Android from A to D

575 Pages·2015·18.391 MB·English

by  Scott L. Hecht

A D
NDROI
A D
from to

Second Edition

Scott L. Hecht
Copyright © 2013-2015 Scott L. Hecht
All rights reserved.
ISBN-10: 1494807521
ISBN-13: 978-1494807528
Front/Back Cover Images:
© Can Stock Photo Inc. / kirstypargeter
2
Table of Contents (Chapters)

Preface to the Second Edition ........................................................................................................ 10
Preface to the First Edition ............................................................................................................. 11
Chapter 1: Installing the Android SDK on Windows ........................................................................ 13
Chapter 2: Creating Our First Android Application .......................................................................... 37
Chapter 3: Quick Start Guide to Java Programming ....................................................................... 53
Chapter 4: Exploring Useful Java Classes ...................................................................................... 73
Chapter 5A: Exploring the Eclipse Integrated Development Environment........................................ 88
Chapter 5B: Exploring Android Studio .......................................................................................... 114
Chapter 6: Introduction to the Android Platform ............................................................................ 149
Chapter 7: Android Layouts .......................................................................................................... 156
Chapter 8: Views Parade and the Eclipse Palette ......................................................................... 182
Chapter 9: Activities ..................................................................................................................... 189
Chapter 10: Wiring-Up Event Handlers ......................................................................................... 202
Chapter 11: Intents ...................................................................................................................... 207
Chapter 12: The Android Manifest ................................................................................................ 231
Chapter 13: Android Menus ......................................................................................................... 260
Chapter 14: Saving State: Bundle, SharedPreference and PreferenceActivity............................... 274
Chapter 15: Working with the SQLite Database ............................................................................ 291
Chapter 16: Content Providers ..................................................................................................... 328
Chapter 17: Adapters ................................................................................................................... 358
Chapter 18: Broadcasting Events ................................................................................................. 373
Chapter 19: Services ................................................................................................................... 383
Chapter 20: The Application Class ............................................................................................... 393
Chapter 21: Status Notifications ................................................................................................... 396
Chapter 22: Thread Programming in Android ............................................................................... 400
Chapter 23: Graphics ................................................................................................................... 407
Chapter 24: Pinch! Zoom! Swipe! - Detecting Gestures ................................................................ 452
Chapter 25: Detecting Device Rotation ......................................................................................... 461
Chapter 26: The GridView and ExpandableHeightGridView.......................................................... 463
Chapter 27: Using Tabs in an Activity ........................................................................................... 471
Chapter 28: Using the SlidingDrawer............................................................................................ 475
Chapter 29: Using <include> ........................................................................................................ 478
Chapter 30: Introduction to Fragments ......................................................................................... 488
Chapter 31: Working with WebView and WebViewClient .............................................................. 555
Chapter 32: Styles and Themes ................................................................................................... 558
Chapter 33: Distributing Your Android Application ........................................................................ 566

