SOTTabViewContainer

TabViewContainer.swift

//
//  TabViewContainer.swift
//  BusMap
//
//  Created by Andrea Altea on 24/05/17.
//  Copyright © 2017 StudiOUT. All rights reserved.
//

import UIKit

class TabViewContainer: UIViewController {

    //MARK: - Config
    
    struct Notification {
        
        static let ShowMenu = NSNotification.Name("TabViewContainerShowMenuNotification")
        static let ShowContent = NSNotification.Name("TabViewContainerShowContentNotification")
    }
    
    //MARK: - Model
    
    var builder:TabControllerBuilder? {
        
        didSet {
            self.detailControllers = Dictionary<NSInteger, UIViewController>()
            self.showController(at: 0)
        }
    }
    var detailControllers: Dictionary<NSInteger, UIViewController> = Dictionary<NSInteger, UIViewController>()
    
    fileprivate(set) weak var currentController:UIViewController?
    fileprivate weak var menuController: UIViewController?
    
    //MARK: - Lifecycle

    override func viewDidLoad() {
        super.viewDidLoad()
        
        NotificationCenter.default.addObserver(forName: Notification.ShowMenu, object: nil, queue: nil) { (notification) in
            
            self.showMenu()
        }
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        
        let discardableItems = self.detailControllers.filter { (key: NSInteger, value: UIViewController) -> Bool in
            return value != self.currentController
        }
        
        discardableItems.forEach { (key: NSInteger, value: UIViewController) in
            self.detailControllers.removeValue(forKey: key)
        }
    }
    
    deinit {
        NotificationCenter.default.removeObserver(self)
    }
}

fileprivate typealias TabViewContainerContent = TabViewContainer

extension TabViewContainerContent {

    func showController(at index: NSInteger) {
     
        if self.detailControllers[index] == nil {

            self.detailControllers[index] = self.builder?.controller(at: index)
        }

        guard let detailController = detailControllers[index] else {
            return
        }
        
        self.insertDetailController(detailController)
        self.hideMenu()
    }
    
    private func insertDetailController(_ controller: UIViewController) {

        self.removeDetailController()
        self.insertChildController(controller)
        self.currentController = controller
    }
    
    private func removeDetailController() {
        
        guard let currentController = self.currentController else {
            
            return
        }
        
        currentController.willMove(toParentViewController: nil)
        currentController.removeFromParentViewController()
        currentController.view.removeFromSuperview()
    }
}

fileprivate typealias TabViewContainerMenu = TabViewContainer

extension TabViewContainerMenu: TabMenuControllerDelegate {
    
    func showMenu() {
        
        if(self.menuController != nil) {
            return
        }
        
        guard let builder = self.builder else {
            return
        }
        
        let menuController = builder.menuController()
        menuController.dataSource = builder as? TabMenuControllerDataSource ?? nil
        menuController.delegate = self
        
        self.insertChildController(menuController)
        self.menuController = menuController
    }
    
    func hideMenu() {
        
        guard let menuController = self.menuController else {
            return
        }
        
        menuController.willMove(toParentViewController: nil)
        
        menuController.removeFromParentViewController()
        menuController.view.removeFromSuperview()
    }
    
    //MARK: TabMenuControllerDelegate
    
    func controller(_ controller: TabMenuController, didSelectItemAtIndex index: NSInteger) {
        
        self.showController(at: index)
    }
    
    func dismissMenuFromController(_ controller: TabMenuController) {
        
        self.hideMenu()
    }
}

fileprivate extension UIViewController {
    
    func insertChildController(_ controller: UIViewController) {
        
        self.addChildViewController(controller)
        controller.view.frame = self.view.frame
        controller.view.translatesAutoresizingMaskIntoConstraints = false
        self.view.addSubview(controller.view)
        
        let viewDictionary: Dictionary<String, UIView> = ["view": controller.view]
        let hConstraints = NSLayoutConstraint.constraints(withVisualFormat: "H:|-0-[view]-0-|",
                                                          options: NSLayoutFormatOptions(rawValue: 0),
                                                          metrics: nil,
                                                          views: viewDictionary)
        
        let vConstraints = NSLayoutConstraint.constraints(withVisualFormat: "V:|-0-[view]-0-|",
                                                          options: NSLayoutFormatOptions(rawValue: 0),
                                                          metrics: nil,
                                                          views: viewDictionary)
        self.view.addConstraints(hConstraints)
        self.view.addConstraints(vConstraints)
        
        controller.didMove(toParentViewController: self)
        setNeedsStatusBarAppearanceUpdate()
    }
}