smoothly hide and show a button according to keyboard's availability

Question

so i'm showing a button on top of my keyboard when keyboard is appearing and then hiding it when keyboard dismissed but the flow of animation is not smooth enough

i want to it come up and down with keyboard (without blocking the UI)

images:

WHEN KEYBOARD APPEARS , YOU CAN SEE THAT KEYBOARD IS STILL NOT FULLLY APPEARED BUT MY BUTTON IS HERE

AND WHEN IT HIDES , STILL NOT FULLY DISMISSED BUT BUTTON IS GONE

my code :

CODE:

viewDidLoad ...... {
        // here we have notification observers for tracking the states of Keyboard
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(LaunchScreenViewController.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)

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

}


    func keyboardWillShow(notification:NSNotification) { // in this function i'm changing the origin (Y) axis of my button os that it can appear on top of my keyboard 
    let userInfo:NSDictionary = notification.userInfo!
    let keyboardFrame:NSValue = userInfo.valueForKey(UIKeyboardFrameEndUserInfoKey) as! NSValue
    let keyboardRectangle = keyboardFrame.CGRectValue()
    UIView.animateWithDuration(0.3) {

        self.nextButtonConstraint.constant  = keyboardRectangle.height
    }
}

func keyboardWillHide(notification:NSNotification) {
    UIView.animateWithDuration(0.5) {

        self.nextButtonConstraint.constant  = -50 // here i'm making my button  out of screen bounds 
    }
}

Igor · Accepted Answer · 2016-08-17T13:13:47.580

2

You should apply correct animation:

self.nextButtonConstraint.constant  = keyboardRectangle.height
UIView.animateWithDuration(0.3) {
    <outlet to nextButton>.layoutIfNeeded() // insert correct value in <>
}

And don't use 0.3, but take timeInterval from UIKeyboardAnimationDurationUserInfoKey

edited Aug 17 '16 at 13:13

answered Aug 17 '16 at 13:09

Igor

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hey man its working fine , but what with the `UIKeyboardAnimationDurationUserInfoKey` ?? – remy boys Aug 17 '16 at 13:12
you get exact timeInterval for animation of keyboard appearence (usually 0.25) – Igor Aug 17 '16 at 13:14
but how to get it from `UIKeyboardAnimationDurationUserInfoKey` ? its a string right ? `public let UIKeyboardAnimationDurationUserInfoKey: String // NSNumber of double` – remy boys Aug 17 '16 at 13:15
It's NSTimeInterval – Igor Aug 17 '16 at 13:15
okay got it `let duration: NSTimeInterval = (notification.userInfo![UIKeyboardAnimationDurationUserInfoKey] as! NSTimeInterval)` – remy boys Aug 17 '16 at 13:18
or `let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as Double` – Igor Aug 17 '16 at 13:19
I just wanted to add that for me duration doesn't work with above calculation. A value of 0.03 is working for me which is way off from 0.25. I wonder if there is any exact solution at all? – Raymond May 19 '20 at 22:27

smoothly hide and show a button according to keyboard's availability

1 Answers1