How to loop a dynamically delayed sequence of SKActions - swift

Question

I need to run an unknown amount (from an Array of Dictionaries) of SKAction sequences that are dynamically created and offset in a loop using a delay that increases as I go through the loop. printed output of the loop should appear in the following order
show line 5
hiding everything
show line 6
hiding everything
show line 2
hiding everything
to obtain this functionality I use this code
func display(winningLines: [Int : AnyObject]) {
var delay = 0.0
var actions = [SKAction]()
let hideAction = SKAction.run {
print("hiding everything")
}
for winningLine in winningLines {
let displayAction = SKAction.run {
print("line \(winningLine.key)")
}
let wait = SKAction.wait(forDuration: delay)
var action: SKAction!
//repeatForever = true
if !repeatForever {
action = SKAction.sequence([wait, displayAction, SKAction.wait(forDuration: 1.0), hideAction])
}
else {
let seq = SKAction.sequence([wait, displayAction, SKAction.wait(forDuration: 1.0), hideAction])
action = SKAction.repeatForever(seq)
}
self.run(action)
delay += 1.0
}
}
If the sequence only needs to occur once than it outputs as expected, however there are times that I need the sequence to just keep repeating forever (until the user stops the action). Putting a repeat forever around the action doesn't work because it repeats each individual sequence and messes up the order. The first sequence will repeat every 1 second, the second sequence will repeat every 2 seconds...etc.
Any suggestions on how to get this to loop properly forever?
line 5
hiding everything
line 5
line 6
hiding everything
line 5
hiding everything
line 2
hiding everything
line 5
line 6
hiding everything
hiding everything
line 5
hiding everything
hiding everything
line 5
line 6
line 2
hiding everything
line 5
hiding everything
hiding everything
I've also tried appending the actions to an Array of SKActions and looping through them at the end but it didn't work
var actions = [SKAction]()
...
actions.append(action)
for action in actions {
self.run(action)
}

Answer 1

If your only concern is to repeat forever, the unknown amount of sequences, you can do the following:
create all required sequences
put them in another sequence
loop that forever
So for example, this code will create four boxes, and will apply fade in/out (displayAction/hideAction from your code) sequentially to every box, and will repeat that forever:
import SpriteKit
class GameScene: SKScene {
var boxes:[SKSpriteNode] = []
override func didMove(to view: SKView) {
let distance:CGFloat = 10
for i in 0...3 {
let box = SKSpriteNode(color: .purple, size: CGSize(width: 50, height: 50))
box.name = String(i) //name == index
box.position.x = CGFloat(i) * (box.size.width + distance)
box.alpha = 0.0
addChild(box)
boxes.append(box)
}
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
var actions:[SKAction] = []
let action = SKAction.sequence([
SKAction.fadeIn(withDuration: TimeInterval(1)),
SKAction.fadeOut(withDuration: 0),
])
for index in 0...boxes.count {
let sequence = SKAction.sequence([
SKAction.run(action, onChildWithName: String(index)),
SKAction.wait(forDuration: 1)
])
actions.append(sequence)
}
self.run(SKAction.repeatForever(SKAction.sequence(actions)))
}
}