Show My Location on Button click in Android App

Question

I have created a Floating Button on Maps. I would like to show the current location on Maps on Clicking that Button.

Answer 1

These looks on the end user as a process. But receiving the location and showing it on the map are 2 processes actually. I built a class because I needed it on my use case. But I can show you how to integrate with your case.

class LocationTracker(
    val activity: FragmentActivity,
    val locationTrackerListener: LocationTrackerListener
) {

    private var fusedLocationClient: FusedLocationProviderClient =
        LocationServices.getFusedLocationProviderClient(activity)

    private var locationCallback: LocationCallback? = null
    private var locationRequest: LocationRequest? = null

    fun startLocationRequestProcess() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ContextCompat.checkSelfPermission(
                    activity.applicationContext, Manifest.permission.ACCESS_COARSE_LOCATION
                )
                != PackageManager.PERMISSION_GRANTED
                && ContextCompat.checkSelfPermission(
                    activity.applicationContext, Manifest.permission.ACCESS_FINE_LOCATION
                )
                != PackageManager.PERMISSION_GRANTED
            ) {
                activity.requestPermissions(
                    arrayOf(
                        Manifest.permission.ACCESS_COARSE_LOCATION,
                        Manifest.permission.ACCESS_FINE_LOCATION
                    ), REQUEST_LOCATION_PERMISSION
                )
            } else {
                getUserLocation()
            }
        } else {
            getUserLocation()
        }
    }

    fun getUserLocation() {
        locationRequest = LocationRequest.create()?.apply {
            interval = 10000
            fastestInterval = 5000
            priority = LocationRequest.PRIORITY_HIGH_ACCURACY
        //please check the docs for other constants. this is the minimum used
        }

        val builder = LocationSettingsRequest.Builder()
            .addLocationRequest(locationRequest!!)

        val client: SettingsClient = LocationServices.getSettingsClient(activity)
        val task: Task<LocationSettingsResponse> = client.checkLocationSettings(builder.build())

        task.addOnSuccessListener {
            updateLocation()
        }

        task.addOnFailureListener { exception ->
            if (exception is ResolvableApiException) {
                try {
                    exception.startResolutionForResult(
                        activity,
                        REQUEST_CHECK_LOCATION_SETTINGS
                    )
                } catch (sendEx: IntentSender.SendIntentException) {
                    sendEx.printStackTrace()
                }
            }
        }
    }

    fun updateLocation() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ContextCompat.checkSelfPermission(
                    activity.applicationContext, Manifest.permission.ACCESS_COARSE_LOCATION
                )
                != PackageManager.PERMISSION_GRANTED
                && ContextCompat.checkSelfPermission(
                    activity.applicationContext, Manifest.permission.ACCESS_FINE_LOCATION
                )
                != PackageManager.PERMISSION_GRANTED
            ) {
                activity.requestPermissions(
                    arrayOf(
                        Manifest.permission.ACCESS_COARSE_LOCATION,
                        Manifest.permission.ACCESS_FINE_LOCATION
                    ), REQUEST_LOCATION_PERMISSION
                )
            } else {
                requestLocationUpdates()
            }
        } else {
            requestLocationUpdates()
        }
    }

    private fun requestLocationUpdates() {
        try {
            locationCallback = object : LocationCallback() {
                override fun onLocationResult(locationResult: LocationResult?) {
                    if (locationResult == null) {
                        locationTrackerListener.onLocationError()
                    } else {
                        //you've got the response
                        locationTrackerListener.onLocationResult(locationResult)
                    }
                }
            }
            fusedLocationClient.requestLocationUpdates(locationRequest, locationCallback, null)
        } catch (securityException: SecurityException) {
            securityException.printStackTrace()
        }
    }

    fun removeLocationRequest() {
        fusedLocationClient.removeLocationUpdates(locationCallback)
    }
}

Class is set up: So onClick of your button:

fab.setOnClickListener{
   //hope you have instatiated it
   locationTracker.startLocationRequestProcess()
}

And later in the class you need the lat and long:

override fun onLocationResult(locationResult: LocationResult) {
        for (location in locationResult.locations) {
            addMarkerToMapAndPerhapsZoom(location.latitude, location.longitude)
        }
    }

The interface I am using:

interface LocationTrackerListener {
    fun onLocationError()
    fun onLocationResult(locationResult: LocationResult)
}

Excuse duplicate code for permissions but the IDE shows errors when refactoring that and I really hate it. You can also consider to get the last known location but the problem with that is that it gives null when the user is first time visitor to the app.

