Simple Log of UIGestureRecognizer

LogGesture.m

#import <objc/runtime.h>

void LogGesture(UIGestureRecognizer *gestureRecognizer) {
    id object = [[gestureRecognizer valueForKey:@"targets"] firstObject];
    id target = [object valueForKey:@"target"];
    Ivar ivar = class_getInstanceVariable([object class], "_action");
    SEL action = (__bridge void *)object_getIvar(object, ivar);
    NSMutableString *mString = [NSMutableString stringWithFormat:@"%@; action=%@; target=%@;",
                                NSStringFromClass(gestureRecognizer.class),
                                NSStringFromSelector(action),
                                NSStringFromClass([target class])];
    if ([gestureRecognizer respondsToSelector:@selector(numberOfTouchesRequired)]) {
        NSUInteger number = [(id)gestureRecognizer numberOfTouchesRequired];
        if (number != 0) {
            [mString appendFormat:@" numberOfTouchesRequired=%lu;", (unsigned long)number];
        }
    }
    if ([gestureRecognizer respondsToSelector:@selector(numberOfTapsRequired)]) {
        NSUInteger number = [(id)gestureRecognizer numberOfTapsRequired];
        if (number != 0) {
            [mString appendFormat:@" numberOfTapsRequired=%lu;", (unsigned long)number];
        }
    }
    NSLog(@"%@", mString);
}