144 lines
4.7 KiB
Objective-C
144 lines
4.7 KiB
Objective-C
//
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// MIKMIDIMetaKeySignatureEvent.m
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// MIDI Files Testbed
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//
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// Created by Jake Gundersen on 5/23/14.
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// Copyright (c) 2014 Mixed In Key. All rights reserved.
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//
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#import "MIKMIDIMetaKeySignatureEvent.h"
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#import "MIKMIDIMetaEvent_SubclassMethods.h"
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#import "MIKMIDIUtilities.h"
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#if !__has_feature(objc_arc)
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#error MIKMIDIMetaKeySignatureEvent.m must be compiled with ARC. Either turn on ARC for the project or set the -fobjc-arc flag for MIKMIDIMetaKeySignatureEvent.m in the Build Phases for this target
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#endif
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@implementation MIKMIDIMetaKeySignatureEvent
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+ (void)load { [MIKMIDIEvent registerSubclass:self]; }
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+ (NSArray *)supportedMIDIEventTypes { return @[@(MIKMIDIEventTypeMetaKeySignature)]; }
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+ (Class)immutableCounterpartClass { return [MIKMIDIMetaKeySignatureEvent class]; }
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+ (Class)mutableCounterpartClass { return [MIKMutableMIDIMetaKeySignatureEvent class]; }
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+ (BOOL)isMutable { return NO; }
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+ (NSData *)initialData
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{
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NSMutableData *result = [NSMutableData dataWithBytes:&(MIDIMetaEvent){0} length:sizeof(MIDIMetaEvent)];
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MIDIMetaEvent *metaEvent = (MIDIMetaEvent *)[result mutableBytes];
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metaEvent->dataLength = 2;
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metaEvent->metaEventType = MIKMIDIMetaEventTypeKeySignature;
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NSInteger metaDataLength = result.length - MIKMIDIEventMetadataStartOffset;
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if (metaDataLength < 2) { [result increaseLengthBy:2-metaDataLength]; }
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UInt8 *metaDataBytes = (UInt8 *)[result mutableBytes] + MIKMIDIEventMetadataStartOffset;
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metaDataBytes[0] = 0; // C
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metaDataBytes[1] = 0; // Major
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return [result copy];
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}
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- (instancetype)initWithMusicalKey:(MIKMIDIMusicalKey)musicalKey timeStamp:(MusicTimeStamp)timeStamp
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{
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NSMutableData *metaData = [[NSMutableData alloc] init];
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int8_t scale = [self scaleForMusicalKey:musicalKey];
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UInt8 numberOfFlatsAndSharps = [self numberOfFlatsAndSharpsInMusicalKey:musicalKey];
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[metaData appendBytes:&(UInt8){numberOfFlatsAndSharps} length:1];
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[metaData appendBytes:&(int8_t){scale} length:1];
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return [self initWithMetaData:metaData timeStamp:timeStamp];
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}
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#pragma mark - Private
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- (MIKMIDIMusicalKey)musicalKeyForNumberOfFlatsAndSharps:(int8_t)flatsSharps scale:(MIKMIDIMusicalScale)scale
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{
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return flatsSharps + scale * 100;
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}
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- (MIKMIDIMusicalScale)scaleForMusicalKey:(MIKMIDIMusicalKey)musicalKey
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{
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return musicalKey > 7 ? MIKMIDIMusicalScaleMinor : MIKMIDIMusicalScaleMajor;
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}
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- (int8_t)numberOfFlatsAndSharpsInMusicalKey:(MIKMIDIMusicalKey)musicalKey
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{
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MIKMIDIMusicalScale scale = [self scaleForMusicalKey:musicalKey];
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return musicalKey - scale * 100;
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}
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#pragma mark - Properties
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+ (NSSet *)keyPathsForValuesAffectingValueForKey:(NSString *)key
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{
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NSSet *keyPaths = [super keyPathsForValuesAffectingValueForKey:key];
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if ([key isEqualToString:@"key"] || [key isEqualToString:@"scale"] ||
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[key isEqualToString:@"musicalKey"] || [key isEqualToString:@"numberOfFlatsAndSharps"]) {
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keyPaths = [keyPaths setByAddingObject:@"metaData"];
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}
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return keyPaths;
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}
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- (MIKMIDIMusicalKey)musicalKey
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{
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return [self musicalKeyForNumberOfFlatsAndSharps:self.numberOfFlatsAndSharps scale:self.scale];
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}
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- (void)setMusicalKey:(MIKMIDIMusicalKey)musicalKey
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{
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self.scale = [self scaleForMusicalKey:musicalKey];
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self.numberOfFlatsAndSharps = [self numberOfFlatsAndSharpsInMusicalKey:musicalKey];
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}
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- (int8_t)numberOfFlatsAndSharps
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{
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return *(int8_t*)[self.metaData bytes];
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}
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- (void)setNumberOfFlatsAndSharps:(int8_t)numberOfFlatsAndSharps
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{
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if (![[self class] isMutable]) return MIKMIDI_RAISE_MUTATION_ATTEMPT_EXCEPTION;
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NSMutableData *mutableMetaData = [self.metaData mutableCopy];
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[mutableMetaData replaceBytesInRange:NSMakeRange(0, 1) withBytes:&numberOfFlatsAndSharps length:1];
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[self setMetaData:[mutableMetaData copy]];
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}
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- (MIKMIDIMusicalScale)scale
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{
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return *((MIKMIDIMusicalScale*)[self.metaData bytes] + 1);
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}
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- (void)setScale:(MIKMIDIMusicalScale)scale
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{
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if (![[self class] isMutable]) return MIKMIDI_RAISE_MUTATION_ATTEMPT_EXCEPTION;
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NSMutableData *mutableMetaData = [self.metaData mutableCopy];
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[mutableMetaData replaceBytesInRange:NSMakeRange(1, 1) withBytes:&scale length:1];
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[self setMetaData:[mutableMetaData copy]];
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}
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- (NSString *)additionalEventDescription
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{
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return [NSString stringWithFormat:@"Metadata Type: 0x%02x, Key: %d, Scale %d", self.metadataType, self.numberOfFlatsAndSharps, self.scale];
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}
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@end
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@implementation MIKMutableMIDIMetaKeySignatureEvent
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@dynamic timeStamp;
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@dynamic metadataType;
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@dynamic metaData;
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@dynamic musicalKey;
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@dynamic numberOfFlatsAndSharps;
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@dynamic scale;
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+ (BOOL)isMutable { return YES; }
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@end
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#pragma mark -
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@implementation MIKMIDIMetaKeySignatureEvent (Deprecated)
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- (UInt8)key { return self.numberOfFlatsAndSharps; }
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- (void)setKey:(UInt8)key { self.numberOfFlatsAndSharps = key; }
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@end |