Prevent UINavigationBar from stealing touches

DMNavigationBar.h

@interface DMNavigationBar : UINavigationBar

@property (nonatomic, assign) BOOL shouldOnlyReceiveTouchEventsInsideNavigationBar;

@end

DMNavigationBar.m

#import "DMNavigationBar.h"
#import "UIResponder+FirstResponder.h"

@interface DMNavigationBar ()

@property (nonatomic, assign) BOOL changingUserInteraction;
@property (nonatomic, assign) BOOL userInteractionChangedBySystem;

@end

@implementation DMNavigationBar

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
    if (self.shouldOnlyReceiveTouchEventsInsideNavigationBar)
    {
        if (self.userInteractionChangedBySystem && self.userInteractionEnabled == NO)
        {
            return [super hitTest:point withEvent:event];
        }
        
        UIView *firstResponder = [UIResponder currentFirstResponder];
        BOOL isFirstResponderADescendantView = [firstResponder isKindOfClass:[UIView class]] && [firstResponder isDescendantOfView:self];
        if ([self pointInside:point withEvent:event] || isFirstResponderADescendantView)
        {
            self.changingUserInteraction = YES;
            self.userInteractionEnabled = YES;
            self.changingUserInteraction = NO;
        }
        else
        {
            self.changingUserInteraction = YES;
            self.userInteractionEnabled = NO;
            self.changingUserInteraction = NO;
        }
    }
    
    return [super hitTest:point withEvent:event];
}

- (void)setUserInteractionEnabled:(BOOL)userInteractionEnabled
{
    if (self.shouldOnlyReceiveTouchEventsInsideNavigationBar)
    {
        if (!self.changingUserInteraction)
        {
            self.userInteractionChangedBySystem = YES;
        }
        else
        {
            self.userInteractionChangedBySystem = NO;
        }
    }
    
    [super setUserInteractionEnabled:userInteractionEnabled];
}

@end

UIResponder+FirstResponder.h

@interface UIResponder (FirstResponder)

+ (id)currentFirstResponder;

@end

UIResponder+FirstResponder.m

#import "UIResponder+FirstResponder.h"

static __weak id currentFirstResponder;

@implementation UIResponder (FirstResponder)

+ (id)currentFirstResponder
{
    currentFirstResponder = nil;
    [[UIApplication sharedApplication] sendAction:@selector(findFirstResponder:) to:nil from:nil forEvent:nil];
    return currentFirstResponder;
}

- (void)findFirstResponder:(id)sender
{
    currentFirstResponder = self;
}

@end