Implement keyboard avoidance on any UIScrollView

UIScrollViewExtension.swift

//  Created by Rodolfo Antonici on 12/12/18.
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//  of this software and associated documentation files (the "Software"), to deal
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//
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//  THE SOFTWARE.

import UIKit

extension UIScrollView {
    /// Begin listening to keyboard notifications to add or remove the keyboard size as bottom inset
    func beginKeyboardAvoidance() {
        NotificationCenter.default.addObserver(self,
                                               selector: #selector(keyboardWillShowWithNotification(notification:)),
                                               name: UIResponder.keyboardWillShowNotification,
                                               object: nil)
        
        NotificationCenter.default.addObserver(self,
                                               selector: #selector(keyboardWillHideWithNotification(notification:)),
                                               name: UIResponder.keyboardWillHideNotification,
                                               object: nil)
    }
    
    /// End listening to keyboard notifications
    func endKeyboardAvoidance() {
        NotificationCenter.default.removeObserver(self)
    }
    
    
    /// Add bottom inset on the scroll view the size
    func addDefaultKeyboardPadding(animated: Bool = true) {
        
        let keyboardDefaultHeight: CGFloat = 216
        if animated {
            UIView.animate(withDuration: 0.25) {
                self.contentInset = UIEdgeInsets(top: self.contentInset.top,
                                                 left: self.contentInset.left,
                                                 bottom: keyboardDefaultHeight,
                                                 right: self.contentInset.right)
            }
        }
        else {
            contentInset = UIEdgeInsets(top: contentInset.top,
                                        left: contentInset.left,
                                        bottom: keyboardDefaultHeight,
                                        right: self.contentInset.right)
        }
        
    }
    /// Discussion: This is can be called when the screen already starts with the keyboard shown
    /// the fixed value is based on the value returned on the notifications.
    /// If you know a better way, please do it and comment it below.
    
    @objc fileprivate func keyboardWillShowWithNotification(notification: NSNotification) {
        let info = notification.userInfo!
        
        guard let keyboardFrame: CGRect = info[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect else { return }
        let bottomInset = keyboardFrame.height != 0 ? keyboardFrame.height : 0
        
        UIView.animate(withDuration: 0.25) {
            self.contentInset = UIEdgeInsets(top: self.contentInset.top,
                                            left: self.contentInset.left,
                                            bottom: bottomInset,
                                            right: self.contentInset.right)
        }
        
    }
    
    @objc fileprivate func keyboardWillHideWithNotification(notification: NSNotification) {
        
        UIView.animate(withDuration: 0.25) {
            self.contentInset = UIEdgeInsets(top: self.contentInset.top,
                                            left: self.contentInset.left,
                                            bottom: 0,
                                            right: self.contentInset.right)
        }
    }
}

HEY, it doesn't work magically, you should call it on an UIScrollView, UITableView, UICollectionView beginKeyboardAvoidance() when the element will be show or on viewDidLoad() and should call endKeyBoardAvoidance() when the View is removed or on the deinit