What is the iPhone's default keyboard animation rate?

Question

A while ago I remember seeing a constant of some kind that defined the animation rate of the Keyboard on the iPhone and I can not for the life of me remember where I saw it.

Answer 1

To add a bit more to what Shaggy Frog wrote. The full implementation would be something like:

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardMovement:)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardMovement:)
                                             name:UIKeyboardWillHideNotification
                                           object:nil];


-(void)keyboardMovement:(NSNotification *)notification{
    if (_numericKeyboardShowing == false){
        [UIView animateWithDuration:[self keyboardAnimationDurationForNotification:notification] delay:0
                        options:UIViewAnimationCurveEaseInOut
                     animations:^ {
                         self.bottomContainerView.center = CGPointMake(self.bottomContainerView.center.x, (self.bottomContainerView.center.y - 218));
                                  }
                     completion:NULL];

    _numericKeyboardShowing = true;
   }
   else{
    [UIView animateWithDuration:[self keyboardAnimationDurationForNotification:notification] delay:0
                        options:UIViewAnimationCurveLinear
                     animations:^ {
                         self.bottomContainerView.center = CGPointMake(self.bottomContainerView.center.x, (self.bottomContainerView.center.y + 218));
                     }
                     completion:NULL];

    _numericKeyboardShowing = false;
}

- (NSTimeInterval)keyboardAnimationDurationForNotification:(NSNotification *)notification
{
    NSDictionary *info      = [notification userInfo];
    NSValue* value          = [info objectForKey:UIKeyboardAnimationDurationUserInfoKey];
    NSTimeInterval duration = 0;
    [value getValue:&duration];
    return duration;
}

Answer 2

UIKeyboardAnimationDurationUserInfoKey The key for an NSValue object containing a double that identifies the duration of the animation in seconds.

Answer 3

- (NSTimeInterval)keyboardAnimationDurationForNotification:(NSNotification*)notification
{
    NSDictionary* info = [notification userInfo];
    NSValue* value = [info objectForKey:UIKeyboardAnimationDurationUserInfoKey];
    NSTimeInterval duration = 0;
    [value getValue:&duration];
    return duration;
}

Answer 4

Swift 4 - worked for me:

        if let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as? Double {
            UIView.animate(withDuration: duration, animations: {
                self.view.layoutIfNeeded()
            })
        }

In debug mode my duration was 3.499999

Answer 5

Since this is the first google hit, I'd like to point out that hard-coding 0.3 will mean that your view will incorrectly animate when international users (e.g. Japanese) swap between different-sized keyboards (when that action ought to be instant).

Always use the notification's userInfo dictionary's UIKeyboardAnimationDurationUserInfoKey value - it gets set to 0 when the user is flicking through keyboards.

Answer 6

In Swift your code will look like this:

let keyboardSize: CGSize = userInfo[UIKeyboardFrameBeginUserInfoKey]!.CGRectValue.size

let animationDuration = ((userInfo[UIKeyboardAnimationDurationUserInfoKey]) as! NSNumber).floatValue
let animationOptions = ((userInfo[UIKeyboardAnimationCurveUserInfoKey]) as! NSNumber).unsignedLongValue

UIView.animateWithDuration(NSTimeInterval(animationDuration), delay: 0,
  options: UIViewAnimationOptions(rawValue: animationOptions),
  animations: { () -> Void in
                self.view.frame.origin.y += keyboardSize.height
                }, 
  completion: nil)