##Quick explanation of methods used:

This is an Android Studio project that retrieves a user’s current location and displays it with a marker on a map. It is based on the following blog post

protected void onCreate(Bundle savedInstanceState){
        setContentView(R.layout.activity_maps);
        setUpMapIfNeeded();

        mGoogleApiClient=new GoogleApiClient.Builder(this)
        .addConnectionCallbacks(this)
        .addOnConnectionFailedListener(this)
        .addApi(LocationServices.API)
        .build();

        //Setting a data object that contains quality of service parameters for requests 
        mLocationRequest=LocationRequest.create()
        .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
        .setInterval(10*1000)         // 10 seconds, in milliseconds
        .setFastestInterval(1*1000);
        }

protected void onResume(){
        setUpMapIfNeeded();
        mGoogleApiClient.connect();
        }

protected void onPause(){
        // If connected at onResume, then at onPause stop the location updates and disconnect
        if(mGoogleApiClient.isConnected()){
        LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient,this);
        mGoogleApiClient.disconnect();
        }
        }
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){
        setUpMap();
        }
        }
        }

private void setUpMap(){
//        You can setup markers based on lat and long here as below:
//        mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
        }

public void onConnected(Bundle bundle){
        // Connection callback. After achieving a connected state by calling mGoogleApiClient.connect(), do the following: 
        Location location=LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);

        if(location==null){
        // Requests location updates if location does not have a value, while being connected to mGoogleApiClient,
        // passing in the registered mLocationRequest at onCreate, with this (MainActivity) being the Listener
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,mLocationRequest,this);

        }else{
        // If location does have a value, pass it in the handleNewLocation method and call it
        handleNewLocation(location);
        }
        }

private void handleNewLocation(Location location){
        double currentLatitude=location.getLatitude();
        double currentLongitude=location.getLongitude();
        LatLng latLng=new LatLng(currentLatitude,currentLongitude);

        MarkerOptions options=new MarkerOptions()
        .position(latLng)
        .title("I am here!");
        mMap.addMarker(options);
        //Focus and Zoom in to current lat and long
        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng,12));
        }

//Called when the client is temporarily in a disconnected state
public void onConnectionSuspended(int i){
        }

// Called when there was an error connecting the client to the service
public void onConnectionFailed(ConnectionResult connectionResult){
        if(connectionResult.hasResolution()){
        try{
        // Start an Activity that tries to resolve the error
        connectionResult.startResolutionForResult(this,CONNECTION_FAILURE_RESOLUTION_REQUEST);
        }catch(IntentSender.SendIntentException e){
        e.printStackTrace();
        }
        }else{
        Log.i(TAG,"Location services connection failed with code "+connectionResult.getErrorCode());
        }
        }

public void onLocationChanged(Location location){
        // Call the handleNewLocation again when the location changes
        handleNewLocation(location);
        }