Answer 2

first create MyLocation class like this :

import java.util.Timer;
import java.util.TimerTask;

import android.annotation.SuppressLint;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;

public class MyLocation {
    Timer timer1;
    LocationManager lm;
    LocationResult locationResult;
    boolean gps_enabled = false;
    boolean network_enabled = false;

    @SuppressLint("MissingPermission")
    public boolean getLocation(Context context, LocationResult result) {
        //I use LocationResult callback class to pass location value from MyLocation to user code.
        locationResult = result;
        if (lm == null)
            lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

        //exceptions will be thrown if provider is not permitted.
        try {
            gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
        } catch (Exception ex) {
        }
        try {
            network_enabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
        } catch (Exception ex) {
        }

        //don't start listeners if no provider is enabled
        if (!gps_enabled && !network_enabled)
            return false;

        if (gps_enabled)
            lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
        if (network_enabled)
            lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
        timer1 = new Timer();
        timer1.schedule(new GetLastLocation(), 20000);
        return true;
    }

    LocationListener locationListenerGps = new LocationListener() {
        public void onLocationChanged(Location location) {
            timer1.cancel();
            locationResult.gotLocation(location);
            lm.removeUpdates(this);
            lm.removeUpdates(locationListenerNetwork);
        }

        public void onProviderDisabled(String provider) {
        }

        public void onProviderEnabled(String provider) {
        }

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

    LocationListener locationListenerNetwork = new LocationListener() {
        public void onLocationChanged(Location location) {
            timer1.cancel();
            locationResult.gotLocation(location);
            lm.removeUpdates(this);
            lm.removeUpdates(locationListenerGps);
        }

        public void onProviderDisabled(String provider) {
        }

        public void onProviderEnabled(String provider) {
        }

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

    class GetLastLocation extends TimerTask {
        @SuppressLint("MissingPermission")
        @Override
        public void run() {
            lm.removeUpdates(locationListenerGps);
            lm.removeUpdates(locationListenerNetwork);

            Location net_loc = null, gps_loc = null;
            if (gps_enabled)
                gps_loc = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
            if (network_enabled)
                net_loc = lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

            //if there are both values use the latest one
            if (gps_loc != null && net_loc != null) {
                if (gps_loc.getTime() > net_loc.getTime())
                    locationResult.gotLocation(gps_loc);
                else
                    locationResult.gotLocation(net_loc);
                return;
            }

            if (gps_loc != null) {
                locationResult.gotLocation(gps_loc);
                return;
            }
            if (net_loc != null) {
                locationResult.gotLocation(net_loc);
                return;
            }
            locationResult.gotLocation(null);
        }
    }

    public static abstract class LocationResult {
        public abstract void gotLocation(Location location);
    }
}

then use it in your googleMap class :

floatingButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
                        && context.checkSelfPermission(
                        Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    context.requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
                } else {
                    MyLocation.LocationResult locationResult = new MyLocation.LocationResult() {
        @Override
        public void gotLocation(Location location) {
            if (location != null) {

        LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
         CameraUpdate update = CameraUpdateFactory.newLatLngZoom(latLng, 14);
         mGoogleMap.animateCamera(update);


            }
        }
    };
    MyLocation myLocation = new MyLocation();
    myLocation.getLocation(this, locationResult);
                }
            }
        });

and do not forget to add permission ACCESS_FINE_LOCATION in your AndroidManifest :

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