On 15/07/16 10:41, Sam Bull wrote:
On Thu, 2016-07-14 at 15:13 +0100, Alan Bell wrote:
and the utterly broken location services
https://bugs.launchpad.net/ubuntu/+source/location-service/+bug/15546
04
the only way to get a location is to use a moving dot map
application
and wait and wait for a fix, then you can go to your other location
aware thing so it doesn't give out a spectacularly stale location.
As far as I can see, the location services are not broken, just the API
design. Apps such as the Weather app, typically ask for a location
once, and the location service provides the best location it has at
that moment in time.
The first thing I'd like to see changed, is that the accuracy of the
location should consider the time that has passed since that location
recording. E.g. A GPS position might be 10m accuracy, but if it is 30s
later, then that should give something like 100m accuracy. If it is
hours or days old, then the accuracy becomes 10's of km.
the main thing I would like to see is that if location services is asked
for a location, and it hands out some cached junk, it should pull it's
finger out and turn on the GPS chip and start finding a real location.
It doesn't. It just merrily thinks that it has done a cracking job by
handing out your position from the last time you looked at a maps
application and goes back to sleep. You can refresh and refresh and
refresh a location aware application and it will repeatedly hand out
cached junk, and won't turn on the GPS. It is *only* moving dot mapping
applications that subscribe to updates that cause it to think about
waking up the GPS chip.
Just expanding the accuracy radius isn't really that good, because
applications will use the centre of the circle as the best guess to
where you are. There should be more events that cause it to wake up and
look at the sky, such as turning on the screen, connecting or
disconnecting from wifi (if you connect to wifi, there is a reasonable
chance you are at a destination where you might stop and expect the
phone to know where it is) so that it doesn't hand out misleading junk
to applications.
The second thing I'd like to see, which I've suggested here before, if
an app wants a location one time, such as the Weather app, there should
be a second parameter which defines the minimum level of accuracy. E.g.
for the Weather app I only need a roughly city-level position, so it
could specify a minimum accuracy of 2km or so. If this level of
accuracy (factoring time into it) is less than the minimum, then it
should get a new location that meets the minimum requirements and
return that. The app can then display a 'waiting for location' message
while the location service is working.
that isn't in the API though
https://developer.mozilla.org/en-US/docs/Web/API/Geolocation/Using_geolocation
you can use getCurrentPosition (which is the one which everything uses
and doesn't turn on the GPS), or you can use watchPosition() which is
what moving dot map applications use which does turn on the GPS.
getCurrentPosition does have an option to specify a max age and request
high accuracy
https://developer.mozilla.org/en-US/docs/Web/API/PositionOptions but I
am not sure that we respect those options or just disregard them and
hand out junk.
--
Mailing list: https://launchpad.net/~ubuntu-phone
Post to : ubuntu-phone@lists.launchpad.net
Unsubscribe : https://launchpad.net/~ubuntu-phone
More help : https://help.launchpad.net/ListHelp
