Objective-C properties of protocols that take blocks/closures and accessing them in Swift

CreateImageProtocol.h

//
//  CreateImageProtocol.h
//  test
//
//  Created by Kevin Meaney on 17/10/2014.
//  Copyright (c) 2014 Kevin Meaney. All rights reserved.
//

#import <Foundation/Foundation.h>

@protocol CreateImageProtocol <NSObject>

-(NSInteger)imageWidth;

@optional
@property (nonatomic, copy) CGImageRef(^createImage)(NSDictionary *);
@end

id<CreateImageProtocol>MakeImageProvider();

ImageProvider.h

//
//  ImageProvider.h
//  test
//
//  Created by Kevin Meaney on 17/10/2014.
//  Copyright (c) 2014 Kevin Meaney. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "CreateImageProtocol.h"

@interface ImageProvider : NSObject <CreateImageProtocol>

@end

ImageProvider.m

//
//  ImageProvider.m
//  test
//
//  Created by Kevin Meaney on 17/10/2014.
//  Copyright (c) 2014 Kevin Meaney. All rights reserved.
//

#import "ImageProvider.h"

@implementation ImageProvider

@synthesize createImage;

-(NSInteger)imageWidth
{
    if (self.createImage)
    {
        CGImageRef myImage = self.createImage(
            @{ @"imagefilepath" : @"/Users/ktam/Pictures/julieanneInNZ.jpg" });
        if (myImage)
            return CGImageGetWidth(myImage);
    }
    return -1;
}

@end

id<CreateImageProtocol>MakeImageProvider()
{
    return [[ImageProvider alloc] init];
}

ImageProvider2.h

//
//  ImageProvider2.h
//  test
//
//  Created by Kevin Meaney on 17/10/2014.
//  Copyright (c) 2014 Kevin Meaney. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface ImageProvider2 : NSObject

-(NSInteger)imageWidth;

@property (nonatomic, copy) CGImageRef(^createImage)(NSDictionary *);

@end

ImageProvider2.m

//
//  ImageProvider2.m
//  test
//
//  Created by Kevin Meaney on 17/10/2014.
//  Copyright (c) 2014 Kevin Meaney. All rights reserved.
//

#import "ImageProvider2.h"

@implementation ImageProvider2

@synthesize createImage;

-(NSInteger)imageWidth
{
    if (self.createImage)
    {
        CGImageRef myImage = self.createImage(
            @{ @"imagefilepath" : @"/Users/ktam/Pictures/julieanneInNZ.jpg" });
        if (myImage)
            return CGImageGetWidth(myImage);
    }
    return -1;
}

@end

main.m

//
//  main.m
//  test
//
//  Created by Kevin Meaney on 17/10/2014.
//  Copyright (c) 2014 Kevin Meaney. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "test-Swift.h"

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // NSInteger theWidth = getImageWidth2();
        NSInteger theWidth = ClassMethodWrapper.getImageWidth;
        printf("Image width: %ld\n", theWidth);
        // insert code here...
        // NSLog(@"Hello, World!");
    }
    return 0;
}

SupplyCreateImage

//
//  SupplyCreateImage.swift
//  test
//
//  Created by Kevin Meaney on 17/10/2014.
//  Copyright (c) 2014 Kevin Meaney. All rights reserved.
//

import Foundation

public func makeImage(dict : [ NSObject:AnyObject]! ) -> Unmanaged<CGImageRef>! {
    let thePath = dict["imagefilepath"]! as String
    let jpegURL = NSURL.fileURLWithPath(thePath, isDirectory: false)
    let imageSource = CGImageSourceCreateWithURL(jpegURL, nil)!
    let theImage = CGImageSourceCreateImageAtIndex(imageSource, 0, nil)
    let x = Unmanaged.passUnretained(theImage);
    //    x.autorelease()
    return x
}

/*
public func getImageWidth() -> Int {
    var imageProvider:AnyObject = MakeImageProvider()
    imageProvider.setCreateImage?(makeImage)
    imageProvider.imageWidth()
}
*/

public func getImageWidth2() -> Int {
    let imageProvider = ImageProvider2()
    imageProvider.createImage = makeImage
    return imageProvider.imageWidth()
}

// public class ClassMethodWrapper : NSObject {
class ClassMethodWrapper : NSObject {
    //    public class func getImageWidth() -> Int {
    class func getImageWidth() -> Int {
        let imageProvider = ImageProvider2()
        imageProvider.createImage = makeImage
        return imageProvider.imageWidth()
    }
}