Question

i’ve been trying to create a map-related android app, but i realized that the onLocationChanged of my app had not been called, therefore the map always stay at the default area (US).

my code:

public class MapMainActivity extends MapActivity 
implements OnClickListener, LocationListener {

MapView mapView;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.map_main);

    //reference
    mapView = (MapView)findViewById(R.id.map_view);
    mapView.setBuiltInZoomControls(true);
    this.findViewById(R.id.btn_satellite).setOnClickListener(this);
    this.findViewById(R.id.btn_street).setOnClickListener(this);

}//onCreate

@Override
protected void onResume() {
    super.onResume();

    Toast.makeText(this, "GPS tracking started",
        Toast.LENGTH_SHORT).show();

 // Start location updates; 5s/5m
    LocationManager locManager = (LocationManager)getSystemService(
        Context.LOCATION_SERVICE);
    locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
        5000, 0, this);

    Criteria crit = new Criteria();
    crit.setAccuracy(Criteria.ACCURACY_FINE);
    String provider = locManager.getBestProvider(crit, true);
    Location loc = locManager.getLastKnownLocation(provider);

}//onResume

@Override
protected void onPause() {
    super.onPause();

    Toast.makeText(this, "GPS tracking stopped", 
        Toast.LENGTH_SHORT).show();

    LocationManager locManager = (LocationManager)getSystemService(
            Context.LOCATION_SERVICE);
        locManager.removeUpdates(this);
}//onPause

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    if(v == findViewById(R.id.btn_street))
    {
        mapView.setSatellite(false);
    }//street view

    else if (v == findViewById(R.id.btn_satellite))
    {
        mapView.setSatellite(true);
    }
}//onClick

@Override
protected boolean isRouteDisplayed() {
    // TODO Auto-generated method stub
    return false;
}//isRouteDisplayed

@Override
public void onLocationChanged(Location location) {
    // TODO Auto-generated method stub
    double lat = location.getLatitude();
    double lon = location.getLongitude();

    TextView txtLat = (TextView)findViewById(R.id.txt_lat);
    txtLat.setText(String.format("%.6f", lat));
    TextView txtLon = (TextView)findViewById(R.id.txt_lon);
    txtLon.setText(String.format("%.6f", lon));

    MapView map = (MapView)findViewById(R.id.map_view);
    map.getController().animateTo(new GeoPoint((int)(lat*1E6),//1000000), 
        (int)(lon*1E6)));
}//onLocationChanged

@Override
public void onProviderDisabled(String provider) {
    // TODO Auto-generated method stub
    Toast.makeText(this, "GPS disabled", 
            Toast.LENGTH_SHORT).show();
}//onProviderDisabled

@Override
public void onProviderEnabled(String provider) {
    // TODO Auto-generated method stub
    Toast.makeText(this, "GPS enabled", 
            Toast.LENGTH_SHORT).show();
}//onProviderEnabled

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub

}//onStatusChanged


}//class

the whole of my log cat when i run the app through my device (16/12/2011)

D/InputTransport(5357): Input channel constructed: name='40baf680 Toast (client)', ashmemFd=54, receivePipeFd=57, sendPipeFd=58

I/MapActivity(5357): Handling network change notification:CONNECTED

E/MapActivity(5357): Couldn't get connection factory client

I/ViewRoot(5357): !@FINISH DRAWING : sg.edu.tp/sg.edu.tp.SIP_TestMapActivity

I/ViewRoot(5357): !@finishDrawing is completed : sg.edu.tp/sg.edu.tp.SIP_TestMapActivity

I/ViewRoot(5357): !@FINISH DRAWING : Toast

I/ViewRoot(5357): !@finishDrawing is completed : Toast

D/InputTransport(5357): Input channel destroyed: name='40baf680 Toast (client)', ashmemFd=54, receivePipeFd=57, sendPipeFd=58

manifest :

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="sg.edu.tp"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="10" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:label="@string/app_name"
            android:name=".SIP_MLT_TestActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <uses-library android:name="com.google.android.maps" />
        <activity android:name=".SIP_TestMapActivity"></activity>
        <activity android:name=".SIP_TestDraw1Activity"></activity>
        <activity android:name=".SIP_TestDraw2Activity"></activity>
    </application>

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

</manifest>

Answer 1

Are you testing that while moving about or while sitting tethered to your dev machine with USB and watching logcat?

If sitting at dev machine, I suspect you’re not able to move the 5 meters required to trigger a location change event as you requested in your call to requestLocationUpdates

From API docs: .

If minDistance is greater than 0, a location will only be broadcast if
the device moves by minDistance meters.

try reducing the min distance param in that call to zero and see what happens.

locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,5000, 0, this);

You probably dont want to leave that at zero for anything other than testing.

If that doesnt help you might try to see that your GPS is working at all by doing something like this in your onResume, after you ask for locationUpdates:

Criteria crit = new Criteria();
crit.setAccuracy(Criteria.ACCURACY_FINE);
String provider = lm.getBestProvider(crit, true);
Location loc = lm.getLastKnownLocation(provider);

and see if you are getting good location info.