I'm quite new to swift and I want to implement a piece of code that helps me reach the next song when the one that is currently playing ends. I tried to copy the code inside my "@IBAction func nextAction" (which works fine):
@IBAction func nextAction(sender: AnyObject) {
self.nextTrack()
}
func nextTrack() {
if trackId == 0 || trackId < 4 {
if shuffle.on {
trackId = Int(arc4random_uniform(UInt32(library.count)))
}else {
trackId += 1
}
if let coverImage = library[trackId]["coverImage"]{
coverImageView.image = UIImage(named: "\(coverImage).jpg")
}
songTitleLabel.text = library[trackId]["title"]
artistLabel.text = library[trackId]["artist"]
audioPlayer.currentTime = 0
progressView.progress = 0
let path = NSBundle.mainBundle().pathForResource("\(trackId)", ofType: "mp3")
if let path = path {
let mp3URL = NSURL(fileURLWithPath: path)
do {
audioPlayer = try AVAudioPlayer(contentsOfURL: mp3URL)
audioPlayer.play()
NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: #selector(PlayerViewController.updateProgressView), userInfo: nil, repeats: true)
progressView.setProgress(Float(audioPlayer.currentTime/audioPlayer.duration), animated: false)
} catch let error as NSError {
print(error.localizedDescription)
}
}
}
}
And tried to put it inside an if condition like this (inside the viewDidLoad):
if audioPlayer.currentTime >= audioPlayer.duration {
self.nextTrack()
}
I don't have any errors but at runtime this method isn't working and the song ends without playing the next one.
To make the situation more clear here's my controller:
import UIKit
import AVFoundation
class PlayerViewController: UIViewController {
@IBOutlet weak var coverImageView: UIImageView!
@IBOutlet weak var progressView: UIProgressView!
@IBOutlet weak var songTitleLabel: UILabel!
@IBOutlet weak var artistLabel: UILabel!
@IBOutlet weak var shuffle: UISwitch!
var trackId: Int = 0
var library = MusicLibrary().library
var audioPlayer: AVAudioPlayer!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
if let coverImage = library[trackId]["coverImage"]{
coverImageView.image = UIImage(named: "\(coverImage).jpg")
}
songTitleLabel.text = library[trackId]["title"]
artistLabel.text = library[trackId]["artist"]
let path = NSBundle.mainBundle().pathForResource("\(trackId)", ofType: "mp3")
if let path = path {
let mp3URL = NSURL(fileURLWithPath: path)
do {
audioPlayer = try AVAudioPlayer(contentsOfURL: mp3URL)
audioPlayer.play()
NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: #selector(PlayerViewController.updateProgressView), userInfo: nil, repeats: true)
progressView.setProgress(Float(audioPlayer.currentTime/audioPlayer.duration), animated: false)
} catch let error as NSError {
print(error.localizedDescription)
}
}
}
override func viewWillDisappear(animated: Bool) {
audioPlayer.stop()
}
func updateProgressView(){
if audioPlayer.playing {
progressView.setProgress(Float(audioPlayer.currentTime/audioPlayer.duration), animated: true)
}
}
@IBAction func playAction(sender: AnyObject) {
if !audioPlayer.playing {
audioPlayer.play()
}
}
@IBAction func stopAction(sender: AnyObject) {
audioPlayer.stop()
audioPlayer.currentTime = 0
progressView.progress = 0
}
@IBAction func pauseAction(sender: AnyObject) {
audioPlayer.pause()
}
@IBAction func fastForwardAction(sender: AnyObject) {
var time: NSTimeInterval = audioPlayer.currentTime
time += 5.0
if time > audioPlayer.duration {
stopAction(self)
}else {
audioPlayer.currentTime = time
}
}
@IBAction func rewindAction(sender: AnyObject) {
var time: NSTimeInterval = audioPlayer.currentTime
time -= 5.0
if time < 0 {
stopAction(self)
}else {
audioPlayer.currentTime = time
}
}
@IBAction func previousAction(sender: AnyObject) {
if trackId != 0 || trackId > 0 {
if shuffle.on {
trackId = Int(arc4random_uniform(UInt32(library.count)))
}else {
trackId -= 1
}
if let coverImage = library[trackId]["coverImage"]{
coverImageView.image = UIImage(named: "\(coverImage).jpg")
}
songTitleLabel.text = library[trackId]["title"]
artistLabel.text = library[trackId]["artist"]
audioPlayer.currentTime = 0
progressView.progress = 0
let path = NSBundle.mainBundle().pathForResource("\(trackId)", ofType: "mp3")
if let path = path {
let mp3URL = NSURL(fileURLWithPath: path)
do {
audioPlayer = try AVAudioPlayer(contentsOfURL: mp3URL)
audioPlayer.play()
NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: #selector(PlayerViewController.updateProgressView), userInfo: nil, repeats: true)
progressView.setProgress(Float(audioPlayer.currentTime/audioPlayer.duration), animated: false)
} catch let error as NSError {
print(error.localizedDescription)
}
}
}
}
@IBAction func swipeDownAction(sender: AnyObject) {
self.close()
}
@IBAction func closeAction(sender: AnyObject) {
self.close()
}
@IBAction func nextAction(sender: AnyObject) {
self.nextTrack()
}
func close() {
self.dismissViewControllerAnimated(true, completion: nil)
}
func nextTrack() {
if trackId == 0 || trackId < 4 {
if shuffle.on {
trackId = Int(arc4random_uniform(UInt32(library.count)))
}else {
trackId += 1
}
if let coverImage = library[trackId]["coverImage"]{
coverImageView.image = UIImage(named: "\(coverImage).jpg")
}
songTitleLabel.text = library[trackId]["title"]
artistLabel.text = library[trackId]["artist"]
audioPlayer.currentTime = 0
progressView.progress = 0
let path = NSBundle.mainBundle().pathForResource("\(trackId)", ofType: "mp3")
if let path = path {
let mp3URL = NSURL(fileURLWithPath: path)
do {
audioPlayer = try AVAudioPlayer(contentsOfURL: mp3URL)
audioPlayer.play()
NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: #selector(PlayerViewController.updateProgressView), userInfo: nil, repeats: true)
progressView.setProgress(Float(audioPlayer.currentTime/audioPlayer.duration), animated: false)
} catch let error as NSError {
print(error.localizedDescription)
}
}
}
}
}
All the code is written in Xcode 7.3.1
You should use AVAudioPlayer delegate method audioPlayerDidFinishPlaying(player: AVAudioPlayer, successfully flag: Bool) which is called when the audio player finishes playing a sound.
Make your PlayerViewController confirm to AVAudioPlayerDelegate protocol like this:
class PlayerViewController: UIViewController, AVAudioPlayerDelegate {
Make sure to set self as the delegate of the audioPlayer you create, to do that in your viewDidLoad,previousAction and nextTrack method you need to add
audioPlayer.delegate = self
after this line:
audioPlayer = try AVAudioPlayer(contentsOfURL: mp3URL)
Now you can use the delegate method to know when the audio is finished playing and go to the next track, just add this inside your class:
func audioPlayerDidFinishPlaying(player: AVAudioPlayer, successfully flag: Bool) {
if flag {
self.nextTrack()
} else {
// did not finish successfully
}
}