Android Studio is Generating Deprecated Maps Code

Android Studio is generating code that uses the deprecated method GoogleMap.getMap(). Here I will show you how to change the generated code to use GoogleMap.getMapAsync() instead.

I used the “Create New Project” wizard in Android Studio to create a Google Maps Activity.

_config.yml

The wizard generated this code:

package org.bitmine.mapp;

import android.support.v4.app.FragmentActivity;
import android.os.Bundle;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapsActivity extends FragmentActivity {

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

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

    @Override
    protected void onResume() {
        super.onResume();
        setUpMapIfNeeded();
    }

    /**
     * Sets up the map if it is possible to do so (i.e., the Google Play services APK is correctly
     * installed) and the map has not already been instantiated.. This will ensure that we only ever
     * call {@link #setUpMap()} once when {@link #mMap} is not null.
     * <p/>
     * If it isn't installed {@link SupportMapFragment} (and
     * {@link com.google.android.gms.maps.MapView MapView}) will show a prompt for the user to
     * install/update the Google Play services APK on their device.
     * <p/>
     * A user can return to this FragmentActivity after following the prompt and correctly
     * installing/updating/enabling the Google Play services. Since the FragmentActivity may not
     * have been completely destroyed during this process (it is likely that it would only be
     * stopped or paused), {@link #onCreate(Bundle)} may not be called again so we should call this
     * method in {@link #onResume()} to guarantee that it will be called.
     */
    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) getSupportFragmentManager().findFragmentById(R.id.map))
                    .getMap();
            // Check if we were successful in obtaining the map.
            if (mMap != null) {
                setUpMap();
            }
        }
    }

    /**
     * This is where we can add markers or lines, add listeners or move the camera. In this case, we
     * just add a marker near Africa.
     * <p/>
     * This should only be called once and when we are sure that {@link #mMap} is not null.
     */
    private void setUpMap() {
        mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
    }
}

This code uses GoogleMap.getMap() method. This method has been deprecated since Google Play Services version 6.5, released in December 2014. And for good reason. This generated code is overly complex to support polling for a GoogleMap instance which may not be ready. What happens if getMap() returns null in setUpMapIfNeeded()? You are going to require more retry logic if you want this code to be correct.

I give Google credit for recognizing that their API suffered this weakness and providing getMapAsync() as a replacement. If we use that instead we can do away with setUpMapIfNeeded(). Here is the simplified code:

package org.bitmine.mapp;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

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) getSupportFragmentManager().findFragmentById(R.id.map))
                .getMapAsync(this);
    }

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

    /**
     * This is where we can add markers or lines, add listeners or move the camera. In this case, we
     * just add a marker near Africa.
     * <p/>
     * This should only be called once.
     */
    private void setUpMap() {
        mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
    }
}

Polling is no longer required. Now onMapReady() will be called when the map is ready.

Depending on your target OS versions, you can clean this up a little more by using MapFragment instead of SupportMapFragment.

Hopefully Google will update the wizard in Android Studio as well as their code samples so people will stop using the deprecated getMap() and start using getMapAsync() instead.

_config.yml

Written on July 3, 2015