UIScrollView stops scrolling on keyboard dismiss - ios

Question

I'm currently working on an app for iPhone using Swift 3 however I have ran into an issue with the scrollview.
Prior to selecting a text field and having the keyboard appear, the scrollview work normally (ie.: I can scroll up and down), however after dismissing the keyboard, the scrollview does not allow me to scroll anymore which is my problem.
Note: if I select a text field again and make the keyboard appear it works fine and stops working once it is dismissed again.
I have checked the isScrollEnabled property of the scrollview and it appears to be enabled. Unfortunately I am still not too familiar with all the details of the scrollview and cannot seem to figure out why it has stopped working.
Any help or pointers as to where I could look would be greatly appreciated.
Edit: there is quite a bit of code but here is the narrowed down portion related to scroll view and keyboard:
class ScrollViewController: UIViewController, UITextViewDelegate, UITextFieldDelegate {
//Scroll view
#IBOutlet weak var scrollView: UIScrollView!
//UIView inside the scroll view
#IBOutlet weak var contentView: UIView!
//Save button on the top right corner
#IBOutlet weak var saveButton: UIBarButtonItem!
//Text field being editted
var activeTextField:UITextField?
fileprivate var contentInset:CGFloat?
fileprivate var indicatorInset:CGFloat?
override func viewDidLoad() {
contentInset = scrollView.contentInset.bottom
indicatorInset = scrollView.scrollIndicatorInsets.bottom
NotificationCenter.default.addObserver(self,
selector: #selector(ScrollViewController.keyboardWillShow(_:)),
name: NSNotification.Name.UIKeyboardWillShow,
object: nil)
NotificationCenter.default.addObserver(self,
selector: #selector(ScrollViewController(_:)),
name: NSNotification.Name.UIKeyboardWillHide,
object: nil)
}
func adjustInsetForKeyboardShow(_ show: Bool, notification: Notification) {
let userInfo = notification.userInfo ?? [:]
let keyboardFrame = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
let adjustmentHeight = (keyboardFrame.height + 20) * (show ? 1 : -1)
scrollView.contentInset.bottom = (contentInset! + adjustmentHeight)
scrollView.scrollIndicatorInsets.bottom = (indicatorInset! + adjustmentHeight)
}
func keyboardWillShow(_ notification: Notification) {
adjustInsetForKeyboardShow(true, notification: notification)
}
func keyboardWillHide(_ notification: Notification) {
adjustInsetForKeyboardShow(false, notification: notification)
}
//Tap gesture to dismiss the keyboard
#IBAction func hideKeyboard(_ sender: AnyObject) {
self.view.endEditing(false)
}
deinit {
NotificationCenter.default.removeObserver(self);
}
}

Answer 1

I have create extension of UIViewController and create method for scrollView. Just need to call from viewWillAppear() and viewDidDisappear()
extension UIViewController {
func registerForKeyboradDidShowWithBlock (scrollview:UIScrollView ,block: ((CGSize?) -> Void)? = nil ){
NotificationCenter.default.addObserver(forName: NSNotification.Name.UIKeyboardDidShow, object: nil, queue: nil) { (notification) in
if let userInfo = (notification as NSNotification).userInfo {
if let keyboarRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.findFirstResponder() != nil {
let keyboarRectNew = self.view .convert(keyboarRect, to: self.view)
let scrollViewSpace = scrollview.frame.origin.y + scrollview.contentOffset.y
let textFieldRect:CGRect = self.view.findFirstResponder()!.convert(self.view.findFirstResponder()!.bounds, to: self.view)
let textFieldSpace = textFieldRect.origin.y + textFieldRect.size.height
let remainingSpace = self.view.frame.size.height - keyboarRectNew.size.height
if scrollViewSpace + textFieldSpace > remainingSpace {
let gap = scrollViewSpace + textFieldSpace - remainingSpace
scrollview .setContentOffset(CGPoint(x: scrollview.contentOffset.x, y: gap), animated: true)
}
}
}
}
block?(CGSize.zero)
}
}
func registerForKeyboardWillHideNotificationWithBlock ( scrollview:UIScrollView ,block: ((Void) -> Void)? = nil) {
NotificationCenter.default.addObserver(forName: NSNotification.Name.UIKeyboardWillHide, object: nil, queue: nil, using: { (notification) -> Void in
scrollview.scrollRectToVisible(CGRect(x: 0, y: 0, width: 0, height: 0), animated: true)
scrollview.contentOffset = CGPoint(x: 0, y: 0)
scrollview.contentInset = UIEdgeInsetsMake(0.0, 0.0, 0.0, 0.0)
scrollview.scrollIndicatorInsets = UIEdgeInsetsMake(0.0, 0.0, 0.0, 0.0);
block?()
})
}
func deregisterKeyboardShowAndHideNotification (){
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillHide, object: nil)
self.view.findFirstResponder()?.resignFirstResponder()
}
}
I have created extension of UIView to create find first responder method in that.
extension UIView {
func findFirstResponder() -> UIView? {
if self.isFirstResponder {
return self
}
for subview: UIView in self.subviews {
let firstResponder = subview.findFirstResponder()
if nil != firstResponder {
return firstResponder
}
}
return nil
}
}

Answer 2

Create Extension of UIView and write down this method.
extension UIView {
func findFirstResponder() -> UIView? {
if self.isFirstResponder {
return self
}
for subview: UIView in self.subviews {
let firstResponder = subview.findFirstResponder()
if nil != firstResponder {
return firstResponder
}
}
return nil
}
}

Answer 3

Their is a third party library in Objective C to handle the keyboard with scroll view, collection view and table view. The name of library is tpkeyboardavoidingscrollview. Try to embed this if possible.