Android and Google Maps
This tutorial describes the usage of Google Maps in your Android application. It is based on Eclipse 4.2, Java 1.6 and Android 4.2.
Table of Contents
The following assumes that you have already basic knowledge in Android development. Please check the Android development tutorial for the basics.
Google provides via Google play a library for using Google Maps in your application. The following description is based on the Google Maps Android API v2 which provides significant improvements to the older API version.
The library provides the
com.google.android.gms.maps.MapFragment class and theMapView class for displaying the map component.You need to add additional information to your
AndroidManifest.xml file to use Google Maps.<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.vogella.android.locationapi.maps"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="17"
android:targetSdkVersion="17" />
<permission
android:name="com.vogella.android.locationapi.maps.permission.MAPS_RECEIVE"
android:protectionLevel="signature" />
<uses-feature
android:glEsVersion="0x00020000"
android:required="true" />
<uses-permission android:name="com.vogella.android.locationapi.maps.permission.MAPS_RECEIVE" />
<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" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.vogella.android.locationapi.maps.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_apikey" />
</application>
</manifest>
The
MapFragment class extends the Fragment class and provides the life-cycle management and the services for displaying a GoogleMap widget. GoogleMap is the class which shows the map. TheMapFragment has the getMap() method to access this class.the
LatLng class can be used to interact with the GoogleView class.You can create markers on the map via the
Marker class. This class can be highly customized.The following code shows an example.
public class MainActivity extends Activity {
static final LatLng HAMBURG = new LatLng(53.558, 9.927);
static final LatLng KIEL = new LatLng(53.551, 9.993);
private GoogleMap map;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))
.getMap();
if (map!=null){
Marker hamburg = map.addMarker(new MarkerOptions().position(HAMBURG)
.title("Hamburg"));
Marker kiel = map.addMarker(new MarkerOptions()
.position(KIEL)
.title("Kiel")
.snippet("Kiel is cool")
.icon(BitmapDescriptorFactory
.fromResource(R.drawable.ic_launcher)));
}
}
On the
GoogleMap you can register a listener for the markers in your map via thesetOnMarkerClickListener(OnMarkerClickListener) method. TheOnMarkerClickListener class defines the onMarkerClicked(Marker) method which is called if a marker is clicked.Similar to you also listen to drag events and info window clicks.
The
GoogleMap can be highly customized.The following example code is taken from the offical Google webpage.
static final LatLng HAMBURG = new LatLng(53.558, 9.927);
static final LatLng KIEL = new LatLng(53.551, 9.993);
private GoogleMap map;
... // Obtain the map from a MapFragment or MapView.
//Move the camera instantly to hamburg with a zoom of 15.
map.moveCamera(CameraUpdateFactory.newLatLngZoom(HAMBURG, 15));
// Zoom in, animating the camera.
map.animateCamera(CameraUpdateFactory.zoomTo(10), 2000, null);
Open the Android SDK Manager and install →
Import the library which was downloaded into Eclipse via → → → .
To use this library define a library dependency in your Android project.
To use Google Maps you need to create a valid Google Maps API key. The key is free, you can use it with any of your applications that call the Maps API, and it supports an unlimited number of users.
You get this key via the so-called Google APIS Console. You have to provide your application signature key and the application package name.
This is based on the key with which you sign your Android application during deployment. During development with Eclipse, Eclipse us automatically creates and uses a debug key.
The Eclipse debug key for signing your application can be found in the
userhome/.android/debug.keystore file.To create the SHA-1 for your debug keystore you use the
keytool command from your JDK installation pointing to the debug.keystore file.keytool -list -v -alias androiddebugkey \
-keystore <path_to_debug_keystore>debug.keystore \
-storepass android -keypass android
Copy the SHA-1 output, as you need this later.
You have to register in the Google APIs Console that you want to use Google Maps for Android. You can reach this console via the following link: Google APIs Console . Select here the Services entry.
Activate the Google Maps Android API v2.
You need later to register your application via its package in this console together with the SHA-1 fingerprint of your signature key. For this you select the entry and click on the API Access entry. Afterwards click on the entry.
Enter your SHA-1 fingerprint and the package of your application separated by a semicolon. For example you can use the
com.vogella.android.locationapi.maps package.
The procedure is described in detail in the following link: Getting a Google Maps key .
In the following chapter we will build an Android application which shows a
GoogleMap.Create a new Android project called com.vogella.android.locationapi.maps with an activity calledShowMapActivity.
Change the
AndroidManifest.xml file to the following code. Add the following permissions to your application.<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.vogella.android.locationapi.maps"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="17"
android:targetSdkVersion="17" />
<permission
android:name="com.vogella.android.locationapi.maps.permission.MAPS_RECEIVE"
android:protectionLevel="signature" />
<uses-feature
android:glEsVersion="0x00020000"
android:required="true" />
<uses-permission android:name="com.vogella.android.locationapi.maps.permission.MAPS_RECEIVE" />
<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" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.vogella.android.locationapi.maps.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_apikey" />
</application>
</manifest>
Get a valid API key for your application and enter this key in the
AndroidManifest.xml file.In this example we use the
MapFragment. Change your layout file to the following code.<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/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.MapFragment" />
</RelativeLayout>
Change your activity to the following.
package com.vogella.android.locationapi.maps;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
public class MainActivity extends Activity {
static final LatLng HAMBURG = new LatLng(53.558, 9.927);
static final LatLng KIEL = new LatLng(53.551, 9.993);
private GoogleMap map;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))
.getMap();
Marker hamburg = map.addMarker(new MarkerOptions().position(HAMBURG)
.title("Hamburg"));
Marker kiel = map.addMarker(new MarkerOptions()
.position(KIEL)
.title("Kiel")
.snippet("Kiel is cool")
.icon(BitmapDescriptorFactory
.fromResource(R.drawable.ic_launcher)));
// Move the camera instantly to hamburg with a zoom of 15.
map.moveCamera(CameraUpdateFactory.newLatLngZoom(HAMBURG, 15));
// Zoom in, animating the camera.
map.animateCamera(CameraUpdateFactory.zoomTo(10), 2000, null);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
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