App Inventor 2, 2nd Edition

Chapter 7. Android, Where’s My Car?

You parked as close to the stadium as you possibly could, but when the concert ends, you don’t have a clue where your car is. Your friends are equally clueless. Fortunately, you haven’t lost your Android phone, which never forgets anything, and you remember you have the hot new app, Android, Where’s My Car? With this app, you click a button when you park your car, and the Android uses its location sensor to record the car’s GPS coordinates and address. Later, when you reopen the app, it gives you directions from where you currently are to the saved location—problem solved!

What You’ll Learn

This app covers the following concepts:

• Determining the location of the Android device by using the LocationSensor component.
• Persistently recording data in a database directly on the device by using TinyDB.
• Using the WebViewer component to open Google Maps from your app and show directions from one location to another.

Getting Started

Connect to the App Inventor website and start a new project. Since project names can’t have spaces, name it “AndroidWhere”. Set the screen’s title to “Android, Where’s My Car?” Connect your device or emulator for live testing.

Designing the Components

The user interface for Android, Where’s My Car? consists of labels to show your current and remembered locations, and buttons to record a location and show directions to ...