CODEWITHSUNDEEP
iosswiftuikeyboard
Stranger B.
Stranger B.

Reputation: 9374

Keyboard height change observer

How to detect Keyboard height change, or keyboard change in iOS using Swift.

I'm able to add an observer for my app to detect wether the Keyboard is show or not using :

NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(CommentView.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(CommentView.keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)

and I'm changing my button position according to that :

func keyboardWillShow(notification: NSNotification) {
        animateTextFieldWithKeyboard(notification)
}

func keyboardWillHide(notification: NSNotification) {
        animateTextFieldWithKeyboard(notification)
}

func animateTextFieldWithKeyboard(notification: NSNotification) {


let userInfo = notification.userInfo!

let keyboardSize = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()
let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as! Double
let curve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as! UInt

// baseContraint is your Auto Layout constraint that pins the
// text view to the bottom of the superview.

if notification.name == UIKeyboardWillShowNotification {
    if (BottomConstraint.constant == 0) {
        BottomConstraint.constant += keyboardSize.height
    }

    // move up
}
else {
    BottomConstraint.constant = 0
    // move down
}

view.setNeedsUpdateConstraints()

let options = UIViewAnimationOptions(rawValue: curve << 16)
UIView.animateWithDuration(duration, delay: 0, options: options,
    animations: {
        self.view.layoutIfNeeded()
    },
    completion: nil
)

}

Everything is working fine as you can see in the screenshot :

enter image description here

But the problem comes when I change the keyboard type to Emoji for example. it hides my textField and my Button, so I would like to change the position of the button and the TextFiend according to the keyboard new height

enter image description here

Upvotes: 1

Views: 2210

Answers (2)

Petra Mantičov&#225;
Petra Mantičov&#225;

Reputation: 41

I use this and all notifications are triggered. 

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)

}    

@objc func keyboardWillShow(notification: NSNotification) {
    let keyboardSize = (notification.userInfo![UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue

        if keyboard == false{
            keyboard = true
            lastKeyboardHeight = keyboardSize.height
            chatDetailView.frame.origin.y = chatDetailView.frame.origin.y-(keyboardSize.height-bottomMenu.frame.height)
        }
    }

    @objc func keyboardWillChange(notification: NSNotification) {
        let keyboardSize1 = (notification.userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue

        if keyboard == true && lastKeyboardHeight != keyboardSize1.height {
            if lastKeyboardHeight < keyboardSize1.height{
                let keyboardDifference: CGFloat = keyboardSize1.height-lastKeyboardHeight
                chatDetailView.frame.origin.y -= keyboardDifference

            } else {
                let keyboardDifference: CGFloat = lastKeyboardHeight-keyboardSize1.height
                chatDetailView.frame.origin.y += keyboardDifference
            }
            lastKeyboardHeight = keyboardSize1.height
        }
    }

    @objc func keyboardWillHide(notification: NSNotification) {
        if keyboard == true {
            keyboard = false
            chatDetailView.frame.origin.y = chatDetailView.frame.origin.y+(lastKeyboardHeight-bottomMenu.frame.height)
        }
    }

Upvotes: 1

Duncan C
Duncan C

Reputation: 131491

If you search on UIKeyboardWillShowNotification in the Xcode docs you get to the section on UIWindow, which has a table of notifications at the end.

I suggest trying the UIKeyboardWillChangeFrameNotification.

Time to find the answer: About 30 seconds.

Upvotes: 1

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