Setting up buttons in SKScene

Question

I'm discovering that UIButtons don't work very well with SKScene, So I'm attempting to subclass SKNode to make a button in SpriteKit.

The way I would like it to work is that if I initialize a button in SKScene and enable touch events, then the button will call a method in my SKScene when it is pressed.

I'd appreciate any advice that would lead me to finding the solution to this problem. Thanks.

Answer 1

For people writing their games in Swift! I have rewritten the essential parts of Graf's solution to a swift class. Hope it helps:

import Foundation
import SpriteKit

class FTButtonNode: SKSpriteNode {

    enum FTButtonActionType: Int {
        case TouchUpInside = 1,
        TouchDown, TouchUp
    }

    var isEnabled: Bool = true {
    didSet {
        if (disabledTexture != nil) {
            texture = isEnabled ? defaultTexture : disabledTexture
        }
    }
    }
    var isSelected: Bool = false {
    didSet {
        texture = isSelected ? selectedTexture : defaultTexture
    }
    }
    var defaultTexture: SKTexture
    var selectedTexture: SKTexture

    required init(coder: NSCoder) {
        fatalError("NSCoding not supported")
    }

    init(normalTexture defaultTexture: SKTexture!, selectedTexture:SKTexture!, disabledTexture: SKTexture?) {

        self.defaultTexture = defaultTexture
        self.selectedTexture = selectedTexture
        self.disabledTexture = disabledTexture

        super.init(texture: defaultTexture, color: UIColor.whiteColor(), size: defaultTexture.size())

        userInteractionEnabled = true

        // Adding this node as an empty layer. Without it the touch functions are not being called
        // The reason for this is unknown when this was implemented...?
        let bugFixLayerNode = SKSpriteNode(texture: nil, color: nil, size: defaultTexture.size())
        bugFixLayerNode.position = self.position
        addChild(bugFixLayerNode)

    }

    /**
    * Taking a target object and adding an action that is triggered by a button event.
    */
    func setButtonAction(target: AnyObject, triggerEvent event:FTButtonActionType, action:Selector) {

        switch (event) {
        case .TouchUpInside:
            targetTouchUpInside = target
            actionTouchUpInside = action
        case .TouchDown:
            targetTouchDown = target
            actionTouchDown = action
        case .TouchUp:
            targetTouchUp = target
            actionTouchUp = action
        }

    }

    var disabledTexture: SKTexture?
    var actionTouchUpInside: Selector?
    var actionTouchUp: Selector?
    var actionTouchDown: Selector?
    weak var targetTouchUpInside: AnyObject?
    weak var targetTouchUp: AnyObject?
    weak var targetTouchDown: AnyObject?

    override func touchesBegan(touches: NSSet!, withEvent event: UIEvent!)  {
        let touch: AnyObject! = touches.anyObject()
        let touchLocation = touch.locationInNode(parent)

        if (!isEnabled) {
            return
        }
        isSelected = true
        if (targetTouchDown != nil && targetTouchDown!.respondsToSelector(actionTouchDown!)) {
            UIApplication.sharedApplication().sendAction(actionTouchDown!, to: targetTouchDown, from: self, forEvent: nil)
        }


    }

    override func touchesMoved(touches: NSSet!, withEvent event: UIEvent!)  {

        if (!isEnabled) {
            return
        }

        let touch: AnyObject! = touches.anyObject()
        let touchLocation = touch.locationInNode(parent)

        if (CGRectContainsPoint(frame, touchLocation)) {
            isSelected = true
        } else {
            isSelected = false
        }

    }

    override func touchesEnded(touches: NSSet!, withEvent event: UIEvent!) {

        if (!isEnabled) {
            return
        }

        isSelected = false

        if (targetTouchUpInside != nil && targetTouchUpInside!.respondsToSelector(actionTouchUpInside!)) {
            let touch: AnyObject! = touches.anyObject()
            let touchLocation = touch.locationInNode(parent)

            if (CGRectContainsPoint(frame, touchLocation) ) {
                UIApplication.sharedApplication().sendAction(actionTouchUpInside!, to: targetTouchUpInside, from: self, forEvent: nil)
            }

        }

        if (targetTouchUp != nil && targetTouchUp!.respondsToSelector(actionTouchUp!)) {
            UIApplication.sharedApplication().sendAction(actionTouchUp!, to: targetTouchUp, from: self, forEvent: nil)
        }
    }

}

Answer 2

I wasn't convinced of any of the above options, so based on the latest Swift4 I created my own solution.

