ViewController.swift

import UIKit
import SnapKit
import FLAnimatedImage

class ViewController: UIViewController {
    
    let urlImage = "http://i.giphy.com/13YkBrhLJdziXm.gif"
    
    var aniamtedImageView: FLAnimatedImageView = {
        return FLAnimatedImageView()
    }()
    
    var welcomeTextLabel: UILabel = {
        let welcomeTextLabel = UILabel()
        welcomeTextLabel.text = "Hello world !"
        welcomeTextLabel.textAlignment = .Center
        welcomeTextLabel.textColor = UIColor.whiteColor()
        welcomeTextLabel.font = UIFont.systemFontOfSize(30)
        return welcomeTextLabel
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = UIColor.blackColor()

        self.aniamtedImageView.backgroundColor = UIColor.redColor()
        
        self.view.addSubview(self.aniamtedImageView)
        self.aniamtedImageView.snp_makeConstraints { (make) -> Void in
            make.size.equalTo(CGSizeMake(200, 200))
            make.center.equalTo(self.view)
        }
        
        self.view.addSubview(self.welcomeTextLabel)
        self.welcomeTextLabel.snp_makeConstraints { (make) -> Void in
            make.centerX.equalTo(self.view)
            make.height.equalTo(50)
            make.bottom.equalTo(self.aniamtedImageView).offset(50)
        }
        
        let queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
        dispatch_async(queue) { () -> Void in
            
            if let url = NSURL(string: self.urlImage), let dataImage = NSData(contentsOfURL: url) {
                let img = FLAnimatedImage(GIFData: dataImage)
                dispatch_async(dispatch_get_main_queue(), {
                    self.aniamtedImageView.animatedImage = img
                })
            }
        }
    }
}