Other - Separate contexts

Each BdndProvider is a drag context of its own: its draggables are seen by its drop targets only. Every note on this page has the same type, "note", and every bin accepts it - yet a note of board A cannot go into board B's bin: each board has a provider, and while a note is in the air only the bins of its own context light up (CanDrop), and the keyboard only visits those. The corner of board A has a provider nested in A's: it ignores A's notes, and A's bin ignores its note. Two providers given the same Manager, on the other hand, are one context however far apart they are on the page: the shelf at the top and the tray at the bottom share one, and notes move between them.