scrollView.setContentOffset doesn't work after scrollView.contentInset on iOS 12 - ios

I have screen with scrollView and bottomContainerView with two textFields and two buttons. And I want to scrollView scroll to bottom when keyboard was shown. That is why I firstly set scrollView.contentOffset and then I am trying to make frame of forgetButton visible(to scroll all view to bottom). And in iOS 11.4 it works. But in iOS 12 doesn't.
private func adjustInsetForKeyboardShow(_ show: Bool, notification: Notification) {
let userInfo = notification.userInfo ?? [:]
if let keyboardFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
let adjustmentHeight = (keyboardFrame.height + 24) * (show ? 1 : 0)
scrollView.contentInset.bottom = adjustmentHeight
scrollView.scrollIndicatorInsets.bottom = adjustmentHeight
// set offset
let top = bottomContainerView.frame.minY + forgetButton.frame.minY
let height = forgetButton.frame.height
scrollView.scrollRectToVisible(CGRect(x: 0, y: top, width: 1, height: height), animated: true)
}
}
#objc
private func keyboardWillShow(_ notification: Notification) {
adjustInsetForKeyboardShow(true, notification: notification)
}
#objc
private func keyboardWillHide(_ notification: Notification) {
adjustInsetForKeyboardShow(false, notification: notification)
}
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(_:)), name: Notification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(_:)), name: Notification.Name.UIKeyboardWillHide, object: nil)
}
iOS 11.4
iOS 12.0

You can try to change this part:
let userInfo = notification.userInfo!
let keyboardFrame = info[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect
Alternatively: create a constraint with the bottom of the View, and when the keyboard is open add to the contraint the height dimension of the keyboard (keyboardFrame.height), and update the constraint with animations
UIView.animate(withDuration: 0.3) {
self.view.layoutIfNeeded()
}
Regards

Related

Handling keyboard with bottom constraint

I'm building a chat app with a regular design and UI of a chat app.
I have a "toolbar" that my app needs (0,0 375x66) and I want it to stay where it is when the keyboard is shown. It has 4 constraints: top: 0, leading: 0, trailing: 0, aspect-ratio: 125:22
I have a UICollectionView (0,66 375x530) that I want to be scrolled like any other chat app when the keyboard is shown. It has 4 constraints: top (to the toolbar): 0, leading: 0, trailing: 0, bottom (to the newMessageView I'll explain shortly): 0
I have a UIView that has a UITextField inside it. let's call it newMessageView (0,596 375x71) and it has 4 constraints: bottom: 0, leading: 0, trailing: 0, aspect-ratio: 375:71
Now, I'm trying to bring the newMessageView app when the keyboard is shown. I'm trying to to it like this:
#objc func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y == 0{
self.newMessageViewBottomConstraint.constant += keyboardSize.height
}
}
}
#objc func keyboardWillHide(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y != 0{
self.newMessageViewBottomConstraint.constant -= keyboardSize.height
}
}
}
but it completly doesn't work. The view jumps and hides and I really can't understand why.
Am I doing it right? Can anyone help me and guide me with this?
You have to use self.view.layoutIfNeeded() after Update constraint
i write complete solution for you
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
#objc func keyboardWillShow(notification: Notification) {
self.keyboardControl(notification, isShowing: true)
}
#objc func keyboardWillHide(notification: Notification) {
self.keyboardControl(notification, isShowing: false)
}
private func keyboardControl(_ notification: Notification, isShowing: Bool) {
/* Handle the Keyboard property of Default*/
var userInfo = notification.userInfo!
let keyboardRect = (userInfo[UIKeyboardFrameEndUserInfoKey]! as AnyObject).cgRectValue
let curve = (userInfo[UIKeyboardAnimationCurveUserInfoKey]! as AnyObject).uint32Value
let convertedFrame = self.view.convert(keyboardRect!, from: nil)
let heightOffset = self.view.bounds.size.height - convertedFrame.origin.y
let options = UIViewAnimationOptions(rawValue: UInt(curve!) << 16 | UIViewAnimationOptions.beginFromCurrentState.rawValue)
let duration = (userInfo[UIKeyboardAnimationDurationUserInfoKey]! as AnyObject).doubleValue
var pureheightOffset : CGFloat = -heightOffset
if isShowing { /// Wite space of save area in iphonex ios 11
if #available(iOS 11.0, *) {
pureheightOffset = pureheightOffset + view.safeAreaInsets.bottom
}
}
// Here change you Consrant
// self.actionBarPaddingBottomConstranit?.update(offset:pureheightOffset)
UIView.animate(
withDuration: duration!,
delay: 0,
options: options,
animations: {
self.view.layoutIfNeeded()
},
completion: { bool in
})
}

Swift - move textField over keyboard upon showing

I need to move a textfield over the keyboard when it appears.
