Pro Android 4

Satya Komatineni

Dave MacLean

Contents

Contents at a Glance..... iv

About the Authors xxi

About the Technical Reviewers xxii

Acknowledgments xxiv

Preface xxv

Chapter 1: Introducing the Android Computing Platform 1A New Platform for a New Personal Computer 1

Early History ofAndroid 3

Delving Into the DalvikVM 6

Understanding the Android Software Stack 6

Developing an End-User Application with the Android SDK 8

Android Emulator 8The Android Ul 9

The Android Foundational Components 10

Advanced Ul Concepts 11

Android Service Components 14

Android Media and Telephony Components 14

Android Java Packages 15

Taking Advantage of Android Source Code 20

Browsing Android Sources Online 20

Using Git to Download Android Sources 21

The Sample Projects in this Book 22

Summary 22

Chapter 2: Setting Up Your Development Environment 23Setting Up Your Environment 24

Downloading JDK 6 24

Downloading Eclipse 3.6 25

Downloading the Android SDK 25The Tools Window 28

Installing Android Development Tools (ADT) 28Learning the Fundamental Components 31

View 31

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Activity 31

Fragment 32

Intent 32

Content Provider 32

Service 32

AndroidManifest.xml 33

Android Virtual Devices 33

Hello World! 33

Android Virtual Devices 39

Running on a Real Device 41

Exploring the Structure of an Android Application 42

Examining the Application Life Cycle 44

Simple Debugging 47

Launching the Emulator 48

References 49

Summary 49

Interview Questions 50

Chapter 3: Understanding Android Resources 51

Understanding Resources 51

String Resources 52

Layout Resources 54

Resource Reference Syntax 55

Defining Your Own Resource IDs for Later Use 57

Compiled and Uncompiled Android Resources 58

Enumerating Key Android Resources 59

Working with Arbitrary XML Resource Files 69

Working with Raw Resources 71

Working with Assets 71

Reviewing the Resources Directory Structure 72

Resources and Configuration Changes 72

Reference URLs 76

Summary 77

Interview Questions 77

Chapter 4: Understanding Content Providers 79

Exploring Android's Built-in Providers 80

Exploring Databases on the Emulator and Available Devices 80

Quick SQLite Primer 84

Architecture of Content Providers 84

Structure of Android Content URIs 86

Structure of Android MIME Types 87

Reading Data Using URIs 89

Using the Android Cursor 91

Working with the where Clause 92

Inserting Records 94

Adding a File to a Content Provider 95

Updates and Deletes 96

Implementing Content Providers 96

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Planning a Database 97

Extending ContentProvider 99

Fulfilling MIME-Type Contracts 104

Implementing the Query Method 105

Implementing an Insert Method 105

Implementing an Update Method 105

Implementing a Delete Method 1°6

Using UriMatcher to Figure Out the URIs 106

Using Projection Maps 107

Registering the Provider 108

Exercising the Book Provider 108

Adding a Book 109

Removing a Book 109

Getting a Count of the Books 110

Displaying the List of Books 110

Resources 111

Summary 111

Interview Questions 112

Chapter 5: Understanding Intents 113

Basics of Android Intents 113

Available Intents in Android 115

Exploring Intent Composition 117

Intents and Data URIs 117

Generic Actions 118

Using Extra Information 119

Using Components to Directly Invoke an Activity 121

Understanding Intent Categories 122

Rules for Resolving Intents to Their Components 125

Exercising the ACTION_PICK 127

Exercising the GET_CONTENT Action 130

Introducing Pending Intents 131

Resources 132

Summary 133

Interview Questions 133

Chapter 6: Building User Interfaces and Using Controls 135

Ul Development in Android 135

Building a Ul Completely in Code 137

Building a Ul Completely in XML 139

Building a Ul in XML with Code 140

Understanding Android's Common Controls 142

Text Controls 142

Button Controls 147

The ImageView Control 155

Date and Time Controls 156

The MapView Control 159

Understanding Adapters 159

Getting to Know SimpleCursorAdapter 160

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Getting to Know ArrayAdapter 162

