book

App Inventor

by David Wolber, Hal Abelson, Ellen Spertus, Liz Looney

May 2011

Beginner to intermediate

386 pages

11h 41m

English

O'Reilly Media, Inc.

Read now

Unlock full access

App Inventor
Dedication
A Note Regarding Supplemental Files
Foreword
Preface
A Blocks Language for Mobile PhonesWhat Can You Do with App Inventor?Why App Inventor WorksWhat Kind of Apps Can You Build?Who Can Build Apps?Conventions Used in This BookHow to Use This BookAcknowledgments
1. Hello Purr
What You’ll LearnThe App Inventor EnvironmentDesigning the ComponentsMaking a LabelAdding the ButtonAdding the Meow SoundAdding Behaviors to the ComponentsMaking the Kitty MeowAdding a PurrShaking the PhonePackaging the App for DownloadingSharing the AppVariationsSummary
I. 12 Customizable Apps
2. PaintPot
What You’ll LearnGetting StartedDesigning the ComponentsCreating the Color ButtonsUsing Arrangements for Better LayoutsAdding the CanvasArranging the Bottom Buttons and the Camera ComponentAdding Behaviors to the ComponentsAdding the Touch Event to Draw a DotAdding the Drag Event That Draws a LineAdding Button Event HandlersLetting the User Take a PictureChanging the Dot SizeUsing variablesChanging the values of variablesThe Complete App: PaintPotVariationsSummary
3. MoleMash
What You’ll BuildWhat You’ll LearnGetting StartedDesigning the ComponentsPlacing the Action componentsPlacing the Label componentsAdding Behaviors to the ComponentsMoving the MoleCreating MoveMoleCalling MoveMole when the app startsCalling MoveMole every secondKeeping ScoreResetting the ScoreAdding Behavior When the Mole Is TouchedThe Complete App: MoleMashVariationsSummary
4. No Texting While Driving
What You’ll LearnGetting StartedDesigning the ComponentsAdding Behaviors to the ComponentsProgramming an autoresponseHow the blocks workEntering a Custom ResponseHow the blocks workStoring the Custom Response in a DatabaseHow the blocks workRetrieving the Custom Response When the App OpensHow the blocks workSpeaking the Incoming Texts AloudHow the blocks workAdding Location Information to the ResponseHow the blocks workSending the Location As Part of the ResponseHow the blocks workThe Complete App: No Texting While DrivingVariationsSummary

