Flow Control in Swift - AVAudioPlayer - ios

Question

I wrote an Iphone Swift app that plays a series of sounds in a random order using AVAudioPlayer-- for now a pop sound, a horn sound and a gong. It works when you hit the play button, except....
However, when I hit the stop button nothing happens- it doesn't respond (The stop does work if I have just one sound). I believe it is due to my flow control. If I did not put in the 'while soundPlayer.playing == true {}', the code would "fly" through the sound and not wait for it to finish.
How can I modify the code so the the sound plays to completion before going to the next sound? And also allow the stop button to be functional? See Code and screen shot below. (Actually Stack overflow will not allow me to post an image since I am so new)
//
// ViewController.swift
// InsultSchool2 Swift
//
// Created by JR on 12/3/14.
// Copyright (c) 2014 JR. All rights reserved.
//
import UIKit
import AVFoundation
//---------------------------------------------------
var soundPlayer:AVAudioPlayer = AVAudioPlayer()
// used to try to do some kind of flow control. May not be needed if better way is found.
var stopFlag:Bool = false
//-----------------------------------------------------
class ViewController: UIViewController {
#IBOutlet weak var valueSliderTime: UISlider!
#IBOutlet weak var valueLabelTime: UILabel!
#IBOutlet weak var valueStepperVolume: UIStepper!
#IBOutlet weak var valueLabelVolume: UILabel!
//------------------------------------------------------
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
//Displays an initial Volume value in volume label on load
//Convert to an int. Otherwise you get a weird value when getting close to zero
//Multiply by 10 so the int works. Otherwise you would int'ing a number between 0.0 and 1.0.
// "\()" is a shorthand to convert whatever to a string
valueLabelVolume.text = "\(Int(valueStepperVolume.value * 10))"
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
//------------------------------------------------------
#IBAction func buttonStop(sender: UIBarButtonItem) {
NSLog("Enter Button Stop")
//?1 If a sound is not playing and stop is hit, then it crashes
//?2 the stop button does not work with the whlle loop below
soundPlayer.stop()
}
#IBAction func sliderTime(sender: UISlider) {
valueLabelTime.text = "\(Int(valueSliderTime.value))"
}
#IBAction func stepperVolume(sender: UIStepper) {
//Converted to an int. Otherwise you get a weird value when getting close to zero
valueLabelVolume.text = "\(Int(valueStepperVolume.value * 10))"
}
#IBAction func buttonPlay(sender: UIBarButtonItem) {
NSLog("Enter Button Start")
var soundArray:[String] = ["Sound0", "Sound1", "Sound2"]
// Randomizes a number to indicate which random sound to play in the array
/* Number is from 0 to number in the (). Don't add one or 0 will never play. Go one more than the numbers in the array. For example if you have 3 items in the array go to 3. THis will go from 0 to 2 (ie., 3 items)*/
// Reference----- var soundRandomNumber:Int = Int(arc4random_uniform(3))
var soundRandomNumber:Int
soundRandomNumber = Int(arc4random_uniform(3))
//Creates a random number to wait between sounds based on the slider value.
//arc4random requires a UInt32 (Unsigned is a positive number).
//_uniform is slightly more random than without the Uniform
//The documentation says to use Int otherwise.
println(Int(valueSliderTime.value))
NSLog("valueSliderTime.value")
var waitTimeRandomNumber = Int(arc4random_uniform(UInt32(valueSliderTime.value)))
println(waitTimeRandomNumber)
NSLog("waitTimeRandomNumber")
// Constructs a string with the random number for the URL
//var soundFile:String = soundArray[soundRandomNumber]
var soundFile:String
soundFile = soundArray[soundRandomNumber]
//Reference---- var soundURL = NSBundle.mainBundle().URLForResource(soundFile, withExtension:"mp3")
var soundURL:NSURL!
soundURL = NSBundle.mainBundle().URLForResource(soundFile, withExtension:"mp3")
soundPlayer = AVAudioPlayer(contentsOfURL: soundURL, error: nil)
//?3 How do I set up a loop or control that works until the stop button is pressed?
while stopFlag == false{
NSLog("inside while")
println(stopFlag)
//?4 Is the below correct? The actual volume does not seem to change though the .volume does
soundPlayer.volume = Float(valueStepperVolume.value)
println(Float(valueStepperVolume.value))
NSLog("Float(valueStepperVolume.value)")
println(soundPlayer.volume)
NSLog("soundPlayer.volume")
soundRandomNumber = Int(arc4random_uniform(3))
soundFile = soundArray[soundRandomNumber]
soundURL = NSBundle.mainBundle().URLForResource(soundFile, withExtension:"mp3")
soundPlayer = AVAudioPlayer(contentsOfURL: soundURL, error: nil)
soundPlayer.prepareToPlay()
soundPlayer.play()
//?5 How do I make the player not blow through the sound and wait until is finished
while soundPlayer.playing == true {
}
//?6 How can i make a random timer that waits for a random time before relooping?
waitTimeRandomNumber = Int(arc4random_uniform(UInt32(valueSliderTime.value)))
}// End of while loop
} //ends playButton IBAction
//?7 How to allow this app to play over other music in another player
}

Answer 1

use the repeat while statement instead to control the flow:
here is a link to apple's developers reference:
https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/ControlFlow.html
repeat {
// move up or down for a snake or ladder
square += board[square]
// roll the dice
if ++diceRoll == 7 { diceRoll = 1 }
// move by the rolled amount
square += diceRoll
} while square < finalSquare
print("Game over!")