Flutter-geolocator: Doesn't return anything if GPS is turned off

[praveen-gm]

Although there is Geolocator().isLocationServiceEnabled() to know if the device GPS is turned on/off and then request location. Since there is no way to turn on GPS using this plugin there needs to have a workaround to achieve the same.

Geolocator().getCurrentPosition(desiredAccuracy: LocationAccuracy.high) doesn't return null or anything if the GPS is turned off

[DhavalRKansara]

I am also facing the same issues.

[yy1300326388]

geolocator.getCurrentPosition(desiredAccuracy: LocationAccuracy.medium);
/// I set it to medium
LocationAccuracy.medium

[AdnanKazi]

@praveen-gm Not only high every LocationAccuracy does not return anything have anyone found solution for this

[AdnanKazi]

Solution found may be it would be useful for someone

Use this package
location: ^3.0.2

Dart code
``` var location = permission.Location();
bool enabled = await location.serviceEnabled();
print(enabled);
if (!enabled)
// request location
if (await location.requestService()) {
// set location
Geolocator()
.getCurrentPosition(desiredAccuracy: LocationAccuracy.high)
.then((position) async {
print(position);
});
} else{
// your else part
}

[mvanbeusekom]

We have just released version 6.0.0-rc.1 which includes requesting to enable the location services on Android.

We would appreciate it if you could give it a try and provide feedback.

[nateshmbhat]

facing same issue !

[mvanbeusekom]

@nateshmbhat which version of the geolocator plugin are you using? In our latest release candidate we have included the feature to automatically ask the user to enable the location services when calling the getCurrentPosition or getPositionStream methods.

Note that this will only work on Android with Google Play Services (so you should not use forceAndroidLocationManager). For iOS and Android using the LocationManager there are no SDKs available to automatically ask the user to enable the location services. This means you will receive a LocationServicesDisabledException which you can catch and alert the user that he or she should manually enable the location services (you can use the openLocationSettings to open the settings App, see detailed documentation here).

[nateshmbhat]

Its working in 6.0.0-rc.1 but clicking on "no thanks" in the location services dialog is crashing the whole app.

D/AndroidRuntime(18533): Shutting down VM
E/AndroidRuntime(18533): FATAL EXCEPTION: main
E/AndroidRuntime(18533): Process: com.bank.falcon, PID: 18533
E/AndroidRuntime(18533): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=0, data=Intent { (has extras) }} to activity {com.rakbank.falcon/com.nuclei.falcon.MainActivity}: java.lang.NullPointerException: Attempt to invoke interface method 'void io.flutter.plugin.common.MethodChannel$Result.success(java.lang.Object)' on a null object reference
E/AndroidRuntime(18533):    at android.app.ActivityThread.deliverResults(ActivityThread.java:4976)
E/AndroidRuntime(18533):    at android.app.ActivityThread.handleSendResult(ActivityThread.java:5017)
E/AndroidRuntime(18533):    at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:51)
E/AndroidRuntime(18533):    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
E/AndroidRuntime(18533):    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
E/AndroidRuntime(18533):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2123)
E/AndroidRuntime(18533):    at android.os.Handler.dispatchMessage(Handler.java:107)
E/AndroidRuntime(18533):    at android.os.Looper.loop(Looper.java:214)
E/AndroidRuntime(18533):    at android.app.ActivityThread.main(ActivityThread.java:7710)
E/AndroidRuntime(18533):    at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime(18533):    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:516)
E/AndroidRuntime(18533):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)
E/AndroidRuntime(18533): Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'void io.flutter.plugin.common.MethodChannel$Result.success(java.lang.Object)' on a null object reference
E/AndroidRuntime(18533):    at com.nateshmbhat.card_scanner.CardScannerPlugin.onActivityResult(CardScannerPlugin.java:105)
