Adds support to MIKMIDISequencer for muted, solo, and offset properties of MIKMIDITrack.

Source/MIKMIDINoteEvent.h

@@ -73,7 +73,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic, readonly) Float32 duration;
 
 /**
- *  The time stamp at the end of the notes duration.
+ *  The time stamp at the end of the notes duration. This is simply the event's timeStamp + duration.
  */
 @property (nonatomic, readonly) MusicTimeStamp endTimeStamp;
 

Source/MIKMIDISequencer.m

@@ -326,8 +326,34 @@ - (void)processSequenceStartingFromMIDITimeStamp:(MIDITimeStamp)fromMIDITimeStam
 	}
 
 	// Get other events
+
+	NSMutableArray *nonMutedTracks = [[NSMutableArray alloc] init];
+	NSMutableArray *soloTracks = [[NSMutableArray alloc] init];
 	for (MIKMIDITrack *track in sequence.tracks) {
-		NSArray *events = [track eventsFromTimeStamp:MAX(fromMusicTimeStamp - playbackOffset, 0) toTimeStamp:toMusicTimeStamp - playbackOffset];
+		if (track.isMuted) continue;
+
+		[nonMutedTracks addObject:track];
+		if (track.solo) { [soloTracks addObject:track]; }
+	}
+
+	// Never play muted tracks. If any non-muted tracks are soloed, only play those. Matches MusicPlayer behavior
+	NSArray *tracksToPlay = soloTracks.count != 0 ? soloTracks : nonMutedTracks;
+
+	for (MIKMIDITrack *track in tracksToPlay) {
+		MusicTimeStamp startTimeStamp = MAX(fromMusicTimeStamp - playbackOffset - track.offset, 0);
+		MusicTimeStamp endTimeStamp = toMusicTimeStamp - playbackOffset - track.offset;
+		NSArray *events = [track eventsFromTimeStamp:startTimeStamp toTimeStamp:endTimeStamp];
+		if (track.offset != 0) {
+			// Shift events by offset
+			NSMutableArray *shiftedEvents = [NSMutableArray array];
+			for (MIKMIDIEvent *event in events) {
+				MIKMutableMIDIEvent *shiftedEvent = [event mutableCopy];
+				shiftedEvent.timeStamp += track.offset;
+				[shiftedEvents addObject:shiftedEvent];
+			}
+			events = shiftedEvents;
+		}
+
 		id<MIKMIDICommandScheduler> destination = events.count ? [self commandSchedulerForTrack:track] : nil;	// only get the destination if there's events so we don't create a destination endpoint if not needed
 		for (MIKMIDIEvent *event in events) {
 			NSNumber *timeStampKey = @(event.timeStamp + playbackOffset);

Source/MIKMIDITrack.h

@@ -185,30 +185,28 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  *  A MIDI track’s start time in terms of beat number. By default this value is 0.
  *
- *  This property can be observed using Key Value Observing.
+ *  This can be used to offset playback by MIKMIDISequencer of individual tracks in a sequence.
  *
- *	@note This property is not yet used by MIKMIDISequencer (Issue #99). If this property
- *	is required for your playback situation, you should stick with MIKMIDIPlayer in the meantime.
+ *  This property can be observed using Key Value Observing.
  */
 @property (nonatomic) MusicTimeStamp offset;
 
 /**
- *  Whether or not the MIDI track is muted.
+ *  Whether or not the MIDI track is muted. Muted tracks are not played by MIKMIDISequencer.
  *
  *  This property can be observed using Key Value Observing.
- *
- *	@note This property is not yet used by MIKMIDISequencer (Issue #99). If this property
- *	is required for your playback situation, you should stick with MIKMIDIPlayer in the meantime.
  */
 @property (nonatomic, getter = isMuted) BOOL muted;
 
 /**
  *  Whether or not the MIDI track is soloed.
  *
- *  This property can be observed using Key Value Observing.
+ *  If a track is muted, it is not played by MIKMIDISequencer, and its solo status is ignored.
+ *  If any non-muted tracks in a sequence have this property set to YES, MIKMIDISequencer will only play those,
+ *  and will not play the non-solo tracks. If this is set to NO for all non-muted tracks, then
+ *  all non-muted tracks will be played.
  *
- *	@note This property is not yet used by MIKMIDISequencer (Issue #99). If this property
- *	is required for your playback situation, you should stick with MIKMIDIPlayer in the meantime.
+ *  This property can be observed using Key Value Observing.
  */
 @property (nonatomic, getter = isSolo) BOOL solo;
 

Source/MIKMIDITrack.m

@@ -616,51 +616,87 @@ - (NSInteger)trackNumber
 	return (NSInteger)trackNumber;
 }
 
