UITabBar items jumping on back navigation on iOS 12.1

Question

I have an iOS app with UITabBarController on a master screen, navigating to a detail screen hiding the UITabBarController with setting hidesB

Answer 1

Thanks for the idea of @ElonChan, I just changed the c inline function to OC static method, since I won't use this overrideImplementation too much. And also, this snippet was adjusted to iPhoneX now.

static CGFloat const kIPhoneXTabbarButtonErrorHeight = 33;
static CGFloat const kIPhoneXTabbarButtonHeight = 48;


@implementation FixedTabBar


typedef void(^NewTabBarButtonFrameSetter)(UIView *, CGRect);
typedef NewTabBarButtonFrameSetter (^ImpBlock)(Class originClass, SEL originCMD, IMP originIMP);


+ (BOOL)overrideImplementationWithTargetClass:(Class)targetClass targetSelector:(SEL)targetSelector implementBlock:(ImpBlock)implementationBlock {
    Method originMethod = class_getInstanceMethod(targetClass, targetSelector);
    if (!originMethod) {
        return NO;
    }
    IMP originIMP = method_getImplementation(originMethod);
    method_setImplementation(originMethod, imp_implementationWithBlock(implementationBlock(targetClass, targetSelector, originIMP)));
    return YES;
}


+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        if (@available(iOS 12.1, *)) {
            [self overrideImplementationWithTargetClass:NSClassFromString(@"UITabBarButton")
                                         targetSelector:@selector(setFrame:)
                                         implementBlock:^NewTabBarButtonFrameSetter(__unsafe_unretained Class originClass, SEL originCMD, IMP originIMP) {
                return ^(UIView *selfObject, CGRect firstArgv) {
                    if ([selfObject isKindOfClass:originClass]) {
                        if (!CGRectIsEmpty(selfObject.frame) && CGRectIsEmpty(firstArgv)) {
                            return;
                        }
                        if (firstArgv.size.height == kIPhoneXTabbarButtonErrorHeight) {
                            firstArgv.size.height = kIPhoneXTabbarButtonHeight;
                        }
                    }
                    void (*originSelectorIMP)(id, SEL, CGRect);
                    originSelectorIMP = (void (*)(id, SEL, CGRect))originIMP;
                    originSelectorIMP(selfObject, originCMD, firstArgv);
                };
            }];
        }
    });
}

@end