Swift, scrollview and textfield auto scroll when the keyboard appears - swift

Question

I have input form in popover.
When keyboard appears it shrinks in half..I have added in scroll view in base too but didn’t work..
Initializing:
var popoverViewController = self.storyboard?.instantiateViewControllerWithIdentifier("UnitEditController") as! UnitEditController
popoverViewController.modalPresentationStyle = .Popover
popoverViewController.preferredContentSize = CGSizeMake(820, 820)
popoverViewController.unit = unit
popoverViewController.property = property
popoverViewController.unitDetailProtocolVar = self
let popoverPresentationViewController = popoverViewController.popoverPresentationController
var rect = CGRectMake(cell!.bounds.origin.x+500, cell!.bounds.origin.y+20, 50, 30);
popoverPresentationViewController?.delegate = self
popoverPresentationViewController?.sourceView = cell!.contentView
popoverPresentationViewController?.sourceRect = cell!.frame
popoverPresentationViewController?.permittedArrowDirections = UIPopoverArrowDirection.allZeros
popoverPresentationViewController?.sourceRect = rect
presentViewController(popoverViewController, animated: true, completion: nil)
Prepare code for textfield and textview editing:
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name:UIKeyboardWillHideNotification, object: nil);
let scrollSize = CGSizeMake(900, 820)
self.contentScrollView.contentSize = scrollSize
func keyboardWillShow(sender: NSNotification) {
self.contentScrollView.frame=CGRectMake(0, -300, 320, 700);
}
func keyboardWillHide(sender: NSNotification) {
self.view.frame=CGRectMake(0, +300, 320, 700);
}
it should auto scroll accordingly when i start editing textview and textfield.
Can someone help me on this

Answer 1

this is what I did:
I created a keyboardHandler class
class KeyboardUtils{
static var instance = KeyboardUtils();
static var lastKeyboardSize : CGSize = CGSize();
var keyBoarEventsCallBacks : [(onShow: ()->Void,onHide: ()->Void)] = [];
init(){
self._registerKeyboardHandler()
KeyboardUtils.instance = self;
}
private func _registerKeyboardHandler(){
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name:UIKeyboardWillHideNotification, object: nil);
}
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
let contentInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0);
KeyboardUtils.lastKeyboardSize = keyboardSize.size;
for i in self.keyBoarEventsCallBacks{
i.onShow();
}
}
}
func keyboardWillHide(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
let contentInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0)
for i in self.keyBoarEventsCallBacks{
i.onHide();
}
}
}
}
this class will handle event when keyboard is opened.
now from my scrollView class i did this:
class myScrollView : UIScrollView,UIScrollViewDelegate{
override init(frame: CGRect)
{
super.init(frame:frame)
KeyboardUtils.instance.keyBoarEventsCallBacks.append((onShow:self.onKeyboardAppear,onHide: self.onKeyboardHide));
}
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func onKeyboardAppear(){
//I just resized, you can also do super.contentOffset =...
var size = super.contentSize;
size.height+=KeyboardUtils.lastKeyboardSize.height;
super.contentSize = size;
}
func onKeyboardHide(){
var size = super.contentSize;
size.height-=KeyboardUtils.height;
super.contentSize = size;
}
}
and now every time the keyboard will open, you'll have callback function to your UIViewScroll class. +it'll know the keyboard size that opened, because keyboard sizes might be different from phone to phone
edit:
you don't have to use custom view class, you can register any class
class myClass : anyClass{
override init(...)
{
super.init(...)
//on ViewController class do it on ViewDidLoad
KeyboardUtils.instance.keyBoarEventsCallBacks.append((onShow:self.onKeyboardAppear,onHide: self.onKeyboardHide));
}
func onKeyboardAppear(){
let keyboardSize =KeyboardUtils.lastKeyboardSize.height;
//do your stuff
}
func onKeyboardHide(){
let keyboardSize =KeyboardUtils.lastKeyboardSize.height;
//do your stuff
}
}