How to play next track from Document Directory in swift - ios

Question

I make a simple media player. I have a UITableViewController with mp3 files from Document Directory and UIViewController which plays mp3 files. I pass NSURL of a mp3 file from UITableViewController to UIViewController and I can play it. I want to make buttons are which will be turn track to next or previous. How can I make it?
The code is passing NSURL on a specific file.
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
var playerVC = (segue.destinationViewController as! UINavigationController).topViewController as! PlayMusicViewController
var indexPath = tableView.indexPathForSelectedRow()
var nameOfObjectForPass = listOfMP3Files![indexPath!.row] // default it's name and
var fileManager = NSFileManager.defaultManager()
var wayToFile = fileManager.URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask)
var passMusicFileURL: NSURL? // for pass mp3
if let documentPath: NSURL = wayToFile.first as? NSURL {
let musicFile = documentPath.URLByAppendingPathComponent(nameOfObjectForPass)
println(musicFile)
passMusicFileURL = musicFile
}
if segue.identifier == "listenMusic" {
playerVC.nameMusicFile = nameOfObjectForPass // name
playerVC.mp3URL = passMusicFileURL
// test
playerVC.allUrlsVC = allURLS
}
The code is playing mp3 file
func playMusic() {
AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, error: nil) // == true
AVAudioSession.sharedInstance().setActive(true, error: nil)
var error: NSError?
audioPlayer = AVAudioPlayer(contentsOfURL: mp3URL, error: &error)
// audioPlayer.prepareToPlay()
if currentPause == nil {
} else {
audioPlayer.currentTime = currentPause
}
//
audioPlayer.volume = 0.5
audioPlayer.play()
}
UPDATE
I made following
var arrayMP3url: Array<AnyObject>!
func playNextSound() {
var queue = AVQueuePlayer(URL: mp3URL)
var current = queue.currentItem
var arrayForSearch = arrayMP3url as! [NSURL]
var arrNS = arrayForSearch as NSArray
var index = arrNS.indexOfObject(mp3URL!)
println("index \(index)")
println("array for search \(arrayForSearch)")
println("current song \(current)")
}
But I always get the same index from NSArray

Answer 1

Use your array of mp3 files, and determine current playing index using indexPath, increase or, decrease the current playing index on button click as Next, or, Prev, and change the mp3 file by the index.
Replay the music.
Simple.
Ping if you need more help.
Update
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
var playerVC = (segue.destinationViewController as! UINavigationController).topViewController as! PlayMusicViewController
var indexPath = tableView.indexPathForSelectedRow();
//We only need to pass current index, and array of mp3 urls
playerVC.curIndex=indexPath.row;
playerVC.mp3s= listOfMP3Files;
}
So as described above, just declare two properties in your playerVC, ie
curIndex as int and mp3s as NSArray.
In the function
func playMusic() {
var nameOfObjectForPass = mp3s![curIndex]; // default it's name and
var fileManager = NSFileManager.defaultManager()
var wayToFile = fileManager.URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask)
var passMusicFileURL: NSURL? // for pass mp3
if let documentPath: NSURL = wayToFile.first as? NSURL {
let musicFile = documentPath.URLByAppendingPathComponent(nameOfObjectForPass)
println(musicFile)
passMusicFileURL = musicFile
}
self.nameMusicFile = nameOfObjectForPass // name
self.mp3URL = passMusicFileURL
// test
self.allUrlsVC = allURLS
AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, error: nil) // == true
AVAudioSession.sharedInstance().setActive(true, error: nil)
var error: NSError?
audioPlayer = AVAudioPlayer(contentsOfURL: mp3URL, error: &error)
// audioPlayer.prepareToPlay()
if currentPause == nil {
} else {
audioPlayer.currentTime = currentPause
}
//
audioPlayer.volume = 0.5
audioPlayer.play()
}
Then simply define your next and previous index calculations like
func playNextSound(){
self.curIndex++;
var maxCount=self.mp3s.count-1;
if(self.curIndex>maxCount){
self.curIndex=maxCount;
}
playMusic();
}
func playPrevSound(){
self.curIndex--;
if(self.curIndex<0){
self.curIndex=0;
}
playMusic();
}
Hope it helps. Cheers.