Update Marker

MainActivity.java

package com.myapplication;

import android.location.Location;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;

import com.google.android.gms.location.DetectedActivity;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

import io.nlopez.smartlocation.OnLocationUpdatedListener;
import io.nlopez.smartlocation.SmartLocation;

public class MainActivity extends FragmentActivity {

    private GoogleMap mMap; // Might be null if Google Play services APK is not available.

    Marker mMarker;
    private double lat,lon;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //setup map
        setUpMapIfNeeded();

        SmartLocation.with(this).location()
                .start(new OnLocationUpdatedListener() {
                    @Override
                    public void onLocationUpdated(Location location) {
                        if (location != null){
                            lat = location.getLatitude();
                            lon = location.getLongitude();

                            moveMarker();
                        }
                    }
                });
    }

    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    @Override
    public void onBackPressed(){
        SmartLocation.with(this).location().stop();
        super.onBackPressed();
    }


    /**
     * Sets up the map if it is possible to do so (i.e., the Google Play services APK is correctly
     * installed) and the map has not already been instantiated.. This will ensure that we only ever
     * call {@link #setUpMap()} once when {@link #mMap} is not null.
     * <p/>
     * If it isn't installed {@link SupportMapFragment} (and
     * {@link com.google.android.gms.maps.MapView MapView}) will show a prompt for the user to
     * install/update the Google Play services APK on their device.
     * <p/>
     * A user can return to this FragmentActivity after following the prompt and correctly
     * installing/updating/enabling the Google Play services. Since the FragmentActivity may not
     * have been completely destroyed during this process (it is likely that it would only be
     * stopped or paused), {@link #onCreate(Bundle)} may not be called again so we should call this
     * method in {@link #onResume()} to guarantee that it will be called.
     */
    private void setUpMapIfNeeded() {
        // Do a null check to confirm that we have not already instantiated the map.
        if (mMap == null) {
            // Try to obtain the map from the SupportMapFragment.
            mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                    .getMap();
            // Check if we were successful in obtaining the map.
            if (mMap != null) {
                if (lat != 0.0 && lon != 0.0)
                    addMarker();
            }
        }
    }

    /**
     * This is where we can add markers or lines, add listeners or move the camera. In this case, we
     * just add a marker near Africa.
     * <p/>
     * This should only be called once and when we are sure that {@link #mMap} is not null.
     */
    private void setUpMap() {
        mMap.addMarker(new MarkerOptions().position(new LatLng(lat, lon)).title("Posisi Anda"));
    }

    //add more marker here
    private void addMarker(){
        mMap.clear();
        mMap.addMarker(
                new MarkerOptions()
                        .position(new LatLng(lat, lon))
                        .title("Latitude: " + Double.toString(lat) + " " +
                                "Longitude: " + Double.toString(lon))
                        .draggable(false));
    }

    private void moveMarker(){
        if (mMarker == null){
            mMarker = mMap.addMarker(new MarkerOptions()
                    .position(new LatLng(lat, lon))
                    .title("Latitude: " + Double.toString(lat) + " " +
                            "Longitude: " + Double.toString(lon))
                    .draggable(false));
        }
        else{
            mMarker.setPosition(new LatLng(lat, lon));
            mMarker.setVisible(false);
            mMarker.setVisible(true);
        }
    }
}