Google Maps v2 lag after popping their fragment back from stack

Question

I have an Activity with a MapFragment that I add to the Activity programmatically using a FragmentTransaction:

Answer 1

it only lag if you press the back button?

if thats the problem try to block the back button or make it exit the app try this code:

    @Override
public void onBackPressed(){
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("You wanna leave the aplication?").setPositiveButton("Yes", dialogClickListener)
            .setNegativeButton("No", dialogClickListener).show();

}

or try this code its a way to put a map fragment inside another fragment (nested Map Fragment) it worked for me a weeks ago:

Java Class:

public class Yourfragment extends Fragment {

    private MapView mMapView;
    private GoogleMap mMap;
    private Bundle mBundle;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View inflatedView = inflater.inflate(R.layout.map_fragment, container, false);

        try {
            MapsInitializer.initialize(getActivity());
        } catch (GooglePlayServicesNotAvailableException e) {
            // TODO handle this situation
        }

        mMapView = (MapView) inflatedView.findViewById(R.id.map);
        mMapView.onCreate(mBundle);
        setUpMapIfNeeded(inflatedView);

        return inflatedView;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mBundle = savedInstanceState;
    }

    private void setUpMapIfNeeded(View inflatedView) {
        if (mMap == null) {
            mMap = ((MapView) inflatedView.findViewById(R.id.map)).getMap();
            if (mMap != null) {
                setUpMap();
            }
        }
    }

    private void setUpMap() {
        mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
    }

    @Override
    public void onResume() {
        super.onResume();
        mMapView.onResume();
    }

    @Override
    public void onPause() {
        super.onPause();
        mMapView.onPause();
    }

    @Override
    public void onDestroy() {
        mMapView.onDestroy();
        super.onDestroy();
    }
}

XML:

<com.google.android.gms.maps.MapView
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent" />

put this code on post execute:

View inflatedView = inflater.inflate(R.layout.map_fragment, container, false);

try {
    MapsInitializer.initialize(getActivity());
} catch (GooglePlayServicesNotAvailableException e) {
    // TODO handle this situation
}

mMapView = (MapView) inflatedView.findViewById(R.id.map);
mMapView.onCreate(mBundle);
setUpMapIfNeeded(inflatedView);

return inflatedView;

and call the assynctask on oncreateview

Try this:

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    //Call assyncTask
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mBundle = savedInstanceState;
}

private void setUpMapIfNeeded(View inflatedView) {
    if (mMap == null) {
        mMap = ((MapView) inflatedView.findViewById(R.id.map)).getMap();
        if (mMap != null) {
            setUpMap();
        }
    }
}

private void setUpMap() {
    mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
}

@Override
public void onResume() {
    super.onResume();
    mMapView.onResume();
}

@Override
public void onPause() {
    super.onPause();
    mMapView.onPause();
}

@Override
public void onDestroy() {
    mMapView.onDestroy();
    super.onDestroy();
}
private class GetFlightsTask extends AsyncTask<Double, Void, String> {

@Override
protected void onPreExecute() {
    super.onPreExecute();
    // if I remove the next line, everything gets fixed
    loadingFlightsSpinner.show();
}

@Override
protected String doInBackground(Double... params) {
    // some pretty long remote API call
    // (loading a JSON file from http://some.website.com/flights?...)
    // works fine
    String flightsJSON = loadJSON("flights?flyFrom=CZ&to=...");
}

@Override
protected void onPostExecute(String flightsJSON) {
    super.onPostExecute(flightsJSON);
    loadingFlightsSpinner.dismiss();
    // here I do stuff with the JSON and then replace the fragment
    dohardwork()
}
public view dohardwork(){
    View inflatedView = inflater.inflate(R.layout.map_fragment, container, false);

    try {
        MapsInitializer.initialize(getActivity());
    } catch (GooglePlayServicesNotAvailableException e) {
        // TODO handle this situation
    }

    mMapView = (MapView) inflatedView.findViewById(R.id.map);
    mMapView.onCreate(mBundle);
    setUpMapIfNeeded(inflatedView);

    return inflatedView;
}

Answer 2

I have fixed it by dismissing the ProgressDialog already at the end of the AsyncTask's doInBackground() method rather than at the beginning of the onPostExecute() method.

Which is a bit weird because I actually thought I shouldn't touch things from the UI in the doInBackground() method... If someone wants to elaborate on it a bit, I would be glad to learn why it works like this.

Answer 3

I have run a simple test:

public class MapFragmentOnBackStackExample extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.map_fragment_on_back_stack_example);

        FragmentManager fm = getSupportFragmentManager();
        Fragment f = fm.findFragmentById(R.id.fragment_container);
        if (f == null) {
            f = SupportMapFragment.newInstance();
            FragmentTransaction transaction = fm.beginTransaction();
            transaction.add(R.id.fragment_container, f);
            transaction.commit();
        }
    }

    public void onAddFragmentClick(View view) {
        FragmentManager fm = getSupportFragmentManager();
        FragmentTransaction transaction = fm.beginTransaction();
        transaction.replace(R.id.fragment_container, new MyFragment());
        transaction.addToBackStack(null);
        transaction.commit();
    }

    public static class MyFragment extends Fragment {

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            TextView textView = new TextView(getActivity());
            textView.setText("MyFragment: " + hashCode());
            return textView;
        }
    }
}

and can't see any problems.

I could see the problem when commented if (f == null) { leaving it to always create new fragment on rotation, which is obviously wrong, but that brings some suspicions.

Can you see more than 1 MapFragment in memory at the same time? Try using Eclipse Memory Analyzer (MAT).