use tag to combine #objc func methods - swift

Question

My code declares 2 different #objc func methods using UIPan gestureRecongnizzer. I would think there would be a way to use just 1 objc func method using a tag. All the function currently does is move the imageview around. I dont know if tag is the best way and I am open to other solutions I just want 1 func. Specifically look at pgGestureMethod and sgGestureMethod.
var pg = UIImageView()
var pgGesture = UIPanGestureRecognizer()
var pgCon = [NSLayoutConstraint]()
var sg = UIImageView()
var sgGesture = UIPanGestureRecognizer()
var sgCon = [NSLayoutConstraint]()
override func viewDidLoad() {
super.viewDidLoad()
[pg,sg].forEach({
$0.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview($0)
$0.isUserInteractionEnabled = true
})
pgGesture = UIPanGestureRecognizer(target: self, action: #selector(ViewController.pgGestureMethod(_:)))
pg.addGestureRecognizer(pgGesture)
sgGesture = UIPanGestureRecognizer(target: self, action: #selector(ViewController.sgGestureMethod(_:)))
sg.addGestureRecognizer(sgGesture)
}
#objc func pgGestureMethod(_ sender: UIPanGestureRecognizer){
self.view.bringSubviewToFront(pg)
let tranistioon = sender.translation(in: self.view)
pg.center = CGPoint(x: pg.center.x + tranistioon.x, y: pg.center.y + tranistioon.y)
sender.setTranslation(CGPoint.zero,in: self.view)
}
#objc func sgGestureMethod(_ sender: UIPanGestureRecognizer){
let tranistioon = sender.translation(in: self.view)
sg.center = CGPoint(x: sg.center.x + tranistioon.x, y: sg.center.y + tranistioon.y)
sender.setTranslation(CGPoint.zero,in: self.view)
}

Answer 1

Gesture recognisers have a view property that refers to the view to which they are added, so you don't even need a tag!
Just use one single action method like this:
#objc func pgGestureMethod(_ sender: UIPanGestureRecognizer){
// I replaced every "pg" with "sender.view!"
self.view.bringSubviewToFront(sender.view!)
let tranistioon = sender.translation(in: self.view)
sender.view!.center = CGPoint(x: sender.view!.center.x + tranistioon.x, y: sender.view!.center.y + tranistioon.y)
sender.setTranslation(CGPoint.zero,in: self.view)
}
If not writing self.view.bringSubviewToFront(sg) is actually intentional, you can simply check sender.view!:
#objc func pgGestureMethod(_ sender: UIPanGestureRecognizer){
if sender.view == pg {
self.view.bringSubviewToFront(pg)
}
let tranistioon = sender.translation(in: self.view)
sender.view!.center = CGPoint(x: sender.view!.center.x + tranistioon.x, y: sender.view!.center.y + tranistioon.y)
sender.setTranslation(CGPoint.zero,in: self.view)
}

Answer 2

welcome to the Stackoverflow.
So in your case, you can understand which gesture was called from parameter in gesture function.
class SomeViewController: UIViewController {
var pg = UIImageView()
var pgGesture = UIPanGestureRecognizer()
var pgCon = [NSLayoutConstraint]()
var sg = UIImageView()
var sgGesture = UIPanGestureRecognizer()
var sgCon = [NSLayoutConstraint]()
override func viewDidLoad() {
super.viewDidLoad()
[pg,sg].forEach {[unowned self] in
$0.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview($0)
$0.isUserInteractionEnabled = true
}
pgGesture = UIPanGestureRecognizer(target: self, action: #selector(gestureDidRecognize(_:)))
pg.addGestureRecognizer(pgGesture)
sgGesture = UIPanGestureRecognizer(target: self, action: #selector(gestureDidRecognize(_:)))
sg.addGestureRecognizer(sgGesture)
}
}
#objc private extension SomeViewController {
func gestureDidRecognize(_ gesture: UIPanGestureRecognizer){
guard let gestureView = gesture.view else { return }
let transition = gesture.translation(in: view)
switch gesture {
case pgGesture:
view.bringSubviewToFront(pg)
default: break
}
gestureView.center = CGPoint(
x: gestureView.center.x + transition.x,
y: gestureView.center.y + transition.y)
gesture.setTranslation(.zero, in: view)
}
}