Detect if the OSM Mapview is still loading or not in android

I have included Open Street Maps in my android application. In the mapview, user should be able to capture the screen after the map is fully loaded. But currently user can capture the image even when the mapview is still loading. Can someone tell me how to detect when the mapview is fully loaded?

Below is my code to load the mapview:

public class MainActivity extends Activity  {
    MapView mapView;
    MyLocationOverlay myLocationOverlay = null;
    ArrayList<OverlayItem> anotherOverlayItemArray;
    protected ItemizedOverlayWithBubble<ExtendedOverlayItem> itineraryMarkers;

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

        mapView = (MapView) findViewById(R.id.mapview);

        final ArrayList<ExtendedOverlayItem> waypointsItems = new ArrayList<ExtendedOverlayItem>();
        itineraryMarkers = new ItemizedOverlayWithBubble<ExtendedOverlayItem>(this, waypointsItems, mapView, new ViaPointInfoWindow(R.layout.itinerary_bubble, mapView));
        mapView.getOverlays().add(itineraryMarkers);

        mapView.setTileSource(TileSourceFactory.MAPNIK);
        mapView.setBuiltInZoomControls(true);
        MapController mapController = mapView.getController();
        mapController.setZoom(1);
        GeoPoint point2 = new GeoPoint(51496994, -134733);
        mapController.setCenter(point2);

        Drawable marker=getResources().getDrawable(android.R.drawable.star_big_on);
        GeoPoint myPoint1 = new GeoPoint(0*1000000, 0*1000000);
        ExtendedOverlayItem overlayItem = new ExtendedOverlayItem("Title Test Loc", "Desc", myPoint1, this);
        overlayItem.setMarkerHotspot(OverlayItem.HotspotPlace.BOTTOM_CENTER);
        overlayItem.setMarker(marker);
        overlayItem.setRelatedObject(0);
        itineraryMarkers.addItem(overlayItem);
        mapView.invalidate();



        myLocationOverlay = new MyLocationOverlay(this, mapView);
        mapView.getOverlays().add(myLocationOverlay);
        myLocationOverlay.enableMyLocation();

        myLocationOverlay.runOnFirstFix(new Runnable() {
            public void run() {
             mapView.getController().animateTo(myLocationOverlay.getMyLocation());
               } 
           });


    }

    @Override
     protected void onResume() {
      // TODO Auto-generated method stub
      super.onResume();
      myLocationOverlay.enableMyLocation();
      myLocationOverlay.enableCompass();
      myLocationOverlay.enableFollowLocation();
     } 

     @Override
     protected void onPause() {
      // TODO Auto-generated method stub
      super.onPause();
      myLocationOverlay.disableMyLocation();
      myLocationOverlay.disableCompass();
      myLocationOverlay.disableFollowLocation();
     }