Android - Showing Alert Dialog leads to BadTokenException in Service class

Question

I am reading GPS info and sending it to the network every 10 seconds.

What I am doing is using an handler which runs my service class GPSTracker

public void startGpsService() {
        handler = new Handler();
        task = new Runnable() {
            @Override
            public void run() {
                gps = new GPSTracker(getApplicationContext());

                if (gps.canGetLocation()) {
                    ... do something
                } else {
                    // GPS or Network is not enabled
                    gps.showSettingsAlert();
                }

                handler.postDelayed(task, 10000);
            }
        };
        task.run();
    }

if my GPS setting are not enabled gps.showSettingsAlert(); is executed

import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;

public class GPSTracker extends Service implements LocationListener {

    private final Context mContext;

    // flag for GPS status
    boolean isGPSEnabled = false;

    // flag for network status
    boolean isNetworkEnabled = false;

    // flag for GPS status
    boolean canGetLocation = false;

    Location location; // location
    double latitude; 
    double longitude; 
    double speed; 
    public double altitude; 


    // The minimum distance to change Updates in meters
    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters

    // The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute

    // Declaring a Location Manager
    protected LocationManager locationManager;

    public GPSTracker(Context context) {
        this.mContext = context;
        getLocation();
    }

    public Location getLocation() {
        try {
            locationManager = (LocationManager) mContext
                    .getSystemService(LOCATION_SERVICE);

            // getting GPS status
            isGPSEnabled = locationManager
                    .isProviderEnabled(LocationManager.GPS_PROVIDER);

            // getting network status
            isNetworkEnabled = locationManager
                    .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if (!isGPSEnabled && !isNetworkEnabled) {
                // no network provider is enabled
            } else {
                this.canGetLocation = true;
                if (isNetworkEnabled) {
                    locationManager.requestLocationUpdates(
                            LocationManager.NETWORK_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("Network", "Network");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();

                        }
                    }
                }
                // if GPS Enabled get lat/long using GPS Services
                if (isGPSEnabled) {
                    if (location == null) {
                        locationManager.requestLocationUpdates(
                                LocationManager.GPS_PROVIDER,
                                MIN_TIME_BW_UPDATES,
                                MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                        Log.d("GPS Enabled", "GPS Enabled");
                        if (locationManager != null) {
                            location = locationManager
                                    .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                            if (location != null) {
                                latitude = location.getLatitude();
                                longitude = location.getLongitude();
                            }
                        }
                    }
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return location;
    }

    /**
     * Stop using GPS listener
     * Calling this function will stop using GPS in your app
     * */
    public void stopUsingGPS(){
        if(locationManager != null){
            locationManager.removeUpdates(GPSTracker.this);
        }       
    }

    /**
     * Function to get latitude
     * */
    public double getLatitude(){
        if(location != null){
            latitude = location.getLatitude();
        }

        // return latitude
        return latitude;
    }

    /**
     * Function to get altitude
     * */
    public double getAltitude(){
        if(location != null){
            altitude = location.getAltitude();
        }

        // return latitude
        return altitude;
    }

    /**
     * Function to get longitude
     * */
    public double getLongitude(){
        if(location != null){
            longitude = location.getLongitude();
        }

        // return longitude
        return longitude;
    }

    /**
     * Function to get velocity
     * */
    public double getVelocity(){
        if(location != null){
            speed = location.getSpeed();
        }

        // return longitude
        return speed;
    }

    /**
     * Function to check GPS/wifi enabled
     * @return boolean
     * */
    public boolean canGetLocation() {
        return this.canGetLocation;
    }

    /**
     * Function to show settings alert dialog
     * On pressing Settings button will lauch Settings Options
     * */
    public void showSettingsAlert(){
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

        // Setting Dialog Title
        alertDialog.setTitle("GPS is settings");

        // Setting Dialog Message
        alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

        // On pressing Settings button
        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                mContext.startActivity(intent);
            }
        });

        // on pressing cancel button
        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
            }
        });

        // Showing Alert Message
        alertDialog.show();
    }

    @Override
    public void onLocationChanged(Location location) {
    }

    @Override
    public void onProviderDisabled(String provider) {
    }

    @Override
    public void onProviderEnabled(String provider) {
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
    }

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

}

My problem is that alertDialog.show(); raises this exception:

08-21 09:49:23.906: E/AndroidRuntime(4088): java.lang.RuntimeException: Unable to start activity ComponentInfo{...}: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application

How to solve it? Similar solutions found on here and here dont fix my problem as in that case it happens inside activity classes.

post the whole `GPSTracker` class – Rod_Algonquin Aug 21 '14 at 08:18 — Rod_Algonquin, Aug 21 '14 at 08:18
just added the full code for GPSTracker – eeadev Aug 21 '14 at 08:23 — eeadev, Aug 21 '14 at 08:23

score 1 · Answer 1 · edited May 23 '17 at 11:55

1

you cant really create a dialog in the service but you can use the system alert dialog from this post bottom answer.

He said that you need add the type of dialog

dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);

and also you need permission for it to enable you to use it in your manifest

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>

Now this is only if you really need a dialog, but I wont really recommend dialog within the service.

You can use toast instead.

edited May 23 '17 at 11:55

Community

1
1

answered Aug 21 '14 at 08:15

Rod_Algonquin

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I do need a dialog because I need to show the possibility of changing settings or not ... – eeadev Aug 21 '14 at 08:34

score 1 · Accepted Answer · edited Aug 21 '14 at 12:13

Dialog can not be shown without activity. Your code shows dialog with applicationContext, so it will cause error.

try this below:

 /**
 * Function to show settings alert dialog
 * On pressing Settings button will lauch Settings Options
 * */
public void showSettingsAlert(Activity activity){
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(activity);

        // Setting Dialog Title
        alertDialog.setTitle("GPS is settings");

        // Setting Dialog Message
        alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

        // On pressing Settings button
        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                activity.startActivity(intent);
            }
        });

        // on pressing cancel button
        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
            }
        });

        // Showing Alert Message
        alertDialog.show();
    }

Android - Showing Alert Dialog leads to BadTokenException in Service class

2 Answers2