I am using the following code:
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(self.keyBoardWillShow(_:)), name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyBoardWillHide(_:)), name: .UIKeyboardWillHide, object: nil)
}
and then:
#objc func keyBoardWillShow(_ notification: NSNotification) {
let userInfo:NSDictionary = notification.userInfo! as NSDictionary
let keyboardFrame:NSValue = userInfo.value(forKey: UIKeyboardFrameEndUserInfoKey) as! NSValue
let keyboardRectangle = keyboardFrame.cgRectValue
let keyboardHeight = keyboardRectangle.height
UIView.animate(withDuration: 0.4) {
self.commentViewBottomConstraint.constant = keyboardHeight
self.view.layoutIfNeeded()
}
}
#objc func keyBoardWillHide(_ notification: NSNotification) {
UIView.animate(withDuration: 0.4) {
self.commentViewBottomConstraint.constant = 0
self.view.layoutIfNeeded()
}
}
the problem is that it seems the keyboard height is not correct. In fact the bottom of the view is not aligned with the keyboard. There is a space between the view and the keyboard.
Honestly i don't understand what I am doing wrong...
Thank you for the help!
I think the problem was the fact the bottom constraint was relative to the safe area.
So I have fixed it by adding this:
let safeAreaHeight = self.view.safeAreaInsets.bottom
self.commentViewBottomConstraint.constant = keyboardHeight - safeAreaHeight
Here's the complete code:
#objc func keyBoardWillShow(_ notification: NSNotification) {
let userInfo:NSDictionary = notification.userInfo! as NSDictionary
let keyboardFrame:NSValue = userInfo.value(forKey: UIKeyboardFrameEndUserInfoKey) as! NSValue
let keyboardRectangle = keyboardFrame.cgRectValue
let keyboardHeight = keyboardRectangle.height
let safeAreaHeight = self.view.safeAreaInsets.bottom
UIView.animate(withDuration: 0.4) {
self.commentViewBottomConstraint.constant = keyboardHeight - safeAreaHeight
self.view.layoutIfNeeded()
}
}

Extend iOS 11 Safe Area to include the keyboard

The new Safe Area layout guide introduced in iOS 11 works great to prevent content from displaying below bars, but it excludes the keyboard. That means that when a keyboard is displayed, content is still hidden behind it and this is the problem I am trying to solve.
My approach is based on listening to keyboard notifications and then adjusting the safe area through additionalSafeAreaInsets.
Here is my code:
override func viewDidLoad() {
let notificationCenter = NotificationCenter.default
notificationCenter.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
notificationCenter.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
notificationCenter.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)
}
//MARK: - Keyboard
extension MyViewController {
#objc func keyboardWillShow(notification: NSNotification) {
let userInfo = notification.userInfo!
let keyboardHeight = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.height
additionalSafeAreaInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight, right: 0)
UIView.animate(withDuration: 0.3) {
self.view.layoutIfNeeded();
}
}
#objc func keyboardWillHide(notification: NSNotification) {
additionalSafeAreaInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
UIView.animate(withDuration: 0.3) {
self.view.layoutIfNeeded();
}
}
#objc func keyboardWillChange(notification: NSNotification) {
let userInfo = notification.userInfo!
let keyboardHeight = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.height
additionalSafeAreaInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight, right: 0)
UIView.animate(withDuration: 0.3) {
self.view.layoutIfNeeded();
}
}
}
This works well as the MyController is a UIViewController with a UITableView that extends through the whole safe area. Now when the keyboard appears, the bottom is pushed up so that no cells are behind the keyboard.
