title: Why are my overlays on a mapview not shown?
body: <p>I followed the instructions from the google hellomapview tutorial. I get a working mapview etc. But the two items that are added to the map are not shown. It seems they are there somewhere because tapping at the specified location shows the message that was added to the items.</p>
  
  <p><strong>Edit</strong></p>
  
  <p>Here is my source code. It should be very close to the google tutorial source code. </p>
  
  <pre><code>public class MapOverlay extends ItemizedOverlay&lt;OverlayItem&gt; {
  
  private List&lt;OverlayItem&gt; overlays = new ArrayList&lt;OverlayItem&gt;();
  private Context context;
  
  public MapOverlay(Drawable defaultMarker, Context context) {
      super(defaultMarker);
      overlays = new ArrayList&lt;OverlayItem&gt;();
      this.context = context;
  }
  
  @Override
  protected OverlayItem createItem(int i) {
      return overlays.get(i);
  }
  
  @Override
  public int size() {
       return overlays.size();
  }
  
  public void addOverlay(OverlayItem overlay) {
      overlays.add(overlay);
      this.populate();
  }
  
  @Override
  protected boolean onTap(int index) {
    OverlayItem item = overlays.get(index);
    AlertDialog.Builder dialog = new AlertDialog.Builder(this.context);
    dialog.setTitle(item.getTitle());
    dialog.setMessage(item.getSnippet());
    dialog.show();
    return true;
  }
  
  }
  
  public class MapsActivity extends MapActivity {
  
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
      MapView mapView = (MapView) findViewById(R.id.mapview);
      mapView.setBuiltInZoomControls(true);
  
      MapOverlay overlay = new MapOverlay(this.getResources().getDrawable(
              R.drawable.androidmarker), this);
  
      overlay.addOverlay(new OverlayItem(new GeoPoint(19240000,-99120000), "Blubb", "See?"));
      mapView.getOverlays().add(overlay);
  }
  
  @Override
  protected boolean isRouteDisplayed() {
      return false;
  }
  }
  </code></pre>
  
  <p>Is the source code from the google tutorial available somewhere?</p>