Returns the popup widget for this editor.
        
        :return     <skyline.gui.XPopupWidget>

def popupWidget(self):
        """
        Returns the popup widget for this editor.
        
        :return     <skyline.gui.XPopupWidget>
        """
        if not self._popup:
            btns = QDialogButtonBox.Save | QDialogButtonBox.Cancel
            self._popup = XPopupWidget(self, btns)
            self._popup.setShowTitleBar(False)
            self._popup.setAutoCalculateAnchor(True)
            self._popup.setPositionLinkedTo(self)
        return self._popup