The problem is with bottom bars. I also have a toolbar at the bottom which is already included in the safe area. Therefore, setting full keyboard height as additional safe area inset pushes the bottom of the table view up too much by exactly the height of the bottom bar. For this method to work well, I must set the additionalSafeAreaInsets.bottom to be equal to the keyboard height minus the height of the bottom bar.
Question 1: What is the best way to get the current safe area gap on the bottom? Manually get frame of toolbar and use its height? Or is it possible to get the gap directly from the safe area layout guide?
Question 2: Presumably it should be possible for the bottom bar to change size without the keyboard changing size so I should also implement some method listening to change in frame of the bar. Is this best done in viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator)? Or elsewhere?
Thank you
What seems to be working for me is to calculate the intersection between view.safeAreaLayoutGuide.layoutFrame and the keyboard frame, and then setting the height of that as the additionalSafeAreaInsets.bottom, instead of the whole keyboard frame height. I don't have a toolbar in my view controller, but I do have a tab bar and it is accounted for correctly.
Complete code:
import UIKit
public extension UIViewController
{
func startAvoidingKeyboard()
{
NotificationCenter.default
.addObserver(self,
selector: #selector(onKeyboardFrameWillChangeNotificationReceived(_:)),
name: UIResponder.keyboardWillChangeFrameNotification,
object: nil)
}
func stopAvoidingKeyboard()
{
NotificationCenter.default
.removeObserver(self,
name: UIResponder.keyboardWillChangeFrameNotification,
object: nil)
}
#objc
private func onKeyboardFrameWillChangeNotificationReceived(_ notification: Notification)
{
guard
let userInfo = notification.userInfo,
let keyboardFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
else {
return
}
let keyboardFrameInView = view.convert(keyboardFrame, from: nil)
let safeAreaFrame = view.safeAreaLayoutGuide.layoutFrame.insetBy(dx: 0, dy: -additionalSafeAreaInsets.bottom)
let intersection = safeAreaFrame.intersection(keyboardFrameInView)
let keyboardAnimationDuration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey]
let animationDuration: TimeInterval = (keyboardAnimationDuration as? NSNumber)?.doubleValue ?? 0
let animationCurveRawNSN = userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? NSNumber
let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIView.AnimationOptions.curveEaseInOut.rawValue
let animationCurve = UIView.AnimationOptions(rawValue: animationCurveRaw)
UIView.animate(withDuration: animationDuration,
delay: 0,
options: animationCurve,
animations: {
self.additionalSafeAreaInsets.bottom = intersection.height
self.view.layoutIfNeeded()
}, completion: nil)
}
}
If you need support back to pre IOS11 versions you can
use the function from Fabio and add:
if #available(iOS 11.0, *) { }
final solution:
extension UIViewController {
func startAvoidingKeyboard() {
NotificationCenter.default.addObserver(self,
selector: #selector(_onKeyboardFrameWillChangeNotificationReceived(_:)),
name: NSNotification.Name.UIKeyboardWillChangeFrame,
object: nil)
}
func stopAvoidingKeyboard() {
NotificationCenter.default.removeObserver(self,
name: NSNotification.Name.UIKeyboardWillChangeFrame,
object: nil)
}
#objc private func _onKeyboardFrameWillChangeNotificationReceived(_ notification: Notification) {
if #available(iOS 11.0, *) {
guard let userInfo = notification.userInfo,
let keyboardFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue else {
return
}
let keyboardFrameInView = view.convert(keyboardFrame, from: nil)
let safeAreaFrame = view.safeAreaLayoutGuide.layoutFrame.insetBy(dx: 0, dy: -additionalSafeAreaInsets.bottom)
let intersection = safeAreaFrame.intersection(keyboardFrameInView)
let animationDuration: TimeInterval = (notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
let animationCurveRawNSN = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIViewAnimationOptions.curveEaseInOut.rawValue
let animationCurve = UIViewAnimationOptions(rawValue: animationCurveRaw)
UIView.animate(withDuration: animationDuration, delay: 0, options: animationCurve, animations: {
self.additionalSafeAreaInsets.bottom = intersection.height
self.view.layoutIfNeeded()
}, completion: nil)
}
}
}
I use a different approach. I have a view (KeyboardProxyView) that I add to my view hierarchy.
I pin this to the bottom of the main view, and adjust its height with the keyboard. This means we can treat the keyboardProxy as if it is the keyboard view - except that it is a normal view, so you can use constraints on it.
