How to create a vertical scrolling menu in spritekit?

Question

I\'m looking to create a shop in my game (In SpriteKit) with buttons and images, but I need the items to be scrollable so the player can scroll up and down the shop (Like a

Answer 1

Here's the code we used to simulate UIScrollView behavior for SpriteKit menus.

Basically, you need to use a dummy UIView that matches the height of the SKScene then feed UIScrollView scroll and tap events to the SKScene for processing.

It's frustrating Apple doesn't provide this natively, but hopefully no one else has to waste time rebuilding this functionality!

class ScrollViewController: UIViewController, UIScrollViewDelegate {
    // IB Outlets
    @IBOutlet weak var scrollView: UIScrollView!

    // General Vars
    var scene = ScrollScene()

    // =======================================================================================================
    // MARK: Public Functions
    // =======================================================================================================
    override func viewDidLoad() {
        // Call super
        super.viewDidLoad()

        // Create scene
        scene = ScrollScene()

        // Allow other overlays to get presented
        definesPresentationContext = true

        // Create content view for scrolling since SKViews vanish with height > ~2048
        let contentHeight = scene.getScrollHeight()
        let contentFrame = CGRect(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: contentHeight)
        let contentView = UIView(frame: contentFrame)
        contentView.backgroundColor = UIColor.clear

        // Create SKView with same frame as , must manually compute because  frame not ready at this point
        let scrollViewPosY = CGFloat(0)
        let scrollViewHeight = UIScreen.main.bounds.size.height - scrollViewPosY
        let scrollViewFrame = CGRect(x: 0, y: scrollViewPosY, width: UIScreen.main.bounds.size.width, height: scrollViewHeight)
        let skView = SKView(frame: scrollViewFrame)
        view.insertSubview(skView, at: 0)

        // Configure 
        scrollView.addSubview(contentView)
        scrollView.delegate = self
        scrollView.contentSize = contentFrame.size

        // Present scene
        skView.presentScene(scene)

        // Handle taps on 
        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(scrollViewDidTap))
        scrollView.addGestureRecognizer(tapGesture)
    }

    // =======================================================================================================
    // MARK: UIScrollViewDelegate Functions
    // =======================================================================================================
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        scene.scrollBy(contentOffset: scrollView.contentOffset.y)
    }


    // =======================================================================================================
    // MARK: Gesture Functions
    // =======================================================================================================
    @objc func scrollViewDidTap(_ sender: UITapGestureRecognizer) {
        let scrollViewPoint = sender.location(in: sender.view!)
        scene.viewDidTapPoint(viewPoint: scrollViewPoint, contentOffset: scrollView.contentOffset.y)
    }
}



class ScrollScene : SKScene {
    // Layer Vars
    let scrollLayer = SKNode()

    // General Vars
    var originalPosY = CGFloat(0)


    // ================================================================================================
    // MARK: Initializers
    // ================================================================================================
    override init() {
        super.init()
    }


    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }


    // ================================================================================================
    // MARK: Public Functions
    // ================================================================================================
    func scrollBy(contentOffset: CGFloat) {
        scrollLayer.position.y = originalPosY + contentOffset
    }


    func viewDidTapPoint(viewPoint: CGPoint, contentOffset: CGFloat) {
        let nodes = getNodesTouchedFromView(point: viewPoint, contentOffset: contentOffset)
    }


    func getScrollHeight() -> CGFloat {
        return scrollLayer.calculateAccumulatedFrame().height
    }


    fileprivate func getNodesTouchedFromView(point: CGPoint, contentOffset: CGFloat) -> [SKNode] {
        var scenePoint = convertPoint(fromView: point)
        scenePoint.y += contentOffset
        return scrollLayer.nodes(at: scenePoint)
    }
}