How to observe AVCaptureDevice.isCenterStageEnabled?

There is a great article about Using Key-Value Observing in Swift.

I recommend starting with that article, and then posting back here if you are still having issues observing the center stage enabled property.

@gchiste I already tried the following code but compiler gives errors saying it can not observe a class property.

 AVCaptureDevice.observe(\.isCenterStageEnabled, options: [.new, .old]) { controller, value in

            NSLog("Value \(value)")

        }

Instance member 'observe' cannot be used on type 'AVCaptureDevice'; did you mean to use a value of this type instead?

Hey,

Thanks for reading over the article, I see now that it doesn't cover the case of a class property.

Give something like this a try:

// Add some NSObject (probably a UIViewController) as an observer of the class property, specifying the options you'd like.

AVCaptureDevice.self.addObserver(self, forKeyPath: "centerStageEnabled", options: [.initial, .new], context: nil)

// Override observeValue on your object and handle any values that you expect it to be observing.

override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

        

        if keyPath == "centerStageEnabled" {

            guard let object = object as? AVCaptureDevice.Type else { return }

            print(object.isCenterStageEnabled)

        } else {

            super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)

        }

    }