Answer 3

Here's another version based on Filip's Swift code. I've just simplified it a little and allowed it to take blocks rather than only selectors :

import Foundation
import SpriteKit

enum FTButtonTarget {
    case aSelector(Selector, AnyObject)
    case aBlock(() -> Void)
}

class FTButtonNode: SKSpriteNode {

    var actionTouchUp : FTButtonTarget?
    var actionTouchUpInside : FTButtonTarget?
    var actionTouchDown : FTButtonTarget?

    var isEnabled: Bool = true {
        didSet {
            if (disabledTexture != nil) {
                texture = isEnabled ? defaultTexture : disabledTexture
            }
        }
    }
    var isSelected: Bool = false {
        didSet {
            texture = isSelected ? selectedTexture : defaultTexture
        }
    }

    var defaultTexture: SKTexture
    var selectedTexture: SKTexture

    required init(coder: NSCoder) {
        fatalError("NSCoding not supported")
    }

init(normalTexture defaultTexture: SKTexture!, selectedTexture:SKTexture!, disabledTexture: SKTexture?) {

    self.defaultTexture = defaultTexture
    self.selectedTexture = selectedTexture
    self.disabledTexture = disabledTexture

    super.init(texture: defaultTexture, color: UIColor.whiteColor(), size: defaultTexture.size())

    userInteractionEnabled = true

    // Adding this node as an empty layer. Without it the touch functions are not being called
    // The reason for this is unknown when this was implemented...?
    let bugFixLayerNode = SKSpriteNode(texture: nil, color: nil, size: defaultTexture.size())
    bugFixLayerNode.position = self.position
    addChild(bugFixLayerNode)

}

var disabledTexture: SKTexture?

func callTarget(buttonTarget:FTButtonTarget) {

    switch buttonTarget {
    case let .aSelector(selector, target):
        if target.respondsToSelector(selector) {
            UIApplication.sharedApplication().sendAction(selector, to: target, from: self, forEvent: nil)
        }
    case let .aBlock(block):
        block()
    }

}

override func touchesBegan(touches: NSSet, withEvent event: UIEvent)  {
    let touch: AnyObject! = touches.anyObject()
    let touchLocation = touch.locationInNode(parent)

    if (!isEnabled) {
        return
    }
    isSelected = true

    if let act = actionTouchDown {
        callTarget(act)
    }

}

override func touchesMoved(touches: NSSet, withEvent event: UIEvent)  {

    if (!isEnabled) {
        return
    }

    let touch: AnyObject! = touches.anyObject()
    let touchLocation = touch.locationInNode(parent)

    if (CGRectContainsPoint(frame, touchLocation)) {
        isSelected = true
    } else {
        isSelected = false
    }

}

 override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {

     if (!isEnabled) {
         return
     }

     isSelected = false

     let touch: AnyObject! = touches.anyObject()
     let touchLocation = touch.locationInNode(parent)

     if (CGRectContainsPoint(frame, touchLocation) ) {

         if let act = actionTouchUpInside {
             callTarget(act)
         }
     }

     if let act = actionTouchUp {
         callTarget(act)
     }
 }
}

Use it like this :

       aFTButton.actionTouchUpInside = FTButtonTarget.aBlock({ () -> Void in
        println("button touched")
    })

Hope this helps.

Answer 4

Unfortunately SpriteKit does not have button node, I do not know why, because it is very useful control. So I decided to create my own and share via CocoaPods, please use it OOButtonNode. Buttons can use text/background or images, written in Swift 4.

Answer 5

Edit: I've made a github repo for my SKButtonNode that I'll hopefully be keeping current and updating as swift evolves!

SKButtonNode

---

Unfortunately I cannot comment yet on Filip's swift implementation of SKButton in Swift. Super happy that he made this in Swift! But, I noticed that he didn't include a function to add text to the button. This is a huge feature to me, so that you don't have to create separate assets for every single button, rather just the background and add dynamic text.

I added a simple function to add a text label to SKButton. It likely isn't perfect--I'm new to Swift just like everyone else! Feel free to comment and help me update this to the best it can be. Hope you guys like!

 //Define label with the textures
 var defaultTexture: SKTexture
 var selectedTexture: SKTexture

 //New defining of label
 var label: SKLabelNode

 //Updated init() function:

 init(normalTexture defaultTexture: SKTexture!, selectedTexture:SKTexture!, disabledTexture: SKTexture?) {

    self.defaultTexture = defaultTexture
    self.selectedTexture = selectedTexture
    self.disabledTexture = disabledTexture

    //New initialization of label
    self.label = SKLabelNode(fontNamed: "Helvetica");

    super.init(texture: defaultTexture, color: UIColor.whiteColor(), size: defaultTexture.size())
    userInteractionEnabled = true

    //Creating and adding a blank label, centered on the button
    self.label.verticalAlignmentMode = SKLabelVerticalAlignmentMode.Center;
    self.label.horizontalAlignmentMode = SKLabelHorizontalAlignmentMode.Center;
    addChild(self.label)

    // Adding this node as an empty layer. Without it the touch functions are not being called
    // The reason for this is unknown when this was implemented...?
    let bugFixLayerNode = SKSpriteNode(texture: nil, color: nil, size: defaultTexture.size())
    bugFixLayerNode.position = self.position
    addChild(bugFixLayerNode)

  }




    /*
      New function for setting text. Calling function multiple times does 
      not create a ton of new labels, just updates existing label.
      You can set the title, font type and font size with this function
    */

    func setButtonLabel(#title: NSString, font: String, fontSize: CGFloat) {
        var title = title
        var font = font
        var fontSize = fontSize

        self.label.text = title
        self.label.fontSize = fontSize
        self.label.fontName = font        
     } 

