CODEWITHSUNDEEP
swiftxcodesprite-kit
Callum Williams
Callum Williams

Reputation: 121

UISwipeGestureRecognizer not working Swift 4 SpriteKit

I'm trying to use a UISwipeGestureRecognizer so it executes a function when the user swipes right on the screen in an SKScene. This is my code

I declare it, at the top of the scene.

let swiperight = UISwipeGestureRecognizer();

In the viewDidLoad() function

    swiperight.addTarget(self, action: #selector(GameScene.swipedRight));
    swiperight.direction = .right;
    self.view?.addGestureRecognizer(swiperight);

and then the function to be executed

@objc func swipedRight() {

    print("Object has been swiped right")

}

However, when I run my app and swipe right on the scene, nothing happens, there is no console output whatsoever.

I'm using swift 4, SpriteKit and Xcode 9.2. I'm running the app on my iPhone 6s running the latest non-beta IOS.

Upvotes: 1

Views: 1523

Answers (2)

Aleksandr
Aleksandr

Reputation: 563

Try conforming your SKScene to UIGestureRecognizerDelegate and setting the swiperight.delegate property to your scene. This will make sure that even though you are adding the gesture recognizer to you view, the handling of the gesture is "delegated" to your Scene.

Upvotes: 0

Cameron Porter
Cameron Porter

Reputation: 939

You should be presenting your scene like so:

Inside your viewcontroller, declare your scenes at the top E.G.

var mainMenu: MainMenu?

Override the viewDidLoad method and present your scene as so: (where your SKScene file is called MainMenu.sks)

override func viewDidLoad() {
     super.viewDidLoad()
     if let view = self.view as! SKView? {
        mainMenu = MainMenu(fileNamed: "MainMenu")
        mainMenu?.scaleMode = .fill
        view.presentScene(mainMenu)
     }
}

Make sure the scene your presenting is of type SKScene

import SpriteKit
import GameplayKit

class MainMenu: SKScene {

}

Make sure your viewControllers view is of type SKView. For example my storyboard looks like so.

enter image description here

After the scene is presented, set up your gesture recognizer in the didMoveTo method as this is called after the scene is presented which is what you want. Whereas viewDidLoad is called before the view is presented.

If you don't have an sks file then you will have to present your scene as:

 scene = MainMenu(size: (view.bounds.size))

and the scene you are presenting will have to look like:

class MainMenu: SKScene {
  required init?(coder aDecoder: NSCoder) {
      fatalError("init(coder) is not used in this app")
  }

  override init(size: CGSize) {
      super.init(size: size)
      anchorPoint = CGPoint(x: 0.5, y: 0.5)
      //Setup your sknodes in here.
  }

  override func didMove(to view: SKView) {
      let swipeRight = UISwipeGestureRecognizer(target: self, 
       action:#selector(swipedRight))
      swipeRight.direction = .right
      view.addGestureRecognizer(swipeRight)
  }

  @objc func swipedRight(sender:UISwipeGestureRecognizer){
      print("swiped right")
  }
}

Upvotes: 1

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