This commit contains the infrastructure needed for the
NotificationHandler to send music state information to the device. That
is, it introduces a call onSetMusicState(MusicStateSpec stateSpec), that
in turn sets up an intent to the service, which will then call the
encodeSetMusicState() function of the device. encodeSetMusicState is
available for pebble only. There are empty stubs for other devices.
Previously, the DeviceCommunicationService was invoked directly,
via
Intent intent = new Intent(foo, bar);
intent.setExtra(EXTRA_BAZ, baz);
startService(...);
and this was scattered throughout GadgetBridge.
Now there is a "frontend" available, so that you can call
the service more easily, like
GBApplication.deviceService().connect();
For a start, this client interface (DeviceService) actually
implements the same interface (EventHandler) as the receiving side
(DeviceSupport). This may change in the future.
This will also make testing much easier, because we can use
this client interface to invoke the test service as well.