如何在 Swift 中使用 AVPlayerViewController 检测全屏模式？

Question

I am trying to detect when the AVPlayerViewController is in full-screen mode, but I'm having a difficult time achieving this. I'd like to know when the user selects the expand button to enter full screen as shown here:

I've added the appropriate observer per these suggestions:

1. Detect Video playing full screen in Portrait or landscape
2. How to detect fullscreen mode of AVPlayerViewController

The appropriate code:

var avWidth:CGFloat = 375
var avHeight:CGFloat = 300

override func viewDidLoad()
{
    super.viewDidLoad()

    let path = NSBundle.mainBundle().pathForResource("cable pressback", ofType: "mp4")
    let url = NSURL.fileURLWithPath(path!)
    let player = AVPlayer(URL: url)

    playerViewController.player = player

    playerViewController.view.frame = CGRectMake(0, 100, self.view.frame.size.width, 300)

    playerViewController.view.translatesAutoresizingMaskIntoConstraints = true

    view.addSubview(playerViewController.view)

    self.addChildViewController(playerViewController)

    [playerViewController .addObserver(self, forKeyPath:"videoBounds" , options: NSKeyValueObservingOptions.New, context: nil)]

}

override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>)
{
    print("playerViewController.view.frame = \(playerViewController.view.frame)")

    if keyPath == "videoBounds"
    {
        let rect = change!["new"]! as! NSValue

        if let newrect = rect.CGRectValue() as CGRect?
        {
            if newrect.width > 0 || newrect.height > 0
            {
                if avWidth > 0 || avHeight > 0
                {
                    if newrect.width > avWidth || newrect.height > avHeight
                    {
                        print("Full Screen")
                    }
                    else if newrect.width < avWidth || newrect.height < avHeight
                    {
                        print("Normal screen")
                    }
                }
                avWidth = newrect.width
                avHeight = newrect.height
            }
        }
    }
}

However, it never seems to reach the code print("Full Screen") . It's hitting print("Normal Screen") regardless of whether the player is in normal or full screen mode.

Thanks!

Answer 1

Starting from iOS 12 we can use these AVPlayerViewControllerDelegate delegate methods :

func playerViewController(AVPlayerViewController, willBeginFullScreenPresentationWithAnimationCoordinator: UIViewControllerTransitionCoordinator)
func playerViewController(AVPlayerViewController, willEndFullScreenPresentationWithAnimationCoordinator: UIViewControllerTransitionCoordinator)

Answer 2

Updated for Swift 3 :

Add an observer for the playerViewController object:

playerViewController(self, forKeyPath: "videoBounds", options: NSKeyValueObservingOptions.new, context: nil)

override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?)
{
    if keyPath == "videoBounds"
    {
        if let rect = change?[.newKey] as? NSValue
        {
            if let newrect = rect.cgRectValue as CGRect?
            {
                // 200 is height of playerViewController in normal screen mode
                if newrect.size.height <= 200
                {
                    print("normal screen")
                }
                else
                {
                    print("full screen")
                }
            }
        }
    }
}

Answer 3

Your code helped me handle switching between full screen and back.

But for the identification part, I just changed it slightly to my requirement.

let rect = change!["new"] as! NSValue

if let playerRect: CGRect = rect.CGRectValue() as CGRect {         
   if playerRect.size == UIScreen.mainScreen().bounds.size {
      print("Video in full screen")
   } else {
      print("Video not in full screen")
   }
}

Hope this helps.

Answer 4

In iOS11 your screen's safe area will drop to 0 in the event of an AVPlayer going fullscreen. Though it might be an undocumented feature (and therefor potential bug). I am having a hard time finding more info on it.

[UIApplication sharedApplication].keyWindow.safeAreaLayoutGuide.layoutFrame.size.height == 0?

Answer 5

This is a slightly optimized Swift 4.2 version of @Pangu's answer. It only detects the change, otherwise the observer is called also when interacting with the video like fast forwarding. I also replaced the "videoBounds" with the AVPlayerViewController.videoBounds keypath to avoid the string and use the window bounds to determine if it's fullscreen or not.

avPlayerViewController.addObserver(self, forKeyPath: #keyPath(AVPlayerViewController.videoBounds), options: [.old, .new], context: nil)

override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey: Any]?, context: UnsafeMutableRawPointer?) {
    if keyPath == #keyPath(AVPlayerViewController.videoBounds) {
        // detect only changes
        if let oldValue = change?[.oldKey] as? CGRect, oldValue != CGRect.zero, let newValue = change?[.newKey] as? CGRect {
            // no need to track the initial bounds change, and only changes
            if !oldValue.equalTo(CGRect.zero), !oldValue.equalTo(newValue) {
                if newValue.size.height < UIScreen.main.bounds.height {
                   print("normal screen")
                } else {
                   print("fullscreen")
                }
            }
        }
    }
}