Sorry, I'm a beginner in android.
I have to save when a car parks using a service.
To do this I'm using LocationManager with GPS_PROVIDER to monitor the speed of the car.
I am using requestLocationUpdates but when the machine stops onLocationChanged it is no longer called so I can not get the speed, understand that it is stationary and save the parking space.
How could I do?
If you want continued updates while stopped you need to ensure 'minDistance' is not preventing updates. It is passed to your 'requestLocationUpdates' call. Try setting the value to 0. However this will also have a negative impact on battery life. I would also suggest looking into the location APIs provided by Google Play Services instead of using the LocationManager.
Related
after researching the Android Location FusedLocationProviderClient I am very confused about what you should and should not do!
The use case is: The App holds different locations with latitude and longitude. While the user is walking around the app (with the phone in the pocket, screen off) needs to track if he is close to one of the locations and plays a short beep when closer than a defined range.
Would the Geofence option the best solution? These locations will also change during runtime and periodically - they might also be more than 100. Any suggestion?
I am also thinking about a background service to handle all this when the device moves. This would be more flexible and allows for the reload of the locations as well. Any thoughts?
Thanks!!
You don't actually need to build a background service to monitor if a user is close to a location. There is already a geofence provided by Google. It uses fusedlocation provider internally.
Please refer this
You can combine this with a FusedLocationProviderClient and subscribe to location updates. This way you'll get location updates as well.
I'm building an app that should be able to report the users exact location. There is only a need for a single location, i.e. I don't need to track the device continuously.
I want the location to be as accurate as possible, and it's okay to wait a short while for the location to be determined (max 1-2 minutes).
I've been looking at FusedLocationProviderClient.getLastLocation(), but since I want the location to be as accurate and updated as possible it doesn't fit my needs.
So I started looking at using FusedLocationProviderClient.requestLocationUpdates() instead, and it seems like a better choice.
But I'm not sure how to best configure my LocationRequest to get as good accuracy as possible. For instance, would it be better to use setNumUpdates() so that I only receive a single update and use that as my location, or should I receive multiple updates in hopes of getting better accuracy (GPS locking to more satellites for example)? I'm thinking that if I use the second approach, I could look at the value of getAccuracy() from each location update and only keep the one with the highest accuracy. The downside is that if the device is moving and I keep receiving updates for a minute or so, the first location could have the highest accuracy, but since it's a minute old it's not accurate any more.
As stated above, I need just a single highly accurate location and it's okay for the app to wait 1-2 minutes for it if needed. What would be the best approach in this kind of scenario?
First, make sure the accurate location is turned on. look at Settings.Secure.LOCATION_MODE_HIGH_ACCURACY It has a noticeable advantage over only using GPS. Then listen for the location for a while and calculate the result you get to find out the best location. You can also detect if the user is moving if the number differs a lot or by using Activity Recognition API. It shouldn't be very hard to write this calculate function to get the best result.
I'm not sure about this but I really don't think waiting more than a few seconds gives you an advantage. to be sure you can simply alter this time and watch the result.
You might want to use LocationManager. In my experience FusedLocation will indeed appear to lock faster but may not be as accurate overall, or at least for a while. I have an app that also requires pretty accurate coordinates. My default is to use a LocationManager based approach but users can switch to a FusedLocation provider if they want faster locking (like when indoors).
This is a good overview https://developer.android.com/guide/topics/location/strategies
For the provider when requesting updates I'd use LocationManager.GPS_PROVIDER. It will take longer to lock since it will wait for satellites and not use Wifi or other towers. But you said that's OK. Something along these lines
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, YourLocationListener);
Once you start getting location updates via your listener's onLocationChanged() you can start to inspect the location for accuracy, movement from last location change, etc. to try and evaluate if the GPS receiver is still settling in on a location. Once you are satisfied with the quality of the fix you can stop receiving location updates (locationManager.removeUpdates(YourLocationListener)) and then run your logic that needs the location. The link I provided has good info about this too.
