How to detect volume button press on tvOS remote

Question

Im trying to find a way to observe the player so that I can detect when a user increases or decreases the volume on the Apple TV. I have managed to get this to work for iOS by using:

 var audioSession: AVAudioSession?

 audioSession?.addObserver(self, forKeyPath: "outputVolume", options: [.new], context: &videoPlayerViewControllerKVOContext)


 if keyPath == "outputVolume" {
        guard let mute = (change?[NSKeyValueChangeKey.newKey] as? NSNumber)?.floatValue else {
            return
        }
        
        var isMuted = false
        
        if (mute == 0) && (!player.isMuted) {
            isMuted = true
        } else if (mute.isZero) && (player.isMuted) {
            isMuted = false
        }
        
    }

However this doesn't work for tvOS. Is there a way to do this on tvOS?

Answer 1

It is not clear all other code, but you have to keep reference to created observer.

Here is possible solution (tested with Xcode 12.1)

private var observer: NSKeyValueObservation?

// ... other code

self.observer = audioSession?.observe(\.outputVolume) { [weak self] (audioSession, _) in
    guard let `self` = self else { return }
    let mute = audioSession.outputVolume
    
    var isMuted = false
    if (mute == 0) && (!self.player.isMuted) {
        isMuted = true
    } else if (mute.isZero) && (self.player.isMuted) {
        isMuted = false
    }
    
    // do what's needed here with `isMuted`
}