3
Table of Contents (Details)

Preface to the Second Edition ........................................................................................................ 10
Preface to the First Edition ............................................................................................................. 11
Chapter 1: Installing the Android SDK on Windows ........................................................................ 13
Overview .................................................................................................................................... 13
Overview of the Steps to Be Performed ...................................................................................... 13
Pre-Step 1 - Download and Install the Android Developer Tools (ADT) Bundle ............................ 15
Pre-Step 2 - Download and Install the Java SE 8 Development Kit (JDK) .................................... 17
Step 1 - First Time Start up of Eclipse for Android ....................................................................... 24
Step 2 - Installing SDKs with the Android SDK Manager ............................................................. 26
Post-Step 1 - Installing the Database Perspective with Eclipse DTP ............................................ 30
Post-Step 2 - Setting Up Virtual Devices with Android Virtual Device (AVD) Manager.................. 33
Summary .................................................................................................................................... 36
Chapter 2: Creating Our First Android Application .......................................................................... 37
Hello, World! ............................................................................................................................... 37
Running the Project Using an Android Virtual Device .................................................................. 40
Running the Project Using an Android Physical Device ............................................................... 45
When Things Go Wrong ............................................................................................................. 46
A Quick Look into Our First Android Project ................................................................................ 47
A Quick Note about Debugging ................................................................................................... 49
Accessing the Internet from the Emulator .................................................................................... 51
Summary .................................................................................................................................... 52
Chapter 3: Quick Start Guide to Java Programming ....................................................................... 53
Java Type System ...................................................................................................................... 53
Making Comments ...................................................................................................................... 53
Conditional Execution ................................................................................................................. 54
Looping Constructs ..................................................................................................................... 56
Arithmetic Operators ................................................................................................................... 57
Assignment Operators ................................................................................................................ 57
Comparison Operators................................................................................................................ 57
Logical Operators ....................................................................................................................... 57
Bitwise Operators ....................................................................................................................... 57
Working with Strings ................................................................................................................... 58
Working with Arrays .................................................................................................................... 58
Exceptions .................................................................................................................................. 58
Object-Oriented Programming Concepts ..................................................................................... 59
Interface ..................................................................................................................................... 66
Abstract ...................................................................................................................................... 68
Variable-Length Arguments ........................................................................................................ 70
Running Java Test Programs ...................................................................................................... 71
Summary .................................................................................................................................... 72
Chapter 4: Exploring Useful Java Classes ...................................................................................... 73
Introduction ................................................................................................................................ 73
Text-Related Classes ................................................................................................................. 73
Mathematics-Related Classes..................................................................................................... 78
Collections-Related Classes ....................................................................................................... 82
Date- and Time-Related Classes ................................................................................................ 85
Chapter 5A: Exploring the Eclipse Integrated Development Environment ....................................... 88
A First Look at the IDE ................................................................................................................ 88
Perspectives ............................................................................................................................... 96
Views ......................................................................................................................................... 99
Menus ...................................................................................................................................... 102
Search ...................................................................................................................................... 104
Automatic Code Generation ...................................................................................................... 106
Using the Scrapbook ................................................................................................................ 108
Using Keyboard Short-Cuts ...................................................................................................... 111
Summary .................................................................................................................................. 113
Chapter 5B: Exploring Android Studio .......................................................................................... 114
Overview .................................................................................................................................. 114
Downloading Android Studio ..................................................................................................... 114
4
A First Look at the IDE .............................................................................................................. 119
Running the Project using the Emulator .................................................................................... 124
Running the Project using a Physical Device ............................................................................. 127
A Quick Note about Debugging ................................................................................................. 128
What about Perspectives and Views? ....................................................................................... 129
Bookmarks ............................................................................................................................... 130
TODO, FIXME and Additional Comment Markers ...................................................................... 131
Search ...................................................................................................................................... 133
Code Snippets .......................................................................................................................... 134
Code Completion ...................................................................................................................... 137
Automatic Code Generation ...................................................................................................... 138
Android Studio Plugins.............................................................................................................. 139
Using Keyboard Short-Cuts ...................................................................................................... 141
Version Control with Git ............................................................................................................ 142
Summary .................................................................................................................................. 148
Chapter 6: Introduction to the Android Platform ............................................................................ 149
Overview .................................................................................................................................. 149
Activities and Intents ................................................................................................................. 150
Services ................................................................................................................................... 150
Maintaining State ...................................................................................................................... 151
Content Providers ..................................................................................................................... 151
Broadcast Receivers ................................................................................................................. 152
Layouts..................................................................................................................................... 152
Alerting Users ........................................................................................................................... 153
Application ................................................................................................................................ 153
External Resources .................................................................................................................. 153
Android Platform Versions, API Levels and Version Code Names ............................................. 154
Summary .................................................................................................................................. 155
Chapter 7: Android Layouts .......................................................................................................... 156
