Undo
The undo command reverses the last change to the drawing — one step per invocation. Each addition, deletion, or edit of entities is recorded as a separate history entry. Undo steps back through these entries in reverse order.
How to undo
- Type
undoin the terminal, or - Click the Undo toolbar button.
Each invocation reverses one recorded action. Invoke it repeatedly to step further back.
History behaviour
| Detail | Value |
|---|---|
| Steps per file | Up to 20 |
| Storage | Browser (IndexedDB / localStorage), per file name |
| Survives page reload | Yes — history is restored when you reopen the file |
| New action after undo | Clears all redo entries ahead of the current position |
| Oldest entry when full | Dropped to make room for the newest change |
Every entity mutation is recorded: drawing new entities, deleting entities, grip-editing endpoints, applying Move, Rotate, Scale, Mirror, Trim, Extend, and Offset all create history entries.
Undo vs Redo
| Undo | Redo | |
|---|---|---|
| Direction | Steps backward through history | Steps forward through undone entries |
| Available when | At least one recorded action exists | At least one Undo has been performed and no new action has been taken |
| Cleared by | Nothing — history accumulates until the 20-step limit | Any new drawing action |
Use Redo to reapply an undone action. The toolbar buttons are greyed out when the respective direction is unavailable.