[Libro] Android Application Development

Part I. Development Kit Walk-Through
1. Getting to Know Android . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Why Android? 3
The Open Handset Alliance 4
The Android Execution Environment 5
Components of an Android Application 6
Android Activity Lifecycle 8
Android Service Lifecycle 10
How This Book Fits Together 10
2. Setting Up Your Android Development Environment . . . . . . . . . . . . . . . . . . . . . . . . . 13
Setting Up Your Development Environment 13
Creating an Android Development Environment 14
Hello, Android 18
Where We're Going 18
Starting a New Android Application: HelloWorld 18
Writing HelloWorld 22
Running HelloWorld 24
3. Using the Android Development Environment for Real Applications . . . . . . . . . . . . 27
MicroJobs: This Book's Main Sample Application 27
Android and Social Networking 27
Downloading the MJAndroid Code 30
A Brief Tour of the MJAndroid Code 30
The Project Root Folder (MJAndroid) 30
The Source Folder (src) 31
The Resource Folder (res) 32
First Steps: Building and Running the MicroJobs Application 33
iii
A Very Short Tour of the Android SDK/Eclipse IDE 33
Loading and Starting the Application 35
Digging a Little Deeper: What Can Go Wrong? 36
Running an Application on the T-Mobile Phone 39
Summary 41
4. Under the Covers: Startup Code and Resources in the MJAndroid Application . . . . 43
Initialization Parameters in AndroidManifest.xml 44
Initialization in MicroJobs.java 46
More Initialization of MicroJobs.java 52
Summary 56
5. Debugging Android Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
The Tools 57
Eclipse Java Editor 58
Java Errors 58
The Debugger 64
Logcat 67
Android Debug Bridge (adb) 71
DDMS: Dalvik Debug Monitor Service 74
Traceview 75
Summary 80
6. The ApiDemos Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Application Setup in the Manifest File 81
Finding the Source to an Interesting Example 83
Custom Title Demo 83
Linkify Demo 84
Adding Your Own Examples to ApiDemos 84
7. Signing and Publishing Your Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Test Your Application 88
Attach an End User License Agreement If Desired 89
Create and Attach an Icon and Label 89
Clean Up for Release 90
Version Your Application 90
Obtaining a Signing Certificate and API Key 90
Getting a Signing Certificate for an Application You Are Going to Ship 91
Getting a Signing Certificate While Debugging 93
Signing Your Application 95
Retesting Your Application 96
Publishing on Android Market 96
Signing Up As an Android Developer 96
iv | Table of Contents
Uploading Your Application 96
Part II. Programming Topics
8. Persistent Data Storage: SQLite Databases and Content Providers . . . . . . . . . . . . . 101
Databases 101
Basic Structure of the MicroJobsDatabase Class 102
Reading Data from the Database 107
Modifying the Database 110
Content Providers 114
Introducing NotePad 116
Content Providers 118
Consuming a Content Provider 129
9. Location and Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Location-Based Services 137
Mapping 139
The Google Maps Activity 139
The MapView and MapActivity 140
Working with MapViews 140
MapView and MyLocationOverlay Initialization 141
Pausing and Resuming a MapActivity 144
Controlling the Map with Menu Buttons 145
Controlling the Map with the KeyPad 147
Location Without Maps 148
The Manifest and Layout Files 148
Connecting to a Location Provider and Getting Location Updates 149
Updating the Emulated Location 152
10. Building a View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Android GUI Architecture 157
The Model 157
The View 158
The Controller 159
Putting It Together 159
Assembling a Graphical Interface 161
Wiring Up the Controller 166
Listening to the Model 168
Listening for Touch Events 173
Listening for Key Events 176
Alternative Ways to Handle Events 177
Advanced Wiring: Focus and Threading 179
Table of Contents | v
The Menu 183
11. A Widget Bestiary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Android Views 188
TextView and EditText 188
Button and ImageButton 191
Adapters and AdapterViews 192
CheckBoxes, RadioButtons, and Spinners 193
ViewGroups 198
Gallery and GridView 198
ListView and ListActivity 202
ScrollView 204
TabHost 205
Layouts 208
Frame Layout 209
LinearLayout 209
TableLayout 213
AbsoluteLayout 215
RelativeLayout 216
12. Drawing 2D and 3D Graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Rolling Your Own Widgets 221
Layout 222
Canvas Drawing 226
Drawables 237
Bitmaps 242
Bling 243
Shadows, Gradients, and Filters 246
Animation 247
OpenGL Graphics 252
13. Inter-Process Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Intents: Simple, Low-Overhead IPC 258
Intent Objects Used in Inter-Process Communication 258
Activity Objects and Navigating the User Interface Hierarchy 259
Example: An Intent to Pick How We Say "Hello World" 259
Getting a Result via Inter-Process Communication 262
Remote Methods and AIDL 265
Android Interface Definition Language 266
Classes Underlying AIDL-Generated Interfaces 270
Publishing an Interface 273
Android IPC Compared with Java Native Interface (JNI) 274
What Binder Doesn't Do 275
vi | Table of Contents
Binder and Linux 275
14. Simple Phone Calls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Quick and Easy Phone Calls 277
Creating an Example Application to Run the call Method 278
Embedding the Code Snippet in a Simple Application 279
Exploring the Phone Code Through the Debugger 280
Creating an Instance of an Intent 282
Adding Data to an Instance of an Intent 283
Initiating a Phone Call 284
Exception Handling 284
Android Application-Level Modularity and Telephony 285
15. Telephony State Information and Android Telephony Classes . . . . . . . . . . . . . . . . 287
Operations Offered by the android.telephony Package 287
Package Summary 288
Limitations on What Applications Can Do with the Phone 288
Example: Determining the State of a Call 289
Android Telephony Internals 291
Inter-Process Communication and AIDL in the
android.internal.telephony Package 291
The android.internal.telephony Package 292
The android.internal.telephony.gsm Package 295
Exploring Android Telephony Internals 299
Android and VoIP 302
Appendix: Wireless Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309