Swift - Multiple UILabel click events to same function

Question

I need to add a UITapGestureRecognizer to multiple UILabel and they all need to go to the same function for handling.

What I have is this:

@IBOutlet weak var label_something: UILabel!
let tap = UITapGestureRecognizer(target: self, action: #selector(self.myFunction))
label_something.addGestureRecognizer(tap)

Recieved here:

@objc func myFunction(sender:UITapGestureRecognizer) { // Something... }

Working like a charm. Problem is that its only working with one UILabel (If adding addGestureRecognizer(tap) to multiple UIlabel it only works on the last one added)

So my question is:

How to achieve what I want to do here? Five different UILabels with tapRecognizer going to the same function

How did you determine `myFunction(sender:)` called only for one label? If you tap on the other label, It didn't call. Did you check with log? — Mani, Apr 25 '18 at 12:00
Yes, a simple print("hepp") in the function only showed when clicking the one that worked. — MHopstad, Apr 25 '18 at 12:01
Could you see here some more code? ie how you assign the `label_something`? — Mani, Apr 25 '18 at 12:02
I mean, you have to add gesture for other labels too. like `label_something1.addGestureRecognizer(tap) label_something2.addGestureRecognizer(tap) label_something3.addGestureRecognizer(tap).... etc` — Mani, Apr 25 '18 at 12:06
@Mani Samle like above. Instead of only label_something.addGestureRecognizer(tap) I have 5 rows of this with the different labels. Everything is done the same. Not showed in example to shorten down the text. — MHopstad, Apr 25 '18 at 12:07
did you create new Gesture or assigning the same gesture to all labels? — Mani, Apr 25 '18 at 12:10

score 6 · Accepted Answer · edited Apr 25 '18 at 12:11

UIGestureRecognizer is to be used with a single view, you have to create a new instance of UIGestureRecognizer

func setGesture() -> UITapGestureRecognizer {

     var myRecognizer = UITapGestureRecognizer()

     myRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.myFunction))
     return myRecognizer
}

label_something1.addGestureRecognizer(setGesture())    
label_something2.addGestureRecognizer(setGesture())

score 3 · Answer 2 · answered Apr 25 '18 at 12:03

3

If you add new instance from UITapGestureRecognizer its will work fine, for example

let tap = UITapGestureRecognizer(target: self, action: #selector(self.myFunction))
label_1.addGestureRecognizer(tap)
let tap2 = UITapGestureRecognizer(target: self, action: #selector(self.myFunction))
label_2.addGestureRecognizer(tap)

answered Apr 25 '18 at 12:03

A.Munzer

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Are you sure, need to create new gesture for every label? – Mani Apr 25 '18 at 12:04
@Mani A gesture recognizer can only be attached to one view. The reason is because each recognizer can have it's own gesture state (one is being triggered and the others are untouched). – Crazyrems Apr 25 '18 at 12:06
i think yes, because if you use the same instance, it will be added for the last label. – A.Munzer Apr 25 '18 at 12:07
@Crazyrems ya got your point. after seeing this. https://stackoverflow.com/questions/4747238/can-you-attach-a-uigesturerecognizer-to-multiple-views – Mani Apr 25 '18 at 12:08
@Mani yes. Each label needs to get a tap gesture recognizer, i.e one `UITapGestureRecognizer` can be only assigned to single component, that's why the *last* label recognize the `tap`, it would automatically removed from the previous labels. However, all gestures can have the same selector method. – Ahmad F Apr 25 '18 at 12:10
@AhmadF Ya got it. see my comment above. I think, It should be answer for this question. – Mani Apr 25 '18 at 12:11

score 0 · Answer 3 · answered Apr 25 '18 at 12:50

Each UIView needs its own recognizer, i have a little helper function for this case. Feel free to copy/paste.

private func addTapRecognizer(toView view: UIView) {
        let recognizer = UITapGestureRecognizer(target: self, action: #selector(didTapButton(sender:)))
        view.isUserInteractionEnabled = true
        view.addGestureRecognizer(recognizer)
    }

    @objc private func didTapButton(sender: UIGestureRecognizer) {
        guard let view = sender.view else {
            return
        }

        switch view {
        case self.imageView: // any view you want to check
        default:
            print(sender.debugDescription)
        }
     }

Swift - Multiple UILabel click events to same function

3 Answers3