'Updates the icon and tip based on the validity of the array content.'

def update_warning(self):

    widget = self._button_warning
    if (not self.is_valid()):
        tip = _('Array    dimensions    not    valid')
        widget.setIcon(ima.icon('MessageBoxWarning'))
        widget.setToolTip(tip)
        QToolTip.showText(self._widget.mapToGlobal(QPoint(0, 5)), tip)
    else:
        self._button_warning.setToolTip('')