Overview .................................................................................................................................. 156
Two Views - TextView and Button ............................................................................................. 157
Linear Layout ............................................................................................................................ 160
ScrollView Layout ..................................................................................................................... 162
HorizontalScrollView Layout ..................................................................................................... 164
A Word about the Android Reference Manual ........................................................................... 166
Table Layout ............................................................................................................................. 170
Relative Layout ......................................................................................................................... 172
Frame Layout ........................................................................................................................... 174
ListView and GridView Layout ................................................................................................... 176
Combining Layouts ................................................................................................................... 178
Summary .................................................................................................................................. 181
Chapter 8: Views Parade and the Eclipse Palette ......................................................................... 182
Overview .................................................................................................................................. 182
Form Widgets ........................................................................................................................... 182
Text Fields ................................................................................................................................ 183
Layouts..................................................................................................................................... 185
Composites .............................................................................................................................. 185
Images & Media ........................................................................................................................ 186
Time & Date ............................................................................................................................. 186
Transitions ................................................................................................................................ 187
Advanced ................................................................................................................................. 187
Custom & Library Views ............................................................................................................ 188
Summary .................................................................................................................................. 188
Chapter 9: Activities ..................................................................................................................... 189
Overview .................................................................................................................................. 189
A Look at Our Simple Example ................................................................................................. 189
Accessing Programmer Created Resources .............................................................................. 192
Accessing Android Provided Resources .................................................................................... 195
The Activity Lifecycle ................................................................................................................ 196
Notifications .............................................................................................................................. 199
Summary .................................................................................................................................. 201
Chapter 10: Wiring-Up Event Handlers ......................................................................................... 202
5
Overview .................................................................................................................................. 202
Ways to Wire-Up Event Handlers .............................................................................................. 202
Event Handler Method #1 & #2 ................................................................................................. 202
Event Handler Method #3 ......................................................................................................... 204
Event Handler Method #4 ......................................................................................................... 204
Discussion ................................................................................................................................ 205
Chapter 11: Intents ...................................................................................................................... 207
Overview .................................................................................................................................. 207
Explicit Intents .......................................................................................................................... 208
Implicit Intents .......................................................................................................................... 216
Discussion ................................................................................................................................ 221
Intent Filters.............................................................................................................................. 222
Determining Applications Providing a Specific Intent Filter ........................................................ 227
Summary .................................................................................................................................. 230
Chapter 12: The Android Manifest ................................................................................................ 231
Overview .................................................................................................................................. 231
Structure of the AndroidManifest.xml File .................................................................................. 231
The <manifest> Tag.................................................................................................................. 232
The <uses-sdk> Tag ................................................................................................................. 233
The <application> Tag .............................................................................................................. 234
The <activity> Tag .................................................................................................................... 236
The <activity-alias> Tag ............................................................................................................ 241
The <meta-data> Tag ............................................................................................................... 242
The <intent-filter> Tag .............................................................................................................. 243
The <action> Tag ..................................................................................................................... 243
The <category> Tag ................................................................................................................. 244
The <data> Tag ........................................................................................................................ 244
The <provider> Tag .................................................................................................................. 245
The <receiver> Tag .................................................................................................................. 246
The <service> Tag .................................................................................................................... 247
The <grant-uri-permission> Tag ................................................................................................ 248
The <instrumentation> Tag ....................................................................................................... 249
The <permission> Tag .............................................................................................................. 250
The <permission-group> Tag .................................................................................................... 251
The <permission-tree> Tag ....................................................................................................... 252
The <compatible-screens> Tag................................................................................................. 252
The <supports-screens> Tag .................................................................................................... 253
The <supports-gl-texture> Tag .................................................................................................. 254
The <uses-configuration> Tag .................................................................................................. 255
The <uses-feature> Tag ........................................................................................................... 256
The <uses-library> Tag ............................................................................................................. 257
The <uses-permission> Tag ..................................................................................................... 258
Using the Android Manifest GUI Interface ................................................................................. 258
Summary .................................................................................................................................. 259
Chapter 13: Android Menus ......................................................................................................... 260
Overview .................................................................................................................................. 260
The Menu Resource XML File................................................................................................... 261
The <menu> Tag ...................................................................................................................... 261
The <item> Tag ........................................................................................................................ 261
The <group> Tag ...................................................................................................................... 263
Creating an Options Menu using a Menu Resource XML File .................................................... 263
Handling Item Clicks in Code .................................................................................................... 268
Creating a Context Menu .......................................................................................................... 270
Creating a Popup Menu ............................................................................................................ 273
