How to perform a temporal undo?

[Agobin]

I have a section in my application where I list all the changes made by a user and allow the user to quickly switch between states. I rely on the UndoManager's stack to switch between states. However, when I sometimes perform an undo to switch to a particular state, the stack changes.

Is there a way to temporarily perform an undo without actually changing the stack?

[artf]

Hey @Agobin I've actually started talking about the refactoring of UndoManager here, which should allow better support for what you're doing.
Would you mind describing how did you actually create your list of changes?

undo without actually changing the stack?

I'm wondering how do you perform the undo, as calling undoManager.undo doesn't change the stack.

[Agobin]

Hi @artf ,

In my application, I track every action I do. And whenever I perform an action that can be undone, I add a description of the action in a list. This way, the list has all the changes made by the app but this is highly manual.

I'm wondering how do you perform the undo, as calling undoManager.undo doesn't change the stack.

Performing an undo doesn't change the stack, however, say I have ten models in the stack relating to 10 different actions that can be undone. If I perform 5 undos, the stack doesn't change. If at this point I perform a new undoable action, it changes the stack. The stack will now have 6 models instead of 11. The 5 actions that were undone will be removed from the stack.

Currently, I used an older version of grapes and the undo feature doesn't work effectively. Sometimes when I perform an undo, it performs and undo action but the view doesn't change. I was wondering if there was a way to replace the undo manager of the older version with that of the recent version? Updating the whole library would break certain features of the application.

[artf]

If I perform 5 undos, the stack doesn't change. If at this point I perform a new undoable action, it changes the stack. The stack will now have 6 models instead of 11. The 5 actions that were undone will be removed from the stack.

Well, this is how any UndoManager is supposed to work as you're changing something in the middle.

Currently, I used an older version of grapes and the undo feature doesn't work effectively. Sometimes when I perform an undo, it performs and undo action but the view doesn't change. I was wondering if there was a way to replace the undo manager of the older version with that of the recent version? Updating the whole library would break certain features of the application.

I guess you should try it on your own fork.
Did you try at least to upgrade? What version do you use? What errors are you facing?

[Agobin]

I finally upgraded my version of grapes.

[artf]

Great, anyway I'd suggest following issue #3639
If you have any suggestions on how to make the UndoManager more extendable (eg. events, API, etc.) post it there.

[Agobin]

Okay, I will.