iOS Programming: The Big Nerd Ranch Guide, Second Edition

Using Accelerometer Data

This application will use the accelerometer data to offset the center of drawing in the HypnosisView. So, HypnosisView needs two properties to define the offset. In HypnosisView.h, add these properties.

@​i​n​t​e​r​f​a​c​e​ ​H​y​p​n​o​s​i​s​V​i​e​w​ ​:​ ​U​I​V​i​e​w​
{​
 ​ ​ ​ ​f​l​o​a​t​ ​x​S​h​i​f​t​,​ ​y​S​h​i​f​t​;​
}​
@​p​r​o​p​e​r​t​y​ ​(​n​o​n​a​t​o​m​i​c​,​ ​a​s​s​i​g​n​)​ ​f​l​o​a​t​ ​x​S​h​i​f​t​;​
@​p​r​o​p​e​r​t​y​ ​(​n​o​n​a​t​o​m​i​c​,​ ​a​s​s​i​g​n​)​ ​f​l​o​a​t​ ​y​S​h​i​f​t​;​
@​e​n​d​

Now synthesize these properties in HypnosisView.m:

@​i​m​p​l​e​m​e​n​t​a​t​i​o​n​ ​H​y​p​n​o​s​i​s​V​i​e​w​
@​s​y​n​t​h​e​s​i​z​e​ ​x​S​h​i​f​t​,​ ​y​S​h​i​f​t​;​

HypnosisView needs to know how to use these properties ...