Override Qt method

def flags(self, index):
        """Override Qt method"""
        column = index.column()

        if index.isValid():
            if column in [C.COL_START, C.COL_END]:
#                return Qt.ItemFlags(Qt.ItemIsEnabled | Qt.ItemIsSelectable)
                return Qt.ItemFlags(Qt.ItemIsEnabled)
            else:
                return Qt.ItemFlags(Qt.ItemIsEnabled | Qt.ItemIsSelectable)
#                return Qt.ItemFlags(Qt.ItemIsEnabled)
        else:
            return Qt.ItemFlags(Qt.ItemIsEnabled)