Develop Reference

Android : Setting default zoom level for an area with com.google.android.gms.maps.GoogleMap

I am working on an Android application in which I would like to show user the nearby area to his location. Unfortunately, when I get map data from GoogleMaps, it shows me the entire world and just a dot on the present location and I need to keep zooming in. I tried to set the zoom factor upto 100, but that didn't change anything. Is there something I am doing wrong. Kindly let me know.
Here is my code :
public class MapsActivitiyFragment extends FragmentActivity implements LocationListener {
static GoogleMap googleMap;
LocationManager locationManager;
String provider;
LatLng myPosition;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_maps_activitiy);
SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.googleMap);
googleMap = fm.getMap();
googleMap.setMyLocationEnabled(true);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, true);
Location location = locationManager.getLastKnownLocation(provider);
if (location != null) {
circleDraw(location.getLatitude(),location.getLongitude());
zoomIn(location.getLatitude(), location.getLatitude());
onLocationChanged(location);
}
}
#Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(provider, 400, 1, this);
}
public void circleDraw(double i, double ii) {
googleMap.addCircle(new CircleOptions().center(new LatLng(i, ii))
.radius(10000).strokeColor(Color.BLACK).strokeWidth(5)
.fillColor(Color.argb(50, 238, 116, 116)));
}
public void zoomIn(double Lat, double Long) {
CameraUpdate center = CameraUpdateFactory.newLatLng(new LatLng(Lat,
Long));
CameraUpdate zoom = CameraUpdateFactory.zoomTo(15);
googleMap.moveCamera(center);
googleMap.animateCamera(zoom);
}
#Override
public void onLocationChanged(Location location) {
googleMap.clear();// clean the map
Toast.makeText(this, "Location Changed", Toast.LENGTH_SHORT).show();
double latitude = location.getLatitude();
double longitude = location.getLongitude();
myPosition = new LatLng(latitude, longitude);
circleDraw(latitude, longitude);
zoomIn(latitude, longitude);
}
#Override
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String arg0) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
// TODO Auto-generated method stub
}
}
Update
Image :

remember that onLocationChanged is invoked when you're position is changed. If you stand still you can have a problem with getting it also you will have a lot of problems with that when you work on emulator.
Your code looks fine. Set zoom in the place were you setup you map. Don't set it in onLocationChanged In your code I would set the zoom in onCreate
// EDIT
LatLng center = new LatLng(location.getLatitude(), location.getLongitude());
CameraPosition.Builder cameraPosition = new CameraPosition.Builder();
cameraPosition.target(center);
cameraPosition.zoom((int)configuration.get("zoom"));
map.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition.build()));

The Google Map keep pointing to my current location when I viewing other parts of the map

This is TrackMap.java
public class TrackMap extends FragmentActivity implements LocationListener {
GoogleMap map;
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_track_map);
boolean lowPowerMoreImportantThanAccurancy = true;
LocationRequest request = LocationRequest.create();
request.setPriority(lowPowerMoreImportantThanAccurancy ?
LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY:
LocationRequest.PRIORITY_HIGH_ACCURACY);
map = ((SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map)).getMap();
map.setMapType(GoogleMap.MAP_TYPE_NORMAL);
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);
// Enabling MyLocation Layer of Google Map
map.setMyLocationEnabled(true);
Marker marker = map.addMarker(new MarkerOptions()
.position(new LatLng(0, 0)).draggable(true)
// Set Opacity specified as a float between 0.0 and 1.0,
// where 0 is fully transparent and 1 is fully opaque.
.alpha(0.7f).flat(true)
.getPosition());
}
#Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
map.clear();
MarkerOptions mp = new MarkerOptions();
mp.position(new LatLng(location.getLatitude(), location.getLongitude()));
mp.title("my position");
map.addMarker(mp);
map.animateCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(location.getLatitude(), location.getLongitude()), 16));
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
}
I wonder why it keep points to my current position while I viewing other parts of the map. Your help is very much appreciated.I doesn't really know what to delete the particular code to suit my needs

because every time onLocationChanged is called you animate camera to the new location passed in.

Not getting location coordinates unless location has changed

Here is what I need to do. I need to launch my application and on the click of a button, I need to display the current coordinates, that is latitude and longitude. I followed this tutorial and used the following code for my purpose:
public class MainActivity extends Activity {
public double latitude;
public double longitude;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener locationListener = new MyLocationListener();
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}
#Override
protected void onStart() {
super.onStart();
final TextView latValueLabel = (TextView)findViewById(R.id.latLabel);
final TextView lonValueLabel = (TextView)findViewById(R.id.lonLabel);
Button setButton = (Button)findViewById(R.id.set_button);
setButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
latValueLabel.setText(String.valueOf(latitude));
lonValueLabel.setText(String.valueOf(longitude));
}
});
}
private class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
if(location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
(Copy pasted only a part of the code, please ignore any unclosed brackets or anything like that.)
It continuously gets the latitude longitude as location changes and stores it to two double variables latitude and longitude and when the setButton is clicked, it displays the last stored lat-lon value. That would be the user's current location. Now the issue is, I launched the app and while still staying on the exact location from which the app is launched, I clicked the Set Button. But at that time the location is not changed, so the latitude and longitude are displayed as zero, which is the default value of the double variables. I need to take a walk around with the device so that the location is changed before I can get my actual coordinates. How can I get the lat-lon as soon as the app is launched?

