'Signal handler for \'changed\' event.
:param widg: widget who signaled
Used to supervise if the widget value is ok or not.'

def _changed(self, widg):

    text = self.get_text()
    if self.validate(text):
        self.modify_base(gtk.STATE_NORMAL, self.bg_normal)
    else:
        self.modify_base(gtk.STATE_NORMAL, self.bg_badentry)
