Enlarges the tap radius of small UICollectionViews

SEUIEnlargedTapRadiusCollectionView.h

#import <UIKit/UIKit.h>

IB_DESIGNABLE
@interface SEUIEnlargedTapRadiusCollectionView : UICollectionView
@property (nonatomic, assign) IBInspectable CGFloat enlargedTapRadius;
@end

SEUIEnlargedTapRadiusCollectionView.m

#import "SEUIEnlargedTapRadiusCollectionView.h"

CGPoint ShiftNearbyPointInside(CGPoint point, CGRect bounds, CGFloat radius) {
    if (point.y < 0 && point.y > -radius) {
        point.y = 5;
    }
    
    if (point.y > CGRectGetMaxY(bounds) && point.y < CGRectGetMaxY(bounds) + radius) {
        point.y = CGRectGetMaxY(bounds) - 5;
    }
    
    return point;
}

@implementation SEUIEnlargedTapRadiusCollectionView


- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
    return [super hitTest:ShiftNearbyPointInside(point, self.bounds, self.enlargedTapRadius) withEvent:event];
}

/**
 @discussion
 hitTest:withEvent: is good enough to get the cell to highlight on touch (become the first responder) but then the actual tap calculations are based on the touch, which is not translated.  We will cheat like hell here, it may not be amazing for weird edge cases like dragging.
 */
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    [super touchesEnded:touches withEvent:event];
    
    if (touches.count != 1) {
        return;
    }
    
    UITouch *touch = [touches anyObject];
    CGPoint locationInView = [touch locationInView:self];
    
    UIView *desiredHitView = [self hitTest:locationInView withEvent:event];
    UIView *actualHitView = [super hitTest:locationInView withEvent:event];
    
    if (desiredHitView == actualHitView) {
        return;
    }
    
    while (desiredHitView && ![desiredHitView isKindOfClass:[UICollectionViewCell class]]) {
        desiredHitView = desiredHitView.superview;
    }
    
    if (desiredHitView == nil) {
        return;
    }
    
    NSIndexPath *indexPath = [self indexPathForCell:(UICollectionViewCell *)desiredHitView];
    
    if (indexPath) {
        [self.delegate collectionView:self didSelectItemAtIndexPath:indexPath];
    }
}

@end