ScrollView and keyboard in Swift

IosViewSwiftScroll

Ios Problem Overview

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.

Ios Solutions

Solution 1 - Ios

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
}

Solution 2 - Ios

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
}

Solution 3 - Ios

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
}

Solution 4 - Ios

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
}

Solution 5 - Ios

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
}

Solution 6 - Ios

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.

Solution 7 - Ios

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
}

Solution 8 - Ios

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()
    }
}

Solution 9 - Ios

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):

https://stackoverflow.com/questions/484855/how-programatically-move-a-uiscrollview-to-focus-in-a-control-above-keyboard

https://stackoverflow.com/questions/13056004/how-to-make-a-uiscrollview-auto-scroll-when-a-uitextfield-becomes-a-first-respon

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).

Solution 10 - Ios

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
}

Solution 11 - Ios

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
        }
    }   
}

Solution 12 - Ios

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.")
    }
   }
 }

Solution 13 - Ios

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)
    }
}

Solution 14 - Ios

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];
    }

Solution 15 - Ios

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
        }

    }
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Attributions

All content for this solution is sourced from the original question on Stackoverflow.

The content on this page is licensed under the Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license.

Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionGalinhaVoadoraView Question on Stackoverflow
Solution 1 - IosSudheer Kumar PalchuriView Answer on Stackoverflow
Solution 2 - IosDaniel JonesView Answer on Stackoverflow
Solution 3 - IosElijahView Answer on Stackoverflow
Solution 4 - IosSupanat TechasothonView Answer on Stackoverflow
Solution 5 - IosnikansView Answer on Stackoverflow
Solution 6 - IosZachary ProbstView Answer on Stackoverflow
Solution 7 - IosIvan CarosatiView Answer on Stackoverflow
Solution 8 - IosGalinhaVoadoraView Answer on Stackoverflow
Solution 9 - IosGlynbeardView Answer on Stackoverflow
Solution 10 - IosJohan DrevetView Answer on Stackoverflow
Solution 11 - IosmswlogoView Answer on Stackoverflow
Solution 12 - IosSamView Answer on Stackoverflow
Solution 13 - IosZanyView Answer on Stackoverflow
Solution 14 - IosMubeen QaziView Answer on Stackoverflow
Solution 15 - IosNikiView Answer on Stackoverflow