Using Adapters with AdapterViews 164

The Basic List Control: ListView 164

The GridView Control 172

The Spinner Control 174

The Gallery Control 176

Creating Custom Adapters 177

Other Controls in Android 182

Styles and Themes 183

Using Styles 183

Using Themes 186

Understanding Layout Managers 187

The LinearLayout Layout Manager 187

The TableLayout Layout Manager 191

The RelativeLayout Layout Manager 194

The FrameLayout Layout Manager 196

The GridLayout Layout Manager 198

Customizing the Layout for Various Device Configurations 199

References 200

Summary 201

Interview Questions 201

Chapter 7: Working with Menus 203

Understanding Android Menus 203

Creating a Menu 206

Working with Menu Groups 207

Responding to Menu Items 208

Working with Other Menu Types 210

Expanded Menus 211

Working with Icon Menus 211

Working with Submenus 212

Working with Context Menus 212

Working with Alternative Menus 216

Dynamic Menus 219

Loading Menus Through XML Files 219

Structure of an XML Menu Resource File 220

Inflating XML Menu Resource Files 221

Responding to XML-Based Menu Items 221

Pop-up Menus in 4.0 222

A Brief Introduction to Additional XML Menu Tags 224

Resources 226

Summary 226

Interview Questions 226

Chapter 8: Fragments for Tablets and More 229

What Is a Fragment? 230

When to Use Fragments 231

The Structure of a Fragment 232

A Fragment's Lifecycle 233

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Sample Fragment App Showing the Lifecycle 238

FragmentTransactions and the Fragment Back Stack 244

Fragment Transaction Transitions and Animations 246

The FragmentManager247

Caution When Referencing Fragments 248

Saving Fragment State 249

ListFragments and <fragment> 249

Invoking a Separate Activity When Needed 251

Persistence of Fragments 253

Communications with Fragments 254

Using startActivityO and setTargetFragmentO 255

Custom Animations with ObjectAnimator 255

References 258

Summary 259

Interview Questions 260

Chapter 9: Working with Dialogs 261

Using Dialogs in Android 261

Understanding Dialog Fragments 262

DialogFragment Basics 262

DialogFragment Sample Application 267

Working with Toast 278

Dialog Fragments for Older Android 278

References 279

Summary 279

Interview Questions 280

Chapter 10: Exploring ActionBar 281

Anatomy of an ActionBar 282

Tabbed Navigation Action Bar Activity 283

Implementing Base Activity Classes 285

Assigning Uniform Behavior for the Action Bar 287

Implementing the Tabbed Listener 289

Implementing the Tabbed Action Bar Activity 290

Scrollable Debug Text View Layout 292

Action Bar and Menu Interaction 293

Android Manifest File 296

Examining the Tabbed Action Bar Activity 296

List Navigation Action Bar Activity 297

Creating a Spinner Adapter 298

Creating a List Listener 298

Setting Up a List Action Bar 299

Making Changes to BaseActionBarActivity 300

Making Changes to AndroidManifest.xml 300

Examining the List Action Bar Activity 301

Standard Navigation Action Bar Activity 303

Setting up the Standard Navigation Action Bar Activity 303

Making Changes to BaseActionBarActivity 304

Making Changes to AndroidManifesLxml 305

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Examining the Standard Action Bar activity 305

