Android Application Development Cookbook _ www.bit.ly/taiho123

Android™ Application Development
Cookbook
93 Recipes for Building Winning Apps

Wei-Meng Lee


Android™ Application Development Cookbook: 93 Recipes for Building Winning Apps
Published by
John Wiley & Sons, Inc.
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Copyright © 2013 by John Wiley & Sons, Inc., Indianapolis, Indiana
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in this book.


To my family,
Thanks for the understanding and support while I
worked on getting this book ready. I love you all!



About the Author

Wei-Meng Lee  is a technologist and founder of Developer Learning Solutions (www.learn2develop

.net), a technology company specializing in hands-on training on the latest mobile technologies.
Wei-Meng has many years of training experience and his courses place special emphasis on the learning-by-doing approach. This hands-on approach to learning programming makes understanding the
subject much easier than reading books, tutorials, and other documentation.

Wei-Meng is also the author of Beginning iOS 5 Application Development (Wrox, 2010)
and Beginning Android 4 Application Development (Wrox, 2011). You can contact him at


About the Technical Editor

Chaim Krause  is a Simulation Specialist at the US Army’s Command and General Staff College
where he develops various software products on a multitude of platforms, from iOS and Android
devices to Windows desktops and Linux servers, among other duties. Python is his preferred language,
but he is multilingual and also codes in Java, JavaScript/HTML5/CSS, and others. He was fortunate to
begin his professional career in the software field at Borland where he was a Senior Developer Support
Engineer for Delphi. Outside of computer geek stuff, Chaim enjoys techno and dubstep music, and
scootering with his two sled dogs Dasher and Minnie.


Credits
Executive Editor

Production Manager

Robert Elliott

Tim Tate

Senior Project Editor

Vice President and Executive Group
Publisher

Ami Frank Sullivan

Richard Swadley
Technical Editor

Chaim Krause

Vice President and Executive Publisher

Neil Edde
Production Editor

Christine Mugnolo

Associate Publisher

Jim Minatel
Copy Editor

Luann Rouff

Project Coordinator, Cover

Katie Crocker
Editorial Manager

Mary Beth Wakefield

Compositor

Craig Johnson, Happenstance Type-O-Rama
Freelancer Editorial Manager

Rosemarie Graham

Proofreader

Scott Klemp, Word One New York
Associate Director of Marketing

David Mayhew

Indexer

Robert Swanson
Marketing Manager

Ashley Zurcher

Cover Designer

Ryan Sneed
Business Manager

Amy Knies

Cover Image

© Paul Fleet / iStockPhoto


Acknowledgments

A lot of development  in the Android world has happened since my last book, Beginning Android 4
Application Development, went to print. Google has released a new version of the SDK: Android 4.1
SDK. With the Android 4.1 SDK and the ADT Plugin 20.0.3, it is now much easier to write Android
applications — from those that run on older devices right up to the latest and greatest.

I would like to thank some key people who have worked hard behind the scenes to make this book
a reality.
First, my personal gratitude to Bob Elliott, executive editor at Wrox. Bob is always ready to lend a
listening ear and offer help when it’s needed. It is a great pleasure to work with Bob, as he is one of
the most responsive people I have ever worked with. Thank you, Bob, for the help and guidance.
Of course, I cannot forget Ami Sullivan, my editor (and friend), who is always a pleasure to work
with. Thank you for your guidance and encouragement to keep the project going, Ami.
I am also grateful to my technical editor, Chaim Krause. Chaim has been eagle-eye editing the book
and testing my recipes, ensuring that my code works as written. Thanks, Chaim.
Last but not least, I want to thank my parents and my wife, Sze Wa, for all the support they have
given me. They have selflessly adjusted their schedules to accommodate my busy schedule when I
was working on this book. My wife, as always, has stayed up with me on numerous nights as I was
furiously working to meet the deadlines, and for this I would like to say to her and my parents, “I
love you all!” Finally, to our lovely dog, Ookii, thanks for staying by our side.



