Create Location-Aware Android Apps with Google Maps

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto" 
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/map"

// If Android is going to recognize this fragment as a MapFragment, then you must set the
// fragment’s android:name attribute to "com.google.android.gms.maps.MapFragment”//

android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.jessicathornsby.myapplication.MapsActivity" />

mMapFragment = MapFragment.newInstance();
FragmentTransaction fragmentTransaction =
        getFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.my_container, mMapFragment);
fragmentTransaction.commit();

import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import com.google.android.gms.maps.CameraUpdateFactory;
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;

// Since we’re adding our map via a fragment, this Activity needs to extend FragmentActivity.
// You’ll also notice that your project is implementing onMapReadyCallback, which gets
// triggered when the map is ready to use// 

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback { 
// GoogleMap is the main class of the Maps API and is responsible for handling important
// operations such as connecting to the Google Maps service, downloading map tiles,
// and responding to user interactions//
private GoogleMap mMap;   

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

    // Obtain the map from the SupportMapFragment//
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager() 

    // Call FragmentManager.findFragmentById() and pass it the ID of the UI element where
    // you want to display your map, in this example that’s ‘map’//
    .findFragmentById(R.id.map);

    // You can’t instantiate a GoogleMap object directly, but you can use getMapAsync to set a
    // callback that’s triggered once the GoogleMap instance is ready to use//
      mapFragment.getMapAsync(this);   
    }

@Override
// Set an instance of OnMapReadyCallback on your MapFragment. If the user doesn’t have
// Google Play Services installed,then at this point they’ll be prompted to install it
public void onMapReady(GoogleMap googleMap) {      
    mMap = googleMap;
    
    // This sample app cannot access the user’s location, but it does emulate this functionality
    // by displaying a ‘you are here’-style marker that’s hard-coded to appear at Sydney,
    // Australia. Here, we’re defining the latitude and longitude coordinates this marker will
    // use
    LatLng sydney = new LatLng(-34, 151);

    // Add a marker to the map at the ‘Sydney’ coordinates. Unless you specify otherwise,
    // Android uses Google Maps’ standard marker icon, but you can customize this icon by
    // changing its colour, image or anchor point, if required.
    mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));

    // Use CameraUpdate to move the map’s ‘camera’ to the user's current location - in this
    // example,that’s the hard-coded Sydney coordinates. When you’re creating your own apps,
    // you may want to tweak this line to animate the camera’s movements, which typically
    // provides a better user experience. To animate the camera, replace GoogleMap.moveCamera
    // with GoogleMap.animateCamera//
    mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));   
    } 
}

apply plugin: 'com.android.application'
   ...
   dependencies {
       compile 'com.google.android.gms:play-services:9.8.0'
   }

  dependencies {
       compile 'com.google.android.gms:play-services-maps:9.8.0'
       compile 'com.google.android.gms:play-services-location:9.8.0

   }

 <meta-data
       android:name="com.google.android.geo.API_KEY"
       android:value="YOUR_API_KEY"/>

<meta-data
   android:name="com.google.android.gms.version"
   android:value="@integer/google_play_services_version" />

<uses-permission
       android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<uses-feature android:glEsVersion="0x00020000" android:required="true" />

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<uses-permission android:name="android.permission.INTERNET" />

 <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

package com.jessicathornsby.myapplication;
import android.support.v4.app.ActivityCompat;
import android.os.Build;
import android.os.Bundle;
import com.google.android.gms.common.api.GoogleApiClient;
import android.support.v4.content.ContextCompat;
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.model.Marker;
import com.google.android.gms.maps.SupportMapFragment;
import android.content.pm.PackageManager;
import android.location.Location;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;

// Since it’s the easiest way of adding a map to your project, I’m going to stick with using
// a MapFragment//

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
GoogleApiClient.ConnectionCallbacks, LocationListener {  
 private GoogleMap mMap;  
 GoogleApiClient mGoogleApiClient;  
 Marker mLocationMarker;  
 Location mLastLocation;     
 LocationRequest mLocationRequest;

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

     
  if (Build.VERSION.SDK_INT & gt; = Build.VERSION_CODES.M) {          
   checkLocationPermission();      
  } 

