After quite some pondering, it occured to me that we both
- need some top-level model::Tangible to correspond to the RootMO in the session
- need some Controller to handle globally relevant actions
- need a way to link action invocation to transient interaction state (like focus)
This leads to the introduction of a new top-level controller, which is better
suited to fill that role than the depreacted model-controller or the demoted window-manager
looks like we're in management business here ;-)
we chop off heads, slaughter the holy cows and then install -- a new manager
