Question

I have this MapActivity class below showing a map and putting a pin of the user’s current location.
In the other hand I have an Object class VideoLocation which has latitude and longitude of some places which are extracted from a JSON file from the server. I also wanna have the locations are drawn with pins on the map.

How am I able to do that? What do I need to add on my Class below?

FYI this is how I call the object’s latitude and longitude on my ListActivity:

VideoLocation vidLocation = videoLocations[position];

double lat2 = vidLocation.latitude;
double lng2 = vidLocation.longitude; 

This the class:

public class MyMapActivity extends MapActivity implements OnClickListener {
        public static final String TAG = "GoogleMapsActivity";
        private MapView mapView;
        private LocationManager locationManager;
        Geocoder geocoder;
        Location location;
        LocationListener locationListener;
        CountDownTimer locationtimer;
        MapController mapController;
        MapOverlay mapOverlay = new MapOverlay();

        private VideoLocation[] videoLocations = null;

        @Override
        protected void onCreate(Bundle icicle) {
            super.onCreate(icicle);
            setContentView(R.layout.my_map_activity);
            initComponents();

            JsonDB dbhelper = new JsonDB(MyMapActivity.this);
            SQLiteDatabase db = dbhelper.getWritableDatabase();

            db.beginTransaction();
            videoLocations = dbhelper.getVideoLocations(db);
            db.setTransactionSuccessful();//end transaction
            db.endTransaction();
            db.close();

            final ImageButton refresh = (ImageButton) findViewById(R.id.btn_nav_impressum);
            refresh.setOnClickListener(this);

            final ImageButton search =(ImageButton) findViewById(R.id.btn_nav_locater);
            search.setOnClickListener(this);



            locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
            if (locationManager == null) {
                Toast.makeText(MyMapActivity.this,
                        "Location Manager Not Available", Toast.LENGTH_SHORT)
                        .show();
                return;
            }
            location = locationManager
                    .getLastKnownLocation(LocationManager.GPS_PROVIDER);
            if (location == null)
                location = locationManager
                        .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
            if (location != null) {

                animateMap(location);
                List<Overlay> listOfOverlays = mapView.getOverlays();
                listOfOverlays.clear();
                listOfOverlays.add(mapOverlay);
            }
            locationListener = new LocationListener() {
                @Override
                public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
                }

                @Override
                public void onProviderEnabled(String arg0) {
                }

                @Override
                public void onProviderDisabled(String arg0) {
                }

                @Override
                public void onLocationChanged(Location l) {
                    location = l;
                    locationManager.removeUpdates(this);
                    if (l.getLatitude() == 0 || l.getLongitude() == 0) {
                    } else {
                        double lat = l.getLatitude();
                        double lng = l.getLongitude();
                        showAddress(lat,lng);
                    }
                }
            };
            if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER))
                locationManager.requestLocationUpdates(
                        LocationManager.GPS_PROVIDER, 1000, 10f, locationListener);
            locationManager.requestLocationUpdates(
                    LocationManager.NETWORK_PROVIDER, 1000, 10f, locationListener);
            locationtimer = new CountDownTimer(30000, 5000) {
                @Override
                public void onTick(long millisUntilFinished) {
                    if (location != null)
                        locationtimer.cancel();
                }

                @Override
                public void onFinish() {
                    if (location == null) {
                    }
                }
            };
            locationtimer.start();
        }

        public void animateMap(Location location){
        double lat = location.getLatitude();
            double lng = location.getLongitude();

            GeoPoint point = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
            GeoPoint point2 = new GeoPoint((int) (lat2 * 1E6), (int) (lng2 * 1E6));
            mapController.animateTo(point, new Message());
            mapOverlay.setPointToDraw(point);

        }


        public MapView getMapView() {
            return this.mapView;
        }

        private void initComponents() {
            mapView = (MapView) findViewById(R.id.mapView);
            mapView.setBuiltInZoomControls(true);
            mapController = mapView.getController();
            mapController.setZoom(16);
        }

        @Override
        protected boolean isRouteDisplayed() {
            return false;
        }

        class MapOverlay extends Overlay {
            private GeoPoint pointToDraw;

            public void setPointToDraw(GeoPoint point) {
                pointToDraw = point;
            }

            public GeoPoint getPointToDraw() {
                return pointToDraw;
            }

            @Override
            public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
                    long when) {
                super.draw(canvas, mapView, shadow);

                Point screenPts = new Point();
                mapView.getProjection().toPixels(pointToDraw, screenPts);

                Bitmap bmp = BitmapFactory.decodeResource(getResources(),
                        R.drawable.pin_normal);
                canvas.drawBitmap(bmp, screenPts.x, screenPts.y - 24, null);
                return true;
            }

Answer 1

adding ItemizedOverlay class would be better if you want to add pin (or images) on top of your map.
package com.android.testandroidmap;

import java.util.ArrayList;

import android.app.AlertDialog;
import android.content.Context;
import android.graphics.drawable.Drawable;

import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.OverlayItem;

public class HelloItemizedOverlay extends ItemizedOverlay {

private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
private Context mContext;

public HelloItemizedOverlay(Drawable defaultMarker, Context context) {
    super(boundCenterBottom(defaultMarker));
    // TODO Auto-generated constructor stub
    mContext = context;
}

@Override
protected OverlayItem createItem(int i) {
    // TODO Auto-generated method stub
    return mOverlays.get(i);
}

@Override
public int size() {
    // TODO Auto-generated method stub
    return mOverlays.size();
}

public void addOverlay(OverlayItem overlay) {
    mOverlays.add(overlay);
    populate();
}

@Override
protected boolean onTap(int index) {
  OverlayItem item = mOverlays.get(index);
  AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
  dialog.setTitle(item.getTitle());
  dialog.setMessage(item.getSnippet());
  dialog.show();
  return true;
}
}

I get this code from Android Developer Official Guide, and with this class on your code, you can add the overlays.

Add all the things you need (container, image for pins, and the pin+coordinate overlay)

List<Overlay> mapOverlays = mapView.getOverlays();
Drawable drawable = this.getResources().getDrawable(R.drawable.androidmarker);
HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable, this);

for your icons to be recognized by the class before, and also instantiate the coordinate, add the coordinate to an overlayItem + register the overlayItem with the HelloItemizedOverlay you made before

GeoPoint point = new GeoPoint(19240000,-99120000);
OverlayItem overlayitem = new OverlayItem(point, "Hola, Mundo!", "I'm in Mexico City!");
itemizedoverlay.addOverlay(overlayitem);

finish with adding the overlay to the mapOverlay, which is a collection of overlays.

mapOverlays.add(itemizedoverlay);

This displays a pin on top of my map, which can be customized by any image you want. If you want to also use different images for each location, just instantiate another Drawable with your image and register that Drawable to other HelloItemizedOverlay.