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

    protected Parcelable onSaveInstanceState()
    protected void onRestoreInstanceState(Parcelable state)

These methods do not work like Activity and Fragment’s onSaveInstanceState(Bundle). First, they will only be called if your View has an ID. Second, 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.)

Finally, you must also maintain the saved state of BoxDrawingView’s parent, the View class. Save the result of super.onSaveInstanceState() in your new Bundle and send that same result to the super class when calling super.onRestoreInstanceState(Parcelable).