I've tried building a simple HomeKit app to stream video from a HomeKit Camera and while it appears to be working - the stream is not showing on the View Controller. Any help appreciated.
#IBOutlet weak var liveStreamView: HMCameraView!
// var liveStreamView: HMCameraView?
func startCameraStream(for accessory: HMAccessory) {
// Ensure this is a camera accessory
guard let cameraStreamControl = accessory.cameraProfiles?.first?.streamControl else
{ return }
cameraStreamControl.delegate = self
cameraStreamControl.startStream()
let liveStreamView = HMCameraView()
self.view.addSubview(liveStreamView)
self.liveStreamView = liveStreamView
self.liveStreamView.cameraSource = cameraStreamControl.cameraStream
self.liveStreamView?.setNeedsDisplay()
self.view.layoutIfNeeded()
}
extension ViewController: HMCameraStreamControlDelegate {
func cameraStreamControlDidStartStream(_ cameraStreamControl: HMCameraStreamControl) {
liveStreamView?.cameraSource = cameraStreamControl.cameraStream
}
}
So silly. I forgot to define the liveStreamView attributes including the frame. See below where I set the background color, alpha, tag, etc:
func startCameraStream( for accessory: HMAccessory) {
// Ensure this is a camera accessory
guard let cameraStreamControl = accessory.cameraProfiles?.first?.streamControl else
{ return }
cameraStreamControl.delegate = self
cameraStreamControl.startStream ( )
let liveStreamView = HMCameraView(frame: CGRect(x: 0, y: 0, width: 320, height: 568))
liveStreamView.backgroundColor = .clear
liveStreamView.alpha = 0.5
liveStreamView.tag = 100
liveStreamView.isUserInteractionEnabled = true
self.view.addSubview(liveStreamView)
self.liveStreamView = liveStreamView
}
I am having a horizontal UIScrollview in my xib file. Scrollview looks great in all devices except iPhone X, XS and XR.
It looks good in iPhone 8
iPhone X
I have tried all the possible solutions, Unchecked the under top bar, under bottom bar, auto resize subviews,nothing works for me. iPhone X always looks the same. Top constraint of the scrollview is set to safe area. I am using xib file here.
if #available(iOS 11.0, *) {
scrollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentBehavior.never
} else {
self.automaticallyAdjustsScrollViewInsets = false
edgesForExtendedLayout = []
// Fallback on earlier versions
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
self.scrollView.contentSize = CGSize(width: self.lectureTable.frame.size.width , height: self.scrollView.frame.size.height)
self.automaticallyAdjustsScrollViewInsets = false
}
Please shed some light. Thanks a ton.
I have solved it by myself. Inside my scroll view, I have used UIView.
var hasTopNotch: Bool {
if #available(iOS 11.0, *) {
return UIApplication.shared.delegate?.window??.safeAreaInsets.top ?? 0 > 20
}
return false
}
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
var topbarHeight: CGFloat {
return UIApplication.shared.statusBarFrame.size.height + (self.navigationController?.navigationBar.frame.height ?? 0.0)
}
if hasTopNotch{
let window = UIApplication.shared.keyWindow
if #available(iOS 11.0, *) {
let topPadding = window?.safeAreaInsets.top
self.customView.frame.size.height = UIScreen.main.bounds.height - (topbarHeight + topPadding!)
} else {
// Fallback on earlier versions
}
}else{
let NavBarHeight = self.navigationController!.navigationBar.frame.height + UIApplication.shared.statusBarFrame.height
self.customView.frame.size.height = UIScreen.main.bounds.height - NavBarHeight
}
}
This works great in all the devices.
I want to Mirror (Flip) video playing using AVPlayer.
Like : MirrorTube :- https://chrome.google.com/webstore/detail/mirrortube/olomckflnlligkboahmaihmeaffjdbfm/related?hl=en
i want to achieve same functionality.
I have tried to change CGAffineTransform but it does not work same.
Thanks in advance!
Here's an example how to flip the player vertically and horizontally by using CGAffineTransform:
PlayerView:
import AVKit
class PlayerView: UIView {
var player: AVPlayer? {
get {
return playerLayer.player
}
set {
playerLayer.player = newValue
}
}
var playerLayer: AVPlayerLayer {
return layer as! AVPlayerLayer
}
// Override UIView property
override static var layerClass: AnyClass {
return AVPlayerLayer.self
}
}
ViewController using the playerView defined in xib/storyboard:
#IBOutlet var playerView: PlayerView!
