Added Gimp gpl parser

src/PixiEditor/Helpers/Extensions/ServiceCollectionHelpers.cs

@@ -65,6 +65,7 @@ internal static class ServiceCollectionHelpers
         .AddSingleton<PaletteFileParser, PngPaletteParser>()
         .AddSingleton<PaletteFileParser, PaintNetTxtParser>()
         .AddSingleton<PaletteFileParser, HexPaletteParser>()
+        .AddSingleton<PaletteFileParser, GimpGplParser>()
         // Palette data sources
         .AddSingleton<PaletteListDataSource, LocalPalettesFetcher>();
 }

src/PixiEditor/Models/IO/PaletteParsers/GimpGplParser.cs

@@ -0,0 +1,86 @@
+using System.IO;
+using System.Text;
+using PixiEditor.DrawingApi.Core.ColorsImpl;
+
+namespace PixiEditor.Models.IO.PaletteParsers;
+
+internal class GimpGplParser : PaletteFileParser
+{
+    public override string FileName { get; } = "GIMP Palette";
+    public override string[] SupportedFileExtensions { get; } = { ".gpl" };
+
+    public override async Task<PaletteFileData> Parse(string path)
+    {
+        try
+        {
+            return await ParseFile(path);
+        }
+        catch
+        {
+            return PaletteFileData.Corrupted;
+        }
+    }
+
+    private async Task<PaletteFileData> ParseFile(string path)
+    {
+        var lines = await ReadTextLines(path);
+        string name = Path.GetFileNameWithoutExtension(path);
+
+        lines = lines.Where(x => !x.StartsWith("#") && !String.Equals(x.Trim(), "GIMP Palette", StringComparison.CurrentCultureIgnoreCase)).ToArray();
+
+        if(lines.Length == 0) return PaletteFileData.Corrupted;
+
+        List<Color> colors = new();
+        foreach (var colorLine in lines)
+        {
+            var colorParts = colorLine.Split('\t', StringSplitOptions.RemoveEmptyEntries);
+            if (colorParts.Length < 3)
+            {
+                if (colorLine.Contains(' '))
+                {
+                    colorParts = colorLine.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+                }
+                else
+                {
+                    continue;
+                }
+            }
+
+            var r = byte.Parse(colorParts[0]);
+            var g = byte.Parse(colorParts[1]);
+            var b = byte.Parse(colorParts[2]);
+            var color = new Color(r, g, b, 255); // alpha is ignored in PixiEditor
+            if (colors.Contains(color)) continue;
+
+            colors.Add(color);
+        }
+
+        return new PaletteFileData(name, colors.ToArray());
+    }
+
+    public override async Task<bool> Save(string path, PaletteFileData data)
+    {
+        StringBuilder sb = new();
+        string name = string.IsNullOrEmpty(data.Title) ? Path.GetFileNameWithoutExtension(path) : data.Title;
+        sb.AppendLine("GIMP Palette");
+        sb.AppendLine($"#Name: {name}");
+        sb.AppendLine($"#Colors {data.Colors.Length}");
+        sb.AppendLine("#Made with PixiEditor");
+        sb.AppendLine("#");
+        foreach (var color in data.Colors)
+        {
+            string hex = $"{color.R:X}{color.G:X}{color.B:X}";
+            sb.AppendLine($"{color.R}\t{color.G}\t{color.B}\t{hex}");
+        }
+
+        try
+        {
+            await File.WriteAllTextAsync(path, sb.ToString());
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+}