Android Cookbook Android Cookbook Android Community Experts Beijing • Cambridge • Farnham • Köln • Sebastopol • Tokyo Android Cookbook by Android Community Experts Copyright © 2011 Ian Darwin and Contributors. All rights reserved. Printed in the United States of America. Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472. O’Reilly books may be purchased for educational, business, or sales promotional use. Online editions are also available for most titles (http://safari.oreilly.com). For more information, contact our corporate/ institutional sales department: (800) 998-9938 or [email protected]. Editor: Ian F. Darwin Indexer: Production Editor: Cover Designer: Copyeditor: Interior Designer: Proofreader: Illustrators: and November 2011: First Edition. Revision History for the First Edition: See http://oreilly.com/catalog/errata.csp?isbn=9781449388416 for release details. 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ISBN: 978-1-449-38841-6 [?] 1318018084 Table of Contents Preface .................................................................... xiii 1. Getting Started ......................................................... 1 1.1 Introduction: Getting Started 1 1.2 Learning the Java Language 1 1.3 Hello World - Command Line 3 1.4 Hello World - Eclipse Version 5 1.5 Set Up an Android Virtual Device for Apps Testing 10 1.6 Set Up an IDE on Windows to Develop for Android 23 1.7 Android Lifecycle 32 1.8 Opening a Web Page, Phone Number or anything else with an Intent 33 1.9 Email Text From a View 35 1.10 Sending an email with attachments 38 1.11 Installing .apk files on the emulator 40 1.12 Installing apps onto an Android Emulator 40 1.13 Android Epoch HTML/Javascript Calendar 43 1.14 Sharing Java classes from another Eclipse Project 48 1.15 Referencing libraries to implement external functionality 49 1.16 Use SDK Samples to Help Avoid Head Scratching 50 1.17 Keeping the Android SDK Updated 55 1.18 Five Ways to Wire Up an Event Listener 61 1.19 Taking a Screenshot from the Emulator/Android Device 69 1.20 Program: A Simple CountDownTimer example 70 1.21 Program: Tipster, a tip calculator for the Android OS 73 2. Designing a successful Application ........................................ 91 2.1 Introduction: Designing a Successful Android application 91 2.2 Keeping a Service running while other apps are on display 95 2.3 Starting a service after phone reboot 97 2.4 Exception Handling 98 2.5 Sending/Receive broadcast message 100 v 2.6 Android's Application Object as a "Singleton" 101 2.7 Keeping data when the user rotates the device 103 2.8 Creating a Responsive Application using Threads 105 2.9 Eating Too Much CPU Time In The UI Causes A Nasty Result 107 2.10 AsyncTask: Do background tasks and modify the GUI 113 2.11 Monitoring the Battery Level of your Android Device 114 2.12 Splash Screens in Android: Method 1 115 2.13 Splash Screens in Android: Method 2 117 2.14 Designing a Conference/*Camp/Hackathon App 123 2.15 Implementing Autocompletion in Android. 124 2.16 Using Google Analytics in Android Application 126 2.17 Using AsyncTask to do background processing 128 2.18 A Simple Torch Light 134 2.19 Adapting Android Phone Application to Tablet 136 2.20 First Run preferences 138 2.21 Formatting the time and date display 139 2.22 Controlling Input with KeyListeners 142 2.23 Android Application Data Backup 145 2.24 Making password fields 151 2.25 Working Without Tooltips: Use Hints Instead 152 3. Testing .............................................................. 157 3.1 Introduction: Testing 157 3.2 How to TDD(test driven development) Android App 157 3.3 How to troubleshoot "The application has stopped unexpectedly. Please try again" 158 3.4 Debugging using Log.d and LogCat 161 3.5 Keep Your App Snappy With StrictMode 163 3.6 Barrel of Monkeys 164 3.7 Sending text messages and placing calls between AVDs 165 3.8 Activity LifeCycle Scenarios for Testing 166 4. Content Providers ..................................................... 175 4.1 Introduction: Content Providers 175 4.2 Retrieving Data from a Content Provider 175 4.3 Writing a Content Provider 177 4.4 Android Remote Service 179 5. Graphics ............................................................. 