Swift - AVPlayer - Stop player in another cell when a new player starts

Programming Languages Swift
oguzhanvarsak OP
Created May ’21
Replies 24
Boosts 0
Views 8.5k
Participants 3
I am working on a podcast application and achieved all the streaming-related parts of the application. The problem explained below, how can I achieve this?

Current:
The player view is hidden by default. When the user presses the "Play" button, the player view unhides and the player starts streaming. But it won't stop streaming if the user presses another "Play" button so both streams play simultaneously.

Goal:
When the user starts playing a new podcast by pressing another Play button, I want other players would stop playing and disappear.

Extra:
The whole podcast view awakes from the xib cell. So, the problem is, how can I manipulate another cell view's member when pressing a button in another cell view
Replies  24
Boosts  0
Views  8.5k
Participants  3
Claude31 OP
May ’21
You should show code, that would be much easier to explain.

 I want other players

You want a single player to play at any time ?
So, you should have a reference to the activePlayer declared at the class level.
It is nil to begin with.

When you Play, you should first stop the activePlayer (after testing it is not nil)
Then dismiss and set to nil
Then create a new player instance and set it to activePlayer.

If you have a stop func, do the same:
stop the active player, dismiss it and set to nil.

Could you better explain your Extra question ?

1
oguzhanvarsak OP
May ’21
@Claude31 my problem here is I have declared my player in ViewCell, not in ViewContoller. So every cell has its player currently, thus I can't reach another cell's player when a player starts.
0
Claude31 OP
May ’21
Why did you do so ? You could have just the button for the player, but have the active player at view level.

However, you could do this:
when you tap on play in a cell, explore all the cells and stop their player if not nil.
That's not a very good design, but that could work.
1
oguzhanvarsak OP
May ’21
Thank you for all of your efforts!

This was my first attempt to work with xibs and it went a little bit messy. I'd like to hear advice for view level player way too.

For now, I will try the second way. How can I achieve exploring all the cells available?
0
Claude31 OP
May ’21
Iin the play button action of the cell:
get the tableView with cell.superview.
tableView.visibleCells,
gives you all visible cells in an array [UITableViewCell]

then loop through this array and test their player to stop if needed.

1
oguzhanvarsak OP
May ’21
I cannot work with cell.superview.tableView.visibleCells in play button action which is in ViewCell file, it gives cannot find in scope error.
0
Claude31 OP
May ’21
It is not
cell.superview.tableView.visibleCells

But
let tableView = cell.superview
then use
tableView.visibleCells

You could have a safety check:
Code Block 
if let tableView = cell.superview as? UITableView {
    // then use 
    tableView.visibleCells
}

1
oguzhanvarsak OP
May ’21
I still get the cannot find in scope error for "cell". I tried to declare tableView in and out of play button action but no chance. My cells awake in CollectionView, not in TableView.

I have found that this way I can get the visible cells:

Code Block 
let visibleIndexPaths = collectionView.indexPathsForVisibleItems


But I don't know what to do with it..
0
Claude31 OP
May ’21
You didn't tell it was a collectionView.

So change with:

Code Block 
        if let collectionView = cell.superview as? UICollectionView {
            let visibleCells = collectionView.visibleCells
            for cell in visibleCells where cell is CollectionViewCell {    // The type of your cells
                // now you can access to properties
                if cell.player != nil {    // I suppose you named the podPlayer as player
                        // stop it playing
                        // dismiss
                        // set to nil
                }
            }
        }


0
oguzhanvarsak OP
May ’21
The problem is still here, I get the same error: "Can't find 'cell' in scope." when I use the code. For more information, here is the file I'm working on:

PodcastCellView: (Where I declare the player, player view's button and button action. But CollectionView is declared in ViewController.)

Code Block swift


I get the same error even I use the code in PodcastViewController.
0
Claude31 OP
May ’21
Sure. cell is not known.

replace line 2 with:
Code Block 
    if let collectionView = self.superview as? UICollectionView {

0
oguzhanvarsak OP
May ’21
After replacing the cell with self in line 2, I get another error on line 5.

Value of type 'UICollectionViewCell' has no member 'player'

If I replace that cell. with self., code compiles successfully. But nothing changes on the application side. When I click another play button while a stream playing, the second stream starts playing.
0
Claude31 OP
May ’21
Could you show your code (complete for PodcastViewCell, the UICollectionViewCell). I have been guessing some missing parts, it is not very efficient.
How did you name the player there ?

Sure it compiles with self instead of cell, but it misses the point which is to stop players from any other cell, not the current one (self).
1
oguzhanvarsak OP
May ’21
My player declared as player in PodcastViewCell

Code Block swift
var player: AVPlayer?



This is the complete code for PodcastViewCell

Code Block swift
import UIKit
import AVKit
import AVFoundation
class PodcastViewCell: UICollectionViewCell {
  // UILabels
  @IBOutlet weak var categoryLabel: UILabel!
  @IBOutlet weak var titleLabel: UILabel!
  @IBOutlet weak var dateLabel: UILabel!
  @IBOutlet weak var podcastUnavailableLbl: UILabel!
   
