FastColoredTextBoxNS.ExportToRTF.GetRtfDescriptor C# (CSharp) Method

        private RTFStyleDescriptor GetRtfDescriptor(StyleIndex styleIndex)
        {
            List<Style> styles = new List<Style>();
            //find text renderer
            TextStyle textStyle = null;
            int mask = 1;
            bool hasTextStyle = false;
            for (int i = 0; i < tb.Styles.Length; i++)
            {
                if (tb.Styles[i] != null && ((int) styleIndex & mask) != 0)
                    if (tb.Styles[i].IsExportable)
                    {
                        var style = tb.Styles[i];
                        styles.Add(style);

                        bool isTextStyle = style is TextStyle;
                        if (isTextStyle)
                            if (!hasTextStyle || tb.AllowSeveralTextStyleDrawing)
                            {
                                hasTextStyle = true;
                                textStyle = style as TextStyle;
                            }
                    }
                mask = mask << 1;
            }
            //add TextStyle css
            RTFStyleDescriptor result = null;

            if (!hasTextStyle)
            {
                //draw by default renderer
                result = tb.DefaultStyle.GetRTF();
            }
            else
            {
                result = textStyle.GetRTF();
            }

            return result;
        }