Initialize Google Map - MapView Android

[noobsplanet]

In the previous guide, we learned about how to get register and get Google Map API key. And In this guide, we assume that you have already created your new google map API key. This guide explains that you must use this article before you do anything on the map. Let us say that this is the must step to do.

The first thing is to add the Google Map Gradle dependency to the project, open build.gradle and add line implementation 'com.google.android.gms:play-services-maps:16.1.0' and synchronize your project. This will look like below:

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.google.android.gms:play-services-maps:16.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

declare Google Map API key in your project manifest.xml inside the application tag like below.

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <meta-data
        android:name="com.google.android.maps.v2.API_KEY"
        android:value="AIzaSyBMhY-xxxxxxxxxxxxxxxxxxxxxx" />
</application>

Be sure to replace AIzaSyBMhY-xxxxxxxxxxxxxxxxxxxxxx with your API KEY into value of android:value. Open activity_main.xml and declare MapView like below:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    tools:context=".MainActivity">

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

</LinearLayout>

Open MainActivity.java, initialize Google Map. Google Map has its features to handle the activity lifecycle for the following methods which will handle automatically as per activity state :

• OnCreate()
• onPause()
• onResume()
• onLowMemory()
• onStop()
• onDestroy()

The above-mentioned methods are not required at all but better if you implement it. Beside this there is another lifecycle as well i.e. onStart() and onExitAmbient() as well, implement this as well if you need. Below is my MainActivity.java

package queendevelopers.com.googlemapdemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapView;
import com.google.android.gms.maps.OnMapReadyCallback;

public class MainActivity extends AppCompatActivity implements OnMapReadyCallback {

    private MapView mapView;
    private GoogleMap mMap;

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

        mapView = findViewById(R.id.mapView);
        mapView.onCreate(savedInstanceState);
        mapView.getMapAsync(this);
    }

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

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

    @Override
    protected void onPause() {
        mapView.onPause();
        super.onPause();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mapView.onDestroy();
    }

    @Override
    protected void onStop() {
        mapView.onStop();
        super.onStop();
    }

    @Override
    public void onLowMemory() {
        mapView.onLowMemory();
        super.onLowMemory();
    }
}

You must implement OnMapReadyCallback() if you're using Google Map V2 which overrides the OnMapReady method. For more information on the life cycle of Google Map see Activity life cycle. We can see the Google Map on the phone now :