Sample creation of button:

    var buttonTexture = SKTexture(imageNamed: "Button");
    var buttonPressedTexture = SKTexture(imageNamed: "Button Pressed");
    var button = SKButton(normalTexture:buttonTexture, selectedTexture:buttonPressedTexture, disabledTexture:buttonPressedTexture);
    button.setButtonLabel(title: "Play",font: "Helvetica",fontSize: 40);
    button.position = CGPointMake(self.frame.size.width/2, self.frame.size.height/2);
    self.addChild(button);

Full Class Listed Below:

import Foundation
import SpriteKit


class SKButton: SKSpriteNode {




enum FTButtonActionType: Int {
    case TouchUpInside = 1,
    TouchDown, TouchUp
}

var isEnabled: Bool = true {
    didSet {
        if (disabledTexture != nil) {
            texture = isEnabled ? defaultTexture : disabledTexture
        }
    }
}
var isSelected: Bool = false {
    didSet {
        texture = isSelected ? selectedTexture : defaultTexture
    }
}
var defaultTexture: SKTexture
var selectedTexture: SKTexture
var label: SKLabelNode


required init(coder: NSCoder) {
    fatalError("NSCoding not supported")
}

init(normalTexture defaultTexture: SKTexture!, selectedTexture:SKTexture!, disabledTexture: SKTexture?) {

    self.defaultTexture = defaultTexture
    self.selectedTexture = selectedTexture
    self.disabledTexture = disabledTexture
    self.label = SKLabelNode(fontNamed: "Helvetica");
    super.init(texture: defaultTexture, color: UIColor.whiteColor(), size: defaultTexture.size())
    userInteractionEnabled = true


    self.label.verticalAlignmentMode = SKLabelVerticalAlignmentMode.Center;
    self.label.horizontalAlignmentMode = SKLabelHorizontalAlignmentMode.Center;
    addChild(self.label)

    // Adding this node as an empty layer. Without it the touch functions are not being called
    // The reason for this is unknown when this was implemented...?
    let bugFixLayerNode = SKSpriteNode(texture: nil, color: nil, size: defaultTexture.size())
    bugFixLayerNode.position = self.position
    addChild(bugFixLayerNode)

}

/**
* Taking a target object and adding an action that is triggered by a button event.
*/
func setButtonAction(target: AnyObject, triggerEvent event:FTButtonActionType, action:Selector) {

    switch (event) {
    case .TouchUpInside:
        targetTouchUpInside = target
        actionTouchUpInside = action
    case .TouchDown:
        targetTouchDown = target
        actionTouchDown = action
    case .TouchUp:
        targetTouchUp = target
        actionTouchUp = action
    }

}


func setButtonLabel(#title: NSString, font: String, fontSize: CGFloat) {
    var title = title;
    var font = font;
    var fontSize = fontSize;

    self.label.text = title;
    self.label.fontSize = fontSize;
    self.label.fontName = font;

}

var disabledTexture: SKTexture?
var actionTouchUpInside: Selector?
var actionTouchUp: Selector?
var actionTouchDown: Selector?
weak var targetTouchUpInside: AnyObject?
weak var targetTouchUp: AnyObject?
weak var targetTouchDown: AnyObject?

override func touchesBegan(touches: NSSet!, withEvent event: UIEvent!)  {
    let touch: AnyObject! = touches.anyObject()
    let touchLocation = touch.locationInNode(parent)

    if (!isEnabled) {
        return
    }
    isSelected = true
    if (targetTouchDown != nil && targetTouchDown!.respondsToSelector(actionTouchDown!)) {
        UIApplication.sharedApplication().sendAction(actionTouchDown!, to: targetTouchDown, from: self, forEvent: nil)
    }


}

override func touchesMoved(touches: NSSet!, withEvent event: UIEvent!)  {

    if (!isEnabled) {
        return
    }

    let touch: AnyObject! = touches.anyObject()
    let touchLocation = touch.locationInNode(parent)

    if (CGRectContainsPoint(frame, touchLocation)) {
        isSelected = true
    } else {
        isSelected = false
    }

}

override func touchesEnded(touches: NSSet!, withEvent event: UIEvent!) {

    if (!isEnabled) {
        return
    }

    isSelected = false

    if (targetTouchUpInside != nil && targetTouchUpInside!.respondsToSelector(actionTouchUpInside!)) {
        let touch: AnyObject! = touches.anyObject()
        let touchLocation = touch.locationInNode(parent)

        if (CGRectContainsPoint(frame, touchLocation) ) {
            UIApplication.sharedApplication().sendAction(actionTouchUpInside!, to: targetTouchUpInside, from: self, forEvent: nil)
        }

    }

    if (targetTouchUp != nil && targetTouchUp!.respondsToSelector(actionTouchUp!)) {
        UIApplication.sharedApplication().sendAction(actionTouchUp!, to: targetTouchUp, from: self, forEvent: nil)
    }
}

}