iOS form next button handling.

FormViewController.swift

 override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)
}

override func viewWillDisappear(animated: Bool) {
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func keyboardWasShown(notification: NSNotification) {
    
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        let kbSize: CGSize = keyboardSize.size
     
        var remaininHeight: CGFloat = self.view.height - self.scrollView.height - self.scrollView.y - 40
        var contentInsets: UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height - remaininHeight, 0.0)
        
        self.scrollView.contentInset = contentInsets
        self.scrollView.scrollIndicatorInsets = contentInsets
    }
}

func keyboardWillBeHidden(notification: NSNotification) {
    var contentInsets: UIEdgeInsets = UIEdgeInsetsZero
    self.scrollView.scrollIndicatorInsets = contentInsets
    self.scrollView.setContentOffset(CGPointZero, animated: true)
}