This allows me to constrain my other views relative to the keyboardProxy manually.
e.g. - my toolbar isn't constrained at all, but I might have inputField.bottom >= keyboardProxy.top
Code below
(note - I use HSObserver and PureLayout for notifications and autolayout - but you could easily rewrite that code if you prefer to avoid them)
import Foundation
import UIKit
import PureLayout
import HSObserver
/// Keyboard Proxy view will mimic the height of the keyboard
/// You can then constrain other views to move up when the KeyboardProxy expands using AutoLayout
class KeyboardProxyView: UIView, HSHasObservers {
weak var keyboardProxyHeight: NSLayoutConstraint!
override func didMoveToSuperview() {
keyboardProxyHeight = self.autoSetDimension(.height, toSize: 0)
let names = [UIResponder.keyboardWillShowNotification,UIResponder.keyboardWillHideNotification]
HSObserver.init(forNames: names) { [weak self](notif) in
self?.updateKeyboardProxy(notification: notif)
}.add(to: self)
activateObservers()
}
var parentViewController: UIViewController? {
var parentResponder: UIResponder? = self
while parentResponder != nil {
parentResponder = parentResponder!.next
if let viewController = parentResponder as? UIViewController {
return viewController
}
}
return nil
}
func updateKeyboardProxy(notification:Notification){
let userInfo = notification.userInfo!
let animationDuration = (userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as! NSNumber).doubleValue
let keyboardEndFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
let convertedKeyboardEndFrame = self.superview!.convert(keyboardEndFrame, from: self.window)
let rawAnimationCurve = (notification.userInfo![UIResponder.keyboardAnimationCurveUserInfoKey] as! NSNumber).uint32Value << 16
let animationCurve = UIView.AnimationOptions(rawValue:UInt(rawAnimationCurve))
keyboardProxyHeight.constant = self.superview!.bounds.maxY - convertedKeyboardEndFrame.minY
//keyboardProxyHeight.constant = keyboardEndFrame.height
UIView.animate(withDuration: animationDuration, delay: 0.0, options: [.beginFromCurrentState, animationCurve], animations: {
self.parentViewController?.view.layoutIfNeeded()
}, completion: nil)
}
}
bottom inset:
var safeAreaBottomInset: CGFloat = 0
if #available(iOS 11.0, *) {
safeAreaBottomInset = UIApplication.shared.keyWindow?.safeAreaInsets.bottom ?? 0
}
whole keyboard function:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
NotificationCenter.default.addObserver(self, selector: #selector(self.onKeyboardWillChangeFrame), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
}
#objc private func onKeyboardWillChangeFrame(_ notification: NSNotification) {
guard let window = self.view.window,
let info = notification.userInfo,
let keyboardFrame = info[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect,
let duration = info[UIResponder.keyboardAnimationDurationUserInfoKey] as? TimeInterval,
let animationCurve = info[UIResponder.keyboardAnimationCurveUserInfoKey] as? NSNumber
else {
return
}
var safeAreaInset: CGFloat = 0
if #available(iOS 11.0, *) {
safeAreaInset = UIApplication.shared.keyWindow?.safeAreaInsets.bottom ?? 0
}
self.keyboardConstraint.constant = max(0, self.view.frame.height - window.convert(keyboardFrame, to: self.view).minY - safeAreaInset)
UIView.animate(
withDuration: duration,
delay: 0,
options: [UIView.AnimationOptions(rawValue: animationCurve.uintValue), .beginFromCurrentState],
animations: { self.view.layoutIfNeeded() },
completion: nil
)
}
Excluding the bottom safe area worked for me:
NSValue keyboardBounds = (NSValue)notification.UserInfo.ObjectForKey(UIKeyboard.FrameEndUserInfoKey);
_bottomViewBottomConstraint.Constant = keyboardBounds.RectangleFValue.Height - UIApplication.SharedApplication.KeyWindow.SafeAreaInsets.Bottom;
View.LayoutIfNeeded();

UIScrollView scroll up on Keyboard

Problem Statement : I have Nib file of UIView contains UIScrollview, In scrollview I have several TextFields and a TextView at the Bottom. What I want is to scroll upward when textfield or Textview starts editing.