5. Ladybug Chase
What You’ll BuildWhat You’ll LearnDesigning the ComponentsGetting StartedAnimating the LadybugAdding the ComponentsAdding the BehaviorDisplaying the Energy LevelAdding a ComponentCreating a Variable: EnergyDrawing the Energy BarStarvationAdding an AphidAdding an ImageSpriteControlling the AphidHow the blocks workHaving the Ladybug Eat the AphidHow the blocks workDetecting a Ladybug–Aphid CollisionHow the blocks workThe Return of the AphidHow the blocks workAdding a Restart ButtonAdding the FrogHaving the Frog Chase the LadybugHow the blocks workHaving the Frog Eat the LadybugHow the blocks workThe Return of the LadybugHow the blocks workAdding Sound EffectsVariationsSummary
6. Paris Map Tour
What You’ll LearnDesigning the ComponentsSetting the Properties of ActivityStarterAdding Behaviors to the ComponentsCreating a List of DestinationsLetting the User Choose a DestinationHow the blocks workOpening Maps with a SearchHow the blocks workSetting Up a Virtual TourFinding the DataUri for Specific MapsDefining the dataURIs ListModifying the ListPicker.AfterPicking BehaviorHow the blocks workVariationsSummary
7. Android, Where’s My Car?
What You’ll LearnGetting StartedDesigning the ComponentsAdding Behaviors to the ComponentsDisplaying the Current LocationHow the blocks workRecording the Current LocationHow the blocks workDisplaying Directions to the Remembered LocationHow the blocks workStoring the Remembered Location PersistentlyHow the blocks workRetrieving the Remembered Location When the App LaunchesHow the blocks workThe Complete App: Android, Where’s My Car?VariationsSummary
8. Presidents Quiz
What You’ll LearnGetting StartedDesigning the ComponentsAdding Behaviors to the ComponentsDefining the Index VariableDisplaying the First QuestionHow the blocks workIterating Through the QuestionsHow the blocks workMaking the Quiz Easy to ModifyHow the Blocks WorkSwitching the Image for Each QuestionHow the Blocks WorkChecking the User’s AnswersHow the Blocks WorkHow the Blocks WorkThe Complete App: The Presidents QuizVariationsSummary
9. Xylophone
What You’ll BuildWhat You’ll LearnGetting StartedDesigning the ComponentsCreating the KeyboardCreating the First Note ButtonsAdding the Sound ComponentConnecting the Sounds to the ButtonsTelling Android to Load the SoundsImplementing the Remaining NotesRecording and Playing Back NotesAdding the ComponentsRecording Notes and TimesHow the blocks workPlaying Back NotesHow the blocks workPlaying Back Notes with Proper DelaysHow the blocks workVariationsSummary
10. MakeQuiz and TakeQuiz
What You’ll LearnGetting StartedDesigning the ComponentsAdding Behaviors to the ComponentsRecording the User’s EntriesHow the blocks workBlanking Out the Question and AnswerHow the blocks workDisplaying Question-Answer Pairs on Multiple LinesHow the blocks workCalling the new procedureStoring the Questions and Answers in a DatabaseHow the blocks workLoading Data from the DatabaseHow the blocks workHow the blocks workThe Complete App: MakeQuizTakeQuiz: An App for Taking the Quiz in the DatabaseTakeQuiz: Modifying the Blocks to Load the Quiz from the DatabaseHow the Blocks WorkThe Complete App: TakeQuizVariationsSummary
11. Broadcast Hub
What You’ll LearnGetting StartedDesigning the ComponentsAdding Behaviors to the ComponentsHow the Blocks WorkAdding Someone to the Broadcast ListHow the blocks workBroadcasting MessagesHow the blocks workCleaning Up Your List DisplayHow the blocks workLogging the Broadcasted TextsHow the blocks workStoring the BroadcastList in a DatabaseHow the blocks workLoading the BroadcastList from a DatabaseHow the blocks workThe Complete App: Broadcast HubVariationsSummary
12. NXT Remote Control
What You’ll LearnGetting StartedDesigning the ComponentsNon-Visible ComponentsVisible ComponentsAdding Behaviors to the ComponentsConnecting to the NXTDisplaying the List of RobotsHow the blocks workMaking the Bluetooth ConnectionHow the blocks workDisconnecting from the NXTHow the blocks workDriving the NXTHow the blocks workUsing the Ultrasonic Sensor to Detect ObstaclesHow the blocks workVariationsSummary
13. Amazon at the Bookstore
What You’ll LearnWhat Is an API?Designing the ComponentsDesigning the BehaviorSearching by KeywordHow the blocks workSearching by ISBNHow the blocks workDon’t Leave Your Users HangingHow the blocks workScanning a BookHow the blocks workImproving the DisplayHow the blocks workCustomizing the APIVariationsSummary
II. Inventor’s Manual
14. Understanding an App’s Architecture
ComponentsBehaviorAn App As a RecipeAn App As a Set of Event HandlersEvent TypesUser-initiated eventsInitialization eventsTimer eventsAnimation eventsExternal eventsEvent Handlers Can Ask QuestionsEvent Handlers Can Repeat BlocksEvent Handlers Can Remember ThingsEvent Handlers Can Talk to the WebSummary
15. Engineering and Debugging an App
