tree 86795102b28973660ff707c1d769ce8e68be9be4
parent 8426e2c7438df2081505087dde9bb002aa527aca
author Alex Fandrianto <alexfandrianto@google.com> 1461104176 -0700
committer Ross Wang <rosswang@google.com> 1461117711 -0700

TBR: TODOs: TodoLists track numCompleted. Can mark all as done.

These changes introduce MainListener, which allows the MainActivity
to update the UI when the tasks of a TodoList have changed.

FirebaseMain also supports tracking the child tasks of the TodoLists.
This also applies when a TodoList is updated.

TodoLists can also mark all as done, though it's an open question
what should happen when all of them are already marked as done.

Bugfix: 50-50's the UI for the message and timestamp correctly.
Bugfix: notifyDataSetChanged a little more often.
Change-Id: I587cb72ff2ea946177e6643310a5402c196fa557