A UIScrollView which scrolls when the keyboard is displayed/hidden. The keyboard is dismissed when tapping outside a responding view like a textfield or textview. Swift 3.0

UIScrollViewWithKeyboard

//
//  UIScrollViewWithKeyboard.swift
//  Repnote
//
//  Created by John Neumann on 29/01/2017.
//  Copyright © 2017 Audioy. All rights reserved.
//

import UIKit

class UIScrollViewWithKeyboard: UIScrollView {
    
    var keyboardIsUp = false
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        
        // Listen to notifications from the keyboard
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
        //NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardDidShow", name: UIKeyboardDidShowNotification, object: nil)
        //NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardDidHide", name: UIKeyboardDidHideNotification, object: nil)
        //NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillChangeFrame:", name: UIKeyboardWillChangeFrameNotification, object: nil)
        //NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardDidChangeFrame:", name: UIKeyboardDidChangeFrameNotification, object: nil)
    }
    
    /*
    convenience init(){
        self.init(frame: CGRect.zero)
    }
    */
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    func keyboardWillShow(notification: NSNotification){
        //print("Keyboard will show")
        
        if
            let keyboardRect = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue,
            let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? TimeInterval,
            let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as? UInt {
            // It may be required to translate the rect to the proper reference frame if rotates. This code does it. Keep it for reference
            //let properlyRotatedRect:CGRect = self.window!.convertRect(keyboardRect, toView: self.window!.rootViewController!.view)
            
            UIView.animateKeyframes(withDuration: duration, delay: 0, options: UIViewKeyframeAnimationOptions(rawValue: curve), animations: {
                self.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardRect.height, right: 0)
            })
            
            // Scroll the view to the frame that became first responder, if found
            if
                let responderView = findFirstResponder(inView: self),
                let responderSuperview = responderView.superview{
                
                let translatedFrame = responderSuperview.convert(responderView.frame, to: self)
                self.scrollRectToVisible(translatedFrame, animated: true)
            }
            
            keyboardIsUp = true
        }
    }
    
    func keyboardWillHide(notification: NSNotification){
        //print("Keyboard will hide")
        
        if
            let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? TimeInterval,
            let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as? UInt {
            // It may be required to translate the rect to the proper reference frame if rotates. This code does it. Keep it for reference
            //let properlyRotatedRect:CGRect = self.window!.convertRect(keyboardRect, toView: self.window!.rootViewController!.view)
            
            UIView.animateKeyframes(withDuration: duration, delay: 0, options: UIViewKeyframeAnimationOptions(rawValue: curve), animations: {
                self.contentInset = UIEdgeInsets.zero
            })

            keyboardIsUp = false
        }
    }
    
    // Search recursively for the view that is first responder within a view and its subviews
    func findFirstResponder(inView view: UIView) -> UIView?{
        
        for subview:UIView in view.subviews{
            if subview.responds(to: #selector(getter: isFirstResponder)) && subview.isFirstResponder{
                return subview
            }
            
            if let result = findFirstResponder(inView: subview){
                return result
            }
        }
        
        return nil
    }
    
    // WARNING!! For touchesEnded to be called, make sure that any tap recogniser added to this scrollView defines tapGestureRecogniser.cancelsTouchesInView = false;
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        super.touchesEnded(touches, with: event)
        
        // Exit if keyboard is down, locationTouch is nil or there is no responder view  or responder superview
        guard
            keyboardIsUp,
            let locationTouch = touches.first,
            let responderView = findFirstResponder(inView: self),
            let responderSuperview = responderView.superview else{
                return
        }
        
        // Get the location point
        let locationPoint = locationTouch.location(in: self)
        // Get the frame of the first responder
        let translatedFrame = responderSuperview.convert(responderView.frame, to: self)
        
        // If the touch point is outside the first responder, dismiss the keyboard
        if !translatedFrame.contains(locationPoint){
            responderView.resignFirstResponder()
        }
    }
    
    deinit{
        NotificationCenter.default.removeObserver(self)
    }

}

// will change frame
// will show
// did change frame
// did show

// will change frame
// will hide
// did change frame
// did hide