Summary .................................................................................................................................. 273
Chapter 14: Saving State: Bundle, SharedPreference and PreferenceActivity .............................. 274
Overview .................................................................................................................................. 274
Using the Bundle Parameter ..................................................................................................... 274
Using SharedPreferences ......................................................................................................... 278
Using Map<K,V> with SharedPreferences ................................................................................ 280
Using PreferenceActivity ........................................................................................................... 280
Summary .................................................................................................................................. 290
6
Chapter 15: Working with the SQLite Database ............................................................................ 291
Overview .................................................................................................................................. 291
Installing SQLite on Windows.................................................................................................... 291
Installing the SQLite Expert Personal Edition Software .............................................................. 292
Read-Only or Read-Write SQLite Database .............................................................................. 293
Storage Location of the SQLite Database ................................................................................. 294
Transferring Your SQLite Database to the Device ..................................................................... 295
Interacting with a SQLite Database ........................................................................................... 296
Installing a SQLite JDBC Driver and Using the Eclipse Database Perspective ........................... 296
Using SQLite from the Command Line ...................................................................................... 299
Introduction to the Structured Query Language (SQL) ............................................................... 302
The Data Manipulation Language (DML) ................................................................................... 304
Limiting the Number of Rows Returned from a Query ................................................................ 306
Joining Tables Together ........................................................................................................... 307
Using the sqlite_master Table ................................................................................................... 308
Using Views .............................................................................................................................. 309
The Data Definition Language (DDL) ........................................................................................ 309
A Discussion on Indexes ........................................................................................................... 311
Using EXPLAIN QUERY PLAN ................................................................................................. 312
Column Constraints .................................................................................................................. 313
Programming with the SQLite Database.................................................................................... 314
Quick Start Guide ..................................................................................................................... 316
So Why Use Anything Else? The SQLiteOpenHelper Class ..................................................... 322
What is a Cursor Factory? ........................................................................................................ 326
A Comment about Database Locale .......................................................................................... 326
A Comment about SQLite Sort-Order Problems ........................................................................ 327
Summary .................................................................................................................................. 327
Chapter 16: Content Providers ..................................................................................................... 328
Overview .................................................................................................................................. 328
The Uri, Uri.Builder, ContentUris and UriMatcher Classes ......................................................... 330
Steps Involved in Creating a Content Provider: Overview .......................................................... 335
Step #1: Creating the SQLite Database .................................................................................... 336
Step #2: Create the Content URIs ............................................................................................. 337
Step #3: Create the MIME Types .............................................................................................. 338
Step #4: Create the Contract Classes ....................................................................................... 338
Step #5: Create the Content Provider ........................................................................................ 341
Step #6: Determine Content Provider Permission(s) .................................................................. 345
Step #7: Update AndroidManifest.xml ....................................................................................... 345
Steps Involved in Using a Content Resolver .............................................................................. 346
Step #1: Compile and Install Your Application ........................................................................... 346
Step #2: Obtain the Contract Class(es) ..................................................................................... 346
Step #3: Create a Test Application ............................................................................................ 347
Step #4: Using the ContentResolver Class ................................................................................ 347
Using an Adapter to Populate the ListView ................................................................................ 349
Summary .................................................................................................................................. 357
Chapter 17: Adapters ................................................................................................................... 358
Overview .................................................................................................................................. 358
What about ListActivity and ExpandableListActivity? ................................................................. 358
Be on the Lookout for the Elusive TextView .............................................................................. 359
Android-Provided Layouts or My Own? ..................................................................................... 359
Simple Data Display - No Need for an Adapter .......................................................................... 359
Less Simple Data Display #1 - Using ArrayAdapter ................................................................... 360
Less Simple Data Display #2 - Using SimpleCursorAdapter ...................................................... 363
Less Simple Data Display #3 - Using SimpleCursorTreeAdapter ............................................... 364
Less Simple Data Display #4 - Using ResourceCursorTreeAdapter ........................................... 366
Less Simple Data Display #5 - Using SpinnerAdapter ............................................................... 369
Summary .................................................................................................................................. 372
Chapter 18: Broadcasting Events ................................................................................................. 373
Overview .................................................................................................................................. 373
Broadcasting an Event .............................................................................................................. 373
Receiving a Broadcasted Event ................................................................................................ 374
Can I Send and Receive My Own Broadcasts? ......................................................................... 375
7
Receiving Android System Broadcasts...................................................................................... 376
Using the DownloadManager Service ....................................................................................... 378
Summary .................................................................................................................................. 382
Chapter 19: Services ................................................................................................................... 383
Overview .................................................................................................................................. 383
Creating a Service .................................................................................................................... 383
Alternate Ways to Stop a Service .............................................................................................. 387
Using IntentService instead of Handling Threading Yourself...................................................... 387
Binding a Client to a Service ..................................................................................................... 389
Summary .................................................................................................................................. 392
Chapter 20: The Application Class ............................................................................................... 393
Overview .................................................................................................................................. 393
Summary .................................................................................................................................. 395
Chapter 21: Status Notifications ................................................................................................... 396
Overview .................................................................................................................................. 396
Steps to Generate a Notification ............................................................................................... 396
Example Code .......................................................................................................................... 396
Additions to the AndroidManifest.xml File .................................................................................. 399
Summary .................................................................................................................................. 399
Chapter 22: Thread Programming in Android ............................................................................... 400
Overview .................................................................................................................................. 400
Using the AsyncTask Class ...................................................................................................... 401
