gwt removing a marker

I have a problem. here's my code:

 map.addMapClickHandler(new MapClickHandler() 
     {
      public void onClick(MapClickEvent e) 
      {
        MapWidget sender = e.getSender();
           Overlay overlay = e.getOverlay();
           LatLng pkt = e.getLatLng();
       if (overlay != null && overlay instanceof Marker) 
       {
       // double a = pkt.getLatitude();
        //double b = pkt.getLongitude();
       // String trr = a+";"+b;
        sender.removeOverlay(overlay);
       } 

       else 
       {
        sender.addOverlay(new Marker(pkt));
        double a = pkt.getLatitude();
        double b = pkt.getLongitude();
        point[akt]=a+";"+b;
          }
         });

and the question is why can't I get Latitude and Longitude when overlay isn't null? (the comented area) all the time there is alert that "uncaught exception escaped". how to do it right?

---

no, after more tests, it isn't working :/

because in

if (overlay != null && overlay instanceof Marker) {
  LatL开发者_Go百科ng pkt = e.getOverlayLatLng();
  double a = pkt.getLatitude();
  double b = pkt.getLongitude();
  String trr = a + ";" + b;
  sender.removeOverlay(overlay);
}

Longitude and Latitude I get is the one of the last Marker I added (no matter which Marker I click on). is it possible to get the right values?

---

The JavaDocs for MapClickEvent indicate that MapClickEvent#getOverlayLatLng() should be used when the user has clicked on an overlay (note that I have not tested this code):

map.addMapClickHandler(new MapClickHandler(){
  public void onClick(MapClickEvent e) {
    MapWidget sender = e.getSender();
    Overlay overlay = e.getOverlay();

    if (overlay != null && overlay instanceof Marker) {
      LatLng pkt = e.getOverlayLatLng();
      double a = pkt.getLatitude();
      double b = pkt.getLongitude();
      String trr = a + ";" + b;
      sender.removeOverlay(overlay);
    } else if (overlay == null) {
      LatLng pkt = e.getLatLng();
      sender.addOverlay(new Marker(pkt));
      double a = pkt.getLatitude();
      double b = pkt.getLongitude();
      point[akt] = a + ";" + b;
    }
});