             }
         }
 
-        coder.encodeDouble(scrollXOffset, forKey: kScrollXOffsetKey)
-        coder.encodeInteger(selectedButtonIndex, forKey: kSelectedButtonIndexKey)
+        coder.encodeDouble(scrollXOffset, forKey: RestorationKeys.scrollXOffset)
+        coder.encodeInteger(selectedButtonIndex, forKey: RestorationKeys.selectedButtonIndex)
     }
 
     public override func restoreStateWithCoder(coder: NSCoder) {
         super.restoreStateWithCoder(coder)
         
-        let scrollXOffset = coder.decodeDoubleForKey(kScrollXOffsetKey)
-        let selectedButtonIndex = coder.decodeIntegerForKey(kSelectedButtonIndexKey)
+        let scrollXOffset = coder.decodeDoubleForKey(RestorationKeys.scrollXOffset)
+        let selectedButtonIndex = coder.decodeIntegerForKey(RestorationKeys.selectedButtonIndex)
         
         var bounds = self.scrollView!.contentView.bounds
         bounds.origin.x = CGFloat(scrollXOffset)

    }
    
    // MARK: - State Restoration
    
    public override func encodeRestorableStateWithCoder(coder: NSCoder) {
        super.encodeRestorableStateWithCoder(coder)
        

        }
    }
}
