title: HERE Map/MapView without using MapFragment popupBackstack issues
body: <p>I have one Activity and loading two fragments (MapScreenFragment and OtherFragment) to the backstack. The issue that I am encountering is that when I start to popup some fragment from the backstack the MapScreenFragment shows black screen. </p>
  
  <p>Should I set anew Map to the MapView?</p>
  
  <pre><code>map = new Map();
  mapView.setMap(map);
  </code></pre>
  
  <blockquote>
    <p>XML Layout</p>
  </blockquote>
  
  <pre><code>&lt;FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"&gt;
  
  &lt;com.here.android.mpa.mapping.MapView
      android:id="@+id/map_view"
      android:layout_height="wrap_content"
      android:layout_width="wrap_content"/&gt;
  
  &lt;/FrameLayout&gt;
  </code></pre>
  
  <blockquote>
    <p>Fragment Class</p>
  </blockquote>
  
  <pre><code>public class MapScreenFragment extends Fragment {
  @Override
  public void onResume() {
      super.onResume();
      Log.d(TAG, "onResume");
  
      if(isMapEngineInitialized &amp;&amp; mapEngine != null) {
          mapEngine.onResume();
          mapView.onResume();
          Log.d(TAG, " onResume Map engine reference " + mapEngine.getResourceReferenceCount());
      }
  }
  
  @Override
  public void onPause() {
      super.onPause();
  
      Log.d(TAG, "onPause");
  
      if(isMapEngineInitialized &amp;&amp; mapEngine != null) {
          mapEngine.onPause();
          mapView.onPause();
          Log.d(TAG, " onPause Map engine reference " + mapEngine.getResourceReferenceCount());
      }
  }
  }
  
  /***** added ******/
  OnEngineInitListener onEngineInitListener = new OnEngineInitListener() {
      @Override
      public void onEngineInitializationCompleted(Error error) {
          if(error == Error.NONE) {
              isMapEngineInitialized = true;
  
              if(map == null) {
                  Log.d(TAG, " Map is null");
                  map = new Map();
              }
  
              mapView.setMap(map);
              mapView.setMapMarkerDragListener(MapScreenFragment.this);
  
              map = mapView.getMap();
              map.addTransformListener(MapScreenFragment.this);
  
              mapGesture = mapView.getMapGesture();
              mapGesture.setAllGesturesEnabled(true);
              mapGesture.addOnGestureListener(MapScreenFragment.this);
  
              setUpMap();
  
              Log.d(TAG, "MapEngine initialized! " + mapEngine.getResourceReferenceCount());
  
          }
  
      }
  };
  </code></pre>
  
  <blockquote>
    <p>MainActivity Backpressed and adding Fragments</p>
  </blockquote>
  
  <pre><code>mapFragment = new MapScreenFragment ();
  mFragmentTransaction =  getSupportFragmentManager().beginTransaction();
  mFragmentTransaction.add(R.id.main_frame_layout, mapFragment , mdmFragmentID);
  mFragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
  mFragmentTransaction.addToBackStack(null);
  mFragmentTransaction.commit();
  
  
  
  otherFragment = new OtherFragment ();
  mFragmentTransaction =  getSupportFragmentManager().beginTransaction();
  mFragmentTransaction.replace(R.id.main_frame_layout, otherFragment , mdmFragmentID);
  mFragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
  mFragmentTransaction.addToBackStack(null);mFragmentTransaction.commit();
  
  
  @Override
  public void onBackPressed() {
      Log.d(TAG, "Back stack count " + getSupportFragmentManager().getBackStackEntryCount());
      if( getSupportFragmentManager().getBackStackEntryCount() == 1) {
          finish();
      } else {
          getSupportFragmentManager().popBackStack();
      }
  }
  </code></pre>