     
  SupportMapFragment mapFragment =
           (SupportMapFragment) getSupportFragmentManager(.findFragmentById(R.id.map);      
  mapFragment.getMapAsync(this);  
 }
   
 public static final int MY_PERMISSIONS_REQUEST_LOCATION = 1;

 public boolean checkLocationPermission() {
  // In Android 6.0 and higher you need to request permissions at runtime, and the user has
  // the ability to grant or deny each permission. Users can also revoke a previously-granted
  // permission at any time, so your app must always check that it has access to each
  // permission, before trying to perform actions that require that permission. Here, we’re using
  // ContextCompat.checkSelfPermission to check whether this app currently has the
  // ACCESS_COARSE_LOCATION permission
    
  if (ContextCompat.checkSelfPermission(this,              
             android.Manifest.permission.ACCESS_COARSE_LOCATION)
   // If your app does have access to COARSE_LOCATION, then this method will return
   // PackageManager.PERMISSION_GRANTED//
                  != PackageManager.PERMISSION_GRANTED) {  
   if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                   android.Manifest.permission.ACCESS_COARSE_LOCATION)) {
    // If your app doesn’t have this permission, then you’ll need to request it by calling
    // the ActivityCompat.requestPermissions method//
    requestPermissions(new String[] {
      android.Manifest.permission.ACCESS_COARSE_LOCATION
     },
     MY_PERMISSIONS_REQUEST_LOCATION);   
   } else {
    // Request the permission by launching Android’s standard permissions dialog.
    // If you want to provide any additional information, such as why your app requires this
    // particular permission, then you’ll need to add this information before calling
    // requestPermission //             
    requestPermissions(new String[] {
      android.Manifest.permission.ACCESS_COARSE_LOCATION
     },
     MY_PERMISSIONS_REQUEST_LOCATION);        
   }        
   return false;
  } else {    
   return true;    
  }
 }

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

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

 @Override
 public void onMapReady(GoogleMap googleMap) {
  mMap = googleMap;
  // Specify what kind of map you want to display. In this example I’m sticking with the
  // classic, “Normal” map
      
  mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);

    
  if (Build.VERSION.SDK_INT & gt; = Build.VERSION_CODES.M) {    
   if (ContextCompat.checkSelfPermission(this,
                   android.Manifest.permission.ACCESS_COARSE_LOCATION)
                   == PackageManager.PERMISSION_GRANTED) {        
    buildGoogleApiClient();
    // Although the user’s location will update automatically on a regular basis, you can also
    // give your users a way of triggering a location update manually. Here, we’re adding a
    // ‘My Location’ button to the upper-right corner of our app; when the user taps this button,
    // the camera will update and center on the user’s current location//
               
    mMap.setMyLocationEnabled(true);
   }
  }    
  else {    
   buildGoogleApiClient();        
   mMap.setMyLocationEnabled(true);    
  }
 }
 protected synchronized void buildGoogleApiClient() {
  // Use the GoogleApiClient.Builder class to create an instance of the
  // Google Play Services API client//      
  mGoogleApiClient = new GoogleApiClient.Builder(this)
              .addConnectionCallbacks(this)
              .addApi(LocationServices.API)
              .build();

  // Connect to Google Play Services, by calling the connect() method//        
  mGoogleApiClient.connect();  
 }

 @Override
 // If the connect request is completed successfully, the onConnected(Bundle) method
 // will be invoked and any queued items will be executed//
 public void onConnected(Bundle bundle) {
  mLocationRequest = new LocationRequest();    
  mLocationRequest.setInterval(2000);    
  if (ContextCompat.checkSelfPermission(this,
               android.Manifest.permission.ACCESS_COARSE_LOCATION)
              == PackageManager.PERMISSION_GRANTED) {  
   // Retrieve the user’s last known location//    
   LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
                                                     mLocationRequest, this);     
  }
 }

 @Override
 public void onConnectionSuspended(int i) {
 }

 // Displaying multiple ‘current location’ markers is only going to confuse your users!
 // To make sure there’s only ever one marker onscreen at a time, I’m using
 // mLocationMarker.remove to clear all markers whenever the user’s location changes.

 @Override
 public void onLocationChanged(Location location) {
  mLastLocation = location;
  if (mLocationMarker != null) {
   mLocationMarker.remove();
  }

  // To help preserve the device’s battery life, you’ll typically want to use
  // removeLocationUpdates to suspend location updates when your app is no longer
  // visible onscreen//
  if (mGoogleApiClient != null) {
   LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
  }
 }

 // Once the user has granted or denied your permission request, the Activity’s
 // onRequestPermissionsResult method will be called, and the system will pass
 // the results of the ‘grant permission’ dialog, as an int//

 @Override
 public void onRequestPermissionsResult(int requestCode,
  String permissions[], int[] grantResults) {
  switch (requestCode) {
   case MY_PERMISSIONS_REQUEST_LOCATION:
    {

     // If the request is cancelled, the result array will be empty (0)// 
     if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

      // If the user has granted your permission request, then your app can now perform all its
      // location-related tasks, including displaying the user’s location on the map//
      if (ContextCompat.checkSelfPermission(this,
        android.Manifest.permission.ACCESS_COARSE_LOCATION)
                      == PackageManager.PERMISSION_GRANTED) {
       if (mGoogleApiClient == null) {
        buildGoogleApiClient();
       }
       mMap.setMyLocationEnabled(true);
      }
     } else {
      // If the user has denied your permission request, then at this point you may want to
      // disable any functionality that depends on this permission//
     }
     return;
    }
  }
 }
}