Because in the first case involves thr presentation layer, and possibly one or more business rules layers and quite possibly the data/stored procs layer. Moreover these objects are dynamic and must keep each other in synch. Thus to use an MVC metafor, the model, the controller, and several items in the view are all *interacting*

In this case we need to position the objects once, and we're done, and it is all hapopening in the realm of the presentation layer. There is no interaction whatsoever.

(Didn't I already say this?).

Please don't confuse logical relationships with "spatial relationships" as you called it. There are no "spatial relationships" whatsoever here.

If you have any more doubts about this please post a question to "All" becoause I'm done repeating myself on this issue.

>>But I don't understand why you'd want to use a mediator to minimize the number and aid the maintainability of dependencies between instances when they depend on each other logically, yet rely on their direct knowledge of each other when it comes to repositioning themselves.