Yes, that's pretty much what I thought I had seen, but apparently only imagined. Maybe I was just remembering WPF's ViewBox control ( http://www.wpftutorial.net/ViewBox.html).
I'd settle for a way to explicitly apply a scale transform to a component. That's what I thought ScaleDecorator was for. But as I mentioned, it doesn't also scale mouse coordinates, so it's of pretty limited utility.