185 5.1 Introduction: Graphics 185 5.2 Getting Screenshots 185 5.3 Using a Custom Font 186 5.4 Draw a spinning cube with OpenGL ES 191 vi | Table of Contents 5.5 Adding control to the OpenGL spinning cube 196 5.6 Taking a Picture Using an Intent 199 5.7 Taking a Picture Using android.media.Camera 201 5.8 Using AndroidPlot to display charts and graphs in your Android application. 205 5.9 Use Inkscape to Create an Android Launcher Icon 207 5.10 Easy Launcher Icons from OpenClipArt.org using Paint.NET 216 5.11 Android HTML5 RGraph Charting 228 5.12 Simple Raster Animation 232 6. Graphical User Interface ............................................... 239 6.1 Introduction: GUI 239 6.2 User Interface Guidelines (placeholder) 240 6.3 SlidingDrawer Overlapping other UI components 240 6.4 Android 3.0 Photo Gallery 244 6.5 Building a UI using Fragments API of Android 3.0 in Android 2.2 246 6.6 Haptic Feedback 250 6.7 Handling Configuration Changes by Decoupling View from Model 254 6.8 Let Them See Stars: Using RatingBar 257 6.9 Invoke an action handler when a Button is pressed 260 6.10 Creating an Alert Dialog. 263 6.11 Customize the SlidingDrawer component to animate/transition from the top down. 264 6.12 Use a Timepicker widget 266 6.13 Formatting with Correct Plurals 268 6.14 Feed AutoCompleteTextView using a SQLite database query 272 6.15 Change The Enter Key to "Next" on the Soft Keyboard 273 6.16 How to Create a Simple Widget 277 6.17 Make a View Shake 280 6.18 Using CheckBoxes and RadioButtons 281 6.19 Creating a Notification in the Status Bar 286 6.20 Autocompletion with Icons/Images 288 6.21 Creating your own Custom Title Bar 295 6.22 iPhone-like wheel picker for selection 298 6.23 Simple Calendar 302 6.24 Formatting Numbers 310 6.25 Start a Second Screen from the First 314 6.26 Creating a Tabbed Dialog 322 6.27 Creating a Custom Dialog with buttons, images and text 326 6.28 Create a Custom Menu 328 6.29 Loading Screen in between two Activities 330 6.30 Implementing reactions on click of items in a Custom Menu. 333 6.31 Navigate different activities within a TabView 336 Table of Contents | vii 6.32 Drop-down Chooser via the Spinner Class 338 6.33 Effective UI design using Image Buttons 340 6.34 Pinch to zoom 343 6.35 Add a Border with Rounded Corners to a Layout 346 6.36 Creating a ProgressDialog in Android. 347 6.37 Creating a Submenu. 349 6.38 Processing key press events in an Activity. 351 6.39 Constrain EditText Values with Attributes and the TextWatcher Interface 352 6.40 Gesture Detection in Android 355 6.41 Customizing the Look of a Toast 362 6.42 Using SlidingDrawer to Overlap Other Components 363 7. GUI: ListView ......................................................... 367 7.1 Introduction: ListView 367 7.2 Building list-based applications with ListView 367 7.3 'No data' View for Lists 372 7.4 Advanced ListView: populating a list with images and text 373 7.5 ListView with Icons/images 379 7.6 Sectioned Headers in ListViews 386 7.7 Making Lists Behave Nicely 392 7.8 Writing A Custom List Adapter 393 7.9 Orientation Changes : From ListView data values to Landscape Charting 396 8. Multimedia .......................................................... 407 8.1 Introduction: Multimedia 407 8.2 Play a Youtube Video 407 8.3 Using Gallery with ImageSwitcher 408 8.4 Grabbing a video using MediaRecorder 411 8.5 Android Face Detection 414 8.6 Playing audio from a file 417 8.7 Playing Audio without Interaction 420 8.8 Using Speech to Text 421 8.9 Making the Device Speak with TTS 423 9. Data Persistence ...................................................... 427 9.1 Listing a Directory 427 9.2 Default shared preferences consistency check 429 9.3 Advanced text search 431 9.4 How to push string-values using Intent.putExtra() 437 9.5 Retrieving data from a Sub-Activity back to your Main Activity 439 9.6 Getting total and free space on the SD card 442 viii | Table of Contents 9.7 Creating a SQLite database in an Android application. 442 9.8 Retrieving data from a SQLite database. 444 9.9 Inserting values into a SQLite database. 445 9.10 Work With Dates in SQLite 445 9.11 Parsing JSON using the Jackson Parser 448 9.12 Parsing an XML document using the DOM API 451 9.13 Parsing an XML document using an XmlPullParser 453 9.14 Accessing data from a file shipped with the App rather than in the filesystem 456 9.15 Adding a Contact 457 9.16 Reading Contact Data 461 9.17 Parsing JSON using JSONObject 463 10.