#IBAction func flipVerticallyBarButtonItemTouched(_ sender: UIBarButtonItem) {
UIView.animate(withDuration: 0.2) { [unowned self] in
self.playerView.transform = self.playerView.transform.concatenating(CGAffineTransform(scaleX: 1, y: -1))
}
}
#IBAction func flipHorizontallyBarButtonItemTouched(_ sender: UIBarButtonItem) {
UIView.animate(withDuration: 0.2) { [unowned self] in
self.playerView.transform = self.playerView.transform.concatenating(CGAffineTransform(scaleX: -1, y: 1))
}
}
Note: For an iOS app in Mac Catalyst (with a AVPlayerController subclass) the root view is AVPlayerView.
But oddly AVPlayerView isn't public on iOS > Mac Catalyst so self.playerView wont work so you cant cast it. You get class not found for 'AVPlayerView'
But when you run the app in Mac Catalyst and inspect it the self.view is an AVPlayerView
workaround just flip the root view itself without casting - self.view
`class MyAVPlayerController: AVPlayerController`
to flip horizontal etc
self.view.transform = self.view.transform.concatenating(CGAffineTransform(scaleX: -1, y: 1))
to flip vertical etc
self.view.transform = self.view.transform.concatenating(CGAffineTransform(scaleX: 1, y: -1))
KNOWN ISSUE this flips the whole AVPlayerView including controls. in iOS 16 the actual player is a view where Swift.type(of:view) is "__AVPlayerLayerView" so you can walk the hierarchy and find the UIView return it then apply the transform to only that subview
func flipHorizontal(){
print("TradAVPlayerViewController.swift flipHorizontal")
if self.player != nil{
//------------------------------------------------------------------
//v1 - flips VC.view which is AVPlayerView
//but also flips TOAST and CONTROLS
//https://developer.apple.com/documentation/uikit/uiview/1622459-transform
//------------------------------------------------------------------
//OK ROTATES VIEW
//self.view.transform = CGAffineTransform(rotationAngle: CGFloat((90 * Double.pi)/180))
//OK FLIP VERTICAL
//self.view.transform = self.view.transform.concatenating(CGAffineTransform(scaleX: 1, y: -1))
//OK FLIPS HORIZONTAL
// self.view.transform = self.view.transform.concatenating(CGAffineTransform(scaleX: -1, y: 1))
//note the flip remains in place as long as self.player isnt recreated so PREV/NEXT will stay flipped
//------------------------------------------------------------------
//ISSUE flipping the whole view also flips the TOAST and SCRUBBER
//------------------------------------------------------------------
//in iOS 15 the player is a class with name "__AVPlayerLayerView"
//find it in the hierarchy and only apply transform to that on
if let rootView = self.view{
let className = "__AVPlayerLayerView"
if let subViewFound
= findSubViewByName(name: className,
view: rootView)
{
print("FOUND className:'\(className)' flipping it")
subViewFound.transform = subViewFound.transform.concatenating(CGAffineTransform(scaleX: -1, y: 1))
}else{
print("NOT FOUND className:'\(className)' CANT FLIP IT - debug hierarchy in 3d and get class name for the AVPlayerLayerView")
}
}else{
logger.error("self.view is nil")
}
print()
}else{
logger.error("self.player is nil")
}
}
func findSubViewByName(name: String, view: UIView) -> UIView?{
var viewFound: UIView? = nil
for subView in view.subviews{
//MUST WRAP IN STRING else types wont match
let typeName = "\(Swift.type(of: subView))"
//print("typeName:\(typeName)")
if typeName == name {
print("SUB VIEW - typeName:\(typeName) - MATCH!!")
viewFound = subView
break
}else{
print("SUB VIEW - typeName:\(typeName) - NO MATCH")
}
//recurse depth first
if let subViewFound = findSubViewByName(name: name, view: subView){
viewFound = subViewFound
break
}else{
//no match in subviewsf
}
}
return viewFound
}
I am currently using a Scroll View with different pages. I am aiming to hide the Status Bar on one specific page. There is a really annoying lag and the screen freezes every time the Status Bar is about to reappear/disappear.
