Multiple Delays in Swift - ios

Question

I'm working on a simple card game, in which after a player presses a button, three AI computers will take their turns one after another. However, I need there to be a pause between each turn.
This is what I need:
playerButton > PAUSE > computer1Goes > PAUSE > computer2Goes > PAUSE > computer3Goes
Code:
#IBAction func placeCardAction(sender: UIButton) {
// playerButton does this action
var playerCardOnTop = game!.player.deck.placeCard()
middleDeck.addSingleCard(playerCardOnTop)
updateCardCount()
// Start computer actions
let delay = 2.0 * Double(NSEC_PER_SEC)
let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
dispatch_after(time, dispatch_get_main_queue()) {
self.game?.computer1PlacesCard(&self.middleDeck)
self.updateCardCount()
}
let delay2 = 2.0 * Double(NSEC_PER_SEC)
let time2 = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
dispatch_after(time2, dispatch_get_main_queue()) {
self.game?.computer2PlacesCard(&self.middleDeck)
self.updateCardCount()
}
let delay3 = 2.0 * Double(NSEC_PER_SEC)
let time3 = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
dispatch_after(time3, dispatch_get_main_queue()) {
self.game?.computer3PlacesCard(&self.middleDeck)
self.updateCardCount()
}
}
Unfortunately, all the delays start/end at the same time, so what ends up happening is that all of the computer functions run at the same time instead of taking turns, one after another.
If anyone can help solve this problem, I would appreciate it!

Answer 1

Easiest solution.... change delay2 to 4 and delay3 to 6. As it stands right now, of course they all go off at the same time, the all have the same delay.
Alternatively, stack them like:
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(delay))) {
// step one
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(delay))) {
// step two
...
}
}

Answer 2

I suggest using array of Computer objects which can perform placeCard function
#IBAction func placeCardAction(sender: UIButton) {
// playerButton does this action
var playerCardOnTop = game!.player.deck.placeCard()
middleDeck.addSingleCard(playerCardOnTop)
updateCardCount()
self.computersPlaceCards(0)
}
private func computersPlaceCards(i: Int) {
if self.game == nil || i >= self.game!.computers.count {
return
}
let delay = 2.0 * Double(NSEC_PER_SEC)
let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
dispatch_after(time, dispatch_get_main_queue()) {
self.game?.computers[i].placeCards(&self.middleDeck)
self.updateCardCount()
self.computersPlaceCards(i+1)
}
}

Answer 3

You can use sleep() inside a dispatch_async:
dispatch_async( dispatch_get_global_queue( QOS_CLASS_USER_INTERACTIVE, 0 ) ) {
dispatch_async(dispatch_get_main_queue()) {
print("first")
}
sleep(1)
dispatch_async(dispatch_get_main_queue()) {
print("second")
}
sleep(1)
dispatch_async(dispatch_get_main_queue()) {
print("third")
}
sleep(1)
dispatch_async(dispatch_get_main_queue()) {
print("fourth")
}
}
(My answer previously used NSOperationQueue--either will work)