Android How to Program, 3/e

1.9 Test-Driving the Tip Calculator App in an Android Virtual Device (AVD)

In this section, you’ll run and interact with your first Android app using an Android Virtual Device and, if you have one, an actual Android device. The Tip Calculator (Fig. 1.16(a))—which you’ll build in Chapter 3—calculates and displays for a restaurant bill the tip amount and the total bill amount. As you enter each digit of the bill amount by touching the numeric keypad, the app calculates and displays the tip and total bill for a tip percentage that you specify with the app’s SeekBar—we use 15% by default (Fig. 1.16(a)). You can select a tip percentage in the range 0–30% by moving the SeekBar’s thumb—this updates the tip percentage TextView and displays the updated ...