Contents

Introduction
Chapter 1: Android Fundamentals

Recipe 1.1  Linking Activities

xv
1

1

Solution2

Recipe 1.2  Passing Data between Activities

5

Solution6

Recipe 1.3  Passing Objects between Activities

11

Solution11

Recipe 1.4  Sending and Receiving Broadcasts

13

Solution14

Recipe 1.5  Assigning Priorities to Broadcast Receivers

18

Solution19

Recipe 1.6  Auto-Launching Your Application at Boot Time

21

Solution21

Recipe 1.7  Calling Built-In Apps

22

Solution23

Recipe 1.8  Making Your Application Callable by Others

32

Solution32

Chapter 2: Using Views to Design the User Interface

Recipe 2.1  Using Buttons

39

40

Solution40

Recipe 2.2  Using Image Buttons

44

Solution44

Recipe 2.3  Using Radio Buttons

46

Solution46

Recipe 2.4  Using CheckBoxes

49

Solution50

Recipe 2.5  Implementing a Star Rating System

52

Solution52

Recipe 2.6  Using AutoCompleteTextView

55

Solution55

Recipe 2.7  Displaying Web Pages

57

Solution58


CONTENTS

Recipe 2.8  Using the TimePicker

62

Solution62

Recipe 2.9  Using the DatePicker

64

Solution65

Recipe 2.10  Using LinearLayout for View Positioning

66

Solution67

Recipe 2.11  Using RelativeLayout for View Positioning

72

Solution72

Recipe 2.12  Using FrameLayout for View Positioning

74

Solution74

Recipe 2.13  Using TableLayout for View Positioning

77

Solution77

Recipe 2.14  Using the ScrollView

79

Solution79

Recipe 2.15  Displaying Context and Options Menus

83

Solution83

Recipe 2.16  Displaying Dialogs

90

Solution91

Recipe 2.17  Implementing Paging

98

Solution98

Chapter 3: Displaying Lists of Items and Images

Recipe 3.1  Displaying a List of Items Using the ListView

105

106

Solution106

Recipe 3.2  Customizing the ListView

108

Solution108

Recipe 3.3  Displaying Multiple ListViews

111

Solution111

Recipe 3.4  Creating Custom ListViews

114

Solution115

Recipe 3.5  Further Customizing Each Row with Additional
TextViews117
Solution Part One: Adding Additional TextViews
Solution Part Two: Recycling Each Row

Recipe 3.6  Displaying a List of Items Using the Spinner View

118
122

125

Solution126

Recipe 3.7  Displaying a List of Images

128

Solution129

Recipe 3.8  Animating the Changing of Images Using the
ImageSwitcher133
Solution133
x


CONTENTS

Recipe 3.9  Displaying Images Using the GridView

138

Solution138

Recipe 3.10   Building a Master-Detail User Interface

141

Solution143

Chapter 4: Telephony

Recipe 4.1  Calling from Your Application

151

151

Solution152

Recipe 4.2   Monitoring the State of the Phone

153

Solution153

Recipe 4.3   Monitoring Phone State in the Background

156

Solution156

Recipe 4.4   Blocking Outgoing Calls

158

Solution159

Recipe 4.5   Auto-Answering an Incoming Call

160

Solution160

Recipe 4.6  Switching to Airplane Mode

163

Solution163

Recipe 4.7  Getting the Phone Number, IMEI, and SIM Card ID

165

Solution166

Recipe 4.8  Enabling Bluetooth

167

Solution167

Recipe 4.9  Displaying the Call Log

173

Solution173

Chapter 5: Messaging

Recipe 5.1  Sending SMS Messages Through the Built-in
Messaging Application

175

175

Solution176

Recipe 5.2  Sending SMS Messages Programmatically in Your
Android Application

178

Solution178

Recipe 5.3  Monitoring the Status of Sent SMS Messages
Programmatically179
Solution180

Recipe 5.4   Monitoring Outgoing SMS Messages

183

Solution184

Recipe 5.5  Intercepting Incoming SMS Messages

187

Solution187

xi


CONTENTS

Chapter 6: Network Programming

Recipe 6.1  Connecting to Servers Using HTTP GET

191

191

Solution192

Recipe 6.2  Connecting to Servers Using HTTP POST

195

Solution195

Recipe 6.3  Downloading Binary Data Using HTTP

198

Solution199

Recipe 6.4  Consuming XML Web Services

200

Solution201

Recipe 6.5  Consuming JSON Web Services

204

Solution205

Recipe 6.6  Getting the IP Address of the Device

210

Solution211

Recipe 6.7  Creating a Socket Server

212

Solution212

Recipe 6.8  Creating a Socket Client

218

Solution218

Recipe 6.9  Checking for the Availability of Bluetooth

222

Solution222

Recipe 6.10   Monitoring the State of Bluetooth

224

Solution225

Recipe 6.11  Creating a Bluetooth Chat Application

226

Solution227

Chapter 7: Using Google Maps

Recipe 7.1  Displaying Google Maps

243

243

Solution244

Recipe 7.2   Zooming in and out of Google Maps

250

Solution250

Recipe 7.3  Changing Map Modes

253

Solution253

Recipe 7.4  Navigating the Map to a Particular Location

256

Solution256

Recipe 7.5   Adding Markers to the Map

258

Solution258

Recipe 7.6  Finding a User-Friendly Address Using Reverse
Geocoding, and Vice Versa

