When ContentResolver.notifyChange() is called for a given URI, are ContentObservers observing descendent URIs of this URI notified?

Question

A hopefully straightforward question: When ContentResolver.notifyChange() is called for a given URI, are ContentObservers observing descendent URIs of this URI notified?

E.g. Say I have a cursor setup to observer the URI of a specific resource:

 Uri uriA = Uri.parse("content://" + AUTHORITY + "/orders/21");
 cursor.setNotificationUri(getContext().getContentResolver(), uriA);

I then notify the ContentResolver of a change to an ancestor of this URI (e.g. because I have deleted all orders):

 Uri uriB = Uri.parse("content://" + AUTHORITY + "/orders");
 getContext().getContentResolver().notifyChange(uriB, null);

Would my Cursor, registered to observe uriA, be notified?

Answer 1

It depends on how it was registered. If the ContentObserver was registered with the notifyForDescendents argument set as true, then yes. Otherwise no.

The registration is done through the method ContentResolver#registerContentObserver:

void registerContentObserver (Uri uri, boolean notifyForDescendents, ContentObserver observer)