Working with Map Fragment Activity

Question

I'm trying to create a basic activity with a google map fragment. Right now I have this:

public class MainScreen extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_screen);

        // add the map fragment to the activity
        if (findViewById(R.id.fragment_container) != null) {
             if (savedInstanceState != null) { return; }
             getSupportFragmentManager().beginTransaction()
             .add(R.id.fragment_container, new FragmentGoogle()).commit();
        }
    }
}

---

public class FragmentGoogle extends android.support.v4.app.Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.map_google, container, false);
    }
}

Which is producing this:

My question is: how can I interact with the fragment itself? Let's supposse I want to zoom in Sidney. Should I put the code in the MainScreen.class or in the Fragment.class? Which methods should I use? It's my first time working with fragments.

Answer 1

you don't need to create your own FragmentGoogle. You can use com.google.android.gms.maps.SupportMapFragment and controll it from you activity code.

in the layout:

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/map"
    tools:context=".MapsActivity"
    android:name="com.google.android.gms.maps.SupportMapFragment" />

and then in the Activity code:

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        // Add a marker in Sydney, Australia, and move the camera.
        LatLng sydney = new LatLng(-34, 151);
        mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
    }
}

The code is taken from this tutorial which is enough to start and use most of the features of the Google Maps Android API, just follow the steps :)