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objective-cswiftxcodeaudiokit

AudioKit: AKFFTTap "'init' is unavailable" in Objective-C

When I try to create new instance of AKFFTap in Objective-C, it claims that the init function is not available

This line gives me the error: "No visible @interface for 'AKFFTTap' declares the selector 'init:'"

AKFFTTap *tap = [[AKFFTTap alloc] init:_player]

This line gives me the error: "'init' is not available"

AKFFTTap *tap = [[AKFFTTap alloc] init];

How can I initialize it in Objective-C?

I'm using version 4.2.2

UPDATE:

AKFFTTap *tap = [[AKFFTTap alloc] initWithInput:_player];

Gives me the error; "No visible @interface for 'AKFFTTap' declares the selector 'initWithInput:'"

I'm importing the following in my header file

#import <AudioKit/AudioKit.h> 
#import <AudioKit/AudioKit-Swift.h>
Solution

  • Figured it out

    The init method in AKFFTTap.swift was missing the @objc flag and so it's not revealed to Objective-C code public init(_ input: AKNode, fftSize: AKSettings.BufferLength = .veryLong)

    This results in AudioKit-Swift.h not having an init method that can be used for AKFFTTap

    SWIFT_CLASS("_TtC8AudioKit8AKFFTTap")
@interface AKFFTTap : NSObject <EZAudioFFTDelegate>
/// Array of FFT data
@property (nonatomic, copy) NSArray<NSNumber *> * _Nonnull fftData;

- (void)fft:(EZAudioFFT * _Null_unspecified)fft updatedWithFFTData:(float * _Nonnull)fftData bufferSize:(vDSP_Length)bufferSize;
- (nonnull instancetype)init SWIFT_UNAVAILABLE;
+ (nonnull instancetype)new SWIFT_UNAVAILABLE_MSG("-init is unavailable");
@end

    I was able to fix this on my end by adding @objc onto the Swift method, which then added the init method to AudioKit-Swift.h. I was able to successfully initialize the tap and get spectral data

    In AKFFTTap.swift: @objc public init(_ input: AKNode, fftSize: AKSettings.BufferLength = .veryLong)

    After rebuilding the framework, resulted in this block of code in AudioKit-Swift.h:

    SWIFT_CLASS("_TtC8AudioKit8AKFFTTap")
@interface AKFFTTap : NSObject <EZAudioFFTDelegate>
/// Array of FFT data
@property (nonatomic, copy) NSArray<NSNumber *> * _Nonnull fftData;
/// Initialze the FFT calculation on a given node
/// \param input Node on whose output the FFT will be computed
///
/// \param fftSize The sample size of the FFT buffer
///
- (nonnull instancetype)init:(AKNode * _Nonnull)input fftSize:(enum BufferLength)fftSize OBJC_DESIGNATED_INITIALIZER;
- (void)fft:(EZAudioFFT * _Null_unspecified)fft updatedWithFFTData:(float * _Nonnull)fftData bufferSize:(vDSP_Length)bufferSize;
- (nonnull instancetype)init SWIFT_UNAVAILABLE;
+ (nonnull instancetype)new SWIFT_UNAVAILABLE_MSG("-init is unavailable");
@end