I am trying to restrict a RadDiagramShape to the bounds of another RadDiagramShape. When I manually set the position of the shape to keep it in the bounds of the other while draging it the adorners do not follow.
Unfortunately at the moment there's no way to restrict the dragging, but this feature will be included in our next major release - Q1 2013. For now there's a partial workaround - you could handle the mouse move event and cancel the dragging in your mouse/shape is not in the diagram's viewport.
I've attached a sample project with the workaround so could you please examine it and if you have further questions feel free to ask.