android - Google Maps Lite Mode causes jank in RecyclerView

Question

I have a RecyclerView which is a vertical scrolling list of items. Each list item contains a Google Maps V2 MapView in Lite Mode. I'm taking advantage of this new feature which returns bitmaps instead of a full-blown map as a replacement to the Google Static Maps API.

MapView requires that you call onCreate(), onResume(), onPause(), onDestroy() etc. from the parent Activity/Fragment's corresponding method. Where is the proper place to call these from the RecyclerView.Adapter and/or RecyclerView.ViewHolder?

How can I clean up recycled MapViews so that memory doesn't leak, while keeping the list jank free?

Google says Lite Mode can be used in lists:

... ‘lite mode’ map option, ideal for situations where you want to provide a number of smaller maps, or a map that is so small that meaningful interaction is impractical, such as a thumbnail in a list.

ListItem.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent">

    <com.google.android.gms.maps.MapView
        android:id="@+id/mapImageView"
        xmlns:map="http://schemas.android.com/apk/res-auto"
        android:layout_width="80dp"
        android:layout_height="100dp"
        map:liteMode="true"
        map:mapType="normal"
        map:cameraZoom="15"/>

<!-- ... -->

</RelativeLayout>

RecyclerView.Adapter and ViewHolder

public class NearbyStopsAdapter extends RecyclerView.Adapter<NearbyStopsAdapter.ViewHolder> {

    private final Context mContext;

    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        MapView map;

        public ViewHolder(View view) {
            super(view);
            map = (MapView) view.findViewById(R.id.mapImageView);
            // Should this be created here?
            map.onCreate(null);
            map.onResume();
        }
    }

    public NearbyStopsAdapter(Context c) {
        this.mContext = c;
    }

    @Override public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int position) {
        View itemView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.list_item_nearby_stop, viewGroup, false);
        return new ViewHolder(itemView);
    }

    @Override public void onBindViewHolder(ViewHolder holder, int position) {
        //Call Async Map here?
        holder.map.getMapAsync(this);
    }

    @Override public void onViewRecycled(ViewHolder holder) {
        // Cleanup MapView here?
//        if (holder.map != null) {
//            holder.map.onPause();
//            holder.map.onDestroy();
//        }
    }

    @Override public void onViewAttachedToWindow(ViewHolder holder) {
        // Setup MapView here?
//            holder.map.onCreate(null);
//            holder.map.onResume();
    }

    @Override public void onViewDetachedFromWindow(ViewHolder holder) {
        // Cleanup MapView here?
//        if (holder.map != null) {
//            holder.map.onPause();
//            holder.map.onDestroy();
//        }
    }

    // ...
}

Logcat:

I/Google Maps Android API﹕ Google Play services package version: 659943
W/Google Maps Android API﹕ Map Loaded callback is not supported in Lite Mode
W/Google Maps Android API﹕ Buildings are not supported in Lite Mode
W/Google Maps Android API﹕ Indoor is not supported in Lite Mode
W/Google Maps Android API﹕ Toggling gestures is not supported in Lite Mode
W/Google Maps Android API﹕ Toggling gestures is not supported in Lite Mode
W/Google Maps Android API﹕ Toggling gestures is not supported in Lite Mode
W/Google Maps Android API﹕ Toggling gestures is not supported in Lite Mode

Update: (Jun 8, 2018) Google has released a code sample for using Lite Maps in a ListView. See here

Answer 1

Solution as following:

1. Implement OnMapReadyCallback in ViewHolder class.
2. In onMapReady, call MapsInitializer.initialize, to gaurantee features can to be used before obtaining a map.

Use this class to initialize the Google Maps Android API if features need to be used before obtaining a map. It must be called because some classes such as BitmapDescriptorFactory and CameraUpdateFactory need to be initialized.

3. Recycle map from onViewRecycled.

    public class NearbyStopsAdapter extends RecyclerView.Adapter<NearbyStopsAdapter.ViewHolder> {


       @Override 
       public void onBindViewHolder(ViewHolder holder, int position)  
       {
          //get 'location' by 'position' from data list
          //get GoogleMap
          GoogleMap thisMap = holder.gMap;
          //then move map to 'location'
          if(thisMap != null) 
             //move map to the 'location' 
             thisMap.moveCamera(...);          
       }


       //Recycling GoogleMap for list item
       @Override 
       public void onViewRecycled(ViewHolder holder) 
       {
          // Cleanup MapView here?
          if (holder.gMap != null) 
          {
              holder.gMap.clear();
              holder.gMap.setMapType(GoogleMap.MAP_TYPE_NONE);
          }
       }



       public class ViewHolder extends RecyclerView.ViewHolder implements OnMapReadyCallback { 

           GoogleMap gMap; 
           MapView map;
            ... ... 

           public ViewHolder(View view) {
              super(view);
              map = (MapView) view.findViewById(R.id.mapImageView);

              if (map != null) 
              {
                 map.onCreate(null);
                 map.onResume();
                 map.getMapAsync(this);
              }

          }


          @Override
          public void onMapReady(GoogleMap googleMap) {
              //initialize the Google Maps Android API if features need to be used before obtaining a map 
              MapsInitializer.initialize(getApplicationContext());
              gMap = googleMap;

              //you can move map here to item specific 'location'
              int pos = getPosition();
              //get 'location' by 'pos' from data list  
              //then move to 'location'
              gMap.moveCamera(...);

                  ... ...
         }

       }
    }