MIKMIDISequencer now sends out a notification prior to looping playba…

…ck. Also added syncedClock properties to MIKMIDIClock and MIKMIDISequencer.

Source/MIKMIDIClock.h

@@ -99,5 +99,22 @@
  */
 - (MIDITimeStamp)midiTimeStampsPerMusicTimeStamp:(MusicTimeStamp)musicTimeStamp;
 
+
+/**
+ *  A readonly copy of the clock that remains synced with this instance.
+ *  
+ *  This clock can be queried and will always return the same timing information
+ *  as the clock instance that dispensed the synced clock.
+ *
+ *  Attempting to call -setMusicTimeStamp:withTempo:atMusicTimeStamp on the synced
+ *  has no effect.
+ */
+- (MIKMIDIClock *)syncedClock;
+
+/**
+ *  The tempo that was set in the last call to -setMusicTimeStamp:withTempo:atMIDITimeStamp:
+ */
+@property (readonly, nonatomic) Float64 tempo;
+
 @end
 

Source/MIKMIDIClock.m

@@ -13,13 +13,24 @@
 #error MIKMIDIClock.m must be compiled with ARC. Either turn on ARC for the project or set the -fobjc-arc flag for MIKMIDIMappingManager.m in the Build Phases for this target
 #endif
 
+
+#pragma mark -
+@interface MIKMIDISyncedClockProxy : NSProxy
++ (instancetype)syncedClockWithClock:(MIKMIDIClock *)masterClock;
+@property (readonly, nonatomic) MIKMIDIClock *masterClock;
+@end
+
+
+#pragma mark -
 @interface MIKMIDIClock ()
+@property (nonatomic) Float64 tempo;
 @property (nonatomic) MIDITimeStamp timeStampZero;
 @property (nonatomic) Float64 musicTimeStampsPerMIDITimeStamp;
 @property (nonatomic) Float64 midiTimeStampsPerMusicTimeStamp;
 @end
 
 
+#pragma mark -
 @implementation MIKMIDIClock
 
 #pragma mark - Lifecycle
@@ -37,14 +48,16 @@ - (void)setMusicTimeStamp:(MusicTimeStamp)musicTimeStamp withTempo:(Float64)temp
 	Float64 secondsPerMusicTimeStamp = 1.0 / (tempo / 60.0);
 	Float64 midiTimeStampsPerMusicTimeStamp = secondsPerMusicTimeStamp / secondsPerMIDITimeStamp;
 
+	self.tempo = tempo;
 	self.timeStampZero = midiTimeStamp - (musicTimeStamp * midiTimeStampsPerMusicTimeStamp);
 	self.midiTimeStampsPerMusicTimeStamp = midiTimeStampsPerMusicTimeStamp;
 	self.musicTimeStampsPerMIDITimeStamp = secondsPerMIDITimeStamp / secondsPerMusicTimeStamp;
 }
 
 - (MusicTimeStamp)musicTimeStampForMIDITimeStamp:(MIDITimeStamp)midiTimeStamp
 {
-	return (midiTimeStamp - self.timeStampZero) * self.musicTimeStampsPerMIDITimeStamp;
+	MIDITimeStamp timeStampZero = self.timeStampZero;
+	return (midiTimeStamp >= timeStampZero) ? ((midiTimeStamp - timeStampZero) * self.musicTimeStampsPerMIDITimeStamp) : -((midiTimeStamp - timeStampZero) * self.musicTimeStampsPerMIDITimeStamp);
 }
 
 - (MIDITimeStamp)midiTimeStampForMusicTimeStamp:(MusicTimeStamp)musicTimeStamp
@@ -87,4 +100,42 @@ - (id)copyWithZone:(NSZone *)zone
 	return clock;
 }
 
+#pragma mark - Synced Clock
+
+- (MIKMIDIClock *)syncedClock
+{
+	return (MIKMIDIClock *)[MIKMIDISyncedClockProxy syncedClockWithClock:self];
+}
+
 @end
+
+
+#pragma mark -
+@implementation MIKMIDISyncedClockProxy
+
++ (instancetype)syncedClockWithClock:(MIKMIDIClock *)masterClock
+{
+	MIKMIDISyncedClockProxy *proxy = [self alloc];
+	proxy->_masterClock = masterClock;
+	return proxy;
+}
+
+- (void)forwardInvocation:(NSInvocation *)invocation
+{
+	SEL selector = invocation.selector;
+	if (selector == @selector(setMusicTimeStamp:withTempo:atMIDITimeStamp:)) return;
+
+	if (selector == @selector(syncedClock)) {
+		MIKMIDISyncedClockProxy *syncedClock = self;
+		return [invocation setReturnValue:&syncedClock];
+	}
+
+	[invocation invokeWithTarget:self.masterClock];
+}
+
+- (NSMethodSignature *)methodSignatureForSelector:(SEL)sel
+{
+	return [self.masterClock methodSignatureForSelector:sel];
+}
+
+@end

