android - Trying to put a map in a fragment activity

Question

In my Android app I am showing a Google Maps map inside a class that extends Fragment.

At the moment, only the map is shown, but I am not able to obtain the map from the SupportFragmentManager.

What I have done is adapting the MapActivity that comes within Android Studio to my app.

Here is my code:

public class Tab2 extends Fragment {

    private GoogleMap mMap; // Might be null if Google Play services APK is not available.

    private double latitud_del_hotel, longitud_del_hotel;
    private String nombre_del_hotel;
    private GoogleMap map;

    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.tab_2, container, false);
        //setUpMapIfNeeded();
        return v;
    }

    @Override
    public void onActivityCreated(Bundle state) {
        super.onActivityCreated(state);
        setUpMapIfNeeded();


    }

    private void setUpMapIfNeeded() {
        // Do a null check to confirm that we have not already instantiated the map.
        if (mMap == null) {
            // Try to obtain the map from the SupportMapFragment.
            mMap = ((SupportMapFragment) getActivity().getSupportFragmentManager().findFragmentById(R.id.map))
                    .getMap();
            // Check if we were successful in obtaining the map.
            if (mMap != null) {
                setUpMap();
            }
        }
    }

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

}

I am getting an exception: java.lang.NullPointerException at com.solinpromex.elpasojuarezexperience.Tab2.setUpMapIfNeeded

I have tried calling method setUpMapIfNeeded() from both methods: onCreateView and onActivityCreated. Both cases throw the exception.

If I remove setUpMapIfNeeded() then the map is shown, but I want to add map objects.

Any help is welcome..

EDIT

Complete exception log from logcat:

09-16 00:34:09.614  13999-13999/com.solinpromex.elpasojuarezexperience E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.solinpromex.elpasojuarezexperience, PID: 13999
    java.lang.NullPointerException
            at com.solinpromex.elpasojuarezexperience.Tab2.setUpMapIfNeeded(Tab2.java:66)
            at com.solinpromex.elpasojuarezexperience.Tab2.onActivityCreated(Tab2.java:57)
            at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:1797)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:979)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1138)
            at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:740)
            at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1501)
            at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:490)
            at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:163)
            at android.support.v4.view.ViewPager.populate(ViewPager.java:1105)
            at android.support.v4.view.ViewPager.populate(ViewPager.java:951)
            at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1473)
            at android.view.View.measure(View.java:16857)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5378)
            at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1621)
            at android.widget.LinearLayout.measureVertical(LinearLayout.java:742)
            at android.widget.LinearLayout.onMeasure(LinearLayout.java:607)
            at android.view.View.measure(View.java:16857)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5378)
            at android.widget.FrameLayout.onMeasure(FrameLayout.java:340)
            at android.support.v7.internal.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:124)
            at android.view.View.measure(View.java:16857)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5378)
            at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1621)
            at android.widget.LinearLayout.measureVertical(LinearLayout.java:742)
            at android.widget.LinearLayout.onMeasure(LinearLayout.java:607)
            at android.view.View.measure(View.java:16857)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5378)
            at android.widget.FrameLayout.onMeasure(FrameLayout.java:340)
            at android.view.View.measure(View.java:16857)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5378)
            at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1621)
            at android.widget.LinearLayout.measureVertical(LinearLayout.java:742)
            at android.widget.LinearLayout.onMeasure(LinearLayout.java:607)
            at android.view.View.measure(View.java:16857)
            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5378)
            at android.widget.FrameLayout.onMeasure(FrameLayout.java:340)
            at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2332)
            at android.view.View.measure(View.java:16857)
            at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2271)
            at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1334)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1532)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1211)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6282)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:788)
            at android.view.Choreographer.doCallbacks(Choreographer.java:591)
            at android.view.Choreographer.doFrame(Choreographer.java:560)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:774)
            at android.os.Handler.handleCallback(Handler.java:808)
            at android.os.Handler.dispatchMessage(Handler.java:103)
            at android.os.Looper.loop(Looper.java:193)
            at android.app.ActivityThread.main(ActivityThread.java:5299)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:825)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:641)
            at dalvik.system.NativeStart.main(Native Method)

EDIT 2

Layout file tab_2

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">

        <fragment xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:name="com.google.android.gms.maps.MapFragment"
            android:id="@+id/map"
            android:layout_alignParentTop="true"
            android:layout_alignParentBottom="true"
            android:layout_alignParentLeft="true"
            android:layout_alignParentRight="true" />
    </LinearLayout>
</RelativeLayout>

Answer 1

If you use the latest GooglePlayServices you can use the getMapAsync function which will automatically initializes the maps system and the view.

Also use a MapView in the layout

This is how I added the map in fragment.

public class MapFragment extends Fragment implements OnMapReadyCallback {

     @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            view = inflater.inflate(R.layout.fragment_tab_fragment1, container, false);

            FragmentManager manager = getFragmentManager();
            FragmentTransaction transaction = manager.beginTransaction();
            SupportMapFragment fragment = new SupportMapFragment();
            transaction.add(R.id.mapView, fragment);
            transaction.commit();

            fragment.getMapAsync(this);

            return view;
        }

   @Override
   public void onMapReady(GoogleMap map) {
      //map is ready
      map.addMarker(...
 }
}

in xml

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

To use the latest GooglePlayService put this in gradle

compile 'com.google.android.gms:play-services:8.3.0'