Cuurent location marker appears multiple times on map . what I have to do?

Question

Below in my code I have to print my current location with movement updates and also I have to print another two locations along with my current location. But my current location marker is getting appeared repeatedly on the map. Please help me. My code -

package com.example.swap.gps;

import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.location.Location;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.support.v4.content.ContextCompat;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.CircleOptions;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
        LocationListener,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener{

private GoogleMap mMap;
GoogleApiClient mGoogleApiClient;

LocationRequest mLocationRequest;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    //show error dialog if GoolglePlayServices not available
    if (!isGooglePlayServicesAvailable()) {
        finish();
    }

    setContentView(R.layout.activity_maps);

    if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        checkLocationPermission();
    }
    // Obtain the SupportMapFragment and get notified when the map is ready to be used.
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
}


public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;

public boolean checkLocationPermission(){
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {

        // Asking user if explanation is needed
        if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                Manifest.permission.ACCESS_FINE_LOCATION)) {

            // Show an explanation to the user *asynchronously* -- don't block
            // this thread waiting for the user's response! After the user
            // sees the explanation, try again to request the permission.

            //Prompt the user once explanation has been shown
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                    MY_PERMISSIONS_REQUEST_LOCATION);


        } else {
            // No explanation needed, we can request the permission.
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                    MY_PERMISSIONS_REQUEST_LOCATION);
        }
        return false;
    } else {
        return true;
    }
}


/**
 * Manipulates the map once available.
 * This callback is triggered when the map is ready to be used.
 * This is where we can add markers or lines, add listeners or move the camera. In this case,
 * we just add a marker near Sydney, Australia.
 * If Google Play services is not installed on the device, the user will be prompted to install
 * it inside the SupportMapFragment. This method will only be triggered once the user has
 * installed Google Play services and returned to the app.
 */
@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);

    //Initialize Google Play Services
    if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            buildGoogleApiClient();
            mMap.setMyLocationEnabled(true);
        }
    }
    else {
        buildGoogleApiClient();
        mMap.setMyLocationEnabled(true);
    }

    LatLng SahidKhudiram = new LatLng(22.466 , 88.3918);
    showMap(SahidKhudiram,"SahidKhudiram Metro");

    LatLng kaviNazrul = new LatLng(22.4641823 , 88.38060670000004);
    showMap(kaviNazrul,"kaviNazrul Metro");
}

protected synchronized void buildGoogleApiClient() {
    mGoogleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();
    mGoogleApiClient.connect();
}

private void showMap(LatLng latLng, String place){
    CameraPosition cameraPosition = new CameraPosition.Builder().target(
            latLng).zoom(14).tilt(60).bearing(30).build();
    /*if(marker!=null){
        marker.remove();
    }*/
    Marker marker = mMap.addMarker(new MarkerOptions().position(latLng).title(place));
    marker.showInfoWindow();
    mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
    mMap.addCircle(new CircleOptions().center(latLng).
            radius(90).
            strokeWidth(3).
            strokeColor(Color.RED).
            fillColor(Color.TRANSPARENT));

}

@Override
public void onLocationChanged(Location location) {

    Toast.makeText(this,"new location found",Toast.LENGTH_SHORT).show();


 //   mLastLocation = location;

    //Place current location marker
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());

    showMap(latLng,"Me");


}

private boolean isGooglePlayServicesAvailable() {
    int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
    if (ConnectionResult.SUCCESS == status) {
        return true;
    } else {
        GooglePlayServicesUtil.getErrorDialog(status, this, 0).show();
        return false;
    }
}

@Override
public void onConnected(Bundle bundle) {

    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(1000);
    mLocationRequest.setFastestInterval(1000);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION)
            == PackageManager.PERMISSION_GRANTED) {
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
    }

}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {

}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_LOCATION: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted. Do the
                // contacts-related task you need to do.
                if (ContextCompat.checkSelfPermission(this,
                        Manifest.permission.ACCESS_FINE_LOCATION)
                        == PackageManager.PERMISSION_GRANTED) {

                    if (mGoogleApiClient == null) {
                        buildGoogleApiClient();
                    }
                    mMap.setMyLocationEnabled(true);
                }

            } else {

                // Permission denied, Disable the functionality that depends on this permission.
                Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show();
            }
            return;
        }

        // other 'case' lines to check for other permissions this app might request.
        // You can add here other case statements according to your requirement.
    }
}

}

score 0 · Answer 1 · edited May 23 '17 at 10:30

You are doing it wrong, you are creating a new marker in onLocationChanged(). You need to create marker only once when you get the location for the first time then it onLocationChaned() you just need to set new position to the marker. Simply do something like this

private Marker yourLocationMarker;

Create two methods

private void addCurrentLocationMarkerMarker(LatLng latLng){
yourLocationMarker = mMap.addMarker(new MarkerOptions().position(latLng).title(place));
yourLocationMarker.showInfoWindow();
mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
mMap.addCircle(new CircleOptions().center(latLng).
        radius(90).
        strokeWidth(3).
        strokeColor(Color.RED).
        fillColor(Color.TRANSPARENT));
}

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

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

        Log.v("isGPSEnabled", "=" + isGPSEnabled);

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

        Log.v("isNetworkEnabled", "=" + isNetworkEnabled);

        if (isGPSEnabled == false && isNetworkEnabled == false) {
            // no network provider is enabled
        } else {
            this.canGetLocation = true;
            if (isNetworkEnabled) {
                location=null;
                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) {
                location=null;
                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;
}

In your onMapReady method

Location location = getLocation();
addCurrentLocationMarkerMarker(new LatLng(location.getLatitude(), location.getLongitude()));

In your onLocationChanged method remove showMap and do this

yourLocationMarker.setPosition(new LatLng(location.getLatitude(), location.getLongitude()));

I hope this helps. See this question

Cuurent location marker appears multiple times on map . what I have to do?

1 Answers1