CODEWITHSUNDEEP
iosswiftsklabelnode
Michael Voline
Michael Voline

Reputation: 383

IOS Swift SpriteKit SKLabel, animate appearance of text

I want to to animate appearance of Label's text so that it looks like it is being typed in at the moment. I was wondering if there is a relatively easy way to do so in SWIFT. Thank you.

Upvotes: 3

Views: 1707

Answers (2)

Burro
Burro

Reputation: 63

I would suggest you use SKAction.wait(forDuration:) instead of timer

extension SKLabelNode{
    func startTyping(_ duration:TimeInterval, completion:(()->Void)?){
        guard let text = self.text else{return}

        self.text = ""
        var index = 0
        var block:(() -> Void)!
        block = {
            index += 1
            if index > text.count{
                completion?()
                return
            }else{
                let action = SKAction.sequence([SKAction.wait(forDuration: duration), SKAction.run{self.text = String(text.prefix(index))}])
                self.run(action, completion: block)
            }
        }
        block()
    }
}

If you want to get a type writer look, set the horizontal alignment in advance

label.horizontalAlignmentMode = .left

Upvotes: 3

Wes
Wes

Reputation: 1042

Try this:

class GameScene : SKScene {

    let text = ["G", "a", "m", "e"]

    var labelText = ""

    let labelNode = SKLabelNode()

    var calls : Int = 0

    var timer : NSTimer!

    override func didMoveToView(view: SKView) {

        timer = NSTimer.scheduledTimerWithTimeInterval(YOUR_DESIRED_INTERVAL, target: self, selector: #selector(self.updateLabelText), userInfo: nil, repeats: true)

        labelNode.text = labelText
        self.addChild(labelNode)
    }


    func updateLabelText() {

        labelText += text[calls]
        labelNode.text = labelText
        calls += 1

        if calls == text.count + 1 {
            timer.invalidate()
    }
}

Upvotes: 3

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