How to synchronize textures animation and sound in SpriteKit - ios

Question

I'm creating a RPGGameKit using SpriteKit to help me develop my iOS games. Now that my player can move, I added animations and an audio system.
I ran on a problem to synchronize textures and sounds. Like a step when my player walk.
let atlas = SKTextureAtlas(named: "Walk")
let textures = atlas.getTextures() // I created an extension that returns textures of atlas
let walkingAnimation = SKAction.animate(with: textures, timePerFrame: 1)
So, walkingAnimation will loop through textures and change it every 1 second.
Now, I want to play a walking sound when the texture changes.
I have look at SKAction and SpriteKit documentation but there is no callback for this SKAction.
If you want to try to get this done with me or you have ideas of how to do it, please leave a comment.
Thanks :)

Answer 1

Try this:
let frame1 = SKAction.setTexture(yourTexture1)
let frame2 = SKAction.setTexture(yourTexture2)
let frame3 = SKAction.setTexture(yourTexture3)
//etc
let sound = SKAction.playSoundFileNamed("soundName", waitForCompletion: false)
let oneSecond = SKAction.wait(forDuration: 1)
let sequence = SKAction.sequence([frame1,sound,oneSecond,frame2,sound,oneSecond,frame3,sound,oneSecond])
node.run(sequence)

Answer 2

So, for now I'm going to do it like this :
let textures = SKTextureAtlas(named: "LeftStep").getTextures()
var actions = [SKAction]()
for texture in textures {
let group = SKAction.group([
SKAction.setTexture(texture),
SKAction.playSoundFileNamed("Step.mp3", waitForCompletion: false)
])
let sequence = SKAction.sequence([
group,
SKAction.wait(forDuration: 0.5)
])
actions.append(sequence)
}
self.node.run(SKAction.repeatForever(SKAction.sequence(actions)))
Thanks #StefanOvomate

Answer 3

I've found myself in the same situation, currently I'm doing the below. From what I have read in the documentation and seen online, the only way to do it is to create the audio file length to match one rotation of the texture animation.
let walkAtlas = global.playerWalkAtlas
var walkFrames: [SKTexture] = []
let numImages = walkAtlas.textureNames.count
for i in 1...numImages {
let texture = "walk\(i)"
walkFrames.append(walkAtlas.textureNamed(texture))
}
walking = walkFrames
isWalking = true
animateMove()
}
func animateMove(){
let animateWalk = SKAction.animate(with: walking, timePerFrame: 0.05)
let soundWalk = global.playSound(sound: .walkSound)
let sequence = SKAction.sequence([soundWalk, animateWalk])
self.run(SKAction.repeatForever(sequence),withKey: "isMoving")
}
func stopMoving(){
self.removeAction(forKey: "isMoving")
isWalking = false
}