//
//  KJNavgationController.m
//
//  Created by mac on 16/2/22.
//  Copyright © 2016年 mac. All rights reserved.
//

#import "KJNavgationController.h"

@interface KJNavgationController ()<UIGestureRecognizerDelegate,UINavigationControllerDelegate>

@end

@implementation KJNavgationController
-(void)viewDidLoad{
    [super viewDidLoad];
    
    __weak KJNavgationController *weakSelf = self;
   
    if ([self respondsToSelector:@selector(interactivePopGestureRecognizer)])
    {
        self.interactivePopGestureRecognizer.delegate = weakSelf;
        self.delegate = weakSelf;
    }
}

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    //控制器入栈过程中禁用手势识别
    if ([self respondsToSelector:@selector(interactivePopGestureRecognizer)])
        self.interactivePopGestureRecognizer.enabled = NO;
    
    [super pushViewController:viewController animated:animated];
}

#pragma mark UINavigationControllerDelegate
- (void)navigationController:(UINavigationController *)navigationController
       didShowViewController:(UIViewController *)viewController
                    animated:(BOOL)animate
{
    //控制器入栈之后,启用手势识别
    if ([self respondsToSelector:@selector(interactivePopGestureRecognizer)])
        self.interactivePopGestureRecognizer.enabled = YES;
}

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
    if ([self.childViewControllers count] == 1) {
        return NO;
    }
    return YES;
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return YES;
}
//运行试一试，发现了新问题，手指在滑动的时候，被 pop 的 ViewController 中的 UIScrollView 会跟着一起滚动，这个效果看起来就很怪（知乎日报现在就是这样的效果），而且也不是原始的滑动返回应有的效果，那么就让我们继续用代码来解决吧
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldBeRequiredToFailByGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
   return [gestureRecognizer isKindOfClass:UIScreenEdgePanGestureRecognizer.class];
}

@end

//
//  KJNavgationController.m
//
//  Created by mac on 16/2/22.
//  Copyright © 2016年 mac. All rights reserved.
//

#import "KJNavgationController.h"

@interface KJNavgationController ()<UIGestureRecognizerDelegate>

@end

@implementation KJNavgationController

-(void)viewDidLoad{
    [super viewDidLoad];
    
    // 获取系统自带滑动手势的target对象
    id target = self.interactivePopGestureRecognizer.delegate;
    
    // 创建全屏滑动手势，调用系统自带滑动手势的target的action方法
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:target action:@selector(handleNavigationTransition:)];
    
    // 设置手势代理，拦截手势触发
    pan.delegate = self;
    
    // 给导航控制器的view添加全屏滑动手势
    [self.view addGestureRecognizer:pan];
    
    // 禁止使用系统自带的滑动手势
    self.interactivePopGestureRecognizer.enabled = NO;
    
}

// 什么时候调用：每次触发手势之前都会询问下代理，是否触发。
// 作用：拦截手势触发
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
    // 注意：只有非根控制器才有滑动返回功能，根控制器没有。
    // 判断导航控制器是否只有一个子控制器，如果只有一个子控制器，肯定是根控制器
    if (self.childViewControllers.count == 1) {
        // 表示用户在根控制器界面，就不需要触发滑动手势，
        return NO;
    }
    return YES;
}
@end

- (void)viewDidLoad
{
    [super viewDidLoad];
     
    // 添加右滑手势
    [self addSwipeRecognizer];
}
 
#pragma mark 添加右滑手势
- (void)addSwipeRecognizer
{
    // 初始化手势并添加执行方法
    UISwipeGestureRecognizer *swipeRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(return)];
     
    // 手势方向
    swipeRecognizer.direction = UISwipeGestureRecognizerDirectionRight;
     
    // 响应的手指数
    swipeRecognizer.numberOfTouchesRequired = 1;
     
    // 添加手势
    [[self view] addGestureRecognizer:swipeRecognizer];
}
 
#pragma mark 返回上一级
- (void)return
{
    // 最低控制器无需返回
    if (self.viewControllers.count <= 1) return;
     
    // pop返回上一级
    [self popToRootViewControllerAnimated:YES];
}


//若在控制器之间跳转时需要做一些事情，可在自定义的控制器里添加下面两个方法
#pragma mark push方法
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    // do something you want
    ...
    [super pushViewController:viewController animated:animated];
}
 
#pragma mark pop方法
- (UIViewController *)popViewControllerAnimated:(BOOL)animated
{
    // 比如停止网络请求
    ...
     
    return [super popViewControllerAnimated:animated];
}