AcManager.Controls.UserPresetsControl.GetHead C# (CSharp) Method

        private static string GetHead(string filename, string from) {
            for (int i = filename.LastIndexOf(Path.DirectorySeparatorChar), t; i > 0; i = t) {
                t = filename.LastIndexOf(Path.DirectorySeparatorChar, i - 1);
                if (t <= from.Length + 1) {
                    return filename.Substring(0, i);
                }
            }
            return from;
        }