Starting queue controller implementation

Audio Players/SMKAVQueuePlayer.h

@@ -34,11 +34,6 @@
 - (void)pause;
 - (void)play;
 
-// Seeking (SMKPlayer @optional)
-- (void)seekToPlaybackTime:(NSTimeInterval)time;
-- (void)seekBackward;
-- (void)seekForward;
-
 // Preloading (SMKPlayer @optional)
 @property (nonatomic, strong, readonly) id<SMKTrack> preloadedTrack;
 - (void)preloadTrack:(id<SMKTrack>)track completionHandler:(void(^)(NSError *error))handler;

Audio Players/SMKAVQueuePlayer.m

@@ -143,7 +143,8 @@ - (void)preloadTrack:(id<SMKTrack>)track completionHandler:(void (^)(NSError *))
 
 - (void)skipToPreloadedTrack
 {
-    [self.audioPlayer advanceToNextItem];
+    if ([self.audioPlayer.items count] == 2)
+        [self.audioPlayer advanceToNextItem];
 }
 
 #if !TARGET_OS_IPHONE

Audio Players/SMKMPMusicPlayer.h

@@ -28,9 +28,4 @@
 
 - (void)pause;
 - (void)play;
-
-// Seeking (SMKPlayer @optional)
-- (void)seekToPlaybackTime:(NSTimeInterval)time;
-- (void)seekBackward;
-- (void)seekForward;
 @end

Audio Players/SMKSFBAudioPlayer.h

@@ -27,13 +27,8 @@
 @property (nonatomic, assign, readonly) BOOL playing;
 @property (nonatomic, strong, readonly) id<SMKTrack> currentTrack;
 
-// Seeking (SMKPlayer @optional)
-@property (nonatomic, strong, readonly) id<SMKTrack> preloadedTrack;
-- (void)seekToPlaybackTime:(NSTimeInterval)time;
-- (void)seekBackward;
-- (void)seekForward;
-
 // Preloading (SMKPlayer @optional)
+@property (nonatomic, strong, readonly) id<SMKTrack> preloadedTrack;
 - (void)preloadTrack:(id<SMKTrack>)track completionHandler:(void(^)(NSError *error))handler;
 - (id<SMKTrack>)preloadedTrack;
 - (void)skipToPreloadedTrack;

Audio Players/SMKSpotifyPlayer.h

@@ -28,11 +28,6 @@
 
 - (id)initWithPlaybackSession:(SPSession *)aSession;
 
-// Seeking (SMKPlayer @optional)
-- (void)seekToPlaybackTime:(NSTimeInterval)time;
-- (void)seekBackward;
-- (void)seekForward;
-
 // Preloading (SMKPlayer @optional)
 @property (nonatomic, strong, readonly) id<SMKTrack> preloadedTrack;
 - (void)preloadTrack:(id<SMKTrack>)track completionHandler:(void(^)(NSError *error))handler;

Master API/SMKQueueController.h

@@ -23,9 +23,9 @@ typedef NSUInteger SMKQueueControllerRepeatMode;
 
 @property (nonatomic, retain, readonly) NSArray *tracks;
 - (id)initWithTracks:(NSArray *)tracks;
-+ (instancetype)queueControllerWithItems:(NSArray *)tracks;
++ (instancetype)queueControllerWithTracks:(NSArray *)tracks;
 
-- (void)insertTrack:(id<SMKTrack>)track afterTrack:(id<SMKTrack>)track;
+- (void)insertTrack:(id<SMKTrack>)newTrack afterTrack:(id<SMKTrack>)track;
 - (void)removeAllTracks;
 - (void)removeTrack:(id<SMKTrack>)track;
 
