general undo methods?

[Thomas McGrath III]

If your using substacks you can save in different states (upon any 
changes or significant changes) with a smart numbering system(backup 
system) and then if/when the user saves, it writes a final version and 
deletes the previous ones.
That's the simpler way.
Other wise all kinds of things need to be kept track off to be able to 
undo them.

TOM

On Feb 18, 2005, at 3:53 PM, Richard Gaskin wrote:

> I need to add more extensive undo to an app I'm working on.  Seems 
> like a lot of work once you step outside of the subset of things the 
> engine takes care of for you.
>
> Any of you have pointers to general methods for implemening undo 
> across an app?
>
> -- 
>  Richard Gaskin

Thomas J. McGrath III
SCS
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