Print UI bug fixing and printer discovery refactoring.
1. Added support for selecting a printer from the all printers activity
that is not in the initial printer selection drop down. The user
initially sees a sub set of the printers in the drop down and the
last option is to see all printers in a separate activity. Some
of the printers in the all printers activity are not shown in the
initial drop down.
2. Refactored printer discovery by adding (private for now) printer
discovery app facing APIs. These APIs are needed to support multiple
printer selection activities (print dialog and all printers activities)
and also the settings for showing all printers for a service.
Now multiple apps can request observing for printers and there is
a centralized mediator that ensures the same printer discovery
session is used. The mediator dispatches printer discovery specific
requests to print services. It also aggregates discovered printers
and delivers them to the interested apps. The mediator minimizes
printer discovery session creation and starting and stopping discovery
by sharing the same discovery session and discovery window with
multiple apps. Lastly, the mediator takes care of print services
enabled during discovery by bringing them up to the current
discovery state (create discovery session and start discovery if
needed). The mediator also reports disappearing of the printers
of a service removed during discovery and notifies a newly
registered observers for the currnet printers if the observers are
added during an active printer discovery session.
3. Fixed bugs in the print UI and implemented some UX tweaks.
Change-Id: I4d0b0c5a6c6f1809b2ba5dbc8e9d63ab3d48f1ef
20 files changed