Adjusting UIScrollView Content to Accommodate the Keyboard

Shane Qi • 2016-03-24 22:30
override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated) 
    /* Add keyboard notification observer. */ 
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(ItemDetailsViewController.keyboardWillShow), name: UIKeyboardWillShowNotification, object: nil) 
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(ItemDetailsViewController.keyboardWillHide), name: UIKeyboardWillHideNotification, object: nil) 
} 

override func viewWillDisappear(animated: Bool) { 
    /* Remove keyboard notification observer. */ 
    NSNotificationCenter.defaultCenter().removeObserver(self) 
} 

func keyboardWillShow(notification: NSNotification) {
    /* Get keyboard height. */ 
    let userInfo:NSDictionary! = notification.userInfo 
    let keyboardHeight = userInfo.objectForKey(UIKeyboardFrameBeginUserInfoKey)!.CGRectValue().size.height 

    /* Add bottom inset. */ 
    scrollView.contentInset.bottom = keyboardHeight 
    scrollView.scrollIndicatorInsets.bottom = keyboardHeight 

    /* If text field is hidden by keyboard, scroll it so it's visible */ 
    var viewport = scrollView.frame 
    viewport.size.height -= keyboardHeight 
    let textFieldOrigin = CGPoint(x: bidForm.frame.origin.x + bidForm.textFieldPosition.x, y: bidForm.frame.origin.y + bidForm.textFieldPosition.y) 
    if CGRectContainsPoint(viewport, textFieldOrigin) { 
        let scrollTo = CGPointMake(0, textFieldOrigin.y + keyboardHeight) 
        scrollView.setContentOffset(scrollTo, animated: true) 
    } 
} 

func keyboardWillHide() { 
    /* Reset bottom inset. */ 
    scrollView.contentInset.bottom = 0 
    scrollView.scrollIndicatorInsets.bottom = 0
}