Animate two titles when scrolling.
See in action
##How to use it?
Create a custom title view by using designated initializer provided by RHAnimatedTitleView.
let titleView = RHAnimatedTitleView(oldTitle: "AAAA", newTitle: "BBBB")
add it to title view of navigationItem of view controller
navigationItem.titleView = titleView
You can set color of title you want
(Default is black.)
titleView.titleColor = UIColor.redColor()
Disable fade in/out transition is easy
(Default is true.)
titleView.transition = false
Change content offset of custom title view to trigger move action
(Note: the maximum distance that custom title view can move is same as the height of custom title view itself)
titleView.contentOffset = CGPointMake(0.0, y)