java - osm での描画に関する問題

Question

ビットマップでGPSの位置を表示するAndroid用の小さなアプリケーションを開発しています。Google mmaps でいくつかのサンプル コードを使用しましたが、maps forge で作成する必要があります。残念ながら、この描画操作の書き方に関するコード例や何かを見つけたことがありません。

私のコードは次のとおりです。

    package hu.uniobuda.nik.k44hvx;



 import java.io.IOException;

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

import org.mapsforge.android.maps.GeoPoint;
import org.mapsforge.android.maps.ItemizedOverlay;
import org.mapsforge.android.maps.MapActivity;
import org.mapsforge.android.maps.MapController;
import org.mapsforge.android.maps.MapView;
import org.mapsforge.android.maps.MapViewMode;
import org.mapsforge.android.maps.Overlay;
import org.mapsforge.android.maps.OverlayItem;
import org.mapsforge.android.maps.Projection;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.drawable.Drawable;
import android.location.Geocoder;
import android.location.Address;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.text.Html;
import android.widget.TextView;
import android.widget.Toast;

public class Night_WatchActivity extends MapActivity  {


    MapView mapview;
    public MapController mc;

    private LocationManager locman;
    private LocationListener loclis;

    List<Overlay> mapOverlays;
    static Drawable pointDefaultMarker;

    MapOverlay pointsOverlay;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


        mapview = new MapView(this);
        mapview.setClickable(true);
        mapview.setBuiltInZoomControls(true);
        mapview.setMapViewMode(MapViewMode.MAPNIK_TILE_DOWNLOAD);
       // mapview.setMapViewMode(MapViewMode.CANVAS_RENDERER);
        //mapview.setMapFile("/sdcard/budapest.map");

        mc = mapview.getController();
        mc.setCenter(new GeoPoint(47.499619,19.046406));

        mc.setZoom(17);

        setContentView(mapview);


        locman = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
       // loclis = new GPSLocationListener();
        if(pointDefaultMarker==null){pointDefaultMarker = getResources().getDrawable(R.drawable.kepont);}
        mapOverlays = mapview.getOverlays();
        pointsOverlay = new MapOverlay(pointDefaultMarker);
        mapOverlays.add(pointsOverlay);



        locman.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, loclis);
    }


    @Override
    protected void onResume() {
        locman.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10*1000, 10, loclis);
        super.onResume();
    }

    @Override
    protected void onPause() {
        locman.removeUpdates(loclis);
        super.onPause();
    }

private class GPSLocationListener implements LocationListener {

        public void onLocationChanged(Location location) {
            if(location!=null){
                GeoPoint gp = new GeoPoint(
                                    (int)(location.getLatitude()*1E6),
                                    (int)(location.getLongitude()*1E6));


                OverlayItem item = new OverlayItem(gp,null,null);

                pointsOverlay.justOneOverlay(item);
                mc.setZoom(16);
                mc.setCenter(gp);
                mapview.invalidate();



                String address = PointToLocation(gp);
                Toast.makeText(getBaseContext(), 
                          address,
                          Toast.LENGTH_SHORT).show();
            }

        }

        public void onProviderDisabled(String provider) {


        }

        public void onProviderEnabled(String provider) {


        }

        public void onStatusChanged(String provider, int status, Bundle extras) {


        }

        public String PointToLocation(GeoPoint hely){
            String s ="";


            Geocoder gcd = new Geocoder(getBaseContext(), Locale.getDefault());
            try{

                List<Address> adresses = gcd.getFromLocation(
                                            hely.getLatitudeE6() / 1E6, 
                                            hely.getLongitudeE6()/1E6 , 1);
                if(adresses.size()>0){
                    for(int i = 0; i < adresses.get(0).getMaxAddressLineIndex(); i++){
                        s += adresses.get(0).getAddressLine(i) + " ";

                    }
                }


            }catch(IOException exception){ exception.printStackTrace();}


            return s;
        }

    }

 class MapOverlay extends ItemizedOverlay<OverlayItem>{

    private GeoPoint toDraw;


    public GeoPoint getToDraw() {
        return toDraw;
    }


    public void setToDraw(GeoPoint toDraw) {
        this.toDraw = toDraw;
    }


    Paint p = new Paint();
    private ArrayList<OverlayItem> overlays = new ArrayList<OverlayItem>();
    private boolean drawLines = false;



    public MapOverlay(Drawable defaultMarker) {
        super(boundCenter(defaultMarker));

        populate();
    }

    public void addOverlay(OverlayItem overlay){
        overlays.add(overlay);

        populate();
    }
    public void justOneOverlay(OverlayItem newOverlay){
        overlays.clear();
        addOverlay(newOverlay);             
    }
    @Override
    protected OverlayItem createItem(int i) {
        return overlays.get(i);
    }
    @Override
    public int size() {
        return overlays.size();
    }

    public boolean isDrawLines() {
        return drawLines;
    }
    public void setDrawLines(boolean drawLines) {
        this.drawLines = drawLines;     
    }   

    @Override
    protected void drawOverlayBitmap(Canvas canvas, Point drawPosition,
            Projection projection, byte drawZoomLevel) {

        Point ScreenPoint = new Point();
        mapview.getProjection().toPixels(toDraw, ScreenPoint);

        Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.kepont);
        canvas.drawBitmap(bmp,ScreenPoint.x,ScreenPoint.y-24, null);
    }



 } 


}