extension for keyboard show notification iOS - ios

Question

I'm using this code. if keyboard appears then it increases the size of the view so user can easily scroll to the bottom. everything works fine but I want to make an extension for this code because I don't want to use such a long code in my controller
import UIKit
extension UIViewController {
func hideKeyboardWhenTappedAround() {
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
tap.cancelsTouchesInView = false
view.addGestureRecognizer(tap)
}
#objc func dismissKeyboard() {
view.endEditing(true)
}
func setnotification()
{
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)
}
#objc func keyboardWasShown(notification: NSNotification)
{
var info = notification.userInfo!
let keyboardSize = (info[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
let contentInsets : UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 0.0, bottom: keyboardSize!.height+10, right: 0.0)
self.scrolView.contentInset = contentInsets
self.scrolView.scrollIndicatorInsets = contentInsets
var aRect : CGRect = self.view.frame
aRect.size.height -= keyboardSize!.height
if let activeField = activeTextField
{
if (!aRect.contains(activeField.frame.origin))
{
self.scrolView.scrollRectToVisible(activeField.frame, animated: true)
}
}
}
// when keyboard hide reduce height of scroll view
#objc func keyboardWillBeHidden(notification: NSNotification){
let contentInsets : UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 0.0,bottom: 0.0, right: 0.0)
myScrolView!.contentInset = contentInsets
myScrolView!.scrollIndicatorInsets = contentInsets
self.view.endEditing(true)
}
}

Answer 1

Extensions add new functionality to an existing class, structure, enumeration, or protocol type.
Syntax for extension:
extension ViewControllerName {
// Put code which you want to
}
/**
If you implement UITableViewDataSource and UITableViewDelegate methods
or you can implement for UIPickerViewDataSource methods and protocol also
*/
extension ViewController: UItableViewDataSource, UITableViewDelegate {
//implement tableview datasource and delegate method
}
/**
Keyboard show/hide
*/
extension ViewController {
/**
Add scrollview functionality to scroll top and you can call
this function from anywhere in the controller.
*/
func scrollToTop() {
}
#objc func keyboardWasShown(notification: NSNotification)
{
var info = notification.userInfo!
let keyboardSize = (info[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
let contentInsets : UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 0.0, bottom: keyboardSize!.height+10, right: 0.0)
self.scrolView.contentInset = contentInsets
self.scrolView.scrollIndicatorInsets = contentInsets
var aRect : CGRect = self.view.frame
aRect.size.height -= keyboardSize!.height
if let activeField = self.activeTextField
{
if (!aRect.contains(activeField.frame.origin))
{
self.scrolView.scrollRectToVisible(activeField.frame, animated: true)
}
}
}
// when keyboard hide reduce height of scroll view
#objc func keyboardWillBeHidden(notification: NSNotification){
let contentInsets : UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 0.0,bottom: 0.0, right: 0.0)
self.scrolView.contentInset = contentInsets
self.scrolView.scrollIndicatorInsets = contentInsets
self.view.endEditing(true)
}
}