change number seed on undo/redo (proof of concept)

[NicoWeio]

My suggested behavior is setting the seed to the just-undone number or (just-redone + 1), respectively.

I'm not familiar with this codebase at all, so my approach might be quite ugly – but it works and currently, no better solution (as in “a PR”) seems to exist.

Fixes #308

[DamirPorobic]

What is the motivation for having this behavior? Do you have scenario where such a behavior is required?

[NicoWeio]

I think #308 describes it pretty well.
The suggested behavior is not strictly required, but more efficient and IMO more intuitive.
If I press Ctrl+Z, I expect all state to be “reset”.
However, currently, adding a number annotation, undoing, then adding one again, would result in a larger annotation number each time you do it.

[DamirPorobic]

That makes sense. Still I don't like the if there, would love to see some inheritance helping us out. Could you add some simple factory that returns one of two types of AddCommands, for NumberTools a AddAnnotationNumberCommand and for all other the usual AddCommand. The AddAnnotationNumberCommand inherits from AddCommand and does all the same (by calling the base) + resets the seed. I know it's a bit more code but I think it's the right way to do it.

[NicoWeio]

I absolutely agree. As I said, this was only a quick draft.

Unfortunately, I'm not that accustomed to C++ and am currently struggling with referencing AddCommand from AddAnnotationNumberCommand. For some reason, all I get is expected class-name before »{« token.

It might take me some weeks or months until I can allocate more time to this, so if you or somebody else would like to, you are more than welcome to take over.