Enabled iOS style UICollectionView multiple selection on Catalyst applications

UICollectionView+CTX.h

//
//  UICollectionView+CTX.h
//  EFClass-Mac
//
//  Created by Stefan Ceriu on 29/11/2019.
//  Copyright © 2019 EF Education First. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface UICollectionView (CTX)

@end

UICollectionView+CTX.m

//
//  UICollectionView+CTX.m
//  EFClass-Mac
//
//  Created by Stefan Ceriu on 29/11/2019.
//  Copyright © 2019 EF Education First. All rights reserved.
//

#import "UICollectionView+CTX.h"

#import <objc/runtime.h>

static void * CTXSelectedItemIndexPathPropertyKey = &CTXSelectedItemIndexPathPropertyKey;

@interface UICollectionView ()

@property (nonatomic, strong) NSIndexPath *ctx_selectedItemIndexPath;

@end

@implementation UICollectionView (CTX)

+ (void)load
{
#if TARGET_OS_MACCATALYST
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        CTXSwizzleInstanceMethod([self class], NSSelectorFromString(@"_userSelectItemAtIndexPath:"), @selector(ctx_userSelectItemAtIndexPath:));
        CTXSwizzleInstanceMethod([self class], NSSelectorFromString(@"_deselectAllAnimated:notifyDelegate:"), @selector(ctx_deselectAllAnimated:notifyDelegate:));
        CTXSwizzleInstanceMethod([self class], NSSelectorFromString(@"_deselectItemAtIndexPath:animated:notifyDelegate:"),
                                 @selector(ctx_deselectItemAtIndexPath:animated:notifyDelegate:));
    });
#endif
}

- (void)ctx_userSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    self.ctx_selectedItemIndexPath = indexPath;
    
    [self ctx_userSelectItemAtIndexPath:indexPath];
}

- (void)ctx_deselectAllAnimated:(BOOL)animated notifyDelegate:(BOOL)notifyDelegate
{
    if(self.ctx_selectedItemIndexPath && [self.indexPathsForSelectedItems containsObject:self.ctx_selectedItemIndexPath]) {
        if([self.delegate respondsToSelector:@selector(collectionView:shouldDeselectItemAtIndexPath:)]) {
            if([self.delegate collectionView:self shouldDeselectItemAtIndexPath:self.ctx_selectedItemIndexPath]) {
                dispatch_async(dispatch_get_main_queue(), ^{
                    [self ctx_deselectItemAtIndexPath:self.ctx_selectedItemIndexPath animated:animated notifyDelegate:YES];
                    self.ctx_selectedItemIndexPath = nil;
                });
            }
        }
    }
}

- (void)ctx_deselectItemAtIndexPath:(NSIndexPath *)indexPath animated:(BOOL)animated notifyDelegate:(BOOL)notifyDelegate
{
    [self ctx_deselectItemAtIndexPath:indexPath animated:animated notifyDelegate:notifyDelegate];
}

- (NSIndexPath *)ctx_selectedItemIndexPath
{
    return objc_getAssociatedObject(self, CTXSelectedItemIndexPathPropertyKey);
}

- (void)setCtx_selectedItemIndexPath:(NSIndexPath *)unicorn {
    objc_setAssociatedObject(self, CTXSelectedItemIndexPathPropertyKey, unicorn, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

static void CTXSwizzleInstanceMethod(Class class, SEL originalSelector, SEL swizzledSelector) {
    Method originalMethod = class_getInstanceMethod(class, originalSelector);
    Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
    
    if (class_addMethod(class, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod))) {
        class_replaceMethod(class, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod));
    } else {
        method_exchangeImplementations(originalMethod, swizzledMethod);
    }
}

@end

This was working great for me but something seems to have changed recently. I've just run my app on Xcode 13.3.1 and macOS 12.3.1 and func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) { is no longer being called when this swizzling is being done. I also ran into problems with indexPathsForSelectedItems returning multiple values on CollectionViews where allowsMultipleSelection is false.