Examples/NetscapeMuteAPIPlugin/AudioPlayer.mm

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#import "AudioPlayer.h"

#import <AVFoundation/AVFoundation.h>

static void *itemStatusKVOContext = &itemStatusKVOContext;

@implementation AudioPlayer

@synthesize audioPlayerDelegate=_audioPlayerDelegate;

- (instancetype)initWithURL:(NSURL *)url
{
    if (!url.absoluteString.length)
        return nil;

    if (!(self = [super init]))
        return nil;

    AVURLAsset *avAsset = [AVURLAsset URLAssetWithURL:url options:nil];
    _playerItem = [[AVPlayerItem alloc] initWithAsset:avAsset];
    [_playerItem addObserver:self forKeyPath:@"status" options:0 context:itemStatusKVOContext];
    _audioPlayer = [[AVPlayer alloc] initWithPlayerItem:_playerItem];

    return self;
}

- (void)dealloc
{
    [_playerItem removeObserver:self forKeyPath:@"status"];
    [_audioPlayer release];
    [_playerItem release];
    [super dealloc];
}

- (BOOL)isReadyToPlay
{
    return _audioPlayer.currentItem.status == AVPlayerItemStatusReadyToPlay;
}

- (BOOL)isPlaying
{
    return _playing;
}

- (void)setPlaying:(BOOL)playing
{
    if (_playing == playing)
        return;

    if (playing && !self.isReadyToPlay)
        return;

    _playing = playing;

    if (_playing)
        [_audioPlayer play];
    else
        [_audioPlayer pause];

    [_audioPlayerDelegate playStateDidChangeForAudioPlayer:self];
}

- (BOOL)isMuted
{
    return _audioPlayer.isMuted;
}

- (void)setMuted:(BOOL)muted
{
    if (self.isMuted == muted)
        return;

    _audioPlayer.muted = muted;
    [_audioPlayerDelegate mutedStateDidChangeForAudioPlayer:self];
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {

    if (context == &itemStatusKVOContext) {
        dispatch_async(dispatch_get_main_queue(), ^{ [_audioPlayerDelegate readyStateDidChangeForAudioPlayer:self]; });
        return;
    }
    [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
@end