Show an animation as far as moved scroll while scrolling at the scroll view for Swift3
This code style is the Protocol Oriented Programming.
So some protocols are configured to implement the parallax scrolling.
This extends the scrollView to make the parallax scrolling feature on the Run time, using objc_getAssociatedObject.

To show the animation as scrolling, Lottie is used.

In addition to, you can provide the funny factor, Haptic feedback.
The haptic feedback is provided by scrolling down.(But only for iOS 10)

• iOS 8.1+
• Swift 3.0+

Add the following to your Podfile.

pod "URParallaxScrollAnimator"

Lottie-iOS

See the Example folder.
Run pod install and open the .xcworkspace file.

import URMovingTransitionAnimator

    // for example...
    func initView() {
        self.tableView.parallaxScrollExtension.makeParallaxScrollExtensionConfiguration(upperImage: #imageLiteral(resourceName: "cloud_by_ur2"), lowerImage: #imageLiteral(resourceName: "mountain_by_ur2"), lowerLottieData: nil)
    }

• You can find the detail Lottie usage guide at the Lottie-iOS
• add the lottie files in the project, and then just use the json file name to load the Lottie View

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        ...
        self.tableView.parallaxScrollExtension.parallaxScrollViewDidScroll(scrollView)
        ...
    }

    func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
        ...
        self.tableView.parallaxScrollExtension.parallaxScrollViewWillBeginDragging(scrollView)
        ...
    }

    func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
        ...
        self.tableView.parallaxScrollExtension.parallaxScrollViewDidEndDragging(scrollView)
        ...
    }

    // for example, if calling the reload function, 
    // you must call the "parallaxScrollViewDidPullToRefresh" function just after reloading
    func handleAPICallFinish() {
        ...
        self.tableView.parallaxScrollExtension.parallaxScrollViewDidPullToRefresh()
        ...
    }

• parallaxScrollRatio : parallax ratio between the target scroll view and upper parallax view and lower parallax view.
• backgroundColor : parallax scrollView's background color.
• isEnabledHapticFeedback : enable the Haptic feedback. Default is "true".(but this feature is only for iOS 10)
• isEnabledPullToRefresh : enable the Pull to refresh. Default is "false".
• refreshAction : callback to handle the Pull to refresh.(If you set this, "isEnabledPullToRefresh" is set automatically "true")

• support gif for scrolling animation.

URParallaxScrollAnimator is available under the MIT license. See the LICENSE file for more info.