What I tried :
In custome Method
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
I am calling this method parent view.
Notification Handling:
func keyboardWasShown(notification: NSNotification)
{
var userInfo = notification.userInfo!
var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
keyboardFrame = self.convert(keyboardFrame, from: nil)
var contentInset:UIEdgeInsets = self.mainScroll.contentInset
contentInset.bottom = keyboardFrame.size.height
self.mainScroll.contentInset = contentInset
}
This is working perfectly for UITextFields, But not working UITextView. Any idea where is the mistake.
PS: I have set the Delegates of UITextField and UITextView as well.
Any help will be much appreciated.
Replace keyboardWasShown function with the below function :
func keyboardWasShown(notification: NSNotification)
{
var userInfo = notification.userInfo!
var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
keyboardFrame = self.convert(keyboardFrame, from: nil)
self.mainScroll.contentOffset = CGPoint(x: 0, y: keyboardFrame.size.height - Any number that fits your need.)
}
In keyBoardWillHide :
self.mainScroll.contentOffset = CGPoint(x: 0, y: 0)
Hope it will help.
Happy Coding!
Demo link : https://github.com/harshilkotecha/UIScrollViewWhenKeyboardAppearInSwift3
when you have multiple textview it is so difficult so best solution ->
step 1 : add UITextFieldDelegate
class ScrollViewController: UIViewController,UITextFieldDelegate {
step 2 :create new IBOutlet but don't connect with any text field
// get current text box when user Begin editing
#IBOutlet weak var activeTextField: UITextField?
step 3 : write this two method when user focus on text filed object pass the reference and store in activeTextField
// get current text field
func textFieldDidBeginEditing(_ textField: UITextField)
{
activeTextField=textField;
}
func textFieldDidEndEditing(_ textField: UITextField)
{
activeTextField=nil;
}
step 5 : set Notification in viewdidload setNotificationKeyboard
override func viewWillAppear(_ animated: Bool) {
// call method for keyboard notification
self.setNotificationKeyboard()
}
// Notification when keyboard show
func setNotificationKeyboard () {
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notification:)), name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: .UIKeyboardWillHide, object: nil)
}
step 6 : two methods for hide and show keyboard
func keyboardWasShown(notification: NSNotification)
{
var info = notification.userInfo!
let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize!.height+10, 0.0)
self.scrollView.contentInset = contentInsets
self.scrollView.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.scrollView.scrollRectToVisible(activeField.frame, animated: true)
}
}
}
// when keyboard hide reduce height of scroll view
func keyboardWillBeHidden(notification: NSNotification){
let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0,0.0, 0.0)
self.scrollView.contentInset = contentInsets
self.scrollView.scrollIndicatorInsets = contentInsets
self.view.endEditing(true)
}
Swift 5
NotificationCenter.default.addObserver(self, selector: #selector(keyboardNotification), name: UIResponder.keyboardDidChangeFrameNotification, object: nil)
#objc func keyboardNotification(_ notification: Notification) {
if let userInfo = (notification as NSNotification).userInfo {
let endFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
let duration:TimeInterval = (userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
let animationCurveRawNSN = userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? NSNumber
let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIView.AnimationOptions().rawValue
let animationCurve:UIView.AnimationOptions = UIView.AnimationOptions(rawValue: animationCurveRaw)
if (endFrame?.origin.y)! >= UIScreen.main.bounds.size.height {
scrollViewBottomConstraint?.constant = 0
} else {
if tabBarController?.tabBar.frame == nil {
return
}
scrollViewBottomConstraint?.constant = endFrame!.size.height - (tabBarController?.tabBar.frame.height)!
let bottomOffset = CGPoint(x: 0, y: 0)
scrollView.setContentOffset(bottomOffset, animated: true)
}
UIView.animate(withDuration: duration, delay: 0, options: animationCurve, animations: { self.view.layoutIfNeeded() }, completion: nil)
}
}
usage:
1.connect the scrollView outlet to your controller and set its name to 'scrollView'
2.connect the scrollView bottom constraint to your controller & set its name to 'scrollViewBottomConstraint'
3.put the notification observer to your ViewDidLoad function.

ScrollView and keyboard in Swift

I started creating a simple iOS app that does some operations.
But I'm having some problems when the keyboard appears, hiding one of my textfields.
