ho to implement Undo/Redo in a Matlab App

I am after a good snippet code that would allow to have some Undo/Redo function.

I have found this intersiting one: uiundo - Matlab's undocumented undo/redo manager - Undocumented Matlab But it seems that uiundo might be removed at some point. I am happy to keep exploring this method, but I would like to find something more general in term of time history.

How to capture previous actions/values from the gui? Should I implement something like having a private property:

app.Data
app.DataBackwardStep
app.DataForwardStep

on new action:

• DataBackwardStep(end+1) = app.Data

on undo:

• app.DataForwardStep = app.Data
• app.Data = app.DataBackwardStep(end-1)
• app.DataBackwardStep(end) = [ ]

on redo

• app.Data = app.DataForwardStep
• DataBackwardStep(end+1) = app.Data

happy to see what others have already implemented

Answer 1

[Hitesh]

Hi Sylvain,

Absolutely, you’re on the right track! Implementing a custom undo/redo stack is a robust, general approach, especially when you want to avoid relying on undocumented or deprecated features like "uiundo". Following is a general undo/redo pattern you need to adapt for your MATLAB GUI app.

You maintained two stacks:

• Undo Stack (DataBackwardStep): stores previous states.
• Redo Stack (DataForwardStep): stores states you can return to after an undo.

I have implemented a similar functionality and attached the .mlapp file for your reference. Please review the code section of the app; it will give you a better understanding of the implementation.

Kindly ensure the following points for the usecase of this application.

• State Storage: If your data is large, consider storing only the differences (deltas) or using lightweight representations.
• Limit Stack Size: To save memory, you might cap the stack size (e.g., keep only the last 20 actions).
• GUI Update: After undo/redo, update any relevant UI components to reflect the restored state.

For more information regarding the "uiButton" in App Designer. Kindly refer to the following MATALB documentation:

https://www.mathworks.com/help/matlab/ref/uibutton.html

[Sylvain]

Thanks, @Hitesh, indeed I need to limit the stack storage (will be set by user parameter in the app). I will need to test the stack size to disable the undo/redo buttons.

I will work around what you suggested, Thanks again