This is my approach:
First of all I defined two variables
private var currentPage = 0
private var isStatusBarPreferablyHidden = true
I then used two functions from the Scroll View Delegate to call setNeedsStatusBarAppearanceUpdate when the user swipes to the first page
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let currentScrollPosition : CGFloat = self.navigation.contentOffset.x / self.navigation.frame.size.width
currentPage = lroundf(Float(currentScrollPosition))
}
func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView) {
if currentPage == 0 {
isStatusBarPreferablyHidden = true
} else {
isStatusBarPreferablyHidden = false
}
self.setNeedsStatusBarAppearanceUpdate()
}
Finally I overrode the Status Bar Functions to update the appearance of the Status Bar.
override var prefersStatusBarHidden: Bool {
return isStatusBarPreferablyHidden
}
override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation {
return UIStatusBarAnimation.none
}
Remove scrollViewWillBeginDecelerating.
Try:
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let currentScrollPosition : CGFloat = scrollView.contentOffset.x / scrollView.frame.size.width
let page = lroundf(Float(currentScrollPosition))
if page != currentPage {
currentPage = page
if currentPage == 0 {
isStatusBarPreferablyHidden = true
} else {
isStatusBarPreferablyHidden = false
}
self.setNeedsStatusBarAppearanceUpdate()
}
}
I've seen posts around here that suggest that UIScrollViews should automatically scroll if a subview UITextField becomes the first responder; however, I can't figure out how to get this to work.
What I have is a UIViewController that has a UIScrollView and within the UIScrollView there are multiple textfields.
I know how to do this manually if necessary; however, from what I've been reading, it seems possible to have it autoscroll. Help please.
I hope this example will help you
You can scroll to any point by this code.
scrollView.contentOffset = CGPointMake(0,0);
So if you have textfield, it must have some x,y position on view, so you can use
CGPoint point = textfield.frame.origin ;
scrollView.contentOffset = point
This should do the trick,
But if you don't know when to call this code, so you should learn UITextFieldDelegate methods
Implement this method in your code
- (void)textFieldDidBeginEditing:(UITextField *)textField {
// Place Scroll Code here
}
I hope you know how to use delegate methods.
I know this question has already been answered, but I thought I would share the code combination that I used from #Adeel and #Basil answer, as it seems to work perfectly for me on iOS 9.
-(void)textFieldDidBeginEditing:(UITextField *)textField {
// Scroll to the text field so that it is
// not hidden by the keyboard during editing.
[scroll setContentOffset:CGPointMake(0, (textField.superview.frame.origin.y + (textField.frame.origin.y))) animated:YES];
}
-(void)textFieldDidEndEditing:(UITextField *)textField {
// Remove any content offset from the scroll
// view otherwise the scroll view will look odd.
[scroll setContentOffset:CGPointMake(0, 0) animated:YES];
}
I also used the animated method, it makes for a much smoother transition.
Here is the Swift 4 update to #Supertecnoboff's answer. It worked great for me.
func textFieldDidBeginEditing(_ textField: UITextField) {
scroll.setContentOffset(CGPoint(x: 0, y: (textField.superview?.frame.origin.y)!), animated: true)
}
func textFieldDidEndEditing(_ textField: UITextField) {
scroll.setContentOffset(CGPoint(x: 0, y: 0), animated: true)
}
Make sure to extend UITextFieldDelegate and set the textfields' delegate to self.
There is nothing you have to do manually. It is the default behavior. There are two possibilities as to why you are not seeing the behavior
The most likely reason is that the keyboard is covering your UITextField. See below for solution
The other possibility is that you have another UIScrollView somewhere in the view hierarchy between the UITextField and the UIScrollView that you want to auto scroll. This is less likely but can still cause problems.
For #1, you want to implement something similar to Apple's recommendations for Moving Content That Is Located Under the Keyboard. Note that the code provided by Apple does not account for rotation. For improvements on their code, check out this blog post's implementation of the keyboardDidShow method that properly translates the keyboard's frame using the window.
- (void)textFieldDidBeginEditing:(UITextField *)textField {
CGRect rect = [textField bounds];
rect = [textField convertRect:rect toView:self.scrollView];
rect.origin.x = 0 ;
rect.origin.y -= 60 ;
rect.size.height = 400;
[self.scrollView scrollRectToVisible:rect animated:YES];
}
You can use this function for autoScroll of UITextField
on UITextFieldDelegate
- (void)textFieldDidBeginEditing:(UITextField *)textField {
[self autoScrolTextField:textField onScrollView:self.scrollView];
}
- (void) autoScrolTextField: (UITextField *) textField onScrollView: (UIScrollView *) scrollView {
float slidePoint = 0.0f;
float keyBoard_Y_Origin = self.view.bounds.size.height - 216.0f;
float textFieldButtomPoint = textField.superview.frame.origin.y + (textField.frame.origin.y + textField.frame.size.height);
if (keyBoard_Y_Origin < textFieldButtomPoint - scrollView.contentOffset.y) {
slidePoint = textFieldButtomPoint - keyBoard_Y_Origin + 10.0f;
CGPoint point = CGPointMake(0.0f, slidePoint);
scrollView.contentOffset = point;
}
EDIT:
Im now using IQKeyboardManager
Kudos to the developer of this, you need to try this.
