Reversing and Recovering Actions

You can erase the changes done to a document to return it to its previous state.

Before you begin:
  • By default, Undo and Redo keep a track of up to ten of your last actions. This can be changed in Me > Preferences > General > PCS.
  • There is one global stack per session and not one stack per document open in the session. Therefore, reversing an action requiring modifications in several documents reverses all the modifications done by this action in all the documents open in the session.
From the standard area of the action bar, click Undo or Redo or choose the appropriate command in the Undo/Redo Overview dialog box:
Command Purpose Notes
Undo

(or press Ctrl+Z)

 Cancels the last performed action. Only the last action, that is, the last single click, is impacted even though a command has been run in repeat mode (by double-clicking). To reverse all repetitions of a command, first press Esc to exit repeat mode then start reversing actions.

Standard reversible actions are:

  • Start of a command: you may reverse it, but not recover it, in most cases. When reversed, you go back to the default command, which is Select. You can only stop this command if you run another exclusive command (that is, a command that creates, modifies, or updates data).
  • User interaction in a command: you may reverse and recover it if allowed by the app. In that case, the command goes back to the previous dialog step.
  • End of a command: modifications made since the beginning of the command are stored in a global reversible and recoverable action, unless the object has not been modified during the command.
  • UI-activation. You revert to the previously UI-activated object.

Undo does not let you restore default preferences.
Redo

(or press Ctrl+Y)

 Recovers the last performed action. The Redo command can only be used to recover actions canceled through the Undo command.

When there is no action to recover, Repeat replaces Redo to let you restart the last command you used. However, when you interrupt a command run in repeat mode (that is, when you double-click a command), it is automatically restarted afterward, even if you click Cancel. The only way to interrupt a command in repeat mode is to press the Esc key, or to select another command.

Important:
  • If you run Undo in repeat mode to reverse a command instance, you cannot recover any action.
  • If you run Undo after exiting repeat mode, you recover the command instance that has been previously canceled. If you recover the first instance in the list, it restarts in repeat mode. Exiting repeat mode means that you also exit the command.

You can reverse then recover local actions when you are in the command. If successively reverse several actions until you reverse the command itself, then you cannot recover the command's local actions.

Undo/Redo Overview Displays an overview of actions that you can reverse or recover in the active objects. The name of the object open in the current editor is displayed on top of the dialog box.

The object might not be impacted by the undo mechanism because the action you choose to reverse might only impact one object open in another editor.

The Undo/Redo Overview dialog box is split into two areas, which let you choose:

  • The actions you can reverse from the numbered list displayed in the left column, the most recent action is displayed at the top of the list.
  • The actions you can recover from the numbered list displayed in the right column, the most recently reversed action is displayed at the top of the list.

Each action is identified by its name. Select an action, and then:

  • Click : the reversed actions are transferred to the right part of the dialog box and you can recover them afterward.
  • Click : the recovered actions are transferred to the left part of the dialog box and you can reverse them afterward. If you cannot recover an action, it is removed from the left column but is not displayed in the right column.

Important: To recover or reverse the first action only, click or : because the first action is already highlighted in the list, it is recovered or reversed and removed from the history. To recover or reverse the first four actions for example, click the fourth action from the list: clicking an action means that all former actions are selected as well and thus, recovered or reversed to keep the history.
Flush Removes from the history all finished global actions performed in the current editor. Lets you manage more precisely the Undo log without modifying the Stack size value in the PCS tab and helps you consume less memory.
Note:
  • The undo stack is flushed after the creation of an entity.
  • The redo stack is emptied after clicking the Redo icon that is then dimmed.
Important: Actions performed through a macro do not behave the same when running the Undo or Redo command. Some macro APIs can create undo steps whereas others cannot. For example, the point creation automation API does not create any undo step whereas the Point command does.

Moreover, actions performed through a macro can be concatenated inside the undo steps of the current command. This is the case when the selection command is active (this is the command activated by default when no other command is running). In that case, a macro can be concatenated inside a selection step. Below is an example:

  • 1. The selection command is active and an undo transaction is created.
  • 2. You run a macro to create some features.
  • 3. You perform an empty selection.
  • 4. This empty selection creates an undo step concatenating all the actions performed during the undo transaction created in step 1, including the actions performed in step 2.