Resizes this widget and updates the mask.
        
        :param      event | <QResizeEvent>

def resizeEvent(self, event):
        """
        Resizes this widget and updates the mask.
        
        :param      event | <QResizeEvent>
        """
        self.setUpdatesEnabled(False)
        super(XPopupWidget, self).resizeEvent(event)
        
        self.adjustMask()
        self.setUpdatesEnabled(True)
        
        x = self.width() - self._sizeGrip.width()
        y = self.height() - self._sizeGrip.height()
        
        self._leftSizeGrip.move(0, y)
        self._sizeGrip.move(x, y)