
+					fileStream.Seek(firstFontOffset, SeekOrigin.Begin);
+					reader.ReadUInt32(); // Skip sfntVersion of inner font
+				}
+				else if (sfntVersion != 0x00010000 && sfntVersion != 0x4F54544F) // Not TTF or OTF
+				{
+					return null;
+				}
+
+				var numTables = ReadUInt16BigEndian(reader);
+				reader.ReadUInt16(); // searchRange
+				reader.ReadUInt16(); // entrySelector
+				reader.ReadUInt16(); // rangeShift
+
+				// Find the 'name' table
+				uint nameTableOffset = 0;
+				uint nameTableLength = 0;
+
+				for (int i = 0; i < numTables; i++)
+				{
+					var tag = Encoding.ASCII.GetString(reader.ReadBytes(4));
+					reader.ReadUInt32(); // checksum
+					var offset = ReadUInt32BigEndian(reader);
+					var length = ReadUInt32BigEndian(reader);
+
+					if (tag == "name")
+					{
+						nameTableOffset = offset;
+						nameTableLength = length;
+						break;
+					}
+				}
+
+				if (nameTableOffset == 0)
+					return null;
+
+				fileStream.Seek(nameTableOffset, SeekOrigin.Begin);
+
+				var version = ReadUInt16BigEndian(reader);
+				var count = ReadUInt16BigEndian(reader);
+				var storageOffset = ReadUInt16BigEndian(reader);
+
+				string? familyName = null;
+				string? subfamilyName = null;
+				string? fullName = null;
+
+				for (int i = 0; i < count; i++)
+				{
+					var platformID = ReadUInt16BigEndian(reader);
+					var encodingID = ReadUInt16BigEndian(reader);
+					var languageID = ReadUInt16BigEndian(reader);
+					var nameID = ReadUInt16BigEndian(reader);
+					var length = ReadUInt16BigEndian(reader);
+					var stringOffset = ReadUInt16BigEndian(reader);
+
+					var isWindows = platformID == 3 && languageID == 0x0409;
+					var isUnicode = platformID == 0 && (languageID == 0 || languageID == 0x0409);
+
+					if (!isWindows && !isUnicode)
+						continue;
+
+					var currentPos = fileStream.Position;
+
+					fileStream.Seek(nameTableOffset + storageOffset + stringOffset, SeekOrigin.Begin);
+					var stringBytes = reader.ReadBytes(length);
+
+					string stringValue;
+					if (platformID == 3 || platformID == 0) // Windows or Unicode - UTF-16BE
+					{
+						stringValue = Encoding.BigEndianUnicode.GetString(stringBytes);
+					}
+					else // Macintosh - ASCII/Latin1
+					{
+						stringValue = Encoding.ASCII.GetString(stringBytes);
+					}
+
+					if (nameID == 4)
+						fullName = stringValue;
+					else if (nameID == 1)
+						familyName = stringValue;
+					else if (nameID == 2)
+						subfamilyName = stringValue;
+
+					fileStream.Seek(currentPos, SeekOrigin.Begin);
+				}
+
+				if (!string.IsNullOrEmpty(fullName))
+					return fullName;
+
+				if (!string.IsNullOrEmpty(familyName) && !string.IsNullOrEmpty(subfamilyName))
+				{
+					if (subfamilyName.Equals("Regular", StringComparison.OrdinalIgnoreCase))
+						return familyName;
+
+					return $"{familyName} {subfamilyName}";
+				}
+
+				return familyName;
+			}
+			catch
+			{
+				return null;
+			}
+		}
+
+		private static uint ReadUInt32BigEndian(BinaryReader reader)
+		{
+			var bytes = reader.ReadBytes(4);
+			if (BitConverter.IsLittleEndian)
+				Array.Reverse(bytes);
+			return BitConverter.ToUInt32(bytes, 0);
+		}
+
+		private static ushort ReadUInt16BigEndian(BinaryReader reader)
+		{
+			var bytes = reader.ReadBytes(2);
+			if (BitConverter.IsLittleEndian)
+				Array.Reverse(bytes);
+			return BitConverter.ToUInt16(bytes, 0);
+		}
+
+		private static FontStyle GetAvailableFontStyle(FontFamily fontFamily)
+		{
+			if (fontFamily.IsStyleAvailable(FontStyle.Regular))
+				return FontStyle.Regular;
+			if (fontFamily.IsStyleAvailable(FontStyle.Bold))
+				return FontStyle.Bold;
+			if (fontFamily.IsStyleAvailable(FontStyle.Italic))
+				return FontStyle.Italic;
+			if (fontFamily.IsStyleAvailable(FontStyle.Bold | FontStyle.Italic))
+				return FontStyle.Bold | FontStyle.Italic;
+
+			return FontStyle.Regular;
+		}
+	}
+}

src/Files.Shared/Helpers/PathHelpers.cs

@@ -60,5 +60,20 @@ public static bool TryGetFullPath(string commandName, out string fullPath)
 				return false;
 			}
 		}
+
+		public static bool IsInSystemFontsFolder(string path)
+		{
+			try
+			{
+				var fullPath = Path.GetFullPath(path);
+				var windowsFontsPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Windows), "Fonts");
+
+				return fullPath.StartsWith(windowsFontsPath, StringComparison.OrdinalIgnoreCase);
+			}
+			catch
+			{
+				return false;
+			}
+		}
 	}
 }