Returns current document selected text metrics.

        :return: Selected text metrics.
        :rtype: tuple

def get_selected_text_metrics(self):
        """
        Returns current document selected text metrics.

        :return: Selected text metrics.
        :rtype: tuple
        """

        selected_text = self.get_selected_text()
        if not selected_text:
            return tuple()

        return (selected_text, self.get_cursor_line(), self.get_cursor_column() - len(selected_text))