`undo_manager.py`¶

In-session undo/redo for IsotopeTrack's editable analysis state.

Constants¶

Name	Value
`_FIELDS`	`('selected_isotopes', 'sample_parameters', 'isotope_metho…`
`MAX_DEPTH`	`40`
`POLL_MS`	`1200`

Polling, snapshot-based undo/redo for one MainWindow.

Method	Signature	Description
`__init__`	`(self, main_window)`	Create the manager and its change-detection timer.
`start`	`(self)`	Begin watching for input changes.
`stop`	`(self)`	Stop watching for input changes.
`_flush_parameters`	`(self)`	Commit any pending parameters-table edit into `sample_parameters`.
`_snapshot`	`(self)`	Return the current editable inputs pickled, or None on failure.
`_has_data`	`(self)`	True when at least one sample is loaded.
`_current_sample_sig`	`(self)`	Signature of the loaded sample set.
`_maybe_record`	`(self)`	Push a new undo step when the inputs changed since the last one.
`can_undo`	`(self)`	True when there is an earlier state to return to.
`can_redo`	`(self)`	True when there is a later state to move forward to.
`undo`	`(self)`	Step back to the previous editable-input state.
`redo`	`(self)`	Step forward again after an undo.
`_apply`	`(self, snap)`	Restore a snapshot's inputs and refresh the UI to match.
`_refresh_ui`	`(self)`	Rebuild the input-facing UI from restored state without side effects.
`_notify`	`(self, msg)`	Show a brief toast for the undo/redo outcome if supported.
`_update_actions`	`(self)`	Keep the Edit-menu Undo/Redo actions' enabled state in sync.