Conversion to Swift of Barry Allard UIView+ClipBackgroundImageToBounds

UIButton+ClipBackgroundImageToBounds.swift

//
//  UIView+ClipBackgroundImageToBounds.m
//
//  Created by Barry Allard on 2013-06-18.
//  Copyright (c) 2013 Stealth Mode Industries LLC. All rights reserved.
//
//  Based on http://stackoverflow.com/questions/262156/uiimage-rounded-corners
//
//  MIT License

import UIKit
import QuartzCore

extension UIButton {
    func setBackgroundImageClippedToBounds(image: UIImage?, forState state: UIControlState)-> Void {
        
        if (!( !self.clipsToBounds && self.layer.cornerRadius != 0 )) {
            self.setBackgroundImage(image, forState: state)
        }
        
        // Begin a new image that will be the new image with the rounded corners
        // (here with the size of an UIImageView)
        UIGraphicsBeginImageContextWithOptions(self.bounds.size, false, 1.0)
        
        // Add a clip before drawing anything, in the shape of an rounded rect
        UIBezierPath(roundedRect: self.bounds, cornerRadius: self.layer.cornerRadius).addClip()
        
        // Draw your image
        image?.drawInRect(self.bounds)
        
        // Get the image, here setting the UIImageView image
        let clippedBackgroundImage: UIImage? = UIGraphicsGetImageFromCurrentImageContext()
        
        // Lets forget about that we were drawing
        UIGraphicsEndImageContext();
        
        // Do what we came here to do
        self.setBackgroundImage(clippedBackgroundImage, forState: state)
    }
}

Gold ⭐ :)