App Inventor for Android: Build Your Own Apps — No Experience Required!

Chapter 7: PunchDroid: An Android Punch Bug Game

In This Chapter

• Using the TinyWebDB component for multi-handset communication

• Using a timer to poll a datasource to keep apps up-to-date

• Employing a choose block for variable situations

• Implementing a multiplayer game between handsets

• Using check boxes as radio buttons

Remember playing the Punch Bug game back in the day when Volkswagen Beetles were a rare sight? You know the game. Whenever someone sees the distinctive little car, she would punch the other player on the arm and yell “Punch Bug!” and get a point. Well, the game you played as a child is about to get an update. The PunchDroid project allows your user to play the same game regardless of the distance between the players. Whether you’re looking for VW Beetles or Android phones, PunchDroid is a fun little game that can be played between two phones.

This application introduces the TinyWebDB component. Previously you used the TinyDB component to store data between application settings. TinyDB stores its data on the local device as an .XML file in the Settings section of the Android file system. TinyWebDB, by contrast, uses either Wi-Fi or cell phone networks to communicate with a database running on a Web server. The TinyWebDB service runs on a Web server, accepts incoming data, and responds to requests for stored data from your application. TinyWebDB is an important part of your skill set for creating connected applications and devices.

The TinyWebDB component ...