Android Programming: The Big Nerd Ranch Guide

Handling Touch Events

One way to listen for touch events is to set a touch event listener using the following View method:

 ​ ​ ​ ​p​u​b​l​i​c​ ​v​o​i​d​ ​s​e​t​O​n​T​o​u​c​h​L​i​s​t​e​n​e​r​(​V​i​e​w​.​O​n​T​o​u​c​h​L​i​s​t​e​n​e​r​ ​l​)​

This method works the same way as setOnClickListener(View.OnClickListener). You provide an implementation of View.OnTouchListener, and your listener will be called every time a touch event happens.

However, because you are subclassing View, you can take a shortcut and override this View method:

 ​ ​ ​ ​p​u​b​l​i​c​ ​b​o​o​l​e​a​n​ ​o​n​T​o​u​c​h​E​v​e​n​t​(​M​o​t​i​o​n​E​v​e​n​t​ ​e​v​e​n​t​)​

This method receives an instance of MotionEvent, a class that describes the touch event, including its location ...