// centre pos, autosized
        public ImageElement AddTextCentred(Point poscentrehorz, Size max, string label, Font fnt, Color c, Color backcolour, float backscale, Object tag = null, string tiptext = null)
        {
            ImageElement lab = new ImageElement();

            lab.TextCentreAutosize(poscentrehorz, max, label, fnt, c, backcolour, backscale, tag, tiptext);
            elements.Add(lab);
            return(lab);
        }
 // centre pos, autosized
 public ImageElement AddTextCentred(Point poscentrehorz, Size max, string label, Font fnt, Color c, Color backcolour, float backscale, Object tag = null, string tiptext = null)
 {
     ImageElement lab = new ImageElement();
     lab.TextCentreAutosize(poscentrehorz, max, label, fnt, c, backcolour, backscale, tag, tiptext);
     elements.Add(lab);
     return lab;
 }