// LYTabBarController.m

@implementation LYTabBarController
#import "LYTabBarController.h"
#import "LYNavigationController.h"
#import "LYTabBar"

- (void)viewDidLoad {
    [super viewDidLoad];

    [self setupChildViewController:[[LYFirstViewController alloc] init] title:@"titleFirst" imageName:@"imageNameFirst" selectedImageName:@"selectedImageNameFirst"];
    [self setupChildViewController:[[LYSecondViewController alloc] init] title:@"titleSecond" imageName:@"imageNameSecond" selectedImageName:@"selectedImageNameSecond"];
    [self setupChildViewController:[[LYThirdViewController alloc] init] title:@"titleThird" imageName:@"imageNameThird" selectedImageName:@"selectedImageNameThird"];
    [self setupChildViewController:[[LYFourthViewController alloc] init] title:@"titleFourth" imageName:@"imageNameFourth" selectedImageName:@"selctedImageNameFourth"];

    // set my tabBar
    [self setValue:[[LYTabBar alloc] init] forKeyPath:@"tabbar"];
}

- (void)setupChildViewController:(UIViewController)vc title:(NSString *)title imageName:(NSString *)imageName selectedImageName:(NSString *)selectedImageName {
    vc.navigationItem.title = title;
    vc.tabBarItem.title = title;
    vc.tabBarItem.image = [UIImage imageNamed:imageName];
    vc.tabBarItem.selectedImage = [UIImage imageNamed:selectedImageName];

    LYNavigationController *navigationController = [[LYNavigationController alloc] initWithRootViewController:vc];
    [self addChildViewController:navigationController];
}

@end

// LYTabBar.m

#import "LYTabBar.h"

@interface LYTabBar()

/**publishButton**/
@propertity(nonatomic, weak) UIButton *publishButton;

@end

@implementation LYTabBar
- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        // set tabBar.backgroundImage
        [self.tabBar setBackgroundImage:[UIImage imageNamed:@"tabBarBackgroundImageName"]];

        // set navigationBar.backgroundImage
        // [navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"navigationBarBackgroundImage"] forBarMetrics:UIBarMetrisDefault];
        // [[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:@"navigationBarBackgroundImage"] forBarMetrics:UIBarMetrisDefault];

        UIButton *publishButton = [UIButton buttonWithType:UIButtonTypeCustom];
        [publishButton setBackgroundImage:[UIImage imageNamed:@"tabBar_publish_icon"] forState:UIControlStateNormal];
        [publishButton setBackgroundImage:[UIImage imageNamed:@"tabBar_publish_click_icon"]];
        [self addSubview:publishButton];
    }
    return self;
}

- (void)layoutSubviews {
    [super layoutSubviews];

    // set publishButton.frame
    self.publishButton.bounds = CGRectMake(0, 0, self.publishButton.currentBackgroundImage.size.width, self.publishButton.currentBackgroundImage.size.height);
    self.publishButton.center = CGPointMake(self.frame.size.width * 0.5, self.frame.size.height * 0.5);

    // set other UITabBarButton.frame
    for (UIView *button in self.subviews) {
    CGFloat buttonY = 0;
    CGFloat buttonW = self.frame.size.width / 5;
    CGFloat buttonH = self.frame.size.height;
    NSInteger index = 0;

    if (![button isKindOfClass:NSClassFromString(@"UITabBarButton")]) continue;

        // set buttonX
        CGFloat buttonX = buttonW * ((index > 1) ? (index + 1) : index);
        button.frame = CGRectMake(indexX, indexY, indexW, indexH);
    }

}

@end