268

Solution268

Recipe 7.7   Responding to Zooming and Panning

275

Solution275

xii


CONTENTS

Chapter 8: Location-Based Data Services

Recipe 8.1  Obtaining Geographical Location Using GPS, Wi-Fi, or
Cellular Networks

279

280

Solution280

Recipe 8.2  Choosing the Best Location Provider to Use

284

Solution284

Recipe 8.3   Monitoring a Location

288

Solution288

Recipe 8.4  Using a BroadcastReceiver to Obtain Locations

289

Solution290

Recipe 8.5  Location Data Logging

293

Solution293

Chapter 9: Accessing the Hardware

Recipe 9.1  Capturing Pictures with the Camera

301

301

Solution301

Recipe 9.2  Detecting the Presence of Hardware Features

304

Solution305

Recipe 9.3  Checking Network State

306

Solution306

Recipe 9.4   Turning GPS On/Off

308

Solution308

Recipe 9.5  Capturing Hardware Buttons Programmatically

310

Solution310

Recipe 9.6  Switching on the Flashlight

313

Solution314

Recipe 9.7  Capturing Barcodes

319

Solution320

Chapter 10: Persisting Data

Recipe 10.1  Saving and Loading User Preferences

325

325

Solution326

Recipe 10.2  Creating a Preference Screen

328

Solution328

Recipe 10.3  Saving Files to the Data Directory

333

Solution333

Recipe 10.4  Saving Files to the Cache Directory

338

Solution338

Recipe 10.5  Saving Files to External Storage

340

Solution341
xiii


CONTENTS

Recipe 10.6   Attaching Files to Your Project

345

Solution346

Recipe 10.7  Creating and Using SQLite Databases Programmatically 347
Solution348

Recipe 10.8  Pre-creating the SQLite Databases

353

Solution353

Chapter 11: Deploying Your Android Applications

Recipe 11.1  Localizing Your Application

357

357

Solution358

Recipe 11.2  Exporting Your Application as an APK File

362

Solution362

Recipe 11.3  Deploying Your App Through E‑mail

365

Solution365

Recipe 11.4  Deploying Your App Through the Web

367

Solution368

Recipe 11.5  Deploying Your App Through an SD Card

369

Solution369

Recipe 11.6  Specifying the Application Installation Location

370

Solution371

Index

xiv

373

Introduction

The pace of Android development  has been fast and furious. Within a short time span of a few
years, Android has matured into a stable platform, rivaling that of its main competitor, iOS. At the
time of writing, the latest version of Android is 4.1 (aka Jelly Bean). Android 4.1 runs on both smartphones and tablets, making it the platform of choice for many developers.

This book was born out of the many frustrations I have had when developing Android applications.
It is often the case that you just need a quick snapshot showing how to do a certain task, and a code
snippet would be a quick fix. However, a trip to the official Android documentation often caused
more confusion than help, as the code samples are not always complete. Hence, this book aims to
fill the void by providing standalone examples that you can quickly “embrace and extend.”
Each recipe tackles a problem that you might face in your daily life as an Android developer —
whether it’s as minor as using a Button view or as involved as implementing a Master-Detail application using fragments. You can read this book from the first recipe until the last recipe, or you can
turn directly to the recipes that interest you most.

Who This Book Is For
This book is targeted at Android programmers who already have some basic knowledge of creating
Android applications. It is assumed that you know how to create an Android project using Eclipse,
and that you are already familiar with the structure of an Android project.
All the code samples in this book were written and tested using the Android 4.1 SDK, together with
Eclipse (Juno release) and the ADT plugin 20.0.3. All projects are able to run on Android devices
beginning with Android version 2.2. In particular, all projects make use of the Android Support package that is by default included in Android 4.1 projects. Using the Android Support Package enables
your applications to make use of the newer features introduced with Android version 3.0 (such as
fragments) and still run on older Android devices.
NOTE   While every effort has been made to ensure that all the tools used in the

examples are the latest, it is always possible that by the time you read this book,
newer versions may be available. If so, some of the instructions and/or screenshots may differ slightly. However, any variations should be manageable.

