A first aproximation to pinch and zoom implementation in MockupSceneEdit...

...or.
In GroupEditorDragListener there is a call to fireTransformed, that is done in the dragStop. This fireTransformed notifies the controller that something has changed and updates the model. Is this method called after this? It's easy to check: if you make zoom and press undo, it should work. Sorry, I can't test myself in desktop.