Action Bar and Search View 307

Defining a Search View Widget as a Menu Item 308

Casting a Search Results Activity 308

Customizing Search Through a Searchable XML File 309

Defining the Search Results Activity in the Manifest File 310

Identifying the Search Target for the Search View Widget 310

The Action Bar and Fragments 311

References 311

Summary 312

Interview Questions 312

Chapter 11: Advanced Debugging and Analysis 315

Enabling Advanced Debugging 315

The Debug Perspective 316

The DDMS Perspective 317

The Hierarchy View Perspective 320

Pixel Perfect View 321

Traceview 321

Theadb Command 323

The Emulator Console 323

StrictMode 323

StrictMode Policies 324

Turning Off StrictMode 325

StrictMode with Old Android Versions 326

StrictMode Exercise 327

References 328

Summary 328

Interview Questions 329

Chapter 12: Responding to Configuration Changes... 331

The Configuration Change Process 331

The Destroy/Create Cycle of Activities 333

The Destroy/Create Cycle of Fragments 334

Using FragmentManager to Save Fragment State 335

Using setRetainlnstance on a Fragment 336

Deprecated Configuration Change Methods 336

References 336

Summary 336

Interview Questions 337

Chapter 13: Working with Preferences and Saving State 339

Exploring the Preferences Framework 339

Understanding ListPreference 340

Understanding CheckBoxPreference 348

Understanding EditTextPreference 350

Understanding RingtonePreference and MultiSelectListPreference 351

Organizing Preferences 351

Using PreferenceCategory 352

Creating Child Preferences with Dependency 355

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Preferences with Headers35b

Manipulating Preferences Programmatically357

Saving State with Preferences358

Using DialogPreference359

Reference360

Summary360

Interview Questions360

Chapter 14: Exploring Security and Permissions 363

Understanding the Android Security Model 363

Overview of Security Concepts 363

Signing Applications for Deployment364

Performing Runtime Security Checks371

Understanding Security at the Process Boundary 371

Declaring and Using Permissions 372

Understanding and Using Custom Permissions 374

Understanding and Using URI Permissions 379

References381

Summary382

Interview Questions 382

Chapter 15: Building and Consuming Services 383

Consuming HTTP Services 383

Using the HttpClient for HTTP GET Requests 384

Using the HttpClient for HTTP POST Requests (a Multipart Example) 386

SOAP, JSON, and XML Parsers 388

Dealing with Exceptions 389

Addressing Multithreading Issues 391

Fun with Timeouts 394

Using the HttpURLConnection 395

Using the AndroidHttpClient 395

Using Background Threads (AsyncTask) 396

Getting Files Using DownloadManager 403

Using Android Services 409

Understanding Services in Android 409

Understanding Local Services 410

Understanding AIDL Services 417

Defining a Service Interface in AIDL 418

Implementing an AIDL Interface 421

Calling the Service from a Client Application 423

Passing Complex Types to Services 427

References 437

Summary 437

Interview Questions 438

Chapter 16: Exploring Packages 441

Packages and Processes 441

Details of a Package Specification 441

Translating the Package Name to a Process Name 442

Listing Installed Packages 442

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Deleting a Package Through the Package Browser 443

Revisiting the Package Signing Process 443

Understanding Digital Signatures: Scenario 1 444

Understanding Digital Signatures: Scenario 2 444

A Pattern for Understanding Digital Signatures 445

So How Do You Digitally Sign? 445

Implications of the Signing Process 446

Sharing Data Among Packages 446

The Nature of Shared User IDs 447

A Code Pattern for Sharing Data 447

Library Projects 449

What Is a Library Project? 449

Library Project Predicates 450

Creating a Library Project 452

Creating an Android Project That Uses a Library 455

Caveats to Using Library Projects 464

References 465

Summary 466

Interview Questions 466

Chapter 17: Exploring Handlers 469

Android Components and Threading 469

Activities Run on the Main Thread 470

Broadcast Receivers Run on the Main Thread 471

Services Run on the Main Thread 471

Content Provider Runs on the Main Thread 471

Implications of a Singular Main Thread 471

Thread Pools, Content Providers, and External Service Components 472

Thread Utilities: Discovering Your Threads 472

Handlers 473

Implications of Holding the Main Thread 475

Using a Handler to Defer Work on the Main Thread 475

Sample Handler Source Code That Defers Work 476

Constructing a Suitable Message Object 477

Sending Message Objects to the Queue 478

Responding to the handleMessage Callback 478

Using Worker Threads 479

Invoking a Worker Thread from a Menu 480

Communicating Between the Worker and the Main Threads 481

Component and Process Lifetimes 483

Activity Life Cycle 484

Service Life Cycle 485

Receiver Life Cycle 485

Provider Life Cycle 486

References 486

Summary 487

Interview Questions 487

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Chapter 18: Exploring the AsyncTask 489