I think it's a common problem and I did some research but I couldn't find anything that solved my problem.
I want to use a ScrollView rather than animate the textfield to make it visible.
In ViewDidLoad, register the notifications:
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name:UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name:UIResponder.keyboardWillHideNotification, object: nil)
Add below observer methods which does the automatic scrolling when keyboard appears.
#objc func keyboardWillShow(notification:NSNotification) {
guard let userInfo = notification.userInfo else { return }
var keyboardFrame:CGRect = (userInfo[UIResponder.keyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
keyboardFrame = self.view.convert(keyboardFrame, from: nil)
var contentInset:UIEdgeInsets = self.scrollView.contentInset
contentInset.bottom = keyboardFrame.size.height + 20
scrollView.contentInset = contentInset
}
#objc func keyboardWillHide(notification:NSNotification) {
let contentInset:UIEdgeInsets = UIEdgeInsets.zero
scrollView.contentInset = contentInset
}
The top answer for swift 3:
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name:NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name:NSNotification.Name.UIKeyboardWillHide, object: nil)
And then:
func keyboardWillShow(notification:NSNotification){
//give room at the bottom of the scroll view, so it doesn't cover up anything the user needs to tap
var userInfo = notification.userInfo!
var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
keyboardFrame = self.view.convert(keyboardFrame, from: nil)
var contentInset:UIEdgeInsets = self.theScrollView.contentInset
contentInset.bottom = keyboardFrame.size.height
theScrollView.contentInset = contentInset
}
func keyboardWillHide(notification:NSNotification){
let contentInset:UIEdgeInsets = UIEdgeInsets.zero
theScrollView.contentInset = contentInset
}
Here is a complete solution, utilizing guard and concise code. Plus correct code in keyboardWillHide to only reset the bottom to 0.
#IBOutlet private weak var scrollView: UIScrollView!
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
registerNotifications()
}
override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(animated)
scrollView.contentInset.bottom = 0
}
private func registerNotifications() {
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
#objc private func keyboardWillShow(notification: NSNotification){
guard let keyboardFrame = notification.userInfo![UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else { return }
scrollView.contentInset.bottom = view.convert(keyboardFrame.cgRectValue, from: nil).size.height
}
#objc private func keyboardWillHide(notification: NSNotification){
scrollView.contentInset.bottom = 0
}
for Swift 4.0
In ViewDidLoad
// setup keyboard event
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
Add below observer methods which does the automatic scrolling when keyboard appears.
#objc func keyboardWillShow(notification:NSNotification){
var userInfo = notification.userInfo!
var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
keyboardFrame = self.view.convert(keyboardFrame, from: nil)
var contentInset:UIEdgeInsets = self.ui_scrollView.contentInset
contentInset.bottom = keyboardFrame.size.height
ui_scrollView.contentInset = contentInset
}
#objc func keyboardWillHide(notification:NSNotification){
let contentInset:UIEdgeInsets = UIEdgeInsets.zero
ui_scrollView.contentInset = contentInset
}
contentInset doesn't work for me, because I want the scrollview move all the way up above the keyboard. So I use contentOffset:
func keyboardWillShow(notification:NSNotification) {
guard let keyboardFrameValue = notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue else {
return
}
let keyboardFrame = view.convert(keyboardFrameValue.cgRectValue, from: nil)
scrollView.contentOffset = CGPoint(x:0, y:keyboardFrame.size.height)
}
func keyboardWillHide(notification:NSNotification) {
scrollView.contentOffset = .zero
}
Swift 5 Only adjust ScrollView when TextField is hidden by keyboard (for multiple TextFields)
Add / Remove Observers:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
NotificationCenter.default.removeObserver(self)
}
Keep track of these values so you can return to your original position:
var scrollOffset : CGFloat = 0
var distance : CGFloat = 0
Adjust ScrollView contentOffset depending on TextField Location:
#objc func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
var safeArea = self.view.frame
safeArea.size.height += scrollView.contentOffset.y
safeArea.size.height -= keyboardSize.height + (UIScreen.main.bounds.height*0.04) // Adjust buffer to your liking
// determine which UIView was selected and if it is covered by keyboard
let activeField: UIView? = [textFieldA, textViewB, textFieldC].first { $0.isFirstResponder }
if let activeField = activeField {
if safeArea.contains(CGPoint(x: 0, y: activeField.frame.maxY)) {
print("No need to Scroll")
return
} else {
distance = activeField.frame.maxY - safeArea.size.height
scrollOffset = scrollView.contentOffset.y
self.scrollView.setContentOffset(CGPoint(x: 0, y: scrollOffset + distance), animated: true)
}
}
// prevent scrolling while typing
scrollView.isScrollEnabled = false
}
}
#objc func keyboardWillHide(notification: NSNotification) {
if distance == 0 {
return
}
// return to origin scrollOffset
self.scrollView.setContentOffset(CGPoint(x: 0, y: scrollOffset), animated: true)
scrollOffset = 0
distance = 0
scrollView.isScrollEnabled = true
}
Make sure to use [UIResponder.keyboardFrameEndUserInfoKey] to get the proper keyboard height the first time.
