I have an Android application that has SupportMapFragment added on xml file.
In fragment I set my location as follows: mMap.setMyLocationEnabled(true); to display my current location
The main issue is that the walking mode is enabled[blue dot] by default, I want free driving mode activated [blue arrow]
How can I achieve free driving mode? To have blue arrow as my position instead of blue dot
There is no Driving Mode for SupportMapFragment and no possibilities to change default My Location Marker, but you can:
1) launch Google Maps application in Driving mode via intent as in this answer of Jason Maderski:
Intent intent = getPackageManager().getLaunchIntentForPackage("com.google.android.apps.maps");
intent.setAction(Intent.ACTION_VIEW);
intent.setData(Uri.parse("google.navigation:/?free=1&mode=d&entry=fnls"));
startActivity(intent);
or
2) change custom current location indicator via custom marker on GoogleMap object like in that answer of antonio.
Because of unpredictability of LocationListener update I think better use NMEA data (RMC sentence) from GPS via GpsStatus.NmeaListener (OnNmeaMessageListener for API >= 24) for updating current location. In that case source code can be something like that:
CustomNmeaListener.java:
public class CustomNmeaListener implements GpsStatus.NmeaListener{
private GoogleMap mGoogleMap;
private Marker mMarkerPosition = null;
private BitmapDescriptor mMarkerMoveDescriptor;
private BitmapDescriptor mMarkerStopDescriptor;
public CustomNmeaListener(GoogleMap googleMap, int markerMoveResource, int markerStopResource){
this.mGoogleMap = googleMap;
mMarkerMoveDescriptor = BitmapDescriptorFactory.fromResource(markerMoveResource);
mMarkerStopDescriptor = BitmapDescriptorFactory.fromResource(markerStopResource);
}
@Override
public void onNmeaReceived(long timestamp, String nmea) {
double latitude;
double longitude;
float speed;
float angle;
// parse NMEA RMC sentence
// Example $GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A
// nmea [0] [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
if (nmea.startsWith("$GPRMC")) {
String[] nmeaParts = nmea.split(",");
// if RMC data valid ("active")
if (nmeaParts[2].equals("A")) {
latitude = parseLatitude(nmeaParts[3], nmeaParts[4]);
longitude = parseLongitude(nmeaParts[5], nmeaParts[6]);
speed = parseSpeed(nmeaParts[7]);
angle = parseAngle(nmeaParts[8]);
// remove marker on "old" position
if (mMarkerPosition != null) {
mMarkerPosition.remove();
}
MarkerOptions positionMarkerOptions;
if (speed > 0) {
positionMarkerOptions = new MarkerOptions()
.position(new LatLng(latitude, longitude))
.icon(mMarkerMoveDescriptor)
.anchor(0.5f, 0.5f)
.rotation(angle);
} else {
positionMarkerOptions = new MarkerOptions()
.position(new LatLng(latitude, longitude))
.icon(mMarkerStopDescriptor)
.anchor(0.5f, 0.5f)
.rotation(0);
}
mMarkerPosition = mGoogleMap.addMarker(positionMarkerOptions);
}
}
}
static float parseLatitude(String lat, String sign) {
float latitude = Float.parseFloat(lat.substring(2)) / 60.0f;
latitude += Float.parseFloat(lat.substring(0, 2));
if(sign.startsWith("S")) {
latitude = -latitude;
}
return latitude;
}
static float parseLongitude(String lon, String sign) {
float longitude = Float.parseFloat(lon.substring(3)) / 60.0f;
longitude += Float.parseFloat(lon.substring(0, 3));
if(sign.startsWith("W")) {
longitude = -longitude;
}
return longitude;
}
static float parseSpeed(String knots) {
float speed;
try {
speed = Float.parseFloat(knots);
} catch (Exception e) {
speed = 0;
}
return speed;
}
static float parseAngle(String ang) {
float angle;
try {
angle = Float.parseFloat(ang);
} catch (Exception e) {
angle = 0;
}
return angle;
}
}
MainActivity.java:
public class MainActivity extends AppCompatActivity implements OnMapReadyCallback, LocationListener {
private static final String TAG = MainActivity.class.getSimpleName();
private static final int LOCATION_PERMISSION_REQUEST_CODE = 101;
private static final int LOCATION_INTERVAL = 1000;
private static final float LOCATION_DISTANCE = 10f;
private GoogleMap mGoogleMap;
private MapFragment mMapFragment;
private LocationManager mLocationManager = null;
private CustomNmeaListener mNmeaListener = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mMapFragment = (MapFragment) getFragmentManager()
.findFragmentById(R.id.map_fragment);
mMapFragment.getMapAsync(this);
}
@Override
public void onMapReady(GoogleMap googleMap) {
mGoogleMap = googleMap;
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
int locationPermission = ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION);
if (locationPermission != PackageManager.PERMISSION_GRANTED) {
makeLocationPermissionRequest();
} else {
setCustomLocationListener();
}
} else {
setCustomLocationListener();
}
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case LOCATION_PERMISSION_REQUEST_CODE: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
setCustomLocationListener();
} else {
}
return;
}
}
}
private void makeLocationPermissionRequest() {
ActivityCompat.requestPermissions(this,
new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, LOCATION_PERMISSION_REQUEST_CODE);
}
private void setCustomLocationListener() {
// disable "standard" location marker
mGoogleMap.setMyLocationEnabled(false);
initializeLocationManager();
mNmeaListener = new CustomNmeaListener(mGoogleMap, R.drawable.ic_marker_move, R.drawable.ic_marker_stop);
mLocationManager.addNmeaListener(mNmeaListener);
try {
mLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
LOCATION_INTERVAL,
LOCATION_DISTANCE,
this
);
} catch (java.lang.SecurityException ex) {
Log.d(TAG, "fail to request location update, ignore", ex);
}
}
private void initializeLocationManager() {
Log.d(TAG, "initializeLocationManager - LOCATION_INTERVAL: "+ LOCATION_INTERVAL + " LOCATION_DISTANCE: " + LOCATION_DISTANCE);
if (mLocationManager == null) {
mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
}
}
}
and R.drawable.ic_marker_move & R.drawable.ic_marker_stop - drawable resources like:
(North orientation is important)
and
respectively.
NB! This is a quick and dirty example without NMEA checksum test, GPS data filtering, saving and restoring marker position on Activity visible/hide, etc.
来源：https://stackoverflow.com/questions/46995113/google-maps-set-to-free-driving-mode