Implementing a simple AsyncTask 490

GettingPpast the Generics in AsyncTask 490

Subclassing an Async Task 491

Implementing Your First Async Task 492

Calling an Async Task 494

onPreExecuteO Callback and Progress Dialog 494

ctolnBackgroundO method 495

Triggering onProgressUpdateO 496

onPostExecuteO Method 496

Upgrading to the Deterministic Progress Dialog 496

Nature of an Async Task 499

Device Rotation and AsyncTask 500

Life Cycle Methods and AsyncTask 501

References 501

Summary 502

Interview Questions 502

Chapter 19: Broadcast Receivers and Long-Running Services 503

Broadcast Receivers 503

Sending a Broadcast 504

Coding a Simple Receiver: Sample Code 504

Registering a Receiver in the Manifest File 505

Accommodating Multiple Receivers 506

Out-of-Process Receivers 508

Using Notifications from a Receiver 508

Monitoring Notifications Through the Notification Manager 509

Sending a Notification 511

Starting an Activity in a Broadcast Receiver 513

Long-Running Receivers and Services 514

Long-Running Broadcast Receiver Protocol 515

IntentService 516

IntentService Source Code 517

Extending IntentService for a Broadcast Receiver 519

Long-Running Broadcast Service Abstraction 519

A Long-Running Receiver 521

Abstracting a Wake Lock with LightedGreenRoom 523

Long-Running Service Implementation 529

Details of a Nonsticky Service 530

Details of a Sticky Service 531

A Variation of Nonsticky; Redeliver Intents 531

Specifying Service Flags in OnStartCommand 531

Picking Suitable Stickiness 532

Controlling the Wake Lockfrom Two Places 532

Long-Running Service Implementation 532

Testing Long-Running Services 534

Your Responsibilities 534

Framework Responsiblities 535

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A Few Notes about the Project Download File 535

References 536

Summary 537

Interview Questions 537

Chapter 20: Exploring the Alarm Manager 539

Alarm Manager Basics: Setting Up a Simple Alarm 539

Getting Access to the Alarm Manager 540

Setting Up the Time for the Alarm 540

Creating a Receiver for the Alarm 541

Creating a Pendinglntent Suitable for an Alarm 541

Setting the Alarm 542

Test Project 542

Exploring Alarm Manager Alternate Scenarios 544

Setting Off an Alarm Repeatedly 544

Cancelling an Alarm 545

Working with Multiple Alarms 546

Intent Primacy in Setting Off Alarms 548

Persistence of Alarms 551

Alarm Manager Predicates 551

References 552

Summary 552

Interview Questions 552

Chapter 21: Exploring 2D Animation 555

Frame-by-Frame Animation 556

Planning for Frame-by-Frame Animation 556

Creating the Activity 557

Adding Animation to the Activity 559

Layout Animation 562

Basic Tweening Animation Types 562

Planning the Layout Animation Test Harness 563

Creating the Activity and the ListView 564

Animating the ListView 566

Using Interpolators 569

View Animation 571

Understanding View Animation 571

Adding Animation 574

Using Camera to Provide Depth Perception in 2D 577

Exploring the AnimationListener Class 579

Notes on Transformation Matrices 579

Property Animations: The New Animation API 580

Property Animation 581

Planning a Test Bed for Property Animation 582

Basic View Animation with Object Animators 585

Sequential Animation with AnimatorSet 586

Setting Animation Relationships with AnimationSetBuiider 587

Using XML to Load Animators 588

Using PropertyValuesHolder 589

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View Properties Animation 590

Type Evaluators 591

Key Frames 594

Layout Transitions 595

Resources 596

Summary 596

Interview Questions 597

Chapter 22: Exploring Maps and Location-based Services 599

Understanding the Mapping Package 600

Obtaining a Maps API Key from Google 600

Understanding MapView and MapActivity 602

Adding Markers Using Overlays 608

Understanding the Location Package 614

Geocoding with Android 614

Geocoding with Background Threads 618

Understanding the LocationManager Service 621

Showing Your Location Using MyLocationOverlay 629

Using Proximity Alerts 633

References 637

Summary 638

Interview Questions 639

Chapter 23: Using the Telephony APIs 641

Working with SMS 641

Sending SMS Messages 641

Monitoring Incoming SMS Messages 645

Working with SMS Folders 647

Sending E-mail 649

Working with the Telephony Manager 650

Session Initiation Protocol (SIP) 653

Experimenting with SipDemo 654

The android.net.sip package 655

References 656

Summary 657

interview Questions 657

Chapter 24: Understanding the Media Frameworks 659

Using the MediaAPIs 659

Using SD Cards 660

Playing Media 665

Playing Audio Content 665

Playing Video Content 678

Recording Media 680

Exploring Audio Recording with MediaRecorder 681

Recording Audio with AudioRecord 685

Exploring Video Recording 689

Exploring the MediaStore Class 699

Recording Audio Using an Intent 700

Adding Media Content to the Media Store 703

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Triggering MediaScanner for the Entire SD Card 706