From the answer by Sudheer Palchuri, converted for Swift 4.
In ViewDidLoad, register the notifications:
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name:NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name:NSNotification.Name.UIKeyboardWillHide, object: nil)
And then:
// MARK: - Keyboard Delegates
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
#objc func keyboardWillShow(notification:NSNotification){
var userInfo = notification.userInfo!
var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
keyboardFrame = self.view.convert(keyboardFrame, from: nil)
var contentInset:UIEdgeInsets = self.scrollView.contentInset
contentInset.bottom = keyboardFrame.size.height
self.scrollView.contentInset = contentInset
}
#objc func keyboardWillHide(notification:NSNotification){
let contentInset:UIEdgeInsets = UIEdgeInsets.zero
self.scrollView.contentInset = contentInset
}
Reading the links you sent to me, I found a way to make it work, thanks!:
func textFieldDidBeginEditing(textField: UITextField) {
if (textField == //your_field) {
scrollView.setContentOffset(CGPointMake(0, field_extra.center.y-280), animated: true)
callAnimation()
viewDidLayoutSubviews()
}
}
func textFieldDidEndEditing(textField: UITextField) {
if (textField == //your_field){
scrollView .setContentOffset(CGPointMake(0, 0), animated: true)
viewDidLayoutSubviews()
}
}
This is a refinement on Zachary Probst solution posted above.
I ran into a few issues with his solution and fixed it and enhanced it a bit.
This version does not need to pass in a list of UITextView controls. It finds the first responder in the current view. It also handles UITextView controls at any level in the View hierarchy.
I think his safeArea calculation wasn't quite right scrollView.contentOffset.y needed sign changed. It didn't show up if it was not scrolled. This fixed incremental scrolling. It might have been from other changes I made.
This works if the user jumps around to other UITextViews while the keyboard is up.
This is a Base Class I use for a bunch of ViewControllers. The inherited ViewController just needs to set the UIScrollViewer which activates this code behavior.
class ThemeAwareViewController: UIViewController
{
var scrollViewForKeyBoard: UIScrollView? = nil
var saveOffsetForKeyBoard: CGPoint?
func findViewThatIsFirstResponder(view: UIView) -> UIView?
{
if view.isFirstResponder {
return view
}
for subView in view.subviews {
if let hit = findViewThatIsFirstResponder(view: subView) {
return hit
}
}
return nil
}
#objc func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if let scrollView = scrollViewForKeyBoard {
var safeArea = self.view.frame
safeArea.size.height -= scrollView.contentOffset.y
safeArea.size.height -= keyboardSize.height
safeArea.size.height -= view.safeAreaInsets.bottom
let activeField: UIView? = findViewThatIsFirstResponder(view: view)
if let activeField = activeField {
// This line had me stumped for a while (I was passing in .frame)
let activeFrameInView = view.convert(activeField.bounds, from: activeField)
let distance = activeFrameInView.maxY - safeArea.size.height
if saveOffsetForKeyBoard == nil {
saveOffsetForKeyBoard = scrollView.contentOffset
}
scrollView.setContentOffset(CGPoint(x: 0, y: distance), animated: true)
}
}
}
}
#objc func keyboardWillHide(notification: NSNotification) {
guard let restoreOffset = saveOffsetForKeyBoard else {
return
}
if let scrollView = scrollViewForKeyBoard {
scrollView.setContentOffset(restoreOffset, animated: true)
self.saveOffsetForKeyBoard = nil
}
}
}
You can animate your scrollview to center on your UITextField on keyboard appearance (ie. making your textfield the first responder) via a scroll offset. Here are a couple of good resources to get you started (there are a bunch on this site):
How programmatically move a UIScrollView to focus in a control above keyboard?