@@ -34,9 +34,10 @@ typedef NSUInteger SMKQueueControllerRepeatMode;
 @property (nonatomic, strong, readonly) id<SMKPlayer> currentPlayer;
 @property (nonatomic, strong, readonly) id<SMKTrack> currentTrack;
 @property (nonatomic, assign, readonly) NSUInteger indexOfCurrentTrack;
+@property (nonatomic, assign, readonly) BOOL playing;
 @property (nonatomic, assign) BOOL shuffle;
 @property (nonatomic, assign) SMKQueueControllerRepeatMode repeatMode;
-#if TARGET_OS_IPHONE
+#if !TARGET_OS_IPHONE
 @property (nonatomic, assign) float volume;
 #endif
 

Master API/SMKQueueController.m

@@ -8,6 +8,232 @@
 
 #import "SMKQueueController.h"
 
+@interface SMKQueueItem : NSObject
+@property (nonatomic, retain) id<SMKTrack> track;
+@end
+
+@interface SMKQueueController ()
+@property (nonatomic, strong) NSMutableArray *items;
+@property (nonatomic, strong, readwrite) id<SMKPlayer> currentPlayer;
+@end
+
 @implementation SMKQueueController
 
+- (id)init
+{
+    if ((self = [super init])) {
+        self.items = [NSMutableArray array];
+    }
+    return self;
+}
+
+- (id)initWithTracks:(NSArray *)tracks
+{
+    if ((self = [super init])) {
+        NSArray *items = [self _queueItemsForTracks:tracks];
+        self.items = [NSMutableArray arrayWithArray:items];
+    }
+    return self;
+}
+
++ (instancetype)queueControllerWithTracks:(NSArray *)tracks
+{
+    return [[self alloc] initWithTracks:tracks];
+}
+
+#pragma mark - Queue
+
+- (void)insertTrack:(id<SMKTrack>)newTrack afterTrack:(id<SMKTrack>)track
+{
+    if (!track) {
+        [self.items addObjectsFromArray:[self _queueItemsForTracks:@[newTrack]]];
+    } else {
+        NSUInteger index = [self _indexOfTrack:track];
+        if (index != NSNotFound)
+            [self insertObject:newTrack inItemsAtIndex:index+1];
+    }
+}
+
+- (void)removeAllTracks
+{
+    [self pause:nil];
+    self.items = [NSMutableArray array];
+}
+
+- (void)removeTrack:(id<SMKTrack>)track
+{
+    NSUInteger index = [self _indexOfTrack:track];
+    if (index == NSNotFound)
+        return;
+    if ([track isEqual:self.currentTrack]) {
+        [self next:nil];
+    }
+    [self removeObjectFromItemsAtIndex:index];
+}
+
+#pragma mark - Accessors
+
+- (NSUInteger)indexOfCurrentTrack
+{
+    return [self.items indexOfObject:self.currentTrack];
+}
+
++ (NSSet *)keyPathsForValuesAffectingIndexOfCurrentTrack
+{
+    return [NSSet setWithObject:@"currentTrack"];
+}
+
+- (NSTimeInterval)playbackTime
+{
+    return [self.currentPlayer playbackTime];
+}
+
+- (void)seekToPlaybackTime:(NSTimeInterval)playbackTime
+{
+    [self.currentPlayer seekToPlaybackTime:playbackTime];
+}
+
++ (NSSet *)keyPathsForValuesAffectingPlaybackTime
+{
+    return [NSSet setWithObject:@"currentPlayer.playbackTime"];
+}
+
+- (BOOL)playing
+{
+    return [self.currentPlayer playing];
+}
+
++ (NSSet *)keyPathsForValuesAffectingPlaying
+{
+    return [NSSet setWithObject:@"currentPlayer.playing"];
+}
+
+- (NSArray *)tracks
+{
+    return [self.items valueForKey:@"track"];
+}
+
++ (NSSet *)keyPathsForValuesAffectingTracks
+{
+    return [NSSet setWithObject:@"items"];
+}
+
+- (id<SMKTrack>)currentTrack
+{
+    return [self.currentPlayer currentTrack];
+}
+
++ (NSSet *)keyPathsForValuesAffectingCurrentTrack
