NetworkIndicatorManager.swift

NetworkIndicatorManager.swift

//
//  NetworkIndicatorManager.swift
//
//  Created by Satori Maru on 15.11.27.
//  Copyright (c) 2015 Satori Maru. All rights reserved.
//

import UIKit

private let kGeneralLifeKey: Int = -1

fileprivate class NetworkIndicatorLife {
	
	var lifeCount: Int = 0 {
		didSet {
			lifeCount = max(lifeCount, 0)
		}
	}
	
}

class NetworkIndicatorManager {
	
	private var lifeTable = [String : NetworkIndicatorLife]()
	
	fileprivate static let shared: NetworkIndicatorManager = {
		return NetworkIndicatorManager()
	}()
	
	fileprivate var lifeCount: Int {
		return lifeTable.values.reduce(0) {
			return $0 + $1.lifeCount
		}
	}
	
	static var life: Int {
		return shared.lifeCount
	}
	
	class func updateIndicatorVisibility() {
		DispatchQueue.main.async {
			if life > 0 && UIApplication.shared.isNetworkActivityIndicatorVisible == false {
				UIApplication.shared.isNetworkActivityIndicatorVisible = true
			}
			else if life == 0 && UIApplication.shared.isNetworkActivityIndicatorVisible == true {
				UIApplication.shared.isNetworkActivityIndicatorVisible = false
			}
		}
	}
	
	class func up(in any: NSObject? = nil) {
		up(with: "\(any?.hash ?? kGeneralLifeKey)")
	}
	
	class func up(with key: String) {
		DispatchQueue.main.async {
			let life = shared.lifeTable[key] ?? NetworkIndicatorLife()
			life.lifeCount += 1
			shared.lifeTable[key] = life
		}
		
		updateIndicatorVisibility()
	}
	
	class func down(in any: NSObject? = nil) {
		down(with: "\(any?.hash ?? kGeneralLifeKey)")
	}
	
	class func down(with key: String) {
		DispatchQueue.main.async {
			if let life = shared.lifeTable[key] {
				life.lifeCount -= 1
				if life.lifeCount == 0 {
					shared.lifeTable[key] = nil
				}
				else {
					shared.lifeTable[key] = life
				}
			}
		}
		
		updateIndicatorVisibility()
	}
	
	class func reset(in any: NSObject? = nil) {
		reset(with: "\(any?.hash ?? kGeneralLifeKey)")
	}
	
	class func reset(with key: String) {
		DispatchQueue.main.async {
			if let life = shared.lifeTable[key] {
				life.lifeCount = 0
				shared.lifeTable[key] = nil
			}
		}
		
		updateIndicatorVisibility()
	}
	
	class func kill() {
		DispatchQueue.main.async {
			shared.lifeTable.removeAll()
		}
		updateIndicatorVisibility()
	}
	
}

extension NSObject {
	
	func networkIndicatorCountUp() {
		NetworkIndicatorManager.up(in: self)
	}
	
	func networkIndicatorCountDown() {
		NetworkIndicatorManager.down(in: self)
	}
	
	func resetNetworkIndicatorCount() {
		NetworkIndicatorManager.reset(in: self)
	}
	
}