void PaintText(Graphics g, Rectangle rect, string text, bool selected, DataGridViewCellStyle cell_style)
        {
            Document = parser.parse_text(text);
            Point pt = rect.Location;
            foreach (var node in Document.Nodes)
            {
                Font font = get_node_font(node, cell_style);
                Color clr = get_node_color(node, selected, cell_style);
                Size size = TextRenderer.MeasureText(node.InnerText, font);
                pt.Y = rect.Top + (rect.Height - size.Height) / 2;
                using (Brush bru = new SolidBrush(clr))
                {
                    g.DrawString(node.InnerText, font, bru, pt);
                }
                pt.X += size.Width;
            }
        }

        Font get_node_font(DOMNode node, DataGridViewCellStyle cell_style)
        {
            Font font = cell_style.Font;
            if (node.Name == "font" && node.Attributes.ContainsKey("name") && node.Attributes.ContainsKey("size"))
            {
                float font_size = cell_style.Font.Size;
                float.TryParse(node.Attributes["size"], out font_size);
                font = new Font(node.Attributes["name"], font_size);
            }
            return font;
        }

        Color get_node_color(DOMNode node, bool selected, DataGridViewCellStyle cell_style)
        {
            Color clr = selected ? cell_style.SelectionForeColor : cell_style.ForeColor;
            if (node.Name == "font" && node.Attributes.ContainsKey("color"))
            {
                clr = ColorTranslator.FromHtml(node.Attributes["color"]);
                if (selected)
                    clr = Color.FromArgb(~(clr.ToArgb()&0x00FFFFFF));
            }
            return clr;