'Datetime option is disable if numerical is disabled as well.
GH-2050 (code fixes)
GH-2120'

def test_check_datetime_disabled(self):

    dat = '                                                01.08.16 DCTB 42.15 DCTB neumann DCTB 2017-02-20\n                                                03.08.16 DCTB 16.08 DCTB neumann DCTB 2017-02-21\n                                                04.08.16 DCTB 23.04 DCTB neumann DCTB 2017-02-22\n                                                03.09.16 DCTB 48.84 DCTB turing DCTB 2017-02-23\n                                                02.02.17 DCTB 23.16 DCTB turing DCTB 2017-02-24'
    with named_file(dat, suffix='.tab') as filename:
        self.open_dataset(filename)
        domain_editor = self.widget.domain_editor
        idx = (lambda x: self.widget.domain_editor.model().createIndex(x, 1))
        qcombobox = QComboBox()
        combo = ComboDelegate(domain_editor, VarTableModel.typenames).createEditor(qcombobox, None, idx(2))
        vartype_delegate = VarTypeDelegate(domain_editor, VarTableModel.typenames)
        vartype_delegate.setEditorData(combo, idx(2))
        counts = [4, 2, 4, 2]
        for i in range(4):
            vartype_delegate.setEditorData(combo, idx(i))
            self.assertEqual(combo.count(), counts[i])
