def calculate_input(self, buffer):
if TriggerMode.ABBREVIATION in self.modes and self.backspace:<EOL><INDENT>if self._should_trigger_abbreviation(buffer):<EOL><INDENT>if self.immediate:<EOL><INDENT>return len(self._get_trigger_abbreviation(buffer))<EOL><DEDENT>else:<EOL><INDENT>return len(self._get_trigger_abbreviation(buffer)) + <NUM_LIT:1><EOL><DEDENT><DEDENT><DEDENT>if self.parent is not None:<EOL><INDENT>return self.parent.calculate_input(buffer)<EOL><DEDENT>return <NUM_LIT:0><EOL>
Calculate how many keystrokes were used in triggering this folder (if applicable).