Class FontsSubsystem

public abstract class FontsSubsystem : IFontsSubsystem
{
    public abstract Font GetFontByName(string name);
    public abstract void AddFont(Font font);
    public abstract void RemoveFont(Font font);
}

protected FontsSubsystem(
      Stream defaultFont,
      Dictionary<string, string> fontsSubstitutions = null)
   {
   }

protected FontsSubsystem(string defaultFontFile, Dictionary<string, string> fontsSubstitutions = null)
   {
   }

protected FontsSubsystem()
   {
   }

public FontFamily DefaultFont
   {
      get;
      protected set;
   }

public void AddFont(Stream stream, string tempFolder)
   {
   }

public void AddFont(Stream stream)
   {
   }

public void AddFont(string file)
   {
   }

public void AddFontSubstitution(string substituted, string substitution)
   {
   }

protected abstract FontFamily FetchFontFamily(string fontName)
   {
   }

protected FontFamily FindFontFamilyInInternalCollection(string fontFamilyName)
   {
      foreach (FontFamily fontFamily in this._internalFontFamilies)
      {
         if (fontFamily.Name == fontFamilyName)
            return fontFamily;
      }
      return null;
   }

public virtual FontFamily GetFontFamily(string fontName)
   {
   }

public void LoadFontsFromFolder(string folder)
   {
      foreach (var file in Directory.GetFiles(folder, "*.ttf"))
      {
         using (var font = new Font(file))
         {
            AddFont(font);
         }
      }
   }

protected string TranslateFontName(string fontName)
   {
   }