React-Native and Mapsforge - react-native

Question

Trying to create native module for my react-native android application. Codes below is my native java to render / display map using mapsforge library.
I need help please, I need to have a function that returns the instance of the application and if possible it is inside the class that extends LinearLayout. I need to call the function as parameter for the AndroidGraphicFactory.createInstance(InstanceOfTheApplication). You think what I am doing is possible?
import android.content.Context;
import android.location.LocationManager;
import android.os.Environment;
import android.os.StrictMode;
import android.widget.LinearLayout;
import org.mapsforge.core.model.LatLong;
import org.mapsforge.map.android.graphics.AndroidGraphicFactory;
import org.mapsforge.map.android.layers.MyLocationOverlay;
import org.mapsforge.map.android.util.AndroidUtil;
import org.mapsforge.map.android.view.MapView;
import org.mapsforge.map.datastore.MapDataStore;
import org.mapsforge.map.layer.cache.TileCache;
import org.mapsforge.map.layer.renderer.TileRendererLayer;
import org.mapsforge.map.model.MapViewPosition;
import org.mapsforge.map.reader.MapFile;
import org.mapsforge.map.rendertheme.InternalRenderTheme;
import java.io.File;
public class CustomMapView extends LinearLayout {
private Context context;
private MapView mapView;
private TileCache tileCache;
private TileRendererLayer tileRendererLayer;
private MyLocationOverlay myLocationOverlay;
private MapViewPosition mapViewPosition;
private LocationManager locationManager;
private static final String map = "philippines.map";
public CustomMapView(Context context) {
super(context);
// set context
this.context = context;
// need help here ...
AndroidGraphicFactory.createInstance(this.getApplication());
// inflate map.xml | setContentView
inflate(this.context, R.layout.map, this);
// create map layout
create();
// start map
start();
}
/**
* Create map layout
* and controls.
*/
private void create() {
this.mapView = (MapView) findViewById(R.id.mapView);
this.mapView.setClickable(true);
this.mapView.getMapScaleBar().setVisible(true);
this.mapView.setBuiltInZoomControls(true);
this.mapView.getMapZoomControls().setZoomLevelMin((byte) 10);
this.mapView.getMapZoomControls().setZoomLevelMax((byte) 20);
// create a tile cache of suitable size
this.tileCache = AndroidUtil.createTileCache(
context,
"mapcache",
mapView.getModel().displayModel.getTileSize(),
1f,
this.mapView.getModel().frameBufferModel.getOverdrawFactor()
);
}
/**
* Start map
*/
private void start() {
this.mapView.getModel().mapViewPosition.setCenter(new LatLong(14.788405, 121.069563));
this.mapView.getModel().mapViewPosition.setZoomLevel((byte) 12);
// tile renderer layer using internal render theme
MapDataStore mapDataStore = new MapFile(getMapFile());
this.tileRendererLayer = new TileRendererLayer(
tileCache,
mapDataStore,
this.mapView.getModel().mapViewPosition,
false,
true,
true,
AndroidGraphicFactory.INSTANCE
);
tileRendererLayer.setXmlRenderTheme(InternalRenderTheme.OSMARENDER);
// only once a layer is associated with a mapView the rendering starts
this.mapView.getLayerManager().getLayers().add(tileRendererLayer);
}
/**
* Get map file
*
* #return
*/
private File getMapFile() {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
// absolute path of internal Downloads folder
String dirDownloads = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getAbsolutePath();
File file = new File(dirDownloads + "/" + map);
return file;
}
}