Using the Thread Class ............................................................................................................ 404
Discussion ................................................................................................................................ 404
Displaying a Progress Bar When Using the AsyncTask Class ................................................... 405
Summary .................................................................................................................................. 406
Chapter 23: Graphics ................................................................................................................... 407
Overview .................................................................................................................................. 407
What is a Drawable? ................................................................................................................. 408
Graphics via XML Resources - An Overview ............................................................................. 408
Graphics via XML Resources - Animations using <animation-list> XML Tag .............................. 410
Graphics via XML Resources - Handling Bitmaps using the <bitmap> XML Tag ........................ 412
Graphics via XML Resources - Clipping Images using the <clip> XML Tag ............................... 414
Graphics via XML Resources - Colors using the <color> XML Tag ............................................ 415
Graphics via XML Resources - Gradients using the <shape> XML Tag .................................... 416
Graphics via XML Resources - Insets using the <inset> XML Tag ............................................. 416
Graphics via XML Resources - Layers using the <layer-list> XML Tag ...................................... 417
Graphics via XML Resources - Levels using the <level-list> XML Tag ....................................... 418
Graphics via XML Resources - Nine-Patch Images using <nine-patch> XML Tag ..................... 418
Graphics via XML Resources - PaintDrawable using the <shape> XML Tag ............................. 419
Graphics via XML Resources - PictureDrawable ....................................................................... 420
Graphics via XML Resources - RotateDrawable using the <rotate> XML Element .................... 420
Graphics via XML Resources - Scaling using the <scale> XML Tag .......................................... 420
Graphics via XML Resources - State Lists using the <selector> XML Tag ................................. 421
Graphics via XML Resources - Shapes using the <shape> XML Tag ........................................ 424
Graphics via XML Resources - Transitions using the <transition> XML Tag .............................. 426
Static Graphics in Two-Dimensions - An Overview .................................................................... 427
Static Graphics in Two-Dimensions - Relevant Classes and Enums - An Overview ................... 428
Static Graphics in Two-Dimensions - Static Graphic Example #1 .............................................. 435
Tweened Animated Graphics in Two-Dimensions - An Overview............................................... 442
Tweened Animated Graphics in Two-Dimensions - View Animation .......................................... 444
Tweened Animated Graphics in Two-Dimensions - Property Animation ..................................... 447
SurfaceView and the SurfaceHolder Interface ........................................................................... 447
A Comment about WindowManager .......................................................................................... 451
A Comment on Infragistics Iguana Chart Widgets ..................................................................... 451
Chapter 24: Pinch! Zoom! Swipe! - Detecting Gestures ................................................................ 452
Overview .................................................................................................................................. 452
Detecting Flings ........................................................................................................................ 453
Detecting Pinch-and-Zoom ....................................................................................................... 457
Controlling the Scrolling of a TextView ...................................................................................... 458
Chapter 25: Detecting Device Rotation......................................................................................... 461
Overview .................................................................................................................................. 461
8
The Android Manifest and Device Orientation Changes............................................................. 461
The Android Manifest and Preventing Orientation Changes ....................................................... 462
Chapter 26: The GridView and ExpandableHeightGridView.......................................................... 463
Overview .................................................................................................................................. 463
The GridView Class .................................................................................................................. 463
Step #1: Add a GridView view to the Layout .............................................................................. 463
Step #2: Define Each Cell's Layout ........................................................................................... 464
Step #3: Create a Custom Adapter Subclassed from BaseAdapter ............................................ 464
Step #4: Modify the Activity's Code ........................................................................................... 465
The ExpandableHeightGridView Class ...................................................................................... 466
Chapter 27: Using Tabs in an Activity ........................................................................................... 471
Overview .................................................................................................................................. 471
Create the Umbrella Activity ...................................................................................................... 471
Create the Activity..................................................................................................................... 471
Chapter 28: Using the SlidingDrawer............................................................................................ 475
Overview .................................................................................................................................. 475
Defining the SlidingDrawer ........................................................................................................ 475
Setting Up Open/Close Listeners for the SlidingDrawer ............................................................. 476
Chapter 29: Using <include> ........................................................................................................ 478
Overview .................................................................................................................................. 478
Using <include> ........................................................................................................................ 485
Coding with <include>............................................................................................................... 485
Chapter 30: Introduction to Fragments ......................................................................................... 488
Overview .................................................................................................................................. 488
Fragment Class and Android Support Libraries ......................................................................... 491
Fragments via the XML <fragment> Tag - Simple Example #1 .................................................. 492
Fragments via the XML LinearLayout Tag - Simple Example #2 ................................................ 497
Fragments via the XML LinearLayout Tag - Simple Example #2.5 ............................................. 502
Fragment Lifecycle ................................................................................................................... 505
Communication between Fragments ......................................................................................... 506
EquityYo! and Fragments - Complex Example #1 ..................................................................... 507
Fragment Subclasses (DialogFragment, ListFragment, PreferenceFragment) ........................... 545
EquityYo! and Fragments - Complex Example #2 ..................................................................... 545
Summary .................................................................................................................................. 554
Chapter 31: Working with WebView and WebViewClient .............................................................. 555
Overview .................................................................................................................................. 555
Step #1 - Add the WebView to the GUI ..................................................................................... 555
Step #2 - Wire up the WebView and the WebViewClient ........................................................... 556
Chapter 32: Styles and Themes ................................................................................................... 558
Overview .................................................................................................................................. 558
Creating Your Own Style........................................................................................................... 558
Modifying a Previously Defined Style of Yours .......................................................................... 559
Modifying an Android-Defined Style .......................................................................................... 559
A Question about the Question Mark (?) ................................................................................... 560
Applying Styles to Activities and/or Applications: Themes ......................................................... 560
Applying Style Changes to Android-Provided Layouts ............................................................... 563
Summary .................................................................................................................................. 565
Chapter 33: Distributing Your Android Application ........................................................................ 566
Overview .................................................................................................................................. 566
Signing Your Application ........................................................................................................... 566
Exporting Your Application ........................................................................................................ 568
Signing Up with Google Play ..................................................................................................... 571
Uploading an Application to Google Play................................................................................... 572
Making Money Selling Your Applications on Google Play .......................................................... 574
Summary .................................................................................................................................. 575

