Mode Protocol

[nixta]

Want to decouple ArcGIS logic from the MapDisplayViewController, but there are some intertwinings between the AGS callbacks and controlling the mode on the app.

Is this a notification framework or a protocol? Do we want all MapViews to be able to follow a mode? A mode determines the operating mode of the map and it's UI.

And it's the UI that typically drives this mode changing, so there's a definite coupling, but let's remove the reliance on a specific class.

Propose a MapModeManager protocol:

mapMode property and a registerForModeChangeNotifications method.