+{
+    return [NSSet setWithObject:@"currentPlayer.currentTrack"];
+}
+
+#pragma mark - Array Accessors
+
+- (NSUInteger)countOfItems
+{
+    return [self.items count];
+}
+
+- (id)objectInItemsIndex:(NSUInteger)index
+{
+    return [self.items objectAtIndex:index];
+}
+
+- (void)insertObject:(id)obj inItemsAtIndex:(NSUInteger)index
+{
+    [self.items insertObject:obj atIndex:index];
+}
+
+- (void)removeObjectFromItemsAtIndex:(NSUInteger)index
+{
+    [self.items removeObjectAtIndex:index];
+}
+
+- (void)replaceObjectInItemsAtIndex:(NSUInteger)index withObject:(id)obj
+{
+    [self.items replaceObjectAtIndex:index withObject:obj];
+}
+
+#pragma mark - Playback
+
+- (IBAction)play:(id)sender
+{
+    if (!self.currentPlayer && [self.items count]) {
+        [self _beginPlayingItemAtIndex:0];
+    }
+    [self.currentPlayer play];
+}
+
+- (IBAction)pause:(id)sender
+{
+    [self.currentPlayer pause];
+}
+
+- (IBAction)playPause:(id)sender
+{
+    [self playing] ? [self pause:nil] : [self play:nil];
+}
+
+- (IBAction)next:(id)sender
+{
+
+}
+
+- (IBAction)previous:(id)sender
+{
+
+}
+
+- (IBAction)seekForward:(id)sender
+{
+
+}
+
+- (IBAction)seekBackward:(id)sender
+{
+
+}
+
+#pragma mark - Private
+
+- (NSArray *)_queueItemsForTracks:(NSArray *)tracks
+{
+    NSMutableArray *items = [NSMutableArray arrayWithCapacity:[tracks count]];
+    [tracks enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
+        SMKQueueItem *item = [SMKQueueItem new];
+        item.track = obj;
+        [items addObject:item];
+    }];
+    return items;
+}
+
+- (NSUInteger)_indexOfTrack:(id<SMKTrack>)track
+{
+    __block NSUInteger index = NSNotFound;
+    [self.items enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
+        if ([[obj track] isEqual:track]) {
+            index = idx;
+            *stop = YES;
+        }
+    }];
+    return index;
+}
+
+- (void)_beginPlayingItemAtIndex:(NSUInteger)index
+{
+    id<SMKTrack> track = [[self.items objectAtIndex:index] track];
+    self.currentPlayer = [[track playerClass] new];
+    __weak SMKQueueController *weakSelf = self;
+    [self.currentPlayer playTrack:track completionHandler:^(NSError *error) {
+        if (error) {
+            SMKQueueController *strongSelf = weakSelf;
+            SMKGenericErrorLog([NSString stringWithFormat:@"Error playing track %@", track], error);
+            [strongSelf removeObjectFromItemsAtIndex:index];
+            strongSelf.currentPlayer = nil;
+            if (index < [self.items count])
+                [self _beginPlayingItemAtIndex:index];
+        }
+    }];
+}
 @end

Protocols/SMKPlayer.h

@@ -61,13 +61,6 @@
  */
 - (NSTimeInterval)playbackTime;
 
-@optional
-
-/**
- @return The player volume from 0.0 to 1.0
- */
-@property (nonatomic, assign) float volume;
-
 /**
  The seek time interval for the -seekBackward and -seekForward methods.
  */
@@ -88,6 +81,13 @@
  */
 - (void)seekForward;
 
+@optional
+
+/**
+ @return The player volume from 0.0 to 1.0
+ */
+@property (nonatomic, assign) float volume;
+
 /**
  Preload the specified track (if the player supports preloading)
  @param handler Completion handler called with an NSError if preloading failed and nil if successful.