9
Preface to the Second Edition

In this edition of Android from A to D, I have made several minor as well as major
changes throughout the book.

Be aware that I have reorganized and renumbered some of the chapters, updated
some images, corrected some sepllnig...uh...spelling mistakes, and so on. For
example, the chapter on distributing your app, which mysteriously appeared in the
middle of the First Edition, now appears at the end of the book in this edition. I
have also placed a text file containing all of the code used throughout the book on
my personal, yet strangely named, website: www.sheepsqueezers.com.

The installation instructions have been updated and now outline how to install the
Android Software Development Kit (SDK) using the Android Developer Tools
(ADT) Bundle. This method of installing the SDK greatly simplifies getting the
prospective Android developer up-and-running in the shortest period of time.

In the previous edition, I included a Java Quick Start Guide. In this edition, that
chapter remains, but I have also included a chapter outlining several useful Java
classes such as Math, String, SimpleDateFormat, ArrayList, and more.

I have included a chapter on the new Android Studio Integrated Development
Environment (IDE). Note that this software is still in early access preview status
and not recommended for production programming projects. With that said, I
explain many of its features and attempt to compare them to similar features found
in Eclipse, where possible.

In this edition, I have included a light-and-fluffy introduction to fragments, for those
of you who are curious. Many Android apps now make use of fragments and an
explanation of this functionality was missing from the previous edition...oops!...my
bad.

Note that there are several Android programming books out there promising to
make you an Android programming guru in a few days or weeks. With all due
respect to the authors of those books, if you are determined to create Android apps
be aware that it will take you months of study - not days, not weeks - to learn how
to program for the Android platform. Sorry if I’m bursting your bubble, but it’s better
to tell you the truth rather than give you false expectations.

Finally, on a personal note, I’d like to thank all of you who have purchased either
the Kindle or the paperback version of this book. I realize it’s not easy to plunk
down money for a book on a complicated topic written by an unknown author, so
thank you very much for giving me a chance!

Good luck with your Android programming studies!

Thanks,
Scott L. Hecht
July 12, 2014

10