code: function (keyboardProxy) {
      var el = keyboardProxy[0];
      if (el.selectionStart) {
        return el.selectionStart;
      }
      else if (document.selection) {
        el.focus();
        var r = document.selection.createRange();
        if (r == null) {
          return 0;
        }
        var re = el.createTextRange(),
          rc = re.duplicate();
        re.moveToBookmark(r.getBookmark());
        rc.setEndPoint('EndToStart', re);
        return rc.text.length;
      }
      return 0;
    }
docs: Returns caret position in edit proxy
  @author http://stackoverflow.com/questions/263743/how-to-get-caret-position-in-textarea
  @return {Number}