+@synthesize offset = _offset;
+
 - (MusicTimeStamp)offset
 {
-    MusicTimeStamp offset = 0;
-    UInt32 offsetLength = sizeof(offset);
-    OSStatus err = MusicTrackGetProperty(self.musicTrack, kSequenceTrackProperty_OffsetTime, &offset, &offsetLength);
-    if (err) NSLog(@"MusicTrackGetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
-    return offset;
+	if (_offset != 0) return _offset;
+
+	if (self.musicTrack) {
+		MusicTimeStamp offset = 0;
+		UInt32 offsetLength = sizeof(offset);
+		OSStatus err = MusicTrackGetProperty(self.musicTrack, kSequenceTrackProperty_OffsetTime, &offset, &offsetLength);
+		if (err) NSLog(@"MusicTrackGetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
+		return offset;
+	} else {
+		return 0;
+	}
 }
 
 - (void)setOffset:(MusicTimeStamp)offset
 {
-    OSStatus err = MusicTrackSetProperty(self.musicTrack, kSequenceTrackProperty_OffsetTime, &offset, sizeof(offset));
-    if (err) NSLog(@"MusicTrackSetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
+	_offset = offset;
+
+	if (self.musicTrack) {
+		OSStatus err = MusicTrackSetProperty(self.musicTrack, kSequenceTrackProperty_OffsetTime, &offset, sizeof(offset));
+		if (err) NSLog(@"MusicTrackSetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
+	}
 }
 
+@synthesize muted = _muted;
+
 - (BOOL)isMuted
 {
-    Boolean isMuted = FALSE;
-    UInt32 isMutedLength = sizeof(isMuted);
-    OSStatus err = MusicTrackGetProperty(self.musicTrack, kSequenceTrackProperty_MuteStatus, &isMuted, &isMutedLength);
-    if (err) NSLog(@"MusicTrackGetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
-    return isMuted ? YES : NO;
+	if (_muted) return YES;
+
+	if (self.musicTrack) {
+		Boolean isMuted = FALSE;
+		UInt32 isMutedLength = sizeof(isMuted);
+		OSStatus err = MusicTrackGetProperty(self.musicTrack, kSequenceTrackProperty_MuteStatus, &isMuted, &isMutedLength);
+		if (err) NSLog(@"MusicTrackGetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
+		return isMuted ? YES : NO;
+	} else {
+		return NO;
+	}
 }
 
 - (void)setMuted:(BOOL)muted
 {
-    Boolean mutedBoolean = muted ? TRUE : FALSE;
-    OSStatus err = MusicTrackSetProperty(self.musicTrack, kSequenceTrackProperty_MuteStatus, &mutedBoolean, sizeof(mutedBoolean));
-    if (err) NSLog(@"MusicTrackSetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
+	_muted = muted;
+
+	if (self.musicTrack) {
+		Boolean mutedBoolean = muted ? TRUE : FALSE;
+		OSStatus err = MusicTrackSetProperty(self.musicTrack, kSequenceTrackProperty_MuteStatus, &mutedBoolean, sizeof(mutedBoolean));
+		if (err) NSLog(@"MusicTrackSetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
+	}
 }
 
+@synthesize solo = _solo;
+
 - (BOOL)isSolo
 {
-    Boolean isSolo = FALSE;
-    UInt32 isSoloLength = sizeof(isSolo);
-    OSStatus err = MusicTrackGetProperty(self.musicTrack, kSequenceTrackProperty_SoloStatus, &isSolo, &isSoloLength);
-    if (err) NSLog(@"MusicTrackGetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
-    return isSolo ? YES : NO;
+	if (_solo) return YES;
+
+	if (self.musicTrack) {
+		Boolean isSolo = FALSE;
+		UInt32 isSoloLength = sizeof(isSolo);
+		OSStatus err = MusicTrackGetProperty(self.musicTrack, kSequenceTrackProperty_SoloStatus, &isSolo, &isSoloLength);
+		if (err) NSLog(@"MusicTrackGetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
+		return isSolo ? YES : NO;
+	} else {
+		return NO;
+	}
 }
 
 - (void)setSolo:(BOOL)solo
 {
-    Boolean soloBoolean = solo ? TRUE : FALSE;
-    OSStatus err = MusicTrackSetProperty(self.musicTrack, kSequenceTrackProperty_SoloStatus, &soloBoolean, sizeof(soloBoolean));
-    if (err) NSLog(@"MusicTrackSetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
+	_solo = solo;
+
+	if (self.musicTrack) {
+		Boolean soloBoolean = solo ? TRUE : FALSE;
+		OSStatus err = MusicTrackSetProperty(self.musicTrack, kSequenceTrackProperty_SoloStatus, &soloBoolean, sizeof(soloBoolean));
+		if (err) NSLog(@"MusicTrackSetProperty() failed with error %@ in %s.", @(err), __PRETTY_FUNCTION__);
+	}
 }
 
 + (NSSet *)keyPathsForValuesAffectingLength