My pan gesture recognizer is very slow and unresponsive - ios

Question

I have a pan gesture recognizer in my app that does a function when swiped down. The animation used to be smooth but all of a sudden (without adding an code to that view controller) it becomes very laggy and I have to swipe down quickly for it to do that animation, It doesn't follow my finger.
What is the cause of that
class PhotoViewController: UIViewController, CLLocationManagerDelegate, UIPickerViewDataSource, UIPickerViewDelegate {
override var prefersStatusBarHidden: Bool {
return true
}
private var backgroundImage: UIImage
private var backgroundImageView: UIImageView?
private var picker: UIPickerView
var list: [String]
var locationPicked: String
var locationArray: [Any]
var partyIndex: Int = Int()
init(image: UIImage) {
self.backgroundImage = image
self.picker = UIPickerView()
self.list = ["Loading..."]
self.locationPicked = list[0]
self.locationArray = []
super.init(nibName: nil, bundle: nil)
print(image)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
/************************************/
override func viewDidLoad() {
super.viewDidLoad()
if Reachability.isConnectedToNetwork() == true{
mapApi()
}
let backgroundImageView = UIImageView(frame: view.frame)
backgroundImageView.image = backgroundImage
backgroundImageView.isUserInteractionEnabled = true
self.backgroundImageView = backgroundImageView
let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(panGestureRecognizerAction(_:)))
backgroundImageView.addGestureRecognizer(panGestureRecognizer)
let longGesture = UILongPressGestureRecognizer(target: self, action: #selector(longTap(sender:)))
backgroundImageView.addGestureRecognizer(longGesture)
view.addSubview(backgroundImageView)
view.backgroundColor = greenColor
picker.dataSource = self
picker.delegate = self
picker.frame = CGRect(x: ((self.view.frame.width)/2)-84, y: (self.view.frame.height)-70, width: 160, height: 40)
picker.clipsToBounds = true
picker.layer.cornerRadius = picker.bounds.size.width/20
picker.layer.borderColor = redColor.cgColor
picker.layer.borderWidth = 0
picker.backgroundColor = UIColor(colorLiteralRed: 217/255, green: 83/255, blue: 79/255, alpha: 0.85)
backgroundImageView.addSubview(picker)
print(list)
}
func panGestureRecognizerAction(_ gesture: UIPanGestureRecognizer){
let translation = gesture.translation(in: view)
if let bgImage = gesture.view{
if list.count > 1{
bgImage.frame.origin.y = translation.y
}
}
if gesture.state == .ended{
let tickName = "Tick.png"
let tickImage = UIImage(named: tickName)
let tick = UIImageView(image: tickImage!)
tick.frame = CGRect(x: ((self.view.frame.width)/2)-25, y: 150, width: 70, height: 70)
self.view.addSubview(tick)
tick.alpha = 0
let crossName = "Cross.png"
let crossImage = UIImage(named: crossName)
let cross = UIImageView(image: crossImage!)
cross.frame = CGRect(x: ((self.view.frame.width)/2)-25, y: (self.view.frame.height)-75, width: 50, height: 50)
self.view.addSubview(cross)
cross.alpha = 0
let velocity = gesture.velocity(in: view)
if (gesture.view?.frame.origin.y)! > CGFloat(100) || velocity.y > 1500 {
UIView.animate(withDuration: 0.4, animations: {
self.view.backgroundColor = greenColor
gesture.view?.frame.origin = CGPoint(x: 0, y: 275)
tick.alpha = 1
}, completion: { (true) in
UIView.animate(withDuration: 0.4, delay: 0.2, animations: {
tick.alpha = 0
})
if partyAt != nil{
self.uploadPartyPost()
} else{
self.uploadPost()
}
})
UIView.animate(withDuration: 0.5, delay: 1, animations: {
gesture.view?.frame.origin = CGPoint(x: 0, y: 0)
}, completion: { (true) in
self.dismiss(animated: true, completion: nil)
})
//send image here tick
} else if (gesture.view?.frame.origin.y)! < CGFloat(-80) || velocity.y > 1500 {
UIView.animate(withDuration: 0.2, animations: {
self.view.backgroundColor = redColor
gesture.view?.frame.origin = CGPoint(x: 0, y: -150)
cross.alpha = 1
}, completion: { (true) in
UIView.animate(withDuration: 0.5, delay: 0.7, animations: {
cross.alpha = 0
})
})
UIView.animate(withDuration: 0.2, delay: 1, animations: {
gesture.view?.frame.origin = CGPoint(x: 0, y: 0)
}, completion: { (true) in
self.dismiss(animated: true, completion: nil)
})
print("Done")
//send image here cross
} else {
UIView.animate(withDuration: 0.3, animations: {
gesture.view?.frame.origin = CGPoint(x: 0, y: 0)
})
}
}
}

Answer 1

After playing with translation of Pan gesture you need to set translation point back to zero.