You can use getLastKnownLocation(...) to initialise the longitude and latitude values like this:
LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
double longitude = location.getLongitude();
double latitude = location.getLatitude();

This is your total class.
public class MainActivity extends Activity {
public double latitude;
public double longitude;
private TextView latValueLabel,lonValueLabel ;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener locationListener = new MyLocationListener();
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}
#Override
protected void onStart() {
super.onStart();
latValueLabel = (TextView)findViewById(R.id.latLabel);
lonValueLabel = (TextView)findViewById(R.id.lonLabel);
Button setButton = (Button)findViewById(R.id.set_button);
setButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
latValueLabel.setText(String.valueOf(latitude));
lonValueLabel.setText(String.valueOf(longitude));
}
});
}
private class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location location) {
if(location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
latValueLabel.setText(String.valueOf(latitude));
lonValueLabel.setText(String.valueOf(longitude));
}
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
}

Arcgis : how to get device location

Hie i tried to implement this codes in my application but it doesnt work , i dont know where i went wrong.
basically, when i launch the sample of the device location. it doesnt show me where is my current location and i dont see any blue dots that resembles the current location i am at.
the only thing that i see is the map . just a plain zoom out map.
I would be really thankful if someone who could help me out on how to get the current location with the blue dots that is displayed on the map..
this is my MainActivity.class
public class HelloWorld extends Activity {
MapView mMapView = null;
ArcGISTiledMapServiceLayer tileLayer;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Retrieve the map and initial extent from XML layout
mMapView = (MapView) findViewById(R.id.map);
mMapView.addLayer(new ArcGISTiledMapServiceLayer(
"http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"));
mMapView.setOnStatusChangedListener(new OnStatusChangedListener() {
public void onStatusChanged(Object source, STATUS status) {
if (source == mMapView && status == STATUS.INITIALIZED) {
LocationService ls = mMapView.getLocationService();
ls.setAutoPan(false);
ls.start();
}
}
});
}
protected void onPause() {
super.onPause();
mMapView.pause();
}
#Override
protected void onResume() {
super.onResume();
mMapView.unpause();
}
}

this is a code that draws my location every 1 second via provider and GPS .
let's first declare variables :
private GraphicsLayer myGraphicalLayer;
MapView mMapView;
ArcGISLocalTiledLayer baseLayer;
private LocationManager mlocManager;
private LocationListener mlocListener;
in onCreate function WE CALL LocationListener:
mlocManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0, mlocListener);
mlocManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 1000, 0, mlocListener);
// loading the map
mMapView = (MapView) findViewById(R.id.localMap);
baseLayer = new ArcGISLocalTiledLayer(basemapurl);
mMapView.addLayer(baseLayer);
// defining my position layer
myGraphicalLayer = new GraphicsLayer();
then a function to draw my location :
private void SetMyLocationPoint(final double x, final double y) {
PictureMarkerSymbol myPin = new PictureMarkerSymbol(getResources().getDrawable(
R.drawable.mylocation_icon));
Point wgspoint = new Point(x, y);
Point mapPoint = (Point) GeometryEngine.project(wgspoint, SpatialReference.create(4326),
mMapView.getSpatialReference());
Graphic myPinGraphic = new Graphic(mapPoint, myPin);
try {
myGraphicalLayer.removeAll();
} catch (Exception e) {
e.printStackTrace();
}
myGraphicalLayer.addGraphic(myPinGraphic);
myGraphicalLayer.setVisible(true);
mMapView.addLayer(myGraphicalLayer);
}
make internal class that implements MyLocationListener to get you instant location, and let it call the function named SetMyLocationPoint like this way :
public class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location loc) {
SetMyLocationPoint(loc.getLongitude(), loc.getLatitude());
}
#Override
public void onProviderDisabled(String provider) {
Toast.makeText(getApplicationContext(), "provider enabled", Toast.LENGTH_SHORT)
.show();
}
#Override
public void onProviderEnabled(String provider) {
Toast.makeText(getApplicationContext(), "provider disabled", Toast.LENGTH_SHORT)
.show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}

You need to use your own location manager or the location client to get the device's current location and then you will have to add that point on the map.
Your map should be in a MapFragment.
Get the googleMap object from the fragment and then add your custom blue dot on it.
LocationManager locationManager = (LocationManager) getApplicationContext()
.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
5000, 5, listener);
}
private LocationListener listener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
Log.e("Google", "Location Changed");
if (location == null)
return;
Log.e("latitude", location.getLatitude() + "");
Log.e("longitude", location.getLongitude() + "");
}
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
};
The above code gets you the location in onLocationChanged method.
Note: i have used GPS_PROVIDER to get the location.
There are other ways to get the current location too.

how to get address information when I click on a location icon

I have a set location code in my app. I want to get address information when I click on a location icon. How to use a click event
public class MyActivity extends MapActivity implements LocationListener
{
MapView mapView;
MapController mc;
private MyLocationOverlay myLocOverlay;
private String provider;
private LocationManager lm;
Drawable location = null;
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.location);
mapView = (MapView) findViewById(R.id.mview);
mc = mapView.getController();
mapView.setBuiltInZoomControls(true);
mc.setZoom(15);
lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
provider = lm.getBestProvider(criteria, false);
Location location = lm.getLastKnownLocation(provider);
if(location != null){
onLocationChanged(location);
}
}
#Override
protected void onResume(){
super.onResume();
lm.requestLocationUpdates(provider, 400, 1, this);
myLocOverlay = new MyLocationOverlay(location.this, mapView);
myLocOverlay.enableMyLocation();
mapView.getOverlays().add(myLocOverlay);
myLocOverlay.runOnFirstFix(new Runnable() {
#Override
public void run() {
mc.animateTo(myLocOverlay.getMyLocation());
}
});
mapView.postInvalidate();
}
#Override
protected void onPause() {
super.onPause();
lm.removeUpdates(this);
myLocOverlay.disableMyLocation();
}
#Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
#Override
public void onLocationChanged(Location location) {
double lat = location.getLatitude();
double lng = location.getLongitude();
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}