introduction

What This Book Covers
This book covers all key areas of Android programming using the Android 4.1 SDK. It is divided
into 11 chapters.
Chapter 1: Android Fundamentals covers basic topics such as how to link activities, pass data
between activities, send and receive broadcasts, call built-in apps, and more.
Chapter 2: Using Views to Design the User Interface explains how to use the various views to build
the user interface of your Android applications. Also covered are the different types of layouts supported in Android to arrange the views, including LinearLayout, RelativeLayout, FrameLayout, and
others. You will also learn how to display context and option menus.
Chapter 3: Displaying Lists of Items and Images covers how to use the ListView and Spinner, and
how to customize them to display a list of items. It also demonstrates how to use fragments to create
Master-Detail applications.
Chapter 4: Telephony covers topics related to the phone on your Android device, such as how to
block outgoing calls, auto-answering incoming calls, enabling Bluetooth, and more.
Chapter 5: Messaging covers how to send and intercept SMS messages on your Android phone. You
will also learn how to monitor for SMS messages sent by your users.
Chapter 6: Network Programming covers topics related to getting your Android application connected to the outside world. You will learn about how to consume XML and JSON web services,
sockets programming, and Bluetooth communications.
Chapter 7: Using Google Maps includes topics about how to display Google Maps in your Android
application, how to perform reverse geocoding, and more.
Chapter 8: Location-Based Data Services covers the key techniques you need to know to build
location-based services. You will also learn how to implement location data logging.
Chapter 9: Accessing the Hardware covers how to access the many hardware features from your
Android application. It includes recipes demonstrating how to take pictures using the built-in camera, how to turn GPS on/off, as well as how to enable the device’s flashlight.
Chapter 10: Persisting Data covers several methods for persisting your data, including internal storage, external storage, a database, and more.
Chapter 11: Deploying your Android Applications covers the different ways to deploy your Android
applications, such as through an SD card, a web server, or e‑mail.

xvi


introduction

How This Book Is Structured
Chapters in this book are divided into main topics, with each chapter containing multiple “recipes”
that address specific subtopics in more detail. Instead of adopting the step-by-step approach of
creating a project and then explaining how the code works, this books demonstrates the key ingredients of each recipe — the key points you need to understand in order to meet a requirement or
solve a problem (or complete a common task) in Android programming. Each recipe covers the core
concepts you need to understand, without any unnecessary code that can complicate an example.
Using this approach, it would be easiest for you to copy-and-paste the code into your own project
and then enhance it for your own purpose. This, in my opinion, is the best way to learn Android
programming.
To that end, every chapter has a very defined structure. Each recipe is numbered and has a title. The
recipe begins with a list of components needed to successfully complete the solution, like so:

Recipe 0.0   the recipe requirements
Android Versions
Each recipe uses APIs from the Android SDK. The Android Versions section
states the version (level number) from which the APIs are from. For example,
you might see “Level 1 and above.” This indicates that the APIs used in this
recipe are available from Android level 1 (i.e., version 1.0) and above.

Permissions
The Permissions section shows the permissions that you need to add into
your application, specifically the AndroidManifest.xml file, in order to use
the APIs described in the recipe. Be sure to add the permission; forgetting to
do so will usually cause the application to crash during run time.

Source Code to Download from Wrox.com
The Source Code section shows the name of the ZIP file that you can download from the support web site of this book from Wrox.com. The ZIP file
contains the complete project used to illustrate the concept in that recipe. If
you want to quickly get the code for the recipe into your own project, downloading the source code is your fastest option.
Then, the main goal of the recipe is explained. Next the solution follows. Sometimes, the solution is
short and sweet, and sometimes the solution is more complex and requires multiple steps.

xvii


introduction

A Note About Including Permissions in Code
To make the recipes succinct and easy to follow, this book assumes that you know
how to add permissions in your application. For example, instead of listing the entire
AndroidManifest.xml file and highlighting the permissions that you need to add,
like this:
<manifest xmlns:android=" />package="net.learn2develop.http"
android:versionCode="1"
android:versionName="1.0" >
android:minSdkVersion="8"
android:targetSdkVersion="15" />
<uses-permission android:name="android.permission.INTERNET" />
android:name="android.permission.ACCESS_NETWORK_STATE"/>
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"

android:theme="@style/AppTheme" >
android:name=".MainActivity"
android:label="@string/title_activity_main" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

</intent-filter>
</activity>
</application>
</manifest>

… the recipe will simply indicate that you need to add the following permissions:
<uses-permission android:name="android.permission.INTERNET" />
android:name="android.permission.ACCESS_NETWORK_STATE"/>

In the event that the above step is not explicitly mentioned, you should always
check the Permissions section at the beginning of each recipe and add the
permission(s) to the AndroidManifest.xml file.

xviii


introduction

What You Need to Use This Book
Most of the examples in this book run on the Android emulator, which is included as part of the
Android SDK. However, to get the most out of this book, using a real Android device is recommended (though not absolutely necessary).

