MPMusicPlayerController snippets

gistfile1.m

- (void)setupiPodPlayer;
{
    if (!self.ipodPlayer) {
        self.ipodPlayer = [MPMusicPlayerController iPodMusicPlayer];
        
        
        // Register for music player notifications
        NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
        [notificationCenter addObserver:self 
                               selector:@selector(handleNowPlayingItemChanged:)
                                   name:MPMusicPlayerControllerNowPlayingItemDidChangeNotification 
                                 object:self.ipodPlayer];
        [notificationCenter addObserver:self 
                               selector:@selector(handlePlaybackStateChanged:)
                                   name:MPMusicPlayerControllerPlaybackStateDidChangeNotification 
                                 object:self.ipodPlayer];
        [notificationCenter addObserver:self 
                               selector:@selector(handleExternalVolumeChanged:)
                                   name:MPMusicPlayerControllerVolumeDidChangeNotification 
                                 object:self.ipodPlayer];
        [self.ipodPlayer beginGeneratingPlaybackNotifications];
        
        [[MPMediaLibrary defaultMediaLibrary] beginGeneratingLibraryChangeNotifications];
    }
}

- (NSString *)currentSongPlaying
{
    MPMediaItem *currentItem = self.ipodPlayer.nowPlayingItem;
    NSString *songName = [NSString stringWithFormat:@"%@ - %@", 
                          [currentItem valueForProperty:MPMediaItemPropertyArtist],
                          [currentItem valueForProperty:MPMediaItemPropertyTitle]];
    
    return songName;
}


#pragma mark - Button actions

- (IBAction)playOrPauseMusic:(id)sender
{
	MPMusicPlaybackState playbackState = self.ipodPlayer.playbackState;
	if (playbackState == MPMusicPlaybackStateStopped || playbackState == MPMusicPlaybackStatePaused) {
        
		[self.ipodPlayer play];
        
        

        [[TKAlertCenter defaultCenter] postAlertWithMessage:[self currentSongPlaying]
                                                      image:[UIImage imageNamed:@"play"]];
        
	} else if (playbackState == MPMusicPlaybackStatePlaying) {
		[[TKAlertCenter defaultCenter] postAlertWithMessage:NSLocalizedString(@"Pause", nil)
                                                      image:[UIImage imageNamed:@"pause"]];
        
        [self.ipodPlayer pause];
	}
}

- (IBAction)playNextSong:(id)sender
{
    [self.ipodPlayer skipToNextItem];
    
    [[TKAlertCenter defaultCenter] postAlertWithMessage:[self currentSongPlaying]
                                                  image:[UIImage imageNamed:@"fastforward"]];
}

- (IBAction)playPreviousSong:(id)sender
{
    
    
    static NSTimeInterval skipToBeginningOfSongIfElapsedTimeLongerThan = 3.5;
    
    NSTimeInterval playbackTime = self.ipodPlayer.currentPlaybackTime;
    if (playbackTime <= skipToBeginningOfSongIfElapsedTimeLongerThan) {
        [self.ipodPlayer skipToPreviousItem];
    } else {
        [self.ipodPlayer skipToBeginning];
    }
    
    [[TKAlertCenter defaultCenter] postAlertWithMessage:[self currentSongPlaying]
                                                  image:[UIImage imageNamed:@"rewind"]];
}

- (IBAction)volumeSliderChanged:(id)sender
{
    self.ipodPlayer.volume = self.volumeSlider.value;
}

#pragma mark - Swiping

- (void)volumeUp
{
    
    float volume = self.ipodPlayer.volume;
    
    if (volume == 1.0) return;
    volume += 0.2;
    
    if (volume > 1.0) volume = 1.0;
    
    self.ipodPlayer.volume = volume;
}

- (void)volumeDown
{
    
    
    float volume = self.ipodPlayer.volume;
    
    if (volume == 0.0) return;
    volume -= 0.2;
    
    if (volume < 0.0) volume = 0.0;
    
    self.ipodPlayer.volume = volume;
}



#pragma mark - Notifications

// When the now playing item changes, update song info labels and artwork display.
- (void)handleNowPlayingItemChanged:(id)notification
{
    /*
    // Ask the music player for the current song.
    MPMediaItem *currentItem = self.ipodPlayer.nowPlayingItem;
    
    // Display the artist, album, and song name for the now-playing media item.
    // These are all UILabels.
    self.songLabel.text   = [currentItem valueForProperty:MPMediaItemPropertyTitle];
    self.artistLabel.text = [currentItem valueForProperty:MPMediaItemPropertyArtist];
    self.albumLabel.text  = [currentItem valueForProperty:MPMediaItemPropertyAlbumTitle];    
    
    // Display album artwork. self.artworkImageView is a UIImageView.
    CGSize artworkImageViewSize = self.artworkImageView.bounds.size;
    MPMediaItemArtwork *artwork = [currentItem valueForProperty:MPMediaItemPropertyArtwork];
    if (artwork != nil) {
        self.artworkImageView.image = [artwork imageWithSize:artworkImageViewSize];
    } else {
        self.artworkImageView.image = nil;
    }
     */
}

// When the playback state changes, set the play/pause button appropriately.
- (void)handlePlaybackStateChanged:(id)notification
{
    /*
    MPMusicPlaybackState playbackState = self.ipodPlayer.playbackState;
    if (playbackState == MPMusicPlaybackStatePaused || playbackState == MPMusicPlaybackStateStopped) {
        [self.playPauseButton setTitle:@"Play" forState:UIControlStateNormal];
    } else if (playbackState == MPMusicPlaybackStatePlaying) {
        [self.playPauseButton setTitle:@"Pause" forState:UIControlStateNormal];
    }
     */
}

// When the volume changes, sync the volume slider
- (void)handleExternalVolumeChanged:(id)notification {
    // self.volumeSlider is a UISlider used to display music volume.
    // self.musicPlayer.volume ranges from 0.0 to 1.0.
    //[self.volumeSlider setValue:self.musicPlayer.volume animated:YES];
}