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Google Maps API

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Google Maps on Android

A nice API for mapping applications


Pre-reqs

Need to have the Google API added in Eclipse’s Android Manager

Make sure your build target and Android Virtual Device (AVD, or the simulator) support the maps

More info:

http://developer.android.com/resources/tutorials/views/hello-mapview.html




Add the MapView

In the res/layout/main.xml file: Add your MapView

Details in the Tutorial





A Key

You will need a Google Maps API Key

It’s free - you can register with the SDK debug certificate. When deploying your app for real, you’ll need a

real certificate

http://code.google.com/android/add-ons/google-apis/mapkey.html





Using the Map Controller

Using the Map is easy… MapController myMC =

myMapView.getController();

myMC.setZoom(17); // set the zoom level myMapView.setSatellite(); // sets sat view


Map Control

You can zoom, set points, routes, etc.

Adding overlays allows you to note all places of interest from a list

Overlays are discussed in the tutorial http://

developer.android.com/resources/tutorials/views/hello-mapview.html





Intents


Intents

Intents allow you to pass a message Within your app To existing resources on the phone, such as the dialer


Uses

To launch the dialer… To load another activity in your app… You can also create custom intents…


Launch another Activity

Intent intent = new Intent(FirstActivity.this, AnotherActivity.class); startActivity(intent);

This will launch another activity (screen) without destroying the first


ExampleIntent I = new Intent(Intent.ACTION_DIAL, Uri.parse(“tel:647-722-3888”));

startActivity(i);


Launch Google MapsString uri = “geo:37.523156,-121.084917”

Intent myIntent = New Intent(android.content.Intent.ACTION_VIEW, Uri.parse(uri));

startActivity(myIntent);


Intents can

Return a result. startActivityForResult();

Be filtered by your app so that you can respond to certain intents.

Create your own and respond to them


Android Intent Docs

http://developer.android.com/guide/topics/intents/intents-filters.html





Files and Storage on Android Devices


Storage

Four basic ways

Shared Preferences Database Files on the Device The “cloud”

http://developer.android.com/guide/topics/data/data-storage.html






Shared Preferences

Easy, built in way to save preferences to the device App settings, Similar to the Windows registry SharedPreferences class in the API


SharedPreferences Example SharedPreferences settings =

getSharedPreferences(PREFS_NAME, default_value);

boolean value = settings.getBoolean(“prefName", default_value);


Database

Local database on the device SQLite For heavier-duty data requirements / queries

db.execSQL(“SELECT * …”);


Files

Can store data to a file Useful for saving media files, save games,

etc. Just like writing files in Java

FileOutputStream fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);

fos.write(string.getBytes());

fos.close();


Saving to the Network Persistent storage, but… A network connection

may not always be available

May have to create your own server

android.net libraries stream to a network connection


Amazon AWS

Allows you to save data to Amazon servers

An API for Android

http://aws.amazon.com/




OpenFeint & Scoreloop

A nice resource for games Allows you to easily save high scores and

achievements Creates leaderboards, friend lists, etc.

www.OpenFeint.com www.ScoreLoop.com

http://www.openfeint.com/

http://www.scoreloop.com/


Broadcast Receivers


Broadcast Receivers

These allow you to ‘intercept’ messages That you create, or… That the system sends


The coolest part

The user doesn’t need to start your app

If your receiver listens for the specific Intent that fired, that code will run

Or you can decide when a receiver is active through registering / deregistering


2 ways to create

In xml <receiver> tag in AndroidManifest.xml

In Code Context.registerReceiver(); Gives more control, but not active until your app

has run


Then…

Just fill in the onReceive() method.

This is the code that “handles” the event


Some System Intents

ACTION_TIME_TICK A minute has passed

ACTION_BATTERY_LOW Need to plug it in!

SMS_RECEIVED You got a text!


Android BR Docs

http://developer.android.com/reference/android/content/BroadcastReceiver.html





Android Databases


Databases

Android uses the SQLite Database

A lightweight database server

Returns the Android ‘Cursor’ instead of rows – for efficiency.


Basics

It’s useful to create a “Helper” class to simplify database interactions

Methods will include: getRecord(long rowIndex) to return a specific

record getAllRecords() to return a Cursor


SQLiteOpenHelper

Your helper class can also extend the SQLiteOpenHelper abstract class

To simplify creating and opening databases


Cursors

Instead of returning rows, you get a Cursor to manage the results of a query

Cursor myResult = myDB.query (…);

myResult.getString(columnIndex);


Notepad Tutorial

Great tutorial for database concepts

Includes: Integrating the ListView with a DB ->

http://developer.android.com/resources/tutorials/notepad/index.html




Publishing Your Apps


Signing

This is required to release your application

Several Steps…

The tutorial http://developer.android.com/guide/publishing/app-signing.html

http://developer.android.com/guide/publishing/app-signing.html


Apps

The device will only run signed apps

You can issue your own certificate, or use the developer certificate for testing

To release, you must have a certificate with a 20+ year expiration date


Eclipse

Right-click on the project Android Tools -> Export Signed Application This creates the .apk You can then load it to a web server


Device

Make sure your device allows apps that are not from the app store

In configuration menu


Testing… Very important!

Test on several devices Screen resolutions No network connectivity Orientation Interruption from calls GPS if applicable

The simulator is usually a best-case scenario!


Simulator

Test on all available AVD versions

Specify the <uses-sdk> parameter in the manifest, and test on all devices after that version


Simulator

In Eclipse’s Run->Run Configuration Specify Network speed and latency to test

under varying conditions Test on a real device also


Once fully tested

Submit to the Android Marketplace

Should obfuscate source code Harder to reverse engineer Proguard does the trick

Enabled in eclipse – your app will have a proguard.cfg file


Submission

Google charges $25 to register You may then submit as many apps as you

like Activation in the Google marketplace is

almost instantaneous

Amazon AppStore takes 2-3 weeks for approval


Proguard Documentation

http://developer.android.com/guide/developing/tools/proguard.html

Shrinks, optimizes, and obfuscates the code




google maps api

Documents

google api

android devices

android intent docshttp

google maps api key

launch google mapsstring

android virtual device

real certificate http

tutorial http