Scenes changes do not contribute to the Undo stack

[Fredosixx]

Not strictly related to the API, but is there a reason why changes to scenes (create, delete, rename, ....) do not show in the Undo stack (and thus are not undoable), whereas they contribute to modification of the skp file.

If you add a scene, Undo will not show the change, but you will be prompted for Save confirmation if you close the model.

In contrast, changes to Tags/Layers do show in the Undo stack and are undoable.

[DanRathbun]

RELATED:

The Sketchup::PagesObserver has numerous problems. These may be contributive to not be undoable.

See all the comments in Issue 26 : PagesObserver#onPageUpdate() observer callback

[Fredosixx]

Still, this does not explain why creating, deleting or renaming a scene cannot be considered as an undoable action...

For the observer, I am aware of the numerous issues and the lack of observer for the most important event: update.

[DanRathbun]

I would say that the explanation is that the treatment of pages (scenes) in the core is bugged (which spills over into FrameChangeObserver and PagesObserver.)

[thomthom]

It was a design decision made in the early days of SketchUp. All though the exact details has been lost to time. Been a source of debate even internally.

[DanRathbun]

Okay. So then, ... would there be a way for coders to force an undo when the actions were wrapped in an operation ?

OR .... perhaps add a undo: true hash argument to these methods (and perhaps others that do a "end around" the undo feature) ?