import net.rim.device.api.gps.*;
import net.rim.device.api.system.Application;
import net.rim.device.api.ui.*;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.container.*;
import javax.microedition.location.*;
public class MultipleFixDemo extends UiApplication 
{    
    private static int _interval = 1;
    private EditField _status;    
    public static void main(String[] args)
    {
        new MultipleFixDemo().enterEventDispatcher();
    }
    public MultipleFixDemo()
    {
        MultipleFixScreen screen = new MultipleFixScreen();
        screen.setTitle("Multiple Fix Demo");
        _status = new EditField(Field.NON_FOCUSABLE);
        screen.add(_status);
        startLocationUpdate();
        pushScreen(screen);
    }
    private void updateLocationScreen(final String msg)
    {
        invokeLater(new Runnable()
        {
            public void run()
            {
                _status.setText(msg);
            }
        });
    }
   private void startLocationUpdate()
    {
        try
        {
            BlackBerryCriteria myCriteria = new BlackBerryCriteria();
            myCriteria.enableGeolocationWithGPS();
            try
            {
                BlackBerryLocationProvider myProvider = 
                        (BlackBerryLocationProvider)LocationProvider
                        .getInstance(myCriteria);
                if ( myProvider == null )
                {
                    Runnable showUnsupportedDialog = new Runnable() 
                    {
                        public void run() {
                            Dialog.alert("Location service unsupported, 
                                    exiting...");
                            System.exit( 1 );
                        }
                    };
                    invokeLater( showUnsupportedDialog );  
                }
                else
                {
                    myProvider.setLocationListener(new LocationListenerImpl(), 
                            _interval, 1, 1);
                }
            }
            catch (LocationException le)
            {
                System.err.println("Failed to retrieve a location provider");
                System.err.println(le); 
                System.exit(0);
            }
        }
        catch (UnsupportedOperationException ue)
        {
            System.err.println("Require mode is unavailable");
            System.err.println(ue); 
            System.exit(0);   
        }
        return;
    }
    private class LocationListenerImpl implements LocationListener
    {
        public void locationUpdated(LocationProvider provider, 
                Location location)
        {
            if(location.isValid())
            {
                double longitude = location.getQualifiedCoordinates()
                        .getLongitude();
                double latitude = location.getQualifiedCoordinates()
                        .getLatitude();
                float altitude = location.getQualifiedCoordinates()
                        .getAltitude();
                StringBuffer sb = new StringBuffer();
                sb.append("Longitude: ");
                sb.append(longitude);
                sb.append("\n");
                sb.append("Latitude: ");
                sb.append(latitude);
                sb.append("\n");
                sb.append("Altitude: ");
                sb.append(altitude);
                sb.append(" m");
                MultipleFixDemo.this.updateLocationScreen(sb.toString());
            }
        }
        public void providerStateChanged(LocationProvider provider, 
                 int newState)
        {
            // Not implemented
        }        
    }
    private final static class MultipleFixScreen extends MainScreen
    {
        MultipleFixScreen()
        {
            super(DEFAULT_CLOSE | DEFAULT_MENU);
            RichTextField instructions = new RichTextField(
                    "Waiting for location update...",Field.NON_FOCUSABLE);
            this.add(instructions);
        }
    }     
}