@implementation BaseNavigationController
- (void)viewDidLoad {
    [super viewDidLoad];
    // 在自定义的navigationController中 设置代理, 如果已经使用了代理,
    self.delegate = [SuspensionEntrance shared];
    // 关闭系统返回手势
    self.interactivePopGestureRecognizer.enabled = NO;
}
@end

// 对于可以作为入口界面的Controller,实现SEItem协议
@interface EntranceViewController : UIViewController <SEItem>
@property (copy  , nonatomic) NSString *entranceTitle;
@property (copy  , nonatomic, nullable) NSURL *entranceIconUrl;
@property (copy  , nonatomic, nullable) NSDictionary *entranceUserInfo;
@end

// 并实现下列构造方法, !!! 如果不实现则无法进行序列化存储
+ (instancetype)entranceWithItem:(id<SEItem>)item {
    EntranceViewController *controller = [[EntranceViewController alloc] initWithNibName:nil bundle:nil];
    controller.entranceTitle = item.entranceTitle;
    controller.entranceIconUrl = item.entranceIconUrl;
    controller.entranceUserInfo = item.entranceUserInfo;
    return controller;
}

// 在对应的代理方法里面调用 
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
    [[SuspensionEntrance shared] navigationController:navigationController willShowViewController:viewController animated:animated];
}

- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
    [[SuspensionEntrance shared] navigationController:navigationController didShowViewController:viewController animated:animated];
}

- (id<UIViewControllerInteractiveTransitioning>)navigationController:(UINavigationController *)navigationController interactionControllerForAnimationController:(id<UIViewControllerAnimatedTransitioning>)animationController {
    return [[SuspensionEntrance shared] navigationController:navigationController interactionControllerForAnimationController:animationController];
}

- (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC {
    return [[SuspensionEntrance shared] navigationController:navigationController animationControllerForOperation:operation fromViewController:fromVC toViewController:toVC];
}

// 然后同上面一步, 一样实现SEItem协议, 需要注意的事, 需要手动关闭自定义返回手势, 以避免手势冲突
// 以集成了 forkingdog/FDFullscreenPopGesture(https://github.com/forkingdog/FDFullscreenPopGesture) 为例, 添加下列方法
- (void)fd_interactivePopDisabled { return YES; }

// 实现协议方法, 用于创建自定义的push & pop手势
- (NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext {
    // the duration for animation
}

// 在这里我们将此次使用到的动画效果大致分为三种
// 1. 从圆球----push----->到具体的viewController
// 2. 从viewController  --pop--> 圆球效果
// 3. 交互式滑动, 并根据滑动距离更新界面UI,最后 ---pop---> 圆球效果
- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext {
    // 自定义自己的动画效果, 利用CoreAnimations or [UIView animateWithDuration:0.25 animations:NULL] 都可以
}

// 1. 在对应的view上添加滑动手势, 这边我们直接借助于UIScreenEdgePanGestureRecognizer
{   
    UIScreenEdgePanGestureRecognizer *pan = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:@selector(handleTransition:)];
    pan.edges = UIRectEdgeLeft;
    pan.delegate = self;
    [viewController.view addGestureRecognizer:pan];
}
// 2. 实现手势方法
- (void)handleTransition:(UIScreenEdgePanGestureRecognizer *)pan {
    // ...
    switch (pan.state) {
        case UIGestureRecognizerStateBegan: 
            // 2.1 触发交互式返回, 创建UIPercentDrivenInteractiveTransition对象
            // 2.2 调用返回手势
            // 2.3 处理一些其他的初始化动作...
          	self.interactive = [[UIPercentDrivenInteractiveTransition alloc] init];
            [tempItem.navigationController popViewControllerAnimated:YES];
            break;
        case UIGestureRecognizerStateChanged:
            // 2.4 更新交互式动画进度, 注意因为我们的使用的是自定义动画, 并没有一个完整的动画过程, 
            // 所以我们需要自己更新动画过程, 如果直接使用的系统自带返回, 那么我们只需要更新interactive即可
            [self.animator updateContinousPopAnimationPercent:tPoint.x / SCREEN_WIDTH];
            [self.interactive updateInteractiveTransition:tPoint.x / SCREEN_WIDTH];
            // 2.5 处理其他一些判断条件(例如是否拖动到浮窗检测区域)...
            break;
        case UIGestureRecognizerStateEnded:     // fall through
        case UIGestureRecognizerStateCancelled:
            // 2.6 判断动画完成情况, 是否具体完成 or 取消
            // 2.7 处理一些完成后动作(例如是否添加浮窗等)...
			break;
    }
}

- (void)setupGestures {
    
    // 添加长按手势
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];
    longPress.minimumPressDuration = 0.5;
    longPress.allowableMovement = 5.f;
        // 关闭delays touches began功能, 因为我们在touchesBegan实现了点击方法, 并且动态高亮了点击背景, 所以我们需要实时呈现, 如果手势检测成功, 则会进入touchesCancelled
    longPress.delaysTouchesBegan = NO;
    [self addGestureRecognizer:longPress];
    
    // 添加拖拽手势
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)];
    // 原因同上
    pan.delaysTouchesBegan = NO;
    [self addGestureRecognizer:pan];
    // 注意此处优先检测长按手势, 检测失败后才开始检测拖拽
    [pan requireGestureRecognizerToFail:longPress];
}