docs: def treePopupWidget(self):
          """
          Returns the popup widget for this record box when it is supposed to
          be an ORB tree widget.
          
          :return     <XTreeWidget>
          """
          edit = self.lineEdit()
          if not self._treePopupWidget:
              # create the treewidget
              tree = XTreeWidget(self)
              tree.setWindowFlags(Qt.Popup)
              tree.setFocusPolicy(Qt.StrongFocus)
              tree.installEventFilter(self)
              tree.setAlternatingRowColors(True)
              tree.setShowGridColumns(False)
              tree.setRootIsDecorated(False)
              tree.setVerticalScrollMode(tree.ScrollPerPixel)
              
              # create connections
              tree.itemClicked.connect(self.acceptRecord)
              
              if edit:
                  edit.textEdited.connect(tree.filterItems)
                  edit.textEdited.connect(self.showPopup)
              
              self._treePopupWidget = tree
          
          return self._treePopupWidget