Solution
extension UIScrollView {
func scrollVerticallyToFirstResponderSubview(keyboardFrameHight: CGFloat) {
guard let firstResponderSubview = findFirstResponderSubview() else { return }
scrollVertically(toFirstResponder: firstResponderSubview,
keyboardFrameHight: keyboardFrameHight, animated: true)
}
private func scrollVertically(toFirstResponder view: UIView,
keyboardFrameHight: CGFloat, animated: Bool) {
let scrollViewVisibleRectHeight = frame.height - keyboardFrameHight
let maxY = contentSize.height - scrollViewVisibleRectHeight
if contentOffset.y >= maxY { return }
var point = view.convert(view.bounds.origin, to: self)
point.x = 0
point.y -= scrollViewVisibleRectHeight/2
if point.y > maxY {
point.y = maxY
} else if point.y < 0 {
point.y = 0
}
setContentOffset(point, animated: true)
}
}
extension UIView {
func findFirstResponderSubview() -> UIView? { getAllSubviews().first { $0.isFirstResponder } }
func getAllSubviews<T: UIView>() -> [T] { UIView.getAllSubviews(from: self) as [T] }
class func getAllSubviews<T: UIView>(from parenView: UIView) -> [T] {
parenView.subviews.flatMap { subView -> [T] in
var result = getAllSubviews(from: subView) as [T]
if let view = subView as? T { result.append(view) }
return result
}
}
}
Full Sample
Do not forget to paste the Solution code here
import UIKit
class ViewController: UIViewController {
private weak var scrollView: UIScrollView!
private lazy var keyboard = KeyboardNotifications(notifications: [.willHide, .willShow], delegate: self)
override func viewDidLoad() {
super.viewDidLoad()
let scrollView = UIScrollView()
view.addSubview(scrollView)
scrollView.translatesAutoresizingMaskIntoConstraints = false
scrollView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor).isActive = true
scrollView.leftAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leftAnchor).isActive = true
scrollView.rightAnchor.constraint(equalTo: view.safeAreaLayoutGuide.rightAnchor).isActive = true
scrollView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor).isActive = true
scrollView.contentSize = CGSize(width: view.frame.width, height: 1000)
scrollView.isScrollEnabled = true
scrollView.indicatorStyle = .default
scrollView.backgroundColor = .yellow
scrollView.keyboardDismissMode = .interactive
self.scrollView = scrollView
addTextField(y: 20)
addTextField(y: 300)
addTextField(y: 600)
addTextField(y: 950)
}
private func addTextField(y: CGFloat) {
let textField = UITextField()
textField.borderStyle = .line
scrollView.addSubview(textField)
textField.translatesAutoresizingMaskIntoConstraints = false
textField.topAnchor.constraint(equalTo: scrollView.topAnchor, constant: y).isActive = true
textField.leftAnchor.constraint(equalTo: scrollView.leftAnchor, constant: 44).isActive = true
textField.widthAnchor.constraint(equalToConstant: 120).isActive = true
textField.heightAnchor.constraint(equalToConstant: 44).isActive = true
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
keyboard.isEnabled = true
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
keyboard.isEnabled = false
}
}
extension ViewController: KeyboardNotificationsDelegate {
func keyboardWillShow(notification: NSNotification) {
guard let userInfo = notification.userInfo as? [String: Any],
let keyboardFrame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect else { return }
scrollView.contentInset.bottom = keyboardFrame.height
scrollView.scrollVerticallyToFirstResponderSubview(keyboardFrameHight: keyboardFrame.height)
}
func keyboardWillHide(notification: NSNotification) {
scrollView.contentInset.bottom = 0
}
}
/// Solution
extension UIScrollView {
func scrollVerticallyToFirstResponderSubview(keyboardFrameHight: CGFloat) {
guard let firstResponderSubview = findFirstResponderSubview() else { return }
scrollVertically(toFirstResponder: firstResponderSubview,
keyboardFrameHight: keyboardFrameHight, animated: true)
}
private func scrollVertically(toFirstResponder view: UIView,
keyboardFrameHight: CGFloat, animated: Bool) {
let scrollViewVisibleRectHeight = frame.height - keyboardFrameHight
let maxY = contentSize.height - scrollViewVisibleRectHeight
if contentOffset.y >= maxY { return }
