A misplaced drag, an accidental deletion, or an edit that takes a structure in the wrong direction can interrupt a molecular modeling session. The first question is often simple: What changed, and can I get back to where I was? In SAMSON, each document keeps its own history of undoable actions, giving you a way to step through earlier document states while you work.
The History view is useful when you want more context than a single Undo command provides. Open it from Interface > History, or use Ctrl+3 on Windows and Linux, or Cmd+3 on Mac. The view lists document actions; clicking an action lets you move through the corresponding history states.
Recover without guessing
If you notice an unwanted change immediately, use Undo. If you are unsure when the problem began, open History and review the actions around that point. This can help you identify a useful earlier state rather than repeatedly undoing and trying to remember each step.
You can undo or redo from the Edit menu, or use these shortcuts:
- Undo: Ctrl+Z on Windows and Linux; Cmd+Z on Mac.
- Redo: Ctrl+Y on Windows and Linux; Cmd+Y on Mac.
Undo and redo can be helpful while editing, building, or moving structures. For example, after trying a transformation, you can use the history to return to an earlier state if the result is not what you wanted. You can also use the action list to understand the sequence of undoable operations in the current document.
One important limitation
History is not a guarantee that every operation can be reversed. SAMSON notes that some operations are not undoable. If a non-undoable operation occurs between undoable actions, SAMSON may not be able to undo the sequence properly, and data loss may result.
That limitation is worth keeping in mind when experimenting. Before a substantial or hard-to-recreate change, consider saving a separate copy of your work as a general precaution. If you do need to recover, pause before making further edits, open the History view, and inspect the available actions. This does not make every operation reversible, but it helps you understand what the document history can—and cannot—restore.
A practical habit is to use Undo for a recent, clearly identified action and the History view when you need to inspect a longer sequence. Keep in mind that each document has its own history, so check that you are working in the document whose state you want to review.
For details on navigating document states and the history limitations, see the SAMSON History documentation.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON at www.samson-connect.net.