I'm gussying up a Cocoa-Touch UI composed of basically two view hierarchies. Users need to drag objects from one (hierarchyA) INTO the other (hierarchyB). The problem I'm having is with the layering of these views, especially as they're being dragged. I don't know of a way to allow parts of hierarchyB be layered below a UIView from hierarchyA while other parts of hierarchyB remain above it?!?
Assuming this is a design requirement how should one approach this? I have some ideas but they get complicated quickly. They basically revolve around splitting B in two and using notifications to somehow tie them together?!? Really, I just want B to act as one object in that its hidden, frame, transform, etc. properties are easily kept in sync.