E/AndroidRuntime(18533):    at io.flutter.embedding.engine.FlutterEnginePluginRegistry$FlutterEngineActivityPluginBinding.onActivityResult(FlutterEnginePluginRegistry.java:691)
E/AndroidRuntime(18533):    at io.flutter.embedding.engine.FlutterEnginePluginRegistry.onActivityResult(FlutterEnginePluginRegistry.java:378)
E/AndroidRuntime(18533):    at io.flutter.embedding.android.FlutterActivityAndFragmentDelegate.onActivityResult(FlutterActivityAndFragmentDelegate.java:619)
E/AndroidRuntime(18533):    at io.flutter.embedding.android.FlutterFragment.onActivityResult(FlutterFragment.java:704)
E/AndroidRuntime(18533):    at io.flutter.embedding.android.FlutterFragmentActivity.onActivityResult(FlutterFragmentActivity.java:508)
E/AndroidRuntime(18533):    at android.app.Activity.dispatchActivityResult(Activity.java:8140)
E/AndroidRuntime(18533):    at android.app.ActivityThread.deliverResults(ActivityThread.java:4969)
E/AndroidRuntime(18533):    ... 11 more

[praveen-gm]

The issue has been fixed in the version https://pub.dev/packages/geolocator/versions/6.0.0-rc.3 and works as expected.
as @mvanbeusekom discussed above, It now asks for the user to enable location services when getCurrentPosition() is called and when the user denies enabling location it returns a PlatformException

[nateshmbhat]

@praveen-gm it is still crashing the app even in 6.0.0-rc.3 when user clicks on "no thanks"

[mvanbeusekom]

@praveen-gm thank you very much for testing and giving feedback, it is much appreciated.

@nateshmbhat I will have a look into what maybe causing this issue, thank you very much for the feedback.

[nateshmbhat]

I used 6.0.0-rc.3 itself. Same crash was there when i used rc.1 too.

[praveen-gm]

Its working in 6.0.0-rc but clicking on "no thanks" in the location services dialog is crashing the whole app.

D/AndroidRuntime(18533): Shutting down VM
E/AndroidRuntime(18533): FATAL EXCEPTION: main
E/AndroidRuntime(18533): Process: com.bank.falcon, PID: 18533
E/AndroidRuntime(18533): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=0, data=Intent { (has extras) }} to activity {com.rakbank.falcon/com.nuclei.falcon.MainActivity}: java.lang.NullPointerException: Attempt to invoke interface method 'void io.flutter.plugin.common.MethodChannel$Result.success(java.lang.Object)' on a null object reference
E/AndroidRuntime(18533):  at android.app.ActivityThread.deliverResults(ActivityThread.java:4976)
E/AndroidRuntime(18533):  at android.app.ActivityThread.handleSendResult(ActivityThread.java:5017)
E/AndroidRuntime(18533):  at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:51)
E/AndroidRuntime(18533):  at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
E/AndroidRuntime(18533):  at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
E/AndroidRuntime(18533):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2123)
E/AndroidRuntime(18533):  at android.os.Handler.dispatchMessage(Handler.java:107)
E/AndroidRuntime(18533):  at android.os.Looper.loop(Looper.java:214)
E/AndroidRuntime(18533):  at android.app.ActivityThread.main(ActivityThread.java:7710)
E/AndroidRuntime(18533):  at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime(18533):  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:516)
E/AndroidRuntime(18533):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)
E/AndroidRuntime(18533): Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'void io.flutter.plugin.common.MethodChannel$Result.success(java.lang.Object)' on a null object reference
E/AndroidRuntime(18533):  at com.nateshmbhat.card_scanner.CardScannerPlugin.onActivityResult(CardScannerPlugin.java:105)
E/AndroidRuntime(18533):  at io.flutter.embedding.engine.FlutterEnginePluginRegistry$FlutterEngineActivityPluginBinding.onActivityResult(FlutterEnginePluginRegistry.java:691)
E/AndroidRuntime(18533):  at io.flutter.embedding.engine.FlutterEnginePluginRegistry.onActivityResult(FlutterEnginePluginRegistry.java:378)
E/AndroidRuntime(18533):  at io.flutter.embedding.android.FlutterActivityAndFragmentDelegate.onActivityResult(FlutterActivityAndFragmentDelegate.java:619)
E/AndroidRuntime(18533):  at io.flutter.embedding.android.FlutterFragment.onActivityResult(FlutterFragment.java:704)
