Note that this method waits for a pause in scrolling, which is not an ideal solution in your case. If you keep this timeout at 0.3s, for users who scroll slowly (when they want to precisely adjust object size), undo will be saved every 0.3 seconds, which is still too frequent.

If you set a larger timeout like 1-2 seconds, undo step will be saved with a big delay, during which user may do something else, for example delete the object. And this again can cause the situation when two undo steps are saved at the same time.

Yes 0.3s is a bit slow (but safe) so I just did some tests and I stretched it to a faster delay such as 0.1 sec it works GREAT! even if I go like CRAZY FAST with the wheel I can easily undo back to the MAX limit on the UNDO object until it reaches the end "maxSteps" which I can easily change manually thanks to your dynamic Undo/Redo system dop2000! :)

True that slow scroll is acting weird as you explained, but I don't see other way WITHOUT extra key to add for release to call the undo, so this is good for the Z-Order changes.

I believe that it's very stable because it's only calling the UNDO function "SaveStep" AFTER as I wanted so it's emulating the same timing as I release a key real fast. maybe without the manual delay the scroll do multiple scrolls each time and it SUPER fast, that's the only reason I think it crashed originally.

I WISH we had a built-in action for "AFTER WHEEL FINISHED" like this, it could be sooo useful for many things I do! I'm using the code by rokstars322 which is kind of tiny without the logs/coneole so it's still very nice!

I'm sooo happy that it's solved and works exactly as I imagined! it is very efficient for my project :)

UNDO / Memory Question:

dop2000 I'm curious if you can tell me if it will be a problem if I'll push the maximum amount of undos from 30 to something like 64 or even 128 (which is too much but I'm curious)

Memory wise... will this be an issue to old machines with 4GB RAM? consider there will be many objects on the screen that may also take memory.

What is your suggestion about the maximum amount of UNDO'S for my software to keep it work nicely even on older machines?

It's not that I'm making it FOR old machines, but it's always nice to have MORE machines be able to run my software.

I still don't understand the Debugger/Profiler that should help me out with the memory and CPU (I GUESS?) so I'm asking in Theory if I should go for a HIGHER maximum UNDO limit without risk memory issues on older machines.

I can always let the user change it with a menu I'll make but I'm talking about the defaults for now.

Will 64 / 128 Undos be a REALLY bad idea? or not an issue at all?

> AFTER I scroll

Its easy to make custom event, that will be triggered when user stop scrolling.

A quck example: drive.google.com/file/d/1CUUe5aoDkdxJyfV1KOWbCrcDPETb6ORH/view

YES!!! you're awesome rokstars322 THIS IS THE SOLUTION I was looking for!

Thank you so much :)

I wonder if someone could make this into a plugin or addon that could be used as a simple action because I could use it A LOT!

You wrote "if I just press and RELEASE CTRL by itself... it will create an UNDO"

If you are using the flag correctly, this should not happen. When you press and release Ctrl or any other button, without actually changing any objects, undo step will not be saved. Only when anything about the object has been modified (scaled, moved on z-axis etc.), then you set the flag and undo step will be saved.

Exactly!

You still don't understand the issue... I NEED it to be saved why should I disable the undo?

and it works fine but again... not as I need it to work, I described it few times above.

I wish I could explain it better, sorry about my bad English.

> The problem here is if I just press and RELEASE CTRL by itself... it will create an UNDO which doesn't make any sense

Sigh... We've been through this many times.

You need to use a boolean flag IsUndoSaveRequired (or something like this). Set this flag to true when the object is resized. Check this flag when Ctrl is released and call SaveStep function only when the flag is true. If user just pressed and released Ctrl, the flag will false, and the undo step will not be saved.

I don't understand what this is have to do with the issue I have mentioned with the issue at all?

I'm afraid you didn't understand my issue with Releasing CTRL (by itself) since I must save after changing the Z-Order, so why should I not save it or using the isUndoSave boolean? it's nothing to do with the SaveStep or resizing since they work perfectly fine.

