'Change the current selection of modules to be applied to hosts file.
.. note:: This method is the slot responses to the signal argument
:attr:`item` from Functionlist widget while the item selection is
changed.
:param item: Row number of the item listed in Functionlist which is
changed by user.
:type item: int'

def on_Selection_changed(self, item):

    ip_flag = self._ipv_id
    func_id = self.ui.Functionlist.row(item)
    if (self._funcs[ip_flag][func_id] == 0):
        self._funcs[ip_flag][func_id] = 1
    else:
        self._funcs[ip_flag][func_id] = 0
    mutex = RetrieveData.get_ids(self.choice[ip_flag][func_id][2])
    for (c_id, c) in enumerate(self.choice[ip_flag]):
        if (c[0] == self.choice[ip_flag][func_id][0]):
            if ((c[1] in mutex) and (self._funcs[ip_flag][c_id] == 1)):
                self._funcs[ip_flag][c_id] = 0
    self.refresh_func_list()
