Any physical contact between the user and the touch screen display of a device can be considered a “gesture”. Lacking the physical keyboard and mouse pointer of a traditional computer system, gestures are widely used as a method of interaction between user and application. While a gesture can be comprised of just about any sequence of motions, there is a widely used set of gestures with which users of touch screen devices have become familiar. A number of these so-called “common gestures” can be easily detected within an application by making use of the Android Gesture Detector classes. In this chapter, the use of this technique has been outlined both in theory and through the implementation of an example project.
Having covered common gestures in this chapter, the next chapter will look at detecting a wider range of gesture types including the ability to both design and detect your own gestures.