paiai_ios/PaiAi/PaiaiUIKit/Reusable/UIKit/NavigationController/NavigationBar.swift

//
//  NavigationBar.swift
//  PaiaiUIKit
//
//  Created by FFIB on 2019/4/23.
//  Copyright © 2019 FFIB. All rights reserved.
//

import UIKit

class NavigationBar: UINavigationBar {
    
    override init(frame: CGRect) {
        super.init(frame: frame)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func getNavigationBarBounds() -> CGRect {
        let statusHeight = UIApplication.shared.statusBarFrame.height
        return CGRect(x: 0, y: -statusHeight, width: bounds.width, height: bounds.height + statusHeight)
    }

    override func value(forUndefinedKey key: String) -> Any? {
        return nil
    }
}

public extension UINavigationBar {
    func getBarBackground() -> UIView? {
        return value(forKeyPath: "_backgroundView") as? UIView
    }
    
    func getBarContentView() -> UIView? {
        for val in subviews {
            if let contentClass = NSClassFromString("_UINavigationBarContentView"),
                val.isKind(of: contentClass) {
                return val
            }
        }
        return nil
    }
    
    func getShadowView() -> UIView? {
        guard let barBackground = getBarBackground() else { return nil }
        for view in barBackground.subviews where view.bounds.height == 0.5 {
            return view
        }
        return nil
    }
    
    internal func apply(for configure: NavigationBarConfiguration) {
        isHidden = configure.isHidden
        isTranslucent = configure.isTranslucent
        
        barStyle = configure.barStyle
        shadowImage = configure.shadowImage
        setBackgroundImage(configure.backgroundImage, for: .default)
    }
    
    internal convenience init(configure: NavigationBarConfiguration) {
        self.init()
        apply(for: configure)
    }
}

public extension UIToolbar {
    func getBarBackground() -> UIView? {
        return value(forKeyPath: "_backgroundView") as? UIView
    }
    
    func getShadowView() -> UIView? {
        guard let barBackground = getBarBackground() else { return nil }
        for view in barBackground.subviews where view.bounds.height == 0.5 {
            return view
        }
        return nil
    }
    
    internal convenience init(configure: NavigationBarConfiguration) {
        self.init()
        isHidden = configure.isHidden
        isTranslucent = configure.isTranslucent
        
        barStyle = configure.barStyle
        setShadowImage(configure.shadowImage, forToolbarPosition: .any)
        setBackgroundImage(configure.backgroundImage, forToolbarPosition: .any, barMetrics: .default)
    }
}

extension UIViewController {
    internal func getFakeBarFrame(for navigationBar: UINavigationBar) -> CGRect? {
        guard let backgroundView = navigationBar.getBarBackground(),
            var frame = backgroundView.superview?.convert(backgroundView.frame, to: self.view)
            else { return nil }
        
        frame.origin.x = self.view.bounds.origin.x
        return frame
    }
}