Themes: Fused Location, Geofencing, LocationRequest.
API changes
o Fused location is always returned when asking for location by Criteria.
o Fused location is never returned as a LocationProvider object, nor returned
as a provider String. This wouldn't make sense because the current API
design assumes that LocationProvider's have fixed properties (accuracy, power
etc).
o The fused location engine will tune itself based on the criteria passed
by applications.
o Deprecate LocationProvider. Apps should use fused location (via Criteria
class), instead of enumerating through LocationProvider objects. It is
also over-engineered: designed for a world with a plethora of location
providers that never materialized.
o The Criteria class is also over-engineered, with many methods that aren't
currently used, but for now we won't deprecate them since they may have
value in the future. It is now used to tune the fused location engine.
o Deprecate getBestProvider() and getProvider().
o Add getLastKnownLocation(Criteria), so we can return last known
fused locations.
o Apps with only ACCESS_COARSE_LOCATION _can_ now use the GPS, but the location
they receive will be fudged to a 1km radius. They can also use NETWORK
and fused locatoins, which are fudged in the same way if necessary.
o Totally deprecate Criteria, in favor of LocationRequest.
Criteria was designed to map QOS to a location provider. What we
really need is to map QOS to _locations_.
The death knell was the conflicting ACCURACY_ constants on
Criteria, with values 1, 2, 3, 1, 2. Yes not a typo.
o Totally deprecate LocationProvider.
o Deprecate test/mock provider support. They require a named provider,
which is a concept we are moving away from. We do not yet have a
replacement, but I think its ok to deprecate since you also
need to have 'allow mock locations' checked in developer settings.
They will continue to work.
o Deprecate event codes associated with provider status. The fused
provider is _always_ available.
o Introduce Geofence data object to provide an easier path fowards
for polygons etc.
Implementation changes
o Fused implementation: incoming (GPS and NLP) location fixes are given
a weight, that exponentially decays with respect to age and accuracy.
The half-life of age is ~60 seconds, and the half-life of accuracy is
~20 meters. The fixes are weighted and combined to output a fused
location.
o Move Fused Location impl into
frameworks/base/packages/FusedLocation
o Refactor Fused Location behind the IProvider AIDL interface. This allow us
to distribute newer versions of Fused Location in a new APK, at run-time.
o Introduce ServiceWatcher.java, to refactor code used for run-time upgrades of
Fused Location, and the NLP.
o Fused Location is by default run in the system server (but can be moved to
any process or pacakge, even at run-time).
o Plumb the Criteria requirements through to the Fused Location provider via
ILocation.sendExtraCommand(). I re-used this interface to avoid modifying the
ILocation interface, which would have broken run-time upgradability of the
NLP.
o Switch the geofence manager to using fused location.
o Clean up 'adb shell dumpsys location' output.
o Introduce config_locationProviderPackageNames and
config_overlay_locationProviderPackageNames to configure the default
and overlay package names for Geocoder, NLP and FLP.
o Lots of misc cleanup.
o Improve location fudging. Apply random vector then quantize.
o Hide internal POJO's from clients of com.android.location.provider.jar
(NLP and FLP). Introduce wrappers ProviderRequestUnbundled and
ProviderPropertiesUnbundled.
o Introduce ProviderProperties to collapse all the provider accuracy/
bearing/altitude/power plumbing (that is deprecated anyway).
o DELETE lots of code: DummyLocationProvider,
o Rename the (internal) LocationProvider to LocationProviderBase.
o Plumb pid, uid and packageName throughout
LocationManagerService#Receiver to support future features.
TODO: The FLP and Geofencer have a lot of room to be more intelligent
TODO: Documentation
TODO: test test test
Change-Id: Iacefd2f176ed40ce1e23b090a164792aa8819c55
This fixes a problem where applications could ask the location
manager to do very heavy-weight things (like... say... update
location every minute), which would get accounted against the
system instead of the application because ultimately it is the
system making the heavy calls (wake locks, etc).
To solve this, we introduce a new class WorkSource representing
the source of some work. Wake locks and Wifi locks allow you
to set the source to use (but only if you are system code and thus
can get the permission to do so), which is what will be reported
to the battery stats until the actual caller.
For the initial implementation, the location manager keeps track
of all clients requesting periodic updates, and tells its providers
about them as a WorkSource param when setting their min update time.
The network location provider uses this to set the source on the
wake and wifi locks it acquires, when doing work because of the
update period.
This should also be used elsewhere, such as in the GPS provider,
but this is a good start.
Change-Id: I2b6ffafad9e90ecf15d7c502e2db675fd52ae3cf
Use MS-Assisted mode for single shot GPS fixes if it is supported.
Add finer grained control over accuracy to the android.location.Criteria class
and location criteria logic from LocationManager to LocationManagerService
Change-Id: I156b1f6c6a45d255c87ff917cf3e9726a6d7a75b
Signed-off-by: Mike Lockwood <lockwood@android.com>