  // Constraints
  @IBOutlet weak var linehg: NSLayoutConstraint!
  @IBOutlet weak var categoryLabelHeight: NSLayoutConstraint!
  @IBOutlet weak var podcastBtnWd: NSLayoutConstraint!
   
  // UISliders
  @IBOutlet weak var slider: UISlider!
   
  // UIViews
  @IBOutlet weak var podcastView: UIView!
   
  // UIButtons
  @IBOutlet weak var playPauseBtn: UIButton!
  @IBOutlet weak var podcastBtn: UIButton!
  var player: AVPlayer?
  var playerItem: AVPlayerItem?
  var timeObserverToken: Any?
   
  var urlString: String?
  var podcastLink: String?
   
  var played = false
   
   
  override func awakeFromNib() {
    super.awakeFromNib()
    podcastViewVisibility()
    slider.value = 0
  }
   
  var item: News? {
    didSet {
      if let news = item {
        titleLabel.text = news.title ?? ""
        categoryLabel.text = news.category?.title ?? ""
        dateLabel.text = news.publishDate ?? ""
      }
    }
  }
  func prepareCell(news: News?) {
    item = news
  }
   
  func prepareCellAuthor(author: AuthorSubList?) {
    itemAuthor = author
  }
   
  var itemAuthor: AuthorSubList? {
    didSet {
      if let column = itemAuthor {
        titleLabel.text = column.title ?? ""
        categoryLabel.text = ""
        categoryLabelHeight.constant = 0
        dateLabel.text = column.publishDate ?? ""
      }
    }
  }
   
  @IBAction func selectItem(_ sender: Any) {
    if let news = item {
      if let id = news.itemId {
        delegate?.selectItemAction(itemId: id)
        delegate?.selectPopularNews(news: news, index: tag)
      }
    }
       
    else if let author = itemAuthor {
      if let id = author.itemId {
        delegate?.selectItemAction(itemId: id)
      }
    }
  }
  @IBAction func playPodcast(_ sender: Any) {
     
    if let collectionView = self.superview as? UICollectionView {
     let visibleCells = collectionView.visibleCells
     for cell in visibleCells where cell is PodcastViewCell {
        if cell.player != nil {         }
     }
    }
    if played == false {
      NotificationCenter.default.addObserver(self, selector: #selector(playerItemDidReachEnd), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: nil)
       
      if let itemOffset = allItems?.itemListv2.firstIndex(where: {$0.itemId == itemAuthor?.itemId}) {
        podcastLink = allItems?.itemListv2[itemOffset].podcastsound
      }
      let url = podcastLink ?? " "
       
      if url != "" {
        let playerItem = AVPlayerItem( url:NSURL( string:url )! as URL )
        player = AVPlayer(playerItem:playerItem)
        player!.rate = 1.0;
         
        podcastView.isHidden = false
         
        player!.play()
        playPauseBtn.setImage(UIImage(systemName: "pause.fill"), for: .normal)
         
        player?.addProgressObserver { progress in
          self.slider.setValue(Float(progress), animated: true)
        }
        played = true
      } else {
        podcastUnavailableLbl.isHidden = false
      }
    } else {
      podcastView.isHidden = true
      player?.replaceCurrentItem(with: nil)
      slider.value = 0
      played = false
    }
  }
  deinit {
    NotificationCenter.default.removeObserver(self)
  }
   
  @IBAction func playPause(_ sender: Any) {
    if player?.timeControlStatus == .playing {
      player?.pause()
      playPauseBtn.setImage(UIImage(systemName: "play.fill"), for: .normal)
    } else {
      player?.play()
       playPauseBtn.setImage(UIImage(systemName: "pause.fill"), for: .normal)
    }
  }
}
extension AVPlayer {
  func addProgressObserver(action:@escaping ((Double) -> Void)) -> Any {
    return self.addPeriodicTimeObserver(forInterval: CMTime.init(value: 1, timescale: 1), queue: .main, using: { time in
      if let duration = self.currentItem?.duration {
        let duration = CMTimeGetSeconds(duration), time = CMTimeGetSeconds(time)
        let progress = (time/duration)
        action(progress)
      }
    })
  }
}
                                                     


0
Claude31 OP
May ’21
Do you still get the error on line 93 ?

If so, try the following:

Code Block 
  @IBAction func playPodcast(_ sender: Any) {
     
    if let collectionView = self.superview as? UICollectionView {
     let visibleCells = collectionView.visibleCells
     for cell in visibleCells {
        if let podCell = cell as? PodcastViewCell {
           print("cell is PodcastViewCell")
            if podCell.player != nil {
                print("podCell.player found")
            } else {
                print("podCell.player NOT found")
           }
        } else {
           print("cell is NOT PodcastViewCell")
       }
     }
    }

And tell what you get exactly on console.

Or simply change:

Code Block 
    if let collectionView = self.superview as? UICollectionView {
     let visibleCells = collectionView.visibleCells
     for cell in visibleCells where cell is PodcastViewCell {
        if (cell as! PodcastViewCell).player != nil {         }
     }


0
Swift - AVPlayer - Stop player in another cell when a new player starts
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