References 706

Summary 707

Interview Questions 708

Chapter 25: Home Screen Widgets 709

Architecture of Home Screen Widgets 709

What Are Home Screen Widgets? 710

User Experience with Home Screen Widgets 710

Life Cycle of a Widget 714

A Sample Widget Application 721

Defining the Widget Provider 723

Defining Widget Size 724

Widget Layout-Related Files 725

Implementing a Widget Provider, 727

Implementing Widget Models 728

Implementing Widget Configuration Activity 736

Widget Preview Tool 740

Widget Limitations and Extensions 740

Collection-Based Widgets 741

Resources 741

Summary 741

Interview Questions 742

Chapter 26: Exploring List Widgets 745

A Quick Note on Remote Views 745

Working with Lists in Remote Views 746

Preparing a Remote Layout 748

Loading a Remote Layout 751

Setting Up RemoteViewsService 752

Setting Up RemoteViewsFactory 753

Setting Up onClick Events 757

Responding to onClick Events 760

Working Sample: Test Home Screen List Widget 761

Creating the Test Widget Provider 762

Creating the Remote Views Factory 765

Coding Remote Views Service 767

Main Widget Layout File 768

Widget Provider Metadata 768

AndroidManlfest.xml 769

Testing the Test List Widget 769

References 772

Summary 773

Interview Questions 773

Chapter 27: Touch Screens 775

Understanding MotionEvents 775

The MotionEvent Object 775

Recycling MotionEvents 787

Using VelocityTracker 788

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Multitouch 790

The Basics of Multitouch 790

Touches with Maps 797

Gestures 799

The Pinch Gesture 800

GestureDetector and OnGestureListeners 800

Custom Gestures 803

The Gestures Builder Application 803

References 810

Summary 810

Interview Questions 811

Chapter 28: Implementing Drag and Drop 813

Exploring Drag and Drop 813

Basics of Drag and Drop in 3.0+ 819

Drag-and-Drop Example Application 820

List of Files 821

Laying Outthe Example Drag-and-drop Application 821

Responding to onDrag in the Dropzone 823

Setting Up the Drag Source Views 826

Testing the Example Drag-and-Drop Application 830

References 831

Summary 831

Interview Questions 831

Chapter 29: Using Sensors 833

What Is a Sensor? 833

Detecting Sensors 834

What Can We Know About a Sensor? 834

Getting Sensor Events 837

Issues with Getting Sensor Data 839

Interpreting Sensor Data 840

Light Sensors 840

Proximity Sensors 841

Temperature Sensors 841

Pressure Sensors 842

Gyroscope Sensors 842

Accelerometers 842

Magnetic Field Sensors 849

Using Accelerometers and Magnetic Field Sensors Together 849

Orientation Sensors 850

Magnetic Declination and GeomagneticField 856

Gravity Sensors 857

Linear Acceleration Sensors 857

Rotation Vector Sensors 857

Near Field Communication Sensors 858

References 870

Summary 870Interview Questions 871

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i Chapter 30: Exploring the Contacts API 873

Understanding Accounts 874

A Quick Tour of Account Screens 874

Relevance of Accounts to Contacts 878

Enumerating Accounts 878

Understanding the Contacts Application 880

Introducing the Personal Profile 881

Showing Contacts 883

Showing Contact Details 883

Editing Contact Details 885

Setting a Contact's Photo 886

Exporting Contacts 886

Various Contact Data Types 888

Understanding Contacts 889

Examining the Contacts SQLite Database 889

Raw Contacts 890

Data Table 892

Aggregated Contacts 893

view_contacts 895

contact_entities_view 896

Working with the Contacts API 897

Exploring Accounts 897

Exploring Aggregated Contacts 900

Exploring Raw Contacts 908

Exploring Raw Contact Data 912

Adding a Contact and Its Details 915

Controlling Aggregation 917

Impacts of Syncing 917

Understanding the Personal Profile 918

Reading Profile Raw Contacts 919

Reading Profile Contact Data 920

Adding Data to the Personal Profile 921

References 922

Summary 923

Interview Questions 924

Chapter 31: Deploying Your Application: Android Market and Beyond 927

Becoming a Publisher 928

Following the Rules 928

Developer Console 931

Preparing Your Application for Sale.., 933

Testing for Different Devices 934

Supporting Different Screen Sizes 934

Preparing AndroidManifest.xml for Uploading 935

Localizing Your Application 936

Preparing Your Application Icon 937

Considerations for Making Money from Apps 937

Directing Users Back to the Market 938

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The Android Licensing Service 939

Using ProGuard for Optimizing, Fighting Piracy 939

Preparing Your .apk File for Uploading 941

Uploading Your Application 942

Graphics 942

Listing Details 943

Publishing Options 944

Contact Information 945

Consent 945

User Experience on Android Market 945

Beyond Android Market 947

References 948

Summary 948

Interview Questions 949

Index 951

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