var point = view.convert(view.bounds.origin, to: self)
point.x = 0
point.y -= scrollViewVisibleRectHeight/2
if point.y > maxY {
point.y = maxY
} else if point.y < 0 {
point.y = 0
}
setContentOffset(point, animated: true)
}
}
extension UIView {
func findFirstResponderSubview() -> UIView? { getAllSubviews().first { $0.isFirstResponder } }
func getAllSubviews<T: UIView>() -> [T] { UIView.getAllSubviews(from: self) as [T] }
class func getAllSubviews<T: UIView>(from parenView: UIView) -> [T] {
parenView.subviews.flatMap { subView -> [T] in
var result = getAllSubviews(from: subView) as [T]
if let view = subView as? T { result.append(view) }
return result
}
}
}
// https://stackoverflow.com/a/42600092/4488252
import Foundation
protocol KeyboardNotificationsDelegate: class {
func keyboardWillShow(notification: NSNotification)
func keyboardWillHide(notification: NSNotification)
func keyboardDidShow(notification: NSNotification)
func keyboardDidHide(notification: NSNotification)
}
extension KeyboardNotificationsDelegate {
func keyboardWillShow(notification: NSNotification) {}
func keyboardWillHide(notification: NSNotification) {}
func keyboardDidShow(notification: NSNotification) {}
func keyboardDidHide(notification: NSNotification) {}
}
class KeyboardNotifications {
fileprivate var _isEnabled: Bool
fileprivate var notifications: [NotificationType]
fileprivate weak var delegate: KeyboardNotificationsDelegate?
fileprivate(set) lazy var isKeyboardShown: Bool = false
init(notifications: [NotificationType], delegate: KeyboardNotificationsDelegate) {
_isEnabled = false
self.notifications = notifications
self.delegate = delegate
}
deinit { if isEnabled { isEnabled = false } }
}
// MARK: - enums
extension KeyboardNotifications {
enum NotificationType {
case willShow, willHide, didShow, didHide
var selector: Selector {
switch self {
case .willShow: return #selector(keyboardWillShow(notification:))
case .willHide: return #selector(keyboardWillHide(notification:))
case .didShow: return #selector(keyboardDidShow(notification:))
case .didHide: return #selector(keyboardDidHide(notification:))
}
}
var notificationName: NSNotification.Name {
switch self {
case .willShow: return UIResponder.keyboardWillShowNotification
case .willHide: return UIResponder.keyboardWillHideNotification
case .didShow: return UIResponder.keyboardDidShowNotification
case .didHide: return UIResponder.keyboardDidHideNotification
}
}
}
}
// MARK: - isEnabled
extension KeyboardNotifications {
private func addObserver(type: NotificationType) {
NotificationCenter.default.addObserver(self, selector: type.selector, name: type.notificationName, object: nil)
}
var isEnabled: Bool {
set {
if newValue {
for notificaton in notifications { addObserver(type: notificaton) }
} else {
NotificationCenter.default.removeObserver(self)
}
_isEnabled = newValue
}
get { _isEnabled }
}
}
// MARK: - Notification functions
extension KeyboardNotifications {
#objc func keyboardWillShow(notification: NSNotification) {
delegate?.keyboardWillShow(notification: notification)
isKeyboardShown = true
}
#objc func keyboardWillHide(notification: NSNotification) {
delegate?.keyboardWillHide(notification: notification)
isKeyboardShown = false
}
#objc func keyboardDidShow(notification: NSNotification) {
isKeyboardShown = true
delegate?.keyboardDidShow(notification: notification)
}
#objc func keyboardDidHide(notification: NSNotification) {
isKeyboardShown = false
delegate?.keyboardDidHide(notification: notification)
}
}
If you have multiple textfields say Textfield1, Textfield2, Textfield3 and you want to scroll the scrollview along the y-axis when textfield2 becomes first responder:
if([Textfield2 isFirstResponder])
{
scrollView.contentOffset = CGPointMake(0,yourY);
}
As Michael McGuire mentioned in his point #2 above, the system's default behavior misbehaves when the scroll view contains another scroll view between the text field and the scroll view. I've found that the misbehavior also occurs when there's a scroll view merely next to the text field (both embedded in the scroll view that needs to be adjusted to bring the text field into view when the text field wants to start editing. This is on iOS 12.1.
