I guess what I am having trouble understanding is why a user of my widget was unable to get updates if he has his GPS on all the time. It's clear from his email to me that getLastKnownLocation() returned a latitude/logitude of 0.0/0.0. This clearly indicates that a position was not available. But if his GPS always on shouldn't I have gotten back a value. Or is it dependent on whether one of his other apps ever used the GPS to update itself?
>>>>> "d" == davemac <[email protected]> writes: d> There's no magic to the PASSIVE_PROVIDER. While you don't need to d> turn on a location provider to use passive, *somebody* must have d> turned something on, otherwise there won't be any updated d> locations. Passive let's you piggyback on someone else's location d> updates. Which means, if your location-aware widget or clock is d> updating often enough, passive should give you a reasonable d> location. The challenge is to know when to trust a result from d> passive. Anything that is location aware can enable a provider d> (assuming it has permissions to do so), get a location result, d> then disable that provider until it wants another location. This d> has been the recommended advice if you don't need frequent d> location updates so the location hardware is off as much as d> possible. If you check for enabled location providers (using d> getProviders() with the enabledOnly parameter), you could find d> that they're all off. On the positive side, a location should tell d> you when it was acquired (using getTime()). You could use that to d> make a judgment call on whether or not the retrieved location is d> recent enough for your app to trust it. d> - dave d> On Feb 20, 8:17 am, Mark Murphy <[email protected]> wrote: >> On Sat, Feb 19, 2011 at 8:34 PM, Jake Colman <[email protected]> wrote: >> > If my phone is running a location-aware clock or a >> > location-aware weather widget, would getLastKnownLocation() be >> > guaranteed to return a value in my app? >> >> There are no guarantees in life. >> >> For example, a "location-aware clock" might only check location >> sporadically (e.g., daily). >> >> > Or is that the point of the 'passive' provider? >> >> The passive provider is so you can get location data without >> necessarily turning anything on (e.g., GPS radio). >> >> > With my widget installed on my HTC EVO, which runs the HTC >> > standard location-aware clock, it always knows where it is as I >> > travel from home to work. That would imply that my app's call >> > to getLastKnownLocation returned results since the phone knew >> > where it was. Does that make sense? >> >> Yes. Unless your app is only for you, though, you can't exactly rely on >> that. >> >> -- >> Mark Murphy (a Commons >> Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy >> >> Warescription: Three Android Books, Plus Updates, One Low Price! d> -- d> You received this message because you are subscribed to the Google d> Groups "Android Developers" group. d> To post to this group, send email to [email protected] d> To unsubscribe from this group, send email to d> [email protected] d> For more options, visit this group at d> http://groups.google.com/group/android-developers?hl=en -- Jake Colman -- Android Tinkerer -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