E/AndroidRuntime(18533):  at io.flutter.embedding.android.FlutterFragmentActivity.onActivityResult(FlutterFragmentActivity.java:508)
E/AndroidRuntime(18533):  at android.app.Activity.dispatchActivityResult(Activity.java:8140)
E/AndroidRuntime(18533):  at android.app.ActivityThread.deliverResults(ActivityThread.java:4969)
E/AndroidRuntime(18533):  ... 11 more

you need to use try/catch around the getCurrentPosition, catch for LocationServiceDisabledException, and handle when the user taps No Thanks

[nateshmbhat]

The following code crashes the application when user clicks on "No Thanks"

try {
            var location = await getCurrentPosition(desiredAccuracy: LocationAccuracy.low);
            onLocationDetected(location);
          } catch (e) {
            getLogger().w('User denied location service !');
          }

[nateshmbhat]

its not supposed to crash. it's supposed to raise an exception !

Running flutter doctor...
Doctor summary (to see all details, run flutter doctor -v):
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      Or install Xcode via the App Store.
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[✓] Chrome - develop for the web
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[✓] VS Code (version 1.48.0)
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[mvanbeusekom]

@nateshmbhat the problem is not with the geolocator but in the "card_scanner" plugin, as you can see in this stack trace:

E/AndroidRuntime(18533): Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'void io.flutter.plugin.common.MethodChannel$Result.success(java.lang.Object)' on a null object reference
E/AndroidRuntime(18533):    at com.nateshmbhat.card_scanner.CardScannerPlugin.onActivityResult(CardScannerPlugin.java:105)
E/AndroidRuntime(18533):    at io.flutter.embedding.engine.FlutterEnginePluginRegistry$FlutterEngineActivityPluginBinding.onActivityResult(FlutterEnginePluginRegistry.java:691)
E/AndroidRuntime(18533):    at io.flutter.embedding.engine.FlutterEnginePluginRegistry.onActivityResult(FlutterEnginePluginRegistry.java:378)
E/AndroidRuntime(18533):    at io.flutter.embedding.android.FlutterActivityAndFragmentDelegate.onActivityResult(FlutterActivityAndFragmentDelegate.java:619)
E/AndroidRuntime(18533):    at io.flutter.embedding.android.FlutterFragment.onActivityResult(FlutterFragment.java:704)
E/AndroidRuntime(18533):    at io.flutter.embedding.android.FlutterFragmentActivity.onActivityResult(FlutterFragmentActivity.java:508)
E/AndroidRuntime(18533):    at android.app.Activity.dispatchActivityResult(Activity.java:8140)
E/AndroidRuntime(18533):    at android.app.ActivityThread.deliverResults(ActivityThread.java:4969)

The card_scanner plugin also implements the ActivityResultListener interface (which is perfectly fine) and thus also receives the result when the user selects the "no thanks" option. Unfortunately the card_scanner onActivityResult method doesn't correctly test the requestCode and tries to access the FlutterResult object which at that time is null and causes the crash. You can see it in the following code snippet of the card_scanner (here is a link to the code on GitHub):

    @Override
    public boolean onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == SCAN_REQUEST_CODE && resultCode == Activity.RESULT_OK) {
            if (data != null && data.hasExtra(CardScannerCameraActivity.SCAN_RESULT)) {
                CardDetails cardDetails = data.getParcelableExtra(CardScannerCameraActivity.SCAN_RESULT);
                pendingResult.success(cardDetails.toMap());
            } else {
                pendingResult.success(null);
            }

            pendingResult = null;
            return true;
        } else if (resultCode == Activity.RESULT_CANCELED) {
            pendingResult.success(null); // This line is causing the crash
            pendingResult = null;
        }
        return false;
    }

[nateshmbhat]

Hey @mvanbeusekom thanks for the tip !
that was really helpful bro :D

[mvanbeusekom]

Glad I could help! I will close this issue when the final version of 6.0.0 is released (I am aiming to do so this Friday)