I do intend to implement undo. I was going to spend some time looking for examples. Thanks for pointing me in the right direction.
Thanks for this plugin 
It would be nice to program undo/redo. It's really not difficult to implement and you'll find plenty of examples in Sweet Home 3D source code, mainly in PlanController class. Once you retrieved the UndoableEditSupport instance with getUndoableEditSupport(), you just have to create an instance of AbstractUndoableEdit, overriding its undo, redo and getPresentationName methods, and finally call postEdit.
It would be nice to program undo/redo. It's really not difficult to implement and you'll find plenty of examples in Sweet Home 3D source code, mainly in PlanController class. Once you retrieved the UndoableEditSupport instance with getUndoableEditSupport(), you just have to create an instance of AbstractUndoableEdit, overriding its undo, redo and getPresentationName methods, and finally call postEdit.
