#import "UYNavigationController.h"

@interface UYNavigationController ()

@end

@implementation UYNavigationController

+ (void)initialize
{
    // 设置整个项目所有item的主题样式
    UIBarButtonItem *item = [UIBarButtonItem appearance];
    
    // 设置普通状态
    // key：NS****AttributeName
    NSMutableDictionary *textAttrs = [NSMutableDictionary dictionary];
    textAttrs[NSForegroundColorAttributeName] = [UIColor orangeColor];
    textAttrs[NSFontAttributeName] = [UIFont systemFontOfSize:13];
    [item setTitleTextAttributes:textAttrs forState:UIControlStateNormal];
    
    // 设置不可用状态
    NSMutableDictionary *disableTextAttrs = [NSMutableDictionary dictionary];
    disableTextAttrs[NSForegroundColorAttributeName] = [UIColor colorWithRed:0.6 green:0.6 blue:0.6 alpha:0.7];
    disableTextAttrs[NSFontAttributeName] = [UIFont systemFontOfSize:13];
    [item setTitleTextAttributes:disableTextAttrs forState:UIControlStateDisabled];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

/**
 *  重写这个方法目的：能够拦截所有push进来的控制器
 *
 *  @param viewController 即将push进来的控制器
 */
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (self.viewControllers.count > 0) { // 这时push进来的控制器viewController，不是第一个子控制器（不是根控制器）
        /* 自动显示和隐藏tabbar */
        viewController.hidesBottomBarWhenPushed = YES;
    }
    
    [super pushViewController:viewController animated:animated];
}

- (void)back
{
#warning 这里要用self，不是self.navigationController
    // 因为self本来就是一个导航控制器，self.navigationController这里是nil的
    [self popViewControllerAnimated:YES];
}

- (void)more
{
    [self popToRootViewControllerAnimated:YES];
}

@end

    // 2.更换系统自带的tabbar,由于tabbar是realonly，因此使用KVC来重写。如果没有特殊的导航布局，去掉这下面这部分代码即可。
    UYTabBar *tabBar = [[UYTabBar alloc] init];
    tabBar.delegate = self;
    [self setValue:tabBar forKeyPath:@"tabBar"];

#import <UIKit/UIKit.h>
@class UYTabBar;

#warning 因为UYTabBar继承自UITabBar，所以称为UYTabBar的代理，也必须实现UITabBar的代理协议
@protocol UYTabBarDelegate <UITabBarDelegate>
@optional
- (void)tabBarDidClickPlusButton:(UYTabBar *)tabBar;
@end

@interface UYTabBar : UITabBar
@property (nonatomic, weak) id<UYTabBarDelegate> delegate;
@end

#import "UYTabBar.h"

@interface UYTabBar()
@property(nonatomic,weak) UIButton *plusBtn;
@end

@implementation UYTabBar

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // 添加一个+号按钮 到tabbar中
        UIButton *plusBtn = [[UIButton alloc] init];
        //设置背影
        [plusBtn setBackgroundImage:[UIImage imageNamed:@"tabbar_compose_button"] forState:UIControlStateNormal];
        [plusBtn setBackgroundImage:[UIImage imageNamed:@"tabbar_compose_button_highlighted"] forState:UIControlStateHighlighted];
        //增加+号图片
        [plusBtn setImage:[UIImage imageNamed:@"tabbar_compose_icon_add"] forState:UIControlStateNormal];
        [plusBtn setImage:[UIImage imageNamed:@"tabbar_compose_icon_add_highlighted"] forState:UIControlStateHighlighted];
        plusBtn.size = plusBtn.currentBackgroundImage.size;
        [plusBtn addTarget:self action:@selector(plusClick) forControlEvents:UIControlEventTouchUpInside];
        [self addSubview:plusBtn];
        self.plusBtn = plusBtn;
    }
    return self;
}


/**
 *  加号按钮点击
 */
- (void)plusClick
{
    // 通知代理
    if ([self.delegate respondsToSelector:@selector(tabBarDidClickPlusButton:)]) {
        [self.delegate tabBarDidClickPlusButton:self];
    }
}


- (void)layoutSubviews
{
#warning [super layoutSubviews] 一定要调用
    [super layoutSubviews];
    
    // 1.设置加号按钮的位置
    self.plusBtn.centerX = self.width * 0.5;
    self.plusBtn.centerY = self.height * 0.5;
    
    // 2.设置其他tabbarButton的位置和尺寸
    CGFloat tabbarButtonW = self.width / 5;
    CGFloat tabbarButtonIndex = 0;
    for (UIView *child in self.subviews) {
        Class class = NSClassFromString(@"UITabBarButton");
        if ([child isKindOfClass:class]) {
            // 设置宽度
            child.width = tabbarButtonW;
            // 设置x
            child.x = tabbarButtonIndex * tabbarButtonW;
            
            // 增加索引
            tabbarButtonIndex++;
            if (tabbarButtonIndex == 2) {
                tabbarButtonIndex++;
            }
        }
    }
}

@end