Software Engineering PrinciplesDesign for Real People with Real ProblemsBuild a Quick Prototype and Show It to Your Prospective UsersIncremental DevelopmentDesign Before CodingComment Your CodeDivide, Layer, and ConquerUnderstand Your Language: Tracing with Pen and PaperDebugging an AppWatching VariablesTesting Individual BlocksIncremental Development with Do ItActivating and Deactivating BlocksSummary
16. Programming Your App’s Memory
Named Memory SlotsPropertiesDefining VariablesSetting and Getting a VariableSetting a Variable to an ExpressionIncrementing a VariableBuilding Complex ExpressionsDisplaying VariablesSummary
17. Creating Animated Apps
Adding a Canvas Component to Your AppThe Canvas Coordinate SystemAnimating Objects with Timer EventsCreating MovementSpeedHigh-Level Animation FunctionsEdgeReachedCollidingWith and NoLongerCollidingWithInteractive AnimationSpecifying Sprite Animation Without a Clock TimerSummary
18. Programming Your App to Make Decisions: Conditional Blocks
Testing Conditions with if and ifelse BlocksProgramming an Either/Or DecisionProgramming Conditions Within ConditionsProgramming Complex ConditionsSummary
19. Programming Lists of Data
Creating a List VariableSelecting an Item in a ListUsing an Index to Traverse a ListExample: Traversing a List of Paint ColorsCreating Input Forms and Dynamic ListsDefining a Dynamic ListAdding an ItemDisplaying a ListRemoving an Item from a ListLists of ListsSummary
20. Repeating Blocks: Iteration
Controlling an App’s Execution: Branching and LoopingRepeating Functions on a List Using foreachA Closer Look at LoopingWriting Maintainable CodeA Second foreach Example: Displaying a ListRepeating Blocks with whileUsing while to Synchronously Process Two ListsUsing while to Compute a FormulaSummary
21. Defining Procedures: Reusing Blocks
Eliminating RedundancyDefining a ProcedureCalling a ProcedureThe Program CounterAdding Parameters to Your ProcedureReturning Values from a ProcedureReusing Blocks Among AppsA Second Example: distanceBetweenPointsSummary
22. Working with Databases
Storing Persistent Data in TinyDBRetrieving Data from TinyDBStoring and Sharing Data with TinyWebDBStoring Data with TinyWebDBRequesting and Processing Data with TinyWebDBGetValue-GotValue in ActionA More Complex GetValue/GotValue ExampleRequesting Data with Various TagsProcessing Multiple Tags in TinyWebDB.GotValueSetting Up a Web DatabaseSummary
23. Reading and Responding to Sensors
Creating Location-Aware AppsGPSSensing Location with App InventorChecking BoundariesLocation Information Providers: GPS, WiFi, and Cell IDUsing the Orientation SensorUsing the Roll ParameterMoving Any Direction with Heading and MagnitudeUsing the Phone As a CompassUsing the AccelerometerResponding to the Device ShakingUsing the AccelerometerSensor’s ReadingsDetecting Free FallDetecting Acceleration Using Calibrated ValuesSummary
24. Communicating with Web APIs
Talking to Web APIs That Generate ImagesSetting the Image.Picture Property to a Chart APIBuilding a Chart API URL DynamicallyTalking to Web Data APIsExploring the Web Interface of an APIAccessing the API Through TinyWebDBCreating Your Own App Inventor–Compliant APIsCustomizing Template CodeWrapping the Yahoo! Finance APISummary
Index
About the Authors
Colophon
Copyright

Overview

Yes, you can create your own apps for Android phones—and it's easy to do. This extraordinary book introduces App Inventor for Android, a powerful visual tool that lets anyone build apps for Android-based devices. Learn the basics of App Inventor with step-by-step instructions for more than a dozen fun projects, such as creating location-aware apps, data storage, and apps that include decision-making logic.

The second half of the book features an Inventor's manual to help you understand the fundamentals of app building and computer science. App Inventor makes an excellent textbook for beginners and experienced developers alike.

Design games and other apps with 2D graphics and animation
Create custom multi-media quizzes and study guides
Create a custom tour of your city, school, or workplace
Use an Android phone to control a LEGO® MINDSTORMS® NXT robot
Build location-aware apps by working with your phone’s sensors
Explore apps that incorporate information from the Web
Learn computer science as you build your apps

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.

Julian F.

Head of Cybersecurity

I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.

Addison B.

Field Engineer

I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.

Amir M.

Data Platform Tech Lead

I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.

Mark W.

Embedded Software Engineer

Publisher Resources

ISBN: 9781449306786Errata Page

Cloud Computing

Data Engineering

Data Science

AI & ML

Programming Languages

Software Architecture

IT/Ops

Security

Design

Business

Soft Skills