Can't animate to a valid geopoint on button click

Question

One part of the application I am making requires google map. I want the user to be able to type into edittext some search string and then press a search button and the map will animate to the first result.

When I press the button the application searches and takes the first result and puts it into a geopoint, so that part of the program is working. But when I try to animate to that point the application crashes.

Here is the onCreate function where I successfully navigate to the location "Dalvík, Iceland".

public class LocationPicker extends MapActivity {
    static GeoPoint point;
    static MapController mc;
    static MapView mapView;
    private EditText location;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_location_picker);
        MapView mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
        location = (EditText)findViewById(R.id.locationString);
        mc = mapView.getController();
        String tmp = "Dalvík, Iceland";
        try {
            point = searchLocation(tmp);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        mc.animateTo(point);
        mc.setZoom(14); 
        MapOverlay mapOverlay = new MapOverlay();
        List<Overlay> listOfOverlays = mapView.getOverlays();
        listOfOverlays.clear();
        listOfOverlays.add(mapOverlay);   

        mapView.invalidate();

    }

And my code for the button click is, and to be clear the System.out.println(point) prints valid point. But still when I click the button my application crashes.

public void search(View v) throws IOException{
        GeoPoint tmpPoint = searchLocation(location.getText().toString());
        System.out.println(tmpPoint);
        if( tmpPoint != null){
            mc.animateTo(tmpPoint);
            mapView.invalidate();
        }   
    }

And the searchLocation functions is as follows:

public GeoPoint searchLocation (String searchString) throws IOException{
        Geocoder geo = new Geocoder(this);
        List<Address> addr;
        addr = geo.getFromLocationName(searchString, 10);
        if(!addr.isEmpty()){
                    Address loc = addr.get(0);
                    GeoPoint point = new GeoPoint((int) (loc.getLatitude() * 1E6),
                        (int) (loc.getLongitude() * 1E6));
                    return point;
        }
        else {  
            return null;
        }   
}

So to summerize I am clearly doing something wrong in the onclick "search" function.

Any ideas what is wrong?

Answer 1

I found the answer.

The problem causing this was this line

mapView.invalidate();

Answer 2

You are not checking the right variable for null value:

    if( point != null){
        mc.animateTo(tmpPoint);
        mapView.invalidate();
    }   

should be

    if( tmpPoint!= null){
        mc.animateTo(tmpPoint);
        mapView.invalidate();
    }   

Additionnally, you want to make the call to the geoCoder.getFromLocationName method outside the UI thread as this can be time consumming. Use an AsyncTask for that for instance.

Finally, even if you get a list of addresses, they are not guaranted to have latitude and longitude. Use the hasLatitude and hasLongitude functions to pick the first address of the result list with coordinates.