But my solution is different from the above. In my top-level scroll view, which is sub-classed so I can add properties and override methods, I override scrollRectToVisible:animated:. It simply calls its [super scrollRectToVisible:animated:] unless there's a property set that tells it to adjust the rect passed in, which is the frame of the text field. When the property is non-nil, it is a reference to the UITextField in question, and the rect is adjusted so that the scroll view goes further than the system thought it would. So I put this in the UIScrollView's sub-classed header file:
#property (nullable) UITextField *textFieldToBringIntoView;
(with appropriate #synthesize textFieldToBringIntoView; in the implementation. Then I added this override method to the implementation:
- (void)scrollRectToVisible:(CGRect)rect animated:(BOOL)how
{
if (textFieldToBringIntoView) {
// Do whatever mucking with `rect`'s origin needed to make it visible
// based on context or its spatial relationship with the other
// view that the system is getting confused by.
textFieldToBringIntoView = nil; // Go back to normal
}
[super scrollRectToVisible:rect animated:how];
}
In the delegate method for the UITextField for when it's about to begin editing, just set textFieldToBringIntoView to the textField in question:
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
// Ensure it scrolls into view so that keyboard doesn't obscure it
// The system is about to call |scrollRectIntoView:| for the scrolling
// superview, but the system doesn't get things right in certain cases.
UIScrollView *parent = (UIScrollView *)textField.superview;
// (or figure out the parent UIScrollView some other way)
// Tell the override to do something special just once
// based on this text field's position in its parent's scroll view.
parent.textFieldToBringIntoView = textField;
// The override function will set this back to nil
return(YES);
}
It seems to work. And if Apple fixes their bug, it seems like it might still work (fingers crossed).
Building off of Vasily Bodnarchuk's answer I created a gist with a simple protocol that you can implement and it'll do it all for you.
All you need to do is call registerAsTextDisplacer()
I created a BaseViewController in my project and made that implement it
https://gist.github.com/CameronPorter95/cb68767f5f8052fdc70293c167e9430e
Other solutions I saw, let you set the offset to the origin of the textField but this makes the scroller view go beyond it bounds.
I did this adjustment to the offset instead to not go beyond the bottom nor the top offsets.
Set the keyboardHeightConstraint to the bottom of the page.
When the keyboard shows, update its constraint's constant to negative the keyboard height.
Then scroll to the responderField as we will show below.
#IBOutlet var keyboardHeightConstraint: NSLayoutConstraint?
var responderField: String?
#objc func keyboardNotification(notification: NSNotification) {
guard let keyboardValue = notification.userInfo [UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else { return }
let keyboardHeight = keyboardValue.cgRectValue.height
keyboardHeightConstraint?.constant = -keyboardHeight
scroll(field: responderField!)
}
func textFieldDidBeginEditing(_ textField: UITextField) {
responderField = textField
}
Now we want to make sure we do not scroll greater than the bottom offset nor less than the top offset.
At the same time, we want to calculate the offset of the field's maxY value.
To do that, we subtract the scrollView.bounds.size.height from the maxY value.
let targetOffset = field.frame.maxY - scrollView.bounds.size.height
I found it nicer to scroll an extra distance of the keyboard height, but you could neglect that if you want to scroll right below the field.
let targetOffset = keyboardHeight + field.frame.maxY - scrollView.bounds.size.height
Remember to add the scrollView.contentInset.bottom if you have the tab bar visible.
func scroll(field: UITextField) {
guard let keyboardConstraintsConstant = keyboardHeightConstraint?.constant else { return }
let keyboardHeight = -keyboardConstraintsConstant
view.layoutIfNeeded()
let bottomOffset = scrollView.contentSize.height - scrollView.bounds.size.height + scrollView.contentInset.bottom
let topOffset = -scrollView.safeAreaInsets.top
let targetOffset = keyboardHeight + field.frame.maxY + scrollView.contentInset.bottom - scrollView.bounds.size.height
let adjustedOffset = targetOffset > bottomOffset ? bottomOffset : (targetOffset < topOffset ? topOffset : targetOffset)
scrollView.setContentOffset(CGPoint(x: 0, y: adjustedOffset), animated: true)
}
If you have scrollView and tableView with invalidating intrinsicContentSize as the subview, you can disable tableView scrolling in storyboard or set tableView.isScrollEnabled to false in code.