Source/MIKMIDISequencer.h

@@ -15,6 +15,7 @@
 @class MIKMIDICommand;
 @class MIKMIDIDestinationEndpoint;
 @class MIKMIDISynthesizer;
+@class MIKMIDIClock;
 
 /**
  *  Types of click track statuses, that determine when the click track will be audible.
@@ -311,4 +312,12 @@ typedef NS_ENUM(NSInteger, MIKMIDISequencerClickTrackStatus) {
  */
 @property (copy, nonatomic) NSSet *recordEnabledTracks;
 
+/**
+ *  An MIKMIDIClock that is synced with the sequencer's internal clock.
+ */
+@property (readonly, nonatomic) MIKMIDIClock *syncedClock;
+
 @end
+
+
+FOUNDATION_EXPORT NSString * const MIKMIDISequencerWillLoopNotification;

Source/MIKMIDISequencer.m

@@ -29,6 +29,8 @@
 
 #define MIKMIDISequencerDefaultTempo			120
 
+NSString * const MIKMIDISequencerWillLoopNotification = @"MIKMIDISequencerWillLoopNotification";
+
 
 #pragma mark -
 
@@ -91,6 +93,7 @@ - (instancetype)initWithSequence:(MIKMIDISequence *)sequence
 	if (self = [super init]) {
 		_sequence = sequence;
 		_clock = [MIKMIDIClock clock];
+		_syncedClock = [_clock syncedClock];
 		_loopEndTimeStamp = -1;
 		_preRoll = 4;
 		_clickTrackStatus = MIKMIDISequencerClickTrackStatusEnabledInRecord;
@@ -275,6 +278,8 @@ - (void)processSequenceStartingFromMIDITimeStamp:(MIDITimeStamp)fromMIDITimeStam
 
 			MIDITimeStamp loopStartMIDITimeStamp = [clock midiTimeStampForMusicTimeStamp:loopStartTimeStamp + loopLength];
 			[self updateClockWithMusicTimeStamp:loopStartTimeStamp tempo:tempo atMIDITimeStamp:loopStartMIDITimeStamp];
+
+			[[NSNotificationCenter defaultCenter] postNotificationName:MIKMIDISequencerWillLoopNotification object:self userInfo:nil];
 			[self processSequenceStartingFromMIDITimeStamp:loopStartMIDITimeStamp];
 		}
 	} else if (!self.isRecording) { // Don't stop automatically during recording
@@ -360,6 +365,20 @@ - (void)sendPendingNoteOffCommandsUpToMIDITimeStamp:(MIDITimeStamp)toTimeStamp
 	}
 }
 
+- (MIKMIDIClock *)clockForMIDITimeStamp:(MIDITimeStamp)midiTimeStamp
+{
+	MIKMIDIClock *clock;
+	for (NSNumber *historicalClockTimeStamp in [[self.historicalClockMIDITimeStamps reverseObjectEnumerator] allObjects]) {
+		if ([historicalClockTimeStamp unsignedLongLongValue] > midiTimeStamp) {
+			clock = self.historicalClocks[historicalClockTimeStamp];
+		} else {
+			break;
+		}
+	}
+	if (!clock) clock = self.clock;
+	return clock;
+}
+
 - (void)updateClockWithMusicTimeStamp:(MusicTimeStamp)musicTimeStamp tempo:(Float64)tempo atMIDITimeStamp:(MIDITimeStamp)midiTimeStamp
 {
 	// Override tempo if neccessary
@@ -450,16 +469,8 @@ - (void)recordMIDICommand:(MIKMIDICommand *)command
 	if (!self.isRecording) return;
 
 	MIDITimeStamp midiTimeStamp = command.midiTimestamp;
-	MIKMIDIClock *clockAtTimeStamp;
-	for (NSNumber *historicalClockTimeStamp in [[self.historicalClockMIDITimeStamps reverseObjectEnumerator] allObjects]) {
-		if ([historicalClockTimeStamp unsignedLongLongValue] > midiTimeStamp) {
-			clockAtTimeStamp = self.historicalClocks[historicalClockTimeStamp];
-		} else {
-			break;
-		}
-	}
-	if (!clockAtTimeStamp) clockAtTimeStamp = self.clock;
-
+	MIKMIDIClock *clockAtTimeStamp = [self clockForMIDITimeStamp:midiTimeStamp];
+
 	MusicTimeStamp playbackOffset = self.playbackOffset;
 	MusicTimeStamp musicTimeStamp = [clockAtTimeStamp musicTimeStampForMIDITimeStamp:midiTimeStamp] - playbackOffset;