playing sound while button is pressed

[lucatorella]

While the volume button is pressed, if some conditions are met I'd like to play a sound. Unfortunately the sound often is kind of cut of. It is quite easy to reproduce, while the volume button is pressed, play a sound AudioServicesPlaySystemSound(self.beepSound). Is it happening because of the other audio session going on? Any idea how to solve it?

[lucatorella]

I include the code to reproduce the issue:

import UIKit
import MediaPlayer

class ViewController: UIViewController {

    private var beepSound: SystemSoundID = 0
    private var volumeButtonHandler: JPSVolumeButtonHandler?

    override func viewDidLoad() {
        super.viewDidLoad()

        if let URL = NSBundle.mainBundle().URLForResource("beep", withExtension: "wav") {
            AudioServicesCreateSystemSoundID(URL, &beepSound)
        }

        volumeButtonHack()
    }

    private func volumeButtonHack() {
        let block = { [unowned self] () -> Void in
            AudioServicesPlaySystemSound(self.beepSound)
        }
        volumeButtonHandler = JPSVolumeButtonHandler(upBlock: block, downBlock: block)
    }
}

[lucatorella]

Actually it's much easier to reproduce:

    private func volumeButtonHack() {
        let block = { [unowned self] () -> Void in
            let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC)))
            dispatch_after(delayTime, dispatch_get_main_queue()) {
                AudioServicesPlaySystemSound(self.beepSound)
            }
        }
        volumeButtonHandler = JPSVolumeButtonHandler(upBlock: block, downBlock: block)
    }

the solution is to use AVAudioPlayer instead of AudioServicesPlaySystemSound to play the sound. So this snippet works:

    override func viewDidLoad() {
            ...
            player = try! AVAudioPlayer(contentsOfURL: URL)
    }

    private func volumeButtonHack() {
        let block = { [unowned self] () -> Void in
            let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC)))
            dispatch_after(delayTime, dispatch_get_main_queue()) {
                self.player.play()
            }
        }
        volumeButtonHandler = JPSVolumeButtonHandler(upBlock: block, downBlock: block)
    }