'Get the list of columns from the preferences. Clear the current table
and add the current column set'

def add_columns_to_widget(self):

    self.column_order = [x[0] for x in get_qv_field_list(self.fm) if x[1]]
    self.books_table.clear()
    self.books_table.setRowCount(0)
    self.books_table.setColumnCount(len(self.column_order))
    for (idx, col) in enumerate(self.column_order):
        t = QTableWidgetItem(self.fm[col]['name'])
        self.books_table.setHorizontalHeaderItem(idx, t)
