Learning MIT App Inventor A Hands On Guide to Building Your Own Android Apps

With MIT’s App Inventor 2, anyone can build complete, working Android apps—without writing code! This complete tutorial will help you do just that, even if you have absolutely no programming experience.

Unlike books focused on the obsolete Google version, Learning MIT App Inventor is written from the ground up for MIT’s dramatically updated Version 2.

The authors guide you step-by-step through every task and feature, showing you how to create apps by dragging, dropping, and connecting puzzle pieces—not writing code. As you learn, you’ll also master expert design and development techniques you can build on if you ever do want to write code.

Through hands-on projects, you’ll master features ranging from GPS to animation, build high-quality user interfaces, make everything work, and test it all with App Inventor’s emulator. (You won’t even need an Android device!)

All examples for this book are available at theapplanet.com/appinventor 

Coverage includes:

• Understanding mobile devices and how mobile apps run on them
• Planning your app's behavior and appearance with the Designer
• Using the Blocks Editor to tell your app what to do and how to do it
• Creating variables and learning how to use them effectively
• Using procedures to group and reuse pieces of code in larger, more complicated apps
• Storing data in lists and databases
• Using App Inventor's gaming, animation, and media features
• Creating more sophisticated apps by using multiple screens
• Integrating sensors to make your app location-aware
• Debugging apps and fixing problems
• Combining creativity and logical thinking to envision more complex apps

• Understanding mobile devices and how mobile apps run on them
• Planning your app's behavior and appearance with the Designer
• Using the Blocks Editor to tell your app what to do and how to do it
• Creating variables and learning how to use them effectively
• Using procedures to group and reuse pieces of code in larger, more complicated apps
• Storing data in lists and databases
• Using App Inventor's gaming, animation, and media features
• Creating more sophisticated apps by using multiple screens
• Integrating sensors to make your app location-aware
• Debugging apps and fixing problems
• Combining creativity and logical thinking to envision more complex apps

With MIT's App Inventor 2, anyone can build complete, working Android apps -- without writing code! This is a complete tutorial that will help you make the most of App Inventor 2, even if you have absolutely no programming experience. Unlike books focused on the obsolete Google version, Learning MIT App Inventor is written from the ground up for today's dramatically improved MIT version of App Inventor. Step by step, mobile expert and instructional specialist Derek Walter guides you through every App Inventor 2 task and feature in plain, simple English.

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You'll learn through hands-on projects that help you use features ranging from GPS to media and animation. Walter and Sherman walk you through building high-quality app user interfaces, making them function using the drag-and-drop Blocks Editor, and testing them with App Inventor's emulator. (You won't even need to own an Android device!) You'll master high-quality design and development techniques you can build on if you ever do want to write code. Then, building on everything you've learned, you'll create a capstone app project of surprising power and sophistication!

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This book covers:

• Walkthroughs of apps you can build right from within MIT App Inventor
• Step-by-step instructions for a wide variety of apps
• An overview of core computer science principles
• An introduction to the main features of a mobile operating system

Derek Walter is a freelance writer specializing in the mobile ecosystem. He contributes regularly to PCWorld, Macworld, Greenbot, and other sites devoted to consumer technology. He also blogs about mobile apps and other topics in technology at theapplanet.com. His undergraduate degree is in mass communication/journalism, and he holds a master’s degree in educational technology from The George Washington University. Derek has also worked in education for the last 15 years as a classroom teacher and adjunct university instructor.

Mark Sherman is a researcher in computer science education and has taught computing, programming, and robotics to undergraduates in the U.S., India, and China. He is an MIT App Inventor Master Trainer, and he has taught students mobile app design with App Inventor and trained teachers and faculty on best practices and pedagogy of the same. He holds a bachelor’s degree in computer engineering and a master’s degree in computer science, both from UMass Lowell.

