Configuring an Android Google Maps App

The following acronyms will be used: Android Maps applications are much easier to build now compared to few years ago. I believe it was because the Google Maps Android API and Google Play services are constantly revised and were not stable in the past. This page uses the following reference pages: This application will use Start a New Android Studio Project.



Installing Google Play Services SDK
By default, the Android SDK does not include everything you need to start developing. The SDK separates tools, platforms, and other components into packages you can download as needed using the Android SDK Manager. So before you can start, there are a few packages you should add to your Android SDK. To use the latest Google Play services, select the following Android Studio options: 
   Tools ⇒ Android ⇒ SDK Manager


As a minimum when setting up the Android SDK, the following tools and Android platform should be available: The Google Play services APIs provide a variety of features and services for your Android apps, such as Google Maps. Install the Google Play services package including:

Adding Google Play Services to Your Project
Gradle is the foundation of the Android SDK build system. With Gradle, Android developers can use a simple, declarative DSL (Domain Specific Language) to configure Gradle builds supporting a wide variety of Android devices and App stores. To make the Google Play services APIs available to your app, open the build.gradle file inside your application module directory. Android Studio projects contain a top-level build.gradle file and a build.gradle file for each module. Be sure to edit the file for your application module.


Add a new build rule under dependencies for the latest version of play-services. For example: 

apply plugin: 'com.android.application'
    ...
  compileSdkVersion 28
    ...
  minSdkVersion 21
  targetSdkVersion 28
    ...

dependencies {
  ...
  compile 'com.google.android.gms:play-services:8.4.0'
}

Save the changes and click Sync Project with Gradle Files in the toolbar. You can now begin developing features with the Google Play services APIs.

Completing the Manifest File

MapTest1/app/src/main/AndroidManifest.xml 
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.wenchen.maptest1"
  android:versionCode="1"
  android:versionName="1.0">

  <!-- Using Android 9.0 (API 28) -->
  <uses-sdk
    android:minSdkVersion="21"
    android:targetSdkVersion="28" />

  <!-- OpenGL ES version 2 -->
  <uses-feature
    android:glEsVersion="0x00020000"
    android:required="true" />

  <uses-permission android:name="android.permission.INTERNET" />
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
  <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
  <uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />

  <application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme">

    <activity
      android:name="com.wenchen.maptest1.MainActivity"
      android:label="@string/app_name">
      <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="your_39/40-character_apikey" />
  </application>
</manifest>

Completing the Layout File

MapTest1/app/src/main/res/layout/activity_main.xml 
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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">

  <fragment
    android:id            = "@+id/googleMap"
    android:layout_width  = "match_parent"
    android:layout_height = "match_parent"
    class="com.google.android.gms.maps.SupportMapFragment"
    android:layout_above  = "@+id/latlongLocation" />

  <TextView
    android:id            = "@+id/latlongLocation"
    android:layout_width  = "fill_parent"
    android:layout_height = "wrap_content"
    android:gravity       = "bottom"
    android:layout_alignParentBottom="true"
    android:background    = "#ff058fff"
    android:paddingTop    = "5dp"
    android:paddingBottom = "5dp"
    android:textColor     = "#ffffffff"
    android:paddingLeft   = "5dp"
    android:paddingRight  = "5dp" />
</RelativeLayout>

Completing the Java Source Code

MapTest1/app/src/main/java/com/wenchen/maptest1/MainActivity.java 
package com.wenchen.maptest1;

import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import androidx.fragment.app.FragmentActivity;
import android.widget.TextView;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.CameraUpdateFactory;
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 MainActivity extends FragmentActivity implements LocationListener {
  GoogleMap googleMap;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // Show error dialog if GoolglePlayServices not available
    if ( !isGooglePlayServicesAvailable( )) {
      finish( );
    }
    setContentView( R.layout.activity_main );
    SupportMapFragment supportMapFragment =
      (SupportMapFragment) getSupportFragmentManager( ).findFragmentById( R.id.googleMap );
    googleMap = supportMapFragment.getMap( );
    googleMap.setMyLocationEnabled( true );
    LocationManager locationManager = (LocationManager) getSystemService( LOCATION_SERVICE );
    Criteria criteria = new Criteria( );
    String bestProvider = locationManager.getBestProvider( criteria, true );
    Location location = locationManager.getLastKnownLocation( bestProvider );
    if ( location != null ) {
      onLocationChanged( location );
    }
    locationManager.requestLocationUpdates( bestProvider, 20000, 0, this );
  }

  @Override
  public void onLocationChanged( Location location ) {
    googleMap.clear( );
    TextView locationTv = (TextView) findViewById( R.id.latlongLocation );
    double latitude = location.getLatitude( );
    double longitude = location.getLongitude( );
    LatLng latLng = new LatLng( latitude, longitude );
    googleMap.addMarker( new MarkerOptions( ).position( latLng )
      .title( "Current location" )
      .snippet( "DDMS is cool." ) );
    googleMap.moveCamera( CameraUpdateFactory.newLatLngZoom( latLng, 15 ) );
    googleMap.animateCamera( CameraUpdateFactory.zoomTo(14), 2000, null );
    locationTv.setText( "Latitude:" + latitude + ", Longitude:" + longitude );
  }

  @Override
  public void onProviderDisabled( String provider ) {
    // TODO Auto-generated method stub
  }

  @Override
  public void onProviderEnabled( String provider ) {
    // TODO Auto-generated method stub
  }

  @Override
  public void onStatusChanged( String provider, int status, Bundle extras ) {
    // TODO Auto-generated method stub
  }

  private boolean isGooglePlayServicesAvailable( ) {
    int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable( this );
    if ( ConnectionResult.SUCCESS == status ) {
      return true;
    } else {
      GooglePlayServicesUtil.getErrorDialog( status, this, 0 ).show( );
      return false;
    }
  }
}

Creating an Emulator
Select the following Android Studio options: 
   Tools ⇒ Android ⇒ AVD Manager
Create one device with the following features:

Activating the DDMS (Dalvik Debug Monitor Server)
Select the following Android Studio options: 
   Tools ⇒ Android ⇒ Android Device Monitor

Checking the Emulator
Send the location from the DDMS and check the emulator.


Note that