Additionally, each recipe begins with a list of requirements specific to that recipe (versions, permissions, and source code), as previously discussed.

Conventions
To help you get the most from the text and keep track of what’s happening, a number of conventions
are used throughout the book:
➤➤

New terms and important words are highlighted in italics when first introduced.

➤➤

Keyboard combinations are treated like this: Ctrl+R.

➤➤

Filenames, URLs, and code within the text are treated like so: persistence.properties.

➤➤

Code is presented in two different ways:
We use a monofont type with no highlighting for most code examples.
We use bolding to emphasize code that is of particular importance in the
present context.

NOTE   Notes, tips, hints, tricks, and asides to the current discussion look like

this.

Source Code
As you work through the examples in this book, you may choose either to type in all the code manually or to use the source code files that accompany the book. All the source code used in this book

is available for download at www.wrox.com. When at the site, simply locate the book’s title (use the
Search box or one of the title lists) and click the Download Code link on the book’s detail page to
obtain all the source code for the book.
After you download the code, just decompress it with your favorite compression tool. Alternatively,
go to the main Wrox code download page at www.wrox.com/dynamic/books/download.aspx to see
the code available for this book and all other Wrox books.

xix


introduction

NOTE   Because many books have similar titles, you may find it easiest to search

by ISBN; this book’s ISBN is 978-1-118-17767-9.

Errata
We make every effort to ensure that there are no errors in the text or in the code. However, no one
is perfect, and mistakes do occur. If you find an error in one of our books, such as a spelling mistake
or a faulty piece of code, we would be very grateful for your feedback. By sending in errata, you may
save another reader hours of frustration and at the same time help us provide even higher-quality
information.
To find the errata page for this book, go to www.wrox.com and locate the title using the Search box
or one of the title lists. Then, on the book details page, click the Book Errata link. On this page, you
can view all errata that has been submitted for this book and posted by Wrox editors. A complete
book list, including links to each book’s errata, is also available at www.wrox.com/misc-pages/
booklist.shtml.
If you don’t spot “your” error on the Book Errata page, go to www.wrox.com/contact/techsupport
.shtml and complete the form there to send us the error you have found. We’ll check the information and, if appropriate, post a message to the book’s errata page and fix the problem in subsequent
editions of the book.

p2p.wrox.com
For author and peer discussion, join the P2P forums at p2p.wrox.com. The forums are a web-based
system for you to post messages relating to Wrox books and related technologies and to interact with
other readers and technology users. The forums offer a subscription feature to e‑mail you topics of
interest of your choosing when new posts are made to the forums. Wrox authors, editors, other
industry experts, and your fellow readers are present on these forums.
At p2p.wrox.com, you will find a number of different forums that will help you not only as you
read this book but also as you develop your own applications. To join the forums, just follow
these steps:
Go to p2p.wrox.com and click the Register link.



1.
2.
3.



4.

You will receive an e‑mail with information describing how to verify your account and
complete the joining process.




xx

Read the terms of use and click Agree.
Complete the required information to join as well as any optional information you want to
provide and click Submit.


introduction

NOTE   You can read messages in the forums without joining P2P, but in order to

post your own messages you must join.
After you join, you can post new messages and respond to messages that other users post. You can
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For more information about how to use the Wrox P2P, be sure to read the P2P FAQs for answers to
questions about how the forum software works, as well as for many common questions specific to
P2P and Wrox books. To read the FAQs, click the FAQ link on any P2P page.

xxi



1

Android Fundamentals
In this chapter, you learn about the fundamental topics in Android that most developers need to
know, including how to link to other applications using the Intent object, how to communicate
with other applications (or parts of the same application) using broadcast receivers, and how
to pass data between activities.

RECIPE 1.1 LINKING ACTIVITIES

Android Versions
Level 1 and above

Permissions
None

Source Code to Download at Wrox.com
Linking.zip
Unless you are writing a Hello World application, chances are good that your application contains several activities that you need to connect in order to form a cohesive application. This
recipe shows you the various ways to link to another activity in your Android application.