The all point is that I have to hold another key with the middle mouse while scrolling Up or Down and I can't find another solution for this to work as scroll middle mouse (by iself) since it cause the issue, as you explained it is not a good idea to save so often or fast and it's totally make sense so I either NOT saving it to the undo history (which is not an option for me) or MUST hold a key so the SaveStep will execute ONLY once I RELEASE the CTRL (or any other key I choose) in order to slow-down the Undo/Redo so it won't cause the original issue. so yes, I do understand it you (Sensei dop2000) explained it very well from the moment you explained it saving too fast but what unfortunately I think there is no solution to scrolling middle mouse button WITHOUT releasing a key if I want a slowdown functioning Undo save.

Just to be clear: I'm not complaining or anything, my limited English may seem like I do sometimes, it's because I'm trying my best to explain myself or the issue. but I'm always VERY thankful for any help. I must say HUGE THANKS especially to you dop2000 for your many tips, helps and solutions,  Thanks to YOU I have an AMAZING dynamic Undo/Redo system, I hope that you understand how thankful I am. :)

Sorry for making you extremely tired from my posts, it is NOT that I do it on purpose I really try hard and if you'll read my posts and see the screenshots you will see that I'm not just asking things without trying first.

Anyway, I'll continue to my next mission it's not that I didn't solve the current issue, it's just that it's not a very efficient solution to my use as I explained earlier why, once again: it works! (but it's a waste a really good use of the mouse wheel scroll by itself without extra keys because I have no other choice if I want the undo to work while not crashing or saving randomly.

In Overall: it works (but not the way I want it to work, it's a "walk around") so I'll just move on for my next mission. :)

Thanks rokstars322 you sure gave some good advice, I'll explore a bit more what I can do or improve.

At this point I'm using the CTRL + Scroll so the Undo/Redo save to slot once I release the CTRL.

The problem here is if I just press and RELEASE CTRL by itself... it will create an UNDO which doesn't make any sense, and I tried other combinations such as SHIFT or other letters on the keyboard, even Spacebar... nothing make sense in the specific workflow of my software only CTRL or NONE, but Scrolling without any EXTRA key to release will make the UNDO go nuts...

As I said, if I had some action for something like "When Scroll UP (or Down) finished" I could use it not only to FIX this annoying issue, but also for many other features! but once again... there is no such action so it doesn't matter.

Thanks for sharing your advice and experience, I appreciate it! :)

You can change the controls you use to scale objects. Make it Ctrl+Wheel for example, and save undo step on Ctrl released.

Yeah, I it's the only temporary fix I had in mind and it's a waste of use for the wheel alone, but I'll just have to hold a key and use the wheel for something that doesn't need an undo.

Also, it will create an Undo if I'll just release the CTRL by itself which is not ideal.

I wish we had an extra addon or plugin or a feature for extra action such as: "on Finish Wheel Scroll UP" (or Down) I could use that for so many other things on my software not even related to this specific issue that's for sure but oh well... WE DON'T have such feature! lol :)

The correct solution is to not save a new undo step until previous save has completed.

From my tries, it didn't work with the "Wait for previous actions to complete" so what's the alternative way to do it?

Of course other software are using different methods for undo, you are welcome to try some other system if this doesn't work for you.

Unfortunately, I don't even know what are the alternative systems to emulate a safer or more efficient undo/redo system so I don't think it's an option I can go for.

Beside that, I must be honest: not only that I LOVE the current UNDO/REDO system thanks to you of course (I appreciate it A LOT!) so far EVERYTHING I tested works GREAT! but ONLY THIS specific annoying fast-wheel issue which make things go nuts... users will have so many crashes and random SAVE appears from nowhere.

Also, save only one undo step after user finished resizing the object. Saving dozens of steps for one resizing operation is a bad idea anyway

This is how most of my other actions works, on release key it calls: "SaveStep" function so it's very safe.

But the Mouse Wheel actions have no "on release" or something close because it's not a keyboard of course.. I wish it has after or per one-sliding or something... that could solve the issue EASY! (I can only dream for such features hehe)

The only Temporary Fix which is not an actual solution is to hold a key while scrolling so it will call the "SaveStep" function only when releasing it. the reason it's the ideal a solution is because I need to add another key instead of just using the scroll freely without holding any any extra key (waste of use).

Isn't there a other way to somehow LIMIT or Slowing-Down the current code on the wheel up/down over instances?

Thanks ahead! any help is more than welcome and very appreciated! :)