def popup_menu ( self , sender):
        self._cur_control = sender

        proxy    = sender.proxy
        index    = proxy.index
        menu     = MakeMenu( self.list_menu, self, True, sender ).menu
        len_list = len( proxy.list )
        not_full = (len_list < self._trait_handler.maxlen)

        self._menu_before.enabled( not_full )
        self._menu_after.enabled(  not_full )
        self._menu_delete.enabled( len_list > self._trait_handler.minlen )
        self._menu_up.enabled(  index > 0 )
        self._menu_top.enabled( index > 0 )
        self._menu_down.enabled(   index < (len_list - 1) )
        self._menu_bottom.enabled( index < (len_list - 1) )

        menu.exec_(sender.mapToGlobal(QtCore.QPoint(0, 0)))

    #---------------------------------------------------------------------------
    #  Adds a new value at the specified list index:
    #---------------------------------------------------------------------------
Displays the list editor popup menu.
dataset/ETHPy150Open enthought/traitsui/traitsui/qt4/list_editor.py/SimpleEditor.popup_menu