Swift- shifting text field issue - swift

Question

I have 2 text fields both placed on top of a image view. The bottom text field is supposed to shift up when the keyboard appears. When the image view is empty the bottom text field shifts up as expected, but when image is present in image view, the bottom text field doesn't shift up. when executing can see with help of print statements that keyboardWillShow function is not executing. can anyone help here?
Following is my code
class ViewController: UIViewController, UITextFieldDelegate,UINavigationControllerDelegate, UIImagePickerControllerDelegate {
#IBOutlet weak var actualImage: UIImageView!
#IBOutlet weak var shareButton: UIButton!
#IBOutlet weak var deleteButton: UIButton!
#IBOutlet weak var topTextField: UITextField!
#IBOutlet weak var bottomTextField: UITextField!
var activeTextField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
topTextField.delegate = self
bottomTextField.delegate = self
//Animations
topTextField.isHidden = true
bottomTextField.isHidden = true
shareButton.isEnabled = false
deleteButton.isEnabled = false
let center: NotificationCenter = NotificationCenter.default
center.addObserver(self, selector: #selector(keyboardDidShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
center.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
//Editing text Fields
func textFieldDidBeginEditing(_ textField: UITextField) {
activeTextField = textField
}
#objc func keyboardDidShow(notification: Notification) {
print("keyboarddidshow")
if activeTextField != nil {
let info: NSDictionary = notification.userInfo! as NSDictionary
let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
let keyboardY = self.view.frame.size.height - keyboardSize.height
let textFieldY: CGFloat! = self.activeTextField.frame.origin.y
if self.view.frame.origin.y >= 0{
if textFieldY > (keyboardY - 80){
UIView.animate(withDuration: 0.25,delay:0.0,options:UIViewAnimationOptions.curveEaseIn, animations: {
self.view.frame = CGRect(x: 0, y: self.view.frame.origin.y - (textFieldY - (keyboardY - 80)), width: self.view.bounds.width, height: self.view.bounds.height)
}, completion: nil)
}
}
}
}
#objc func keyboardWillHide(notification: Notification){
print("switch field keyboard will hide")
UIView.animate(withDuration: 0.25,delay:0.0,options:UIViewAnimationOptions.curveEaseIn, animations: {
self.view.frame = CGRect(x: 0, y: 0, width: self.view.bounds.width, height: self.view.bounds.height)}, completion: nil
)
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
override func viewDidDisappear(_ animated: Bool) {
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
//share button pressed
#IBAction func sharePressed(_ sender: UIButton) {
topTextField.borderStyle = .none
topTextField.borderStyle = .none
let image: UIImage = generateMemedImage()
let shareImage = UIActivityViewController(activityItems: [image, topTextField,bottomTextField], applicationActivities: nil)
present(shareImage, animated: true, completion: nil)
}
//allow selecting image from photo library
#IBAction func selectFromGallery(_ sender: Any) {
let gallery = UIImagePickerController()
gallery.delegate = self
gallery.sourceType = .photoLibrary
present(gallery, animated: true, completion: nil)
}
#IBAction func selectFromCamera(_ sender: Any) {
let gallery = UIImagePickerController()
gallery.delegate = self
if UIImagePickerController.isSourceTypeAvailable(.camera){
gallery.sourceType = .camera
present(gallery, animated: true, completion: nil)
} else {
displayAlert(title: "Camera not available", message: "")
}
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
let selectedImage = info[UIImagePickerControllerOriginalImage] as! UIImage
actualImage.image = selectedImage
dismiss(animated: true, completion: nil)
topTextField.isHidden = false
bottomTextField.isHidden = false
shareButton.isEnabled = true
deleteButton.isEnabled = true
topTextField.text = " "
bottomTextField.text = " "
}
#IBAction func deletePressed(_ sender: Any) {
actualImage.image = nil
topTextField.isHidden = true
bottomTextField.isHidden = true
shareButton.isEnabled = false
deleteButton.isEnabled = false
topTextField.text = " "
bottomTextField.text = " "
}
//display alert
func displayAlert(title: String, message:String){
let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Dismiss", style: .default, handler: nil))
present(alert, animated: true, completion: nil)
}
func generateMemedImage() -> UIImage {
// Render view to an image
UIGraphicsBeginImageContextWithOptions(CGSize(width: 375, height: 517), false, 0)
view.drawHierarchy(in: CGRect(x: 0, y: -75, width: view.bounds.size.width, height: view.bounds.size.height), afterScreenUpdates: true)
let memedImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return memedImage
}
}

Answer 1

When you show the camera or the gallery, viewDidDisappear is called, which removes your subscription to the notifications. Perhaps you should subscribe to the notifications in viewDidAppear like thus:
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
let center: NotificationCenter = NotificationCenter.default
center.addObserver(self, selector: #selector(keyboardDidShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
center.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}