Learning Android™ Application Programming: A Hands-On Guide to Building Android Applications

Making an Android Device Vibrate

Sometimes a device’s screen may not be visible (for example, if it’s in someone’s pocket), so you need to indicate that time has passed in a nonvisual way. Making the device vibrate is a good way to do this.

Let’s set up the code to vibrate once every 5 minutes, twice every 15 minutes, and three times every hour while the timer is running.

1. Add a property called vibrate of type Vibrator to the TimerActivity class:

protected Vibrator vibrate;

2. Add a property called lastSeconds of type long. This is needed because the run method is called several times a second, and you want the device to vibrate only once.

protected long lastSeconds;

3. In the onStart method, set up the vibrate property by calling getSystemService ...