ihealth_ios/Inhealth/IHNavigationController.swift

//
//  IHNavigationController.swift
//  Inhealth
//
//  Created by weclouds on 2019/12/10.
//  Copyright © 2019 weclouds. All rights reserved.
//

import UIKit

///导航栏返回协议
@objc protocol NavigationProtocol{
    /// 导航栏将要返回的方法
    ///
    /// - Returns : true: 返回上一界面 ，false: 禁止返回
    @objc optional func navigationShouldPopMethod() -> Bool
}
class IHNavigationController: UINavigationController {

    override func viewDidLoad() {
        super.viewDidLoad()
        setNavigationBar()
        interactivePopGestureRecognizer?.delegate = self
    }
    

    func setNavigationBar()  {
        
        let apperance = UINavigationBar.appearance()
        //设置半透明效果
        self.navigationBar.isTranslucent = false
        
        //导航栏上按钮颜色
        apperance.tintColor = UIColor.black
        //设置导航栏颜色
        apperance.barTintColor = UIColor(hexString: "#FFFFFF")
        //去除分割线
        // apperance.setBackgroundImage(UIImage(), for: .default)
        apperance.shadowImage = UIImage()
        let dict  = [NSAttributedString.Key.foregroundColor:UIColor.white,NSAttributedString.Key.font:UIFont(name: PingFangSC_Semibold, size: 18) ]
        apperance.titleTextAttributes = dict as Any as? [NSAttributedString.Key : Any]
        let backAppearance = UIBarButtonItem.appearance()
        //设置导航栏返回按钮
        self.navigationBar.topItem?.title = ""
        if #available(iOS 11, *){
            //              backAppearance.setBackButtonTitlePositionAdjustment(UIOffset(horizontal: -200, vertical: 0), for: UIBarMetrics.default)
            //
            //               let backButtonImage = UIImage(named: "返回")?.withRenderingMode(UIImage.RenderingMode.alwaysOriginal)
            //
            //               apperance.backIndicatorImage = backButtonImage
            //               apperance.backIndicatorTransitionMaskImage = backButtonImage
            
            let backButtonImage = UIImage(named: "返回")?.withRenderingMode(UIImage.RenderingMode.alwaysOriginal)
            
            apperance.backIndicatorImage = backButtonImage
            apperance.backIndicatorTransitionMaskImage = backButtonImage
            
            let leftBtn = UIBarButtonItem.init(image: backButtonImage, style: .plain, target: self, action: #selector(clickBack))
            self.navigationItem.leftBarButtonItem = leftBtn
            
        }else {
            //返回按钮没有文字
            backAppearance.setBackButtonTitlePositionAdjustment(UIOffset(horizontal: -200, vertical: 0), for: UIBarMetrics.default)
            let backButtonImage = UIImage(named: "返回")?.withRenderingMode(UIImage.RenderingMode.alwaysOriginal)
            backAppearance.setBackButtonBackgroundImage(backButtonImage?.resizableImage(withCapInsets: UIEdgeInsets(top: 0, left: 32, bottom: 0, right: 0)), for: UIControl.State.normal, barMetrics: UIBarMetrics.default)
            
        }
    }
       
    override func pushViewController(_ viewController: UIViewController, animated: Bool) {
        if self.viewControllers.count > 0 {
            viewController.hidesBottomBarWhenPushed = true
            viewController.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: UIBarButtonItem.Style.plain, target: self, action: #selector(IHNavigationController.backAction ))
        }
        super.pushViewController(viewController, animated: animated)
    }
       
    @objc func backAction()  {
        
        self.navigationController?.popViewController(animated: true)
    }
    
    @objc private func clickBack(){
        
    }
    
}

extension UIViewController :NavigationProtocol{
    func navigationShouldPopMethod() -> Bool {
        return true
    }
}

extension UINavigationController:UINavigationBarDelegate,UIGestureRecognizerDelegate{
    public func navigationBar(_ navigationBar: UINavigationBar, shouldPop item: UINavigationItem) -> Bool {
        if viewControllers.count < navigationBar.items!.count {
            return true
        }
        var shouldPop = false
        let vc: UIViewController = topViewController!
        if vc.responds(to: #selector(navigationShouldPopMethod)) {
            shouldPop = vc.navigationShouldPopMethod()
        }
        
        if shouldPop  {
            DispatchQueue.main.async {
                self.popViewController(animated: true)
            }
        }else{
            for subview in navigationBar.subviews {
                if 0.0 < subview.alpha && subview.alpha < 1.0 {
                    UIView.animate(withDuration: 0.25) {
                        subview.alpha = 1.0
                    }
                }
            }
        }
        return false
    }
    
    public func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        if children.count == 1 {
            return false
        }else{
            if topViewController?.responds(to: #selector(navigationShouldPopMethod)) != nil {
                return topViewController!.navigationShouldPopMethod()
            }
            return true
        }
    }
    
    open override var preferredStatusBarStyle: UIStatusBarStyle{
        
        return self.topViewController!.preferredStatusBarStyle
    }
    
    open override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation{
        return .none
    }
    open override var prefersStatusBarHidden: Bool{
        return false 
    }
    
    
}