How to make a UIScrollView auto scroll when a UITextField becomes a first responder
Additionally, if you simply use a UITableView with your content in cells, when the textfield becomes first responder, the UITableViewController will automatically scroll to the textfield cell for you (though I'm not sure this is what you want to do).
An answer for Swift 3, based on the one proposed by Daniel Jones, but safer (thanks to the guard), more concise and with consistent scroll indicator insets:
#objc private func keyboardWillBeShown(notification: NSNotification) {
guard let keyboardFrameValue = notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue else { return }
let keyboardFrame = view.convert(keyboardFrameValue.cgRectValue, from: nil)
scrollView.contentInset.bottom = keyboardFrame.size.height
scrollView.scrollIndicatorInsets = scrollView.contentInset
}
#objc private func keyboardWillBeHidden() {
scrollView.contentInset = .zero
scrollView.scrollIndicatorInsets = scrollView.contentInset
}
In Swift4, just add the following extension.
extension UIViewController {
func setupViewResizerOnKeyboardShown() {
NotificationCenter.default.addObserver(self,
selector: #selector(self.keyboardWillShowForResizing),
name:
Notification.Name.UIKeyboardWillShow,
object: nil)
NotificationCenter.default.addObserver(self,
selector: #selector(self.keyboardWillHideForResizing),
name: Notification.Name.UIKeyboardWillHide,
object: nil)
}
#objc func keyboardWillShowForResizing(notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue,
let window = self.view.window?.frame {
// We're not just minusing the kb height from the view height because
// the view could already have been resized for the keyboard before
self.view.frame = CGRect(x: self.view.frame.origin.x,
y: self.view.frame.origin.y,
width: self.view.frame.width,
height: window.origin.y + window.height - keyboardSize.height)
} else {
debugPrint("We're showing the keyboard and either the keyboard size or window is nil: panic widely.")
}
}
#objc func keyboardWillHideForResizing(notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
let viewHeight = self.view.frame.height
self.view.frame = CGRect(x: self.view.frame.origin.x,
y: self.view.frame.origin.y,
width: self.view.frame.width,
height: viewHeight + keyboardSize.height)
} else {
debugPrint("We're about to hide the keyboard and the keyboard size is nil. Now is the rapture.")
}
}
}
There is a simple solution here
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
func keyboardWillShow(_ notification:Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardSize.height, 0)
}
}
func keyboardWillHide(_ notification:Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
tableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0)
}
}
In case anyone is looking for Objective-C code for this solution:
- (void)keyboardWasShown:(NSNotification *)notification {
NSDictionary* info = [notification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
UIEdgeInsets contentInsets = baseScrollView.contentInset;
contentInsets.bottom = kbSize.height;
baseScrollView.contentInset = contentInsets;
}
- (void)keyboardWillBeHidden:(NSNotification *)notification {
UIEdgeInsets contentInsets = UIEdgeInsetsZero;
baseScrollView.contentInset = contentInsets;
[baseScrollView endEditing:YES];
}
In my situation it was
ScrollView
-->
TableView
-->
TableViewCell
So I had to get y position in relative to keyboard frame and check if keyboard y position and my active field y position was intersecting or not
#objc func keyboardWillShow(_ notification: Foundation.Notification) {
var userInfo = notification.userInfo!
var keyboardFrame:CGRect = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
keyboardFrame = self.view.convert(keyboardFrame, from: nil)
var contentInset:UIEdgeInsets = self.scrollView!.contentInset
contentInset.bottom = keyboardFrame.size.height
let loc = self.activeTextField?.convert(activeTextField!.bounds, to: self.view)
if keyboardFrame.origin.y < loc!.origin.y {
self.scrollView?.contentOffset = CGPoint.init(x: (self.scrollView?.contentOffset.x)!, y: loc!.origin.y)
}
if self.scrollView?.contentInset.bottom == 0 {
self.scrollView?.contentInset = contentInset
}
}

Resources