Android Programming: The Big Nerd Ranch Guide

Challenge: Rotations

Figure out how to persist your boxes across orientation changes from within your View. This can be done with the following View methods:

 ​ ​ ​ ​p​r​o​t​e​c​t​e​d​ ​P​a​r​c​e​l​a​b​l​e​ ​o​n​S​a​v​e​I​n​s​t​a​n​c​e​S​t​a​t​e​(​)​
 ​ ​ ​ ​p​r​o​t​e​c​t​e​d​ ​v​o​i​d​ ​o​n​R​e​s​t​o​r​e​I​n​s​t​a​n​c​e​S​t​a​t​e​(​P​a​r​c​e​l​a​b​l​e​ ​s​t​a​t​e​)​

These methods do not work like Activity and Fragment’s onSaveInstanceState(Bundle). Instead of taking in a Bundle, they return and process an object that implements the Parcelable interface. We recommend using a Bundle as the Parcelable instead of implementing a Parcelable class yourself. (Implementing the Parcelable interface is complicated. It is better to avoid doing so when possible.) ...