I just need to understand this clearly, getLastLocation() method will give me the last known location and requestLocationUpdates will give me the current location every period of time.
now, i am developing a simple app to track mobile phones, which will be in cars.
my Question are :
1- how exactly getLastLocation() works, will this last known location be updated when the location change
2- which is better, using getLastLocation() to have the initial location then update the current location by using the method onLocationChanged or using requestLocationUpdates to have an up to date location every n sec ?
getLastLocation gives you the last location which was there in LocationClient, it can be null sometimes, say if you don't have any other application installed which uses location services, that's a rare case as most phones have Google maps or some other location dependent apps installed.
getLastLocation is only helpful, when you want location for once and your done with it, but for location updates you should use requestLocationUpdates, and using a service, your application will always get notified, when the location changes.
I hope you are using the FusedLocation Provider from play services, so you can specify how fast location updates you need, to check cases of battery drain and performance.
Also to note here when you use requestLocationUpdates then only you will get any location change updates.
so according to android docs getLastLocation() :-
Returns the best most recent location currently available. If a
location is not available, which should happen very rarely, null will
be returned. The best accuracy available while respecting the location
permissions will be returned. This method provides a simplified way to
get location. It is particularly well suited for applications that do
not require an accurate location and that do not want to maintain
extra logic for location updates.
This is the problem with getLastLocation(),that it is not accurate and it may return null if it does not have any last known location in cache.I have faced this issue many times in my application.So for getting the accurate location you should use requestLocationUpdates() but define the interval according to your need at which time interval you want the updates as a very short time span may cause more power usage.
I've been working on an app that needs to be location-aware, and I've noticed that there are two (or more) methods of receiving location: with Google Play services (as seen here developer.android.com/training/location/retrieve-current.html#GetLocation) and with Location Manager, Providers etc. (as seen here http://www.vogella.com/tutorials/AndroidLocationAPI/article.html#locationapi_criteria).
What is the difference between these methods (if there is any)? Which one is more accurate?
edit: ok, I see that I sent the wrong link on the first thing. Won't this code (http://developer.android.com/training/location/receive-location-updates.html) give me location updates? Generally, what's the most accurate way to get my location?
The one with the GPS is accurate and that which is based on Network is not. Google Play Service use FUSE api to get the GPS location first, if the location is found (that's great), otherwise it will try to get location fix from Network Tower. In Short the one with GPS is accurate
The first method provides the details of LastKnownLocation. ie. the last location received from GPS or network provider when you or other apps accessed the location services. After that there are chances you moved a lot and it need not be your current location. So if You are planning to create an application that requires accurate location tracing, You should fetch the location as in the "Vogella" method. If the current location is unavailable, you can try using the last known location (As a plan B :-)).
I am developing an android application wherein I need the user location updates pretty frequently. Say 2 times a minute.
Earlier I had been using Google Play Service's "Fused location service" but the location updates were not received as requested.
The location updates got stuck for sometime, the interval between updates jumped to 10min or so.Sometimes even if I put my priority to "PRIORITY_HIGH_ACCURACY" the same happened.
I then went back to the old "Location Manager" and when I used the "NETWORK_PROVIDER", I noticed that the location updates got stuck due to this provider. Also the GPS does not get activated immediately, it takes some time. I am trying to build my custom fused location provider. How can I efficiently switch between providers, without getting lags on location updates.
I want to know what are the best practices for getting location updates regularly, all the time, be it either NW, GPS or both. Like it should work for an application where location updates getting stuck cannot be afforded.
Battery drain is not an issue for me right now.I am aware of all the supporting docs that Google provides regarding location access.
Any help would be much appreciated.
Thankyou !
FusedLocationProvider really is the best option for obtaining locations at the moment, because it uses a lot more than just GPS or Network data to obtain location fixes. I have experienced issues regarding intervals being missed as well, but ultimately this is something down to luck depending on availability of GPS, Network, etc. etc.
My favourite usage of FusedLocationProvider so far is in conjunction with the AlarmManager class: Basically, the idea is to start location tracking at intervals specified by the Alarm Manager (this can be set to every 30 seconds such as in your case). Once the interval is hit, the location provider is to obtain a location fix as soon as possible (so in the setInterval method or whatever it's called, the parameter is a 0). This way, you can avoid having to wait another 30 seconds for a new location, instead having the location tracker attempt to provide a location as soon as possible after the interval specified by the Alarm Manager is hit.
By the way, when making custom location tracking wrappers, be careful of using the .getLastKnownLocation() method as it only uses cached locations - you could end up sending the same location to the user every 30 seconds.
Good luck!