UIImageView+AFNetworking+UIActivityIndicator

UIImageView+AFNetworking+UIActivityIndicator.swift

//
// UIImageView+AFNetworking+UIActivityIndicator.swift
//
// Created by Joel Kopelioff on 8/6/15.
// Copyright (c) 2015 DemandMedia Inc
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

import Foundation
import UIKit
import ObjectiveC

// Declare a global var to produce a unique address as the assoc object handle
var kUIActivityIndicatorView: UInt8 = 0


extension UIImageView
{
	var activityIndicatorView:UIActivityIndicatorView? {
		get {
			return objc_getAssociatedObject(self, &kUIActivityIndicatorView) as? UIActivityIndicatorView
		}
		set {
			objc_setAssociatedObject(self, &kUIActivityIndicatorView, newValue, objc_AssociationPolicy(OBJC_ASSOCIATION_RETAIN_NONATOMIC))
		}
	}
	
	func cancelImageRequestOperationAndRemoveActivityIndicatorView() {
		if let activityIndicator = self.activityIndicatorView {
			self.af_removeActivityIndicator()
		}
	}
	
	func setImageWithURL(url:NSURL, usingActivityIndicatorStyle style:UIActivityIndicatorViewStyle)
	{
		self.setImageWithURLRequest(NSURLRequest(URL: url), placeholderImage: nil, usingActivityIndicatorStyle:style, success: nil, failure: nil)
		
	}
	
	func setImageWithURLRequest(urlRequest:NSURLRequest!, placeholderImage:UIImage!, usingActivityIndicatorStyle style:UIActivityIndicatorViewStyle, success: ((NSURLRequest!, NSHTTPURLResponse!, UIImage!) -> Void)!, failure: ((NSURLRequest!, NSHTTPURLResponse!,NSError!) -> Void)!) {
		
		if urlRequest != nil {
			self.af_addActivityIndicatorWithStyle(style)
		}
		
		self.setImageWithURLRequest(urlRequest, placeholderImage: placeholderImage,
			success: {[weak self] (request:NSURLRequest!, response:NSHTTPURLResponse!, image:UIImage!) -> Void  in
			
				self?.af_removeActivityIndicator()
			
				if success != nil {
					success(request, response, image)
				} else {
					self?.image = image
				}
			
			}, failure: { [weak self] (request:NSURLRequest!, response:NSHTTPURLResponse!, error:NSError!) -> Void in
				
				self?.af_removeActivityIndicator()
				
				if failure != nil {
					failure(request, response, error)
				}
			})
	}


//MARK: - Private Helpers

	func af_addActivityIndicatorWithStyle(style:UIActivityIndicatorViewStyle) {

		if self.activityIndicatorView == nil {
		
			self.activityIndicatorView = self.af_createActivityIndicatorWithStyle(style)
			
			if NSThread.isMainThread() {
				self.addSubview(self.activityIndicatorView!)
				self.activityIndicatorView!.startAnimating()
				
			} else {
				dispatch_async(dispatch_get_main_queue()) {
					self.addSubview(self.activityIndicatorView!)
					self.activityIndicatorView!.startAnimating()
				}
			}
			return
		}
	
		if NSThread.isMainThread() {
			self.activityIndicatorView!.startAnimating()
		} else {
			dispatch_async(dispatch_get_main_queue()) {
				self.activityIndicatorView!.startAnimating()
			}
		}
	}

	func af_removeActivityIndicator() {
		if self.activityIndicatorView != nil {
			self.activityIndicatorView?.removeFromSuperview()
			self.activityIndicatorView = nil
		}
	}
	
	func af_createActivityIndicatorWithStyle (style:UIActivityIndicatorViewStyle) -> UIActivityIndicatorView
	{
		let activityIndicator = UIActivityIndicatorView(activityIndicatorStyle:style)
		activityIndicator.userInteractionEnabled = false
		activityIndicator.center = self.center
		activityIndicator.autoresizingMask = UIViewAutoresizing.FlexibleTopMargin | UIViewAutoresizing.FlexibleBottomMargin | UIViewAutoresizing.FlexibleLeftMargin | UIViewAutoresizing.FlexibleRightMargin
		
		return activityIndicator
	}

}