Preface     xiv

1 An Introduction to Programming     1

  Operating Systems     2

    User Interface     4

  Android Strengths     6

    Extending App Capabilities     8

    Google Services     9

  Applications     10

  Programming Languages     11

  Summary     13

  Exercises     14

2 Building with MIT App Inventor     17

  The MIT App Inventor Site     17

    Signing In     18

    Designer     20

    Blocks Editor     20

    The AI2 Companion App     21

    The Android Emulator     23

    USB Connection to Android Device     23

  Getting Inside an App     25

    Event Handlers     25

    Doing One Thing at a Time     26

  Exercise: Sherlock Is Watching     27

    Adding an Image     29

  What Can You Build?    31

    Speak, Android!    31

    Pollock     31

    Fore     32

    Android Quiz     32

  Uploading to Google Play     32

  Summary     33

  Exercises     34

3 App Inventor Toolkit     35

  Creating a New Project     36

  Designer Essentials     36

    Palette     37

    Viewer     44

    Components     45

    Properties     46

    Media     46

  Exercise: Speak, Android!    47

    Connecting Your Device     48

    See Your App on a Connected Device     50

  Summary     54

  Exercises     54

4 Variables     55

  Component Properties: The Built-in Variables     56

    Clicker-Counter App     56

    Properties: Getters and Setters     57

    Clicker Counter Extensions     58

  Event Parameters: Special Variables    58

  Exercise: Pollock     60

    The Interface     60

    Programming Blocks     62

    Additional Exercises     64

  Scope: Global and Local Variables     64

  Global Variables     66

    Example App: Up/Down Counter     67

  Local Variables     68

    An Example App: Random Guess     69

  What You Can Store in Variables     72

  Summary     72

5 Procedures     75

  What Is a Procedure?    75

  Types of Procedures     76

  Why Use Procedures?    79

  Arguments     79

  Exercise: Flick     81

  Additional Exercises     83

  Summary     84

6 Working with Lists     85

  Modeling Things with Data     85

    The List Block     85

  The Basics     87

    Creating an Empty List     87

    Creating a List with Some Stuff Already In It     88

    Working with Lists     91

    Color as a List     92

  Types of Lists     92

    The One-Dimensional List     92

    Lists as Data Structures     93

    Using Multiple Lists Together (That Expand on Demand)    94

  Abstraction with Lists and Procedures     98

    Lists that Expand on Demand     100

  Common Problems     102

    Running Off the End of the List     102

    Defining a Variable That Depends on Runtime Elements     104

  Exercise: Android Quiz     105

  Additional Exercises     112

  Summary     112

7 Games and Animations     113

  Adding Animations     113

    ImageSprite     114

    Ball     115

    Canvas     116

  Animation Examples     117

    Smoother Animation     118

    Edges and Collisions     119

  Exercise: Fore     119

  Additional Exercises     123

  Summary     123

8 Multiple Screens and Debugging Techniques     125

  Why More Than One Screen?    125

  Building Apps with Multiple Screens     126

    What Screens Are Good At     127

    Issues with Multiple Screens     127

    Switching Screens     128

    Sharing Data Between Screens     129

  Debugging Techniques     130

    Leaving Comments     130

    Test Small and Test Often     131

    Do It     131

    Name Well     132

  Backing up Your Work     133

  Exercise: Pollock Plus One     134

  Additional Exercises     136

  Summary     136

9 Using Media     139

  Audio     140

  Images     141

    The ImagePicker     141

    The Camera     144

  Video 1    45

  Exercise: Camera Action     146

  Additional Exercises     146

  Summary     147

10 Sensors     149

  Building Location-Aware Apps     150

    Using Location     150

    Location Data     152

    Using the Maps App with Intents     153

    Saving Location Data     155

  The Accelerometer     158

    Detecting Tilt (and a Little Background Physics)    159

  The Orientation Sensor     160

  Exercise: Pushpin     161

    Part 1: Designing Current Location Readout     161

    Programming Part 1: The Current Location Readout     165

    Part 2: Pinning a Location to Remember Later     168

    Programming Part 2: Pinning a Location     170

    Extension Activities     172

  Summary     172

11 Databases     173

  TinyDB     174

    Retrieving Data from TinyDB     175

    A Few TinyDB Details     176

  TinyWebDB     176

    Setting Up Your Own Web Database Service     176

    Security and Privacy     177

  FusionTables     177

  Using Web GET and POST     180

    Basic Files     181

    Web APIs     182

  Exercise: WriteMore     182

  Additional Exercises     186

  Summary     187

12 Distributing an App     189

  Live Mode     189

  Security Settings     190

  Creating an APK File     191

    Downloading Directly to a Computer     192

    Downloading with a QR Code     196

  Creating an .aia File     198

  Exercise: App Distribution     200

    Version Codes     200

    Google Play Developer Console     201

  Summary     205

Index     207