UISwipeGestureRecognizer does not work with swipeGesture.direction = .right

Question

Created Aug ’20

Replies 5

Boosts 0

Participants 3

For the UISwipeGestureRecognizer, when I use direction = .left, it works.

However, when I use direction = .right, it does not work

Code Block swift// swipeGesture is the UISwipeGestureRecognizer
if (swipeGesture.direction = .right) {
	// Code does not run
} else if (swipeGesture.direction = .left) {
	// Code runs
}

Does anyone have any idea why this happens?

Boost

Answer 1

Claude31 OP

Aug ’20

How do you test ? = and not == ???

Should write:

Code Block if swipeGesture.direction == .right {
	// Code should run
} else if swipeGesture.direction == .left {
	// Code runs
}

A switch case could be more appropriate here

Code Block switch swipeGesture.direction {
  case .right : print("Right")
  case .left : print("Left")
  case .up : print("Up")
  case .down : print("Down")
}

0

Answer 2

chewethan OP

Aug ’20

Right sorry, there was a mistake in the code I wrote in my original post. It was '==' instead of '=' in my own code. Thanks for pointing that out.

0

Answer 3

chewethan OP

Aug ’20

However, a switch case still did not solve the issue

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Answer 4

OOPer OP

Aug ’20

You need to add a UISwipeGestureRecognizer for each direction:

Code Block     override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        let rightSwipeRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(swipeRight))
        rightSwipeRecognizer.direction = .right
        mySwipableView.addGestureRecognizer(rightSwipeRecognizer)
        
        let leftSwipeRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(swipeLeft))
        leftSwipeRecognizer.direction = .left
        mySwipableView.addGestureRecognizer(leftSwipeRecognizer)
    }
    @objc func swipeRight(_ swipeGesture: UISwipeGestureRecognizer) {
        print("right")
    }
    
    @objc func swipeLeft(_ swipeGesture: UISwipeGestureRecognizer) {
        print("left")
    }

I do not know how you have set direction of the UISwipeGestureRecognizer, but as far as I tested, you cannot detect swipe gestures for multiple directions with one UISwipeGestureRecognizer.

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Answer 5

Claude31 OP

Aug ’20

The following switch